Pulse Motor Design Considerations

Pulse Motor Generator Design Considerations

I spent over a year researching the Adams Pulsed Electric Motor Generator, built several working models, gave a presentation on the subject at the 2021 Energy Science & Technology Conference (ESTC), and even used MyHeritage.com to track down one of the inventor’s daughters in the hope that she would be able to give me the last bits of information I needed to replicate Robert Adams’ impressive results.

Unfortunately, I hit a lot of dead ends, got discourages, and spent most of this year working on Tesla Turbines instead.

However, at this year’s conference, Paul Babcock and Mike Clarke gave two very inspiring presentations and hinted at new avenues to explore, like using state-of-the-art silicon carbide or gallium nitride MOSFETs for superior performance, which fully rekindled my enthusiasm for pulse motors!

Key slide from Paul Babcock’s 2022 ESTC presentation

I already have a design for a new and improved pulse motor in my head, but first I wanted to write this article for anyone who is experimenting with a Bedini SG, Adams Motor, Newman Motor, or any other pulse motor generator, and needs some inspiration on how to push their project to the next level of performance.

I’ll cover each and every part of a pulse motor generator system and how to maximize its potential, as well as how difficult and costly it is to implement.

So let’s go!

Table of Contents

Intro: What are we optimizing for?

In Paul Babcock’s presentation, we hear him say that higher voltage is better, and faster MOSFETs are better, but that raises the question “why”?

To answer that, we have to first determine what it is that we are attempting to optimize.

It seems to me that there are 3 main factors to optimize in a pulse motor generator system:

  1. Charge recovery from the flyback
  2. Generator output
  3. ΔV/Δt, or rate of change of voltage over time

I’ll briefly touch on each of those, as they are crucially important to understand before we can look into ways of maximizing them.

UPDATE 28-01-2023

Recently I received a document written by Julian Perry, who was able to achieve a CoP of 38 (!!) using a solid state coil pulsing system, essentially a pulse motor without a rotor.


He got to this incredible result by tweaking factors like pulse frequency, flyback voltage, duty cycle, and discharge % before swapping.

He found that each battery, especially if they have a different chemistry and/or capacity, has a different optimal pulse frequency and flyback voltage, and so the chance that your pulse motor happens to run at the exact ideal frequency of your particular battery is close to zero, and so your results will most likely disappoint.

UNLESS you reverse the process, and start by finding the optimal frequency, flyback voltage etc. for your battery, and only then design a motor that can run at that frequency.

This was an eye-opener for me, and I believe this is the reason why hardly anyone building pulse motors ever sees any CoP > 1 results, so I urge you to read his work in detail to fully grasp the consequences.

Charge recovery

When we pulse our drive coils, a magnetic field is set up around them.

When the pulse stops, this magnetic field collapses in on itself in a fraction of time, resulting in a high-voltage flyback spike.

We want to try to maximize the energy stored in the magnetic field, and then subsequently recover as much of this collapsing field energy as possible, so we can use it to charge a battery, charge a capacitor bank, or even reroute it to add additional torque.

Generator output

Both Paul Babcock and Peter Lindemann mentioned that the excess energy in the system mainly exists as mechanical energy, and so to extract it, a generator will have to be hooked up to the system.

However, pulse motors are not the strongest, so we’ll have to find ways to maximize the torque of the system in order to be able to run a generator off of it.


Now this last one might seem a little out of place and requires a bit more explanation.

What does rate of change of voltage over time, or ΔV/Δt, have to do with any of this? Everything it seems…

This is what Robert Adams said:

There are a number of various methods of harnessing considerable aetheric energy from these machines. In this respect I strongly urge you to study Tesla radiant energy.


This leads us to a commonly shared, but hard to verify story of how Tesla supposedly started thinking about “radiant energy”.

A curious anomaly occurred in the very first instant of throwing the power switch at the DC generating station: Purple/blue colored spikes radiated in all directions along the axis of the power lines for just a moment. In addition, a stinging, ray-like shocking sensation was felt by those who stood near the transmission lines.

Tesla realized almost immediately that electrons were not responsible for such a phenomena because the blue spike phenomena ceased as soon as the current started flowing in the lines. Something else was happening just before the electrons had a chance to move along the wire.

The phenomena only exhibited itself in the first moment of switch closure, before the electrons could begin moving. There seemed to be a “bunching” or “choking” effect at play, but only briefly. Once the electrons began their movement within the wire, all would return to normal. What was this strange energy that was trying to liberate itself so forcefully at the moment of switch closure?.


So something odd happens the instant a switch closes and the high-voltage DC of the generating station rushes into the transmission line.

This sounds a lot like the “impedance phenomena” Tesla experimented with in his hairpin circuit.

Robert Adams also refers to Wattless, currentless, electron-less power:

Due to the subliminal velocity of the aetheric energy gaseous flow over the surface of the windings, the current becomes “lost” and, therefore, left behind.

Robert Adams. “On The Phenomena Of Wattless (Currentless) Power.” Applied Modern 20th Century Aether Science (1999)

The higher the voltage and the shorter the time period it is delivered in (ΔV/Δt), the higher the impedance, which then seems to result in the curious situation where energy flows over the surface of the conductors at incredible speeds, but no electrons have actually started moving yet, as the pulse hits a brick wall of impedance, like slapping your flat hand on the water at full force.

I’ll share one last comment from Robert Adams on the subject:

There are at least two possible methods of causing a finite delay time thereby retarding current flow within the stator element, in addition to impulsing the source – one, of using doped winding wire (at present a difficult one) and – two, in designing the stators by incorporating sacred geometry, i.e., PI and PHI involving the Golden Ratio.

Robert Adams. “Translocating Potential Gradient To The Motor.” Applied Modern 20th Century Aether Science (1999)

If we somehow manage to achieve this delayed current flow, this means we’ll use way less input power.

Thus it appears that a high ΔV/Δt is essential to unlocking some of these unique pulse motor phenomena, and knowing this, it all of a sudden starts making sense when Paul Babcock suggests to increase your input voltage from 12 to at least 48V, and to get the fastest MOSFETs possible…

Switching: SiC or GaN FETs

I forgot where I read it, but apparently Jean-Louis Naudin once was at a conference in Australia with his Adams Motor prototype, and Robert Adams himself and his wife were there as well.

When Naudin asked Adams about what he should do to improve his motor, Adams had one quick look and said: “use a physical commutator”.

This sentiment is also echoed by Robert Adams in some tips he gave in 1993:

Should you experience any difficulty in designing and constructing the tapered disc contactor (machining, etc.) then use electronic switching, i.e. photo, Hall effect, or inductor effect, with switching current transistor, etc.

…the input current to supply the electronic switching will raise the total input quite steeply. The point to be made here is that in using electronic switching, in a larger machine, the degree of loss due to this use of electronic switching is negligible.

However, for those who are seeking greater efficiency figures, it is advised to stay with the tapered disc contactor method.

Robert Adams

So it seems he said to use a physical commutator for small devices, so you don’t incur extra losses due to the power required to switch a transistor.

The original Adams Motor Manual does include some transistor circuits, which use a TIP32B or 2N3055.

One of Robert Adams’ transistor switching circuits using the old TIP32B

The famous pulse motor circuit diagram from John Bedini’s original 1984 book also contains several 2N3055 transistors.

1984 original Bedini Circuit

We know that in his later years, John Bedini preferred to use MJL21194 transistors, often found in audio equipment.

So why can’t we use those transistors? It worked for them, right?

That was my attitude for a long time, until I realized what it was that we are trying to optimize (ΔV/Δt), and then realized that modern day silicon carbide (SiC) and gallium nitride (GaN) FETs are far superior to anything Adams, Bedini, or Newman had access to in their days.

Remember, they started working on this stuff in the 70’s and 80’s; that’s over 40 years ago!

Like Paul Babcock said, we’re living in a golden age of electronic switching right now, and we should make the most out of it!

These new types of FETs are breathtakingly fast, can handle incredible voltages and currents, and are very energy efficient.

They are however not cheap, at about $20 to $30 a piece, but will be well worth the investment.

From my research so far, it seems GaN FETs are a little easier to control, as most SiC FETs require a gate voltage of 20V and a low of -5V, making it harder to find a proper gate driver and complicating the circuit.

Most GaN FETs I found can be driven from 10V and don’t require negative gate bias.

I’m currently looking into using a TP65H035G4WSQA 650V GaN FET for my next motor project, so lets compare the numbers to a power MOSFET I commonly see in pulse motor circuits, the IRF840LC:

Peak amps28240A
Gate Charge3922nC
Rise time40*10ns
Fall time30*10ns
Diode reverse recovery time49059ns
* Adjusted for 250 V rise for IRF840LC vs 400 V rise for the TP65H035G4WSQA

The GaN FET is the clear and obvious winner on all fronts!

If you want to go even faster, surface mount GaN FETs like the GS66502B take the cake, but I have no idea how to get those soldered onto a circuit board :-p

Gate driver: use one!

Now it’s one thing to have a FET capable of fast switching, but you also need a way to turn it on that fast, and for that you need to dump as much current as possible into the gate capacitance in the shortest amount of time, and the very best way to do this is to use a fast gate driver IC with a high current rating.

I’m currently looking at the UCC27524P by Texas Instruments, which is a 5 Amp high-speed, low-side gate driver with incredible 7 ns rise and 6 ns fall times!

A gate driver essentially boosts a small logic signal from for example a Hall sensor or optical sensor to the higher voltage and current required to fully turn on the FET as fast as possible, thereby maximizing switching speed and minimizing heat generation and thus losses.

It also offers protection to the rest of the circuit, as a switching MOSFET can cause a back-current from the gate back to the driving circuit, which these drivers are designed to handle.

These drivers are also pretty cheap, but they can be a little tricky to implement due to their many pins, and the fact that they sometimes come as surface mount parts, although you can buy through-hole adapters for some of these packages.

However, if you spent $20 on a GaN FET, you should really implement a good gate driver as well and stop switching the gate with a basic transistor.

Diodes: SiC all the way

One of the simplest, and cheapest things you can do to significantly increase the amount of energy captured from the flyback is by upgrading your flyback diode.

Many Bedini SG circuit diagrams online, even some in the Complete Advanced Handbook written by Peter Lindemann, contain basic 1N4007 diodes.

Schematic from the advanced Bedini handbook

Now these diodes are commonly used for 50/60Hz mains rectification, not for high frequency operation, and while their 1000V rating is generally sufficient to handle the flyback spikes, their 1500 ns reverse recovery time is abysmal!

In comparison, modern silicon carbide diodes like the C4D02120A are so incredibly fast that their reverse recovery time is usually not even stated, or else stated as 0 ns, resulting in, quoting the datasheet, “essentially no switching losses”.

A flyback spike contains a certain amount of energy, and this energy will be dissipated over a certain amount of time.

So the slower your diode, the more of the spike’s energy will have already been dissipated as heat before your diode finally turns on, and so less energy will be left over to recover to charge your capacitor bank or charge battery.

This is why an ultra-fast flyback diode is essential, and since it’s a drop-in replacement that costs just $2.50, you have no excuse not to implement it right away!

Connections: low impedance

Now this inductive flyback spike is high-voltage (~300-900V), exists only very briefly, and so has an incredibly high ΔV/Δt.

This means it will be very difficult for this energy to pass through a conductor due to the skin-effect, “which causes alternating currents to flow closer to the surface, rather than through the centre of a conductor, effectively increasing the resistance”.

To counteract this, make sure that all your connections that will receive higher-voltage pulses are short and have as much surface area as possible.

So way thicker wire than the expected amps would require, multiple insulated strands of thin wire (Litz wire), or flat copper strips.

This means the connections between your batteries, between your batteries and the drive coils, between your coils and your MOSFET to ground, and especially the connections to and from your flyback diode!

Coils: lots of copper

No one gets excited about the prospect of re-winding their coils. as it’s a mind-numbing, time-consuming task, but please hear me out 🙂

First, the goal of the drive coils is to act as an electromagnet, either pushing or pulling the rotor magnets, or simply demagnetizing the core, as in the Adams design.

So how can we maximize the coil’s magnetic field strength?

The Basic Electricity Naval handbook tells us there are 4 main factors:

  1. The amount of current flow through the coil
  2. The number of turns of conductor
  3. The ratio of the coil’s length to its width
  4. The type of material in the core

We want to expend as little energy as possible, so increasing current flow like in #1 is not ideal, but lets explore the other options.

Number of turns & copper content: size matters!

Joseph Newman, brilliant inventor of the Newman motor turned crazy person, writes in his book:

For a given energy input into varying materials of identical volume, the generated strength of the magnetic field varies drastically! …I therefore instantly knew that the strength of the magnetic field had to be a result of the nature of the atoms comprising the material and not a result of the electrical energy input.

Joseph Newman

This indeed makes sense, as we know that for the same amount of current input, the magnetic field strength of a coil increases with the number of turns, which is why Magneto Motive Force (MMF) is measured in Ampere-Turns.

Newman says that “the current input simply acts as as a catalyst” for the coil’s copper atoms to align and set up a magnetic field.

He then describes two coils with identical resistance and identical internal diameter, but one uses 40-gauge (0.08 mm) wire and the other 5-gauge (4.6 mm) wire, the first weighing a mere 0.02993 lbs (133 g) and the latter one a whopping 335,469 lbs (16.77 tons)!!

Coil field strength ampere turns
Joseph Newman explaining how more turns of thicker wire is better

When 100V is put on these coils, they both draw about 95 mA of current, or 9.5 W of power, but the second coil’s magnetic field is 1905 times larger, and the energy stored in the field is 8 million times greater!

Holy crap!

Reading this was eye-opening for me, and so to get more power out in the flyback for the same amount of power in, simply use a lot more turns of thicker wire!

Robert Adams seems to have reached a similar conclusion, as he always mentioned how important a high-resistance coil was, which generally means more turns, and so more copper.

The cardinal mistake being made here is that most of these experimenters are concerned about I²R losses!  If you are seeking high/super performance with these powerful magnets [neodymium], then discard all concerns in relation to Ohms Law, for in the Adams technologies Ohms Law becomes a non-entity.

Instead of expecting results of a high order with stators of very low resistance, such as under 10ohms, increase the total series electrical resistance instead to 72ohms.

Robert Adams

By knowing the resistance values Adams targeted and by analyzing the coil dimensions on pictures taken of his original machines, it seems like Adams potentially used 0.35 mm wire on his smaller models, and up to 0.5 mm wire for his multi-kilowatt models.

Much thicker wire was obviously used by Newman on his machine, but you’re also going to want to keep the coils in proportion to the rotor magnets, which is why a larger motor with larger magnets and larger coils will most likely lead to much better results.

If Newman’s theory is true, you could literally just pulse a large coil of wire, and get a ton of flyback in return, without having to add the rotor, which is exactly what Tim Harwood from the Adams CD Motor Project tried to do with his Air Core Generator, in which he tried to replicate the effects of the Adams Motor in the simplest way possible.

This is what he told me in an email:

If you pulse an air cored coil at 2.2khz at 2% duty you get the same physics.

Slam that in @ 360v , in 120v increments, and it starts to get interesting!

Tim Harwood

So maximize copper content of your motor coils, which is in line with Paul Babcock suggesting to forget about the single coil Bedini motors, and instead have as many coils as you have magnets on your rotor.

Coil dimensions

To be honest, I was surprised to see the Basic Electricity handbook mention length to width ratio as a way to tweak the magnetic field strength.

However, when I looked into it, I soon stumbled upon the Brooks Coil, which says that the dimensions that maximize the inductance and minimizes losses of an air core coil are as follows:

A Brooks coil is an inductor wound in such a manner as to produce maximum inductance for a given length of wire. Specifically, it is a coil wound on a circular spool of diameter 2c. The length of the winding is c. The thickness of the winding is also c! Note the winding has a square cross section. The total OD of the coil is 4c. “c” is the Brooks constant.

Source: https://coil32.net/crossover.html

Now this coil shape might or might not work for your setup, as there are other factors to take into account besides maximizing induction.

For example, to get the most torque out of your machine, you’ll want to approximately match the size of your coil face to the size of your rotor magnets, or else a lot of magnetic field lines miss the magnets and therefore won’t assist in making the rotor spin.

So that decides your coil diameter, but how long should your coil be then?

Well, there’s something called the paperclip test, where you place a paperclip on a flat surface with a ruler next to it.

You then slowly move a rotor magnet closer to the paperclip, and note the distance at which the paperclip flies towards the magnet.

That distance should be the length of your coil, according to this test.

But then again, if you want maximum flyback to recharge your batteries, you might have to wind a coil much larger than that…

Finally, there is the fact that when you put a current into your coil, one side of the coil becomes the South pole, and the other side the North pole.

However, in nearly all pulse motors I’ve ever seen, the back of the coil, so one of the poles that you “paid for” with current, doesn’t get used at all!

There seem to be 2 main ways to utilize both sides of your coil:

  1. Wind the coil on a U or C shaped core, like in the image above
  2. Sandwich the coil between two rotor sections, each with magnets of a different polarity

This should give you a significant torque boost for the same amount of input power, but you’ll obviously also need to have a rotor with both North and South facing magnets, like the advanced rotor from Robert Adams pictured below, on which I’m basing my next design.

Rotor with North and South facing magnets, on an iron strip to guide the flux.

As you can see, the ideal coil dimensions are unfortunately not clear-cut, but hopefully this section gave you some things to consider.

Core material

Bedini and Adams used soft iron cores in their drive coils, and DIY researchers are using all types of core materials.

Using a soft iron core has several perks:

  1. It greatly increases the magnetic field strength
  2. It keeps the magnetic field more focused
  3. The rotor magnets will be attracted to it

However, in his presentation, Paul Babcock recommended using air core coils instead, and Joseph Newman’s motor also used an air core coil.

So who’s right?

I’m not sure yet, but cores tend to be expensive and hard to source, so if Paul Babcock and Joseph Newman had success with air core coils, I think that is the cheapest and easiest way to start.

You can then always progress to trying various types of cores, because as soon as you use a core, you’re going to have to deal with eddy currents, hysteresis, saturation, and other complex variables, making it much harder to get it right.

And if you do use an iron core like Adams, then think of following his instructions to have the core diameter be no larger than 75% of the rotor magnet diameter, so for a 20 mm magnet use a 15 mm core.

Other: bifilar windings

There have been countless people emailing me or commenting on my videos saying I should use bifilar windings on my drive coils.

John Bedini even went as far as having, I believe, 16 separate windings on a single coil!

Peter Lindemann once told me that this was because Bedini noticed each wire had its own “radiant element”, so he could capture one spike per winding, which greatly complicated the circuit, but apparently it was worth it.

I haven’t tried this out myself, but the Newman and Adams motors both used simple single layer windings and supposedly were able to achieve similar results, so to me this is a very low priority option you should only consider after trying all the other things in this article.

Air gap: 1 – 1.25 mm

In 1955, E.B. Moullin performed an experiment where he used a variable AC power supply to energize an electromagnet, and then measured the input current, as well as the induced voltage in a search coil placed on the bridging member. 

1955 E.B. Moullin experimental setup

This induced voltage was a proxy for the amount of magnetic flux across the air gap, as magnetic flux determines the amount of mechanical power available.

He gradually increased the air gap, then adjusted the power supply so that the voltage measured in the search coil remained constant, and then noted the amount of input current.

What he found was a big surprise!

At around 1.25mm, current needed to maintain mechanical power starts being lower than theory predicts

The straight line is the amount of current that is expected by today’s theory to be needed to maintain the same mechanical power across an air gap in a magnetic circuit.

However, we see that in reality the amount of current slopes DOWN and is in fact a lot LOWER than theory predicts.

So where is this additional energy coming from? The original experimenter didn’t know, but Adams believed this is proof that energy is entering the machine from the environment.

And you see that the 1.25mm gap Adams used is just in the positive region where excess energy starts to show up.

1993 drawing by Adams depicting how he believes energy from the environment enters the air gap

In the above drawing from 1993, you see two magnets, one of which is the rotor magnet, and the other one is the drive coil, which acts like an electromagnet.

In the accompanying text he explains that the energy from the surrounding space is gated by the magnets into the air gap.

Now whether this is true or not, Robert Adams built countless prototypes over several decades, and found the 1 – 1.25 mm gap to give the best results, and so this might be worth implementing in your own setup.

Magnets: stronger is NOT better

The rotor magnets can be of any type, but Adams said that “there will be much disappointment to a lot of people out there to learn that magnet energy product does not govern efficiency in any way whatsoever.”

Stronger magnets require more input power to achieve the same amount of rotation, and so efficiency remains the same, although torque increases for the same size machine.

So since we already learned that size seems to matter, and we don’t want to be handling large neodymium magnets as you might literally lose a hand, I highly recommend to stick to ferrite / ceramic magnets.

If you do decide to use neodymium magnets, heed the following warnings:

The cardinal mistake being made here is that most of these experimenters are concerned about I²R losses!  If you are seeking high/super performance with these powerful magnets [neodymium], then discard all concerns in relation to Ohms Law, for in the Adams technologies Ohms Law becomes a non-entity. 

Instead of expecting results of a high order with stators of very low resistance, such as under 10ohms, increase the total series electrical resistance instead to 72 ohms and instead of expecting spectacular results using these powerful magnets with only 12 – 24 volts, increase the voltage to a minimum of 120v

Upon having done this you must give attention to other important factors, i.e., stator to magnet air gap should be 1 – 1.25mm… Reduce the face area of stators to 75% of the magnet face.


Many people decide to use ultra-powerful neodymium magnets, but then still try to power it with a wimpy 12V, which means they have to dramatically increase their stator to magnet gap, which then makes the motor way less efficient, less powerful, and they then miss out on the “magic” that Adams believes happens if you use a small 1 – 1.25mm air gap.

So unless you’re ready for 120V+ drive circuits (at least if you’re using iron cores), it seems better to stay away from neodymium magnets.

Batteries: bigger & higher voltage

One of the main things I took away from Paul’s presentation, is that we will never achieve anything remarkable using a small 12V battery.

We need to both significantly increase battery voltage, which will help our ΔV/Δt, and also increase battery size, as larger batteries have lower impedance, and are therefore easier to charge.

Paul suggests a minimum of 48V, as that is also still a relatively safe operating voltage, but the higher the voltage the better (just be very careful).

Adams also went up to 120 and even 240V, and Tim Harwood also told me that the really big effects start to happen between 120 and 360V.

Rick Friedrich explains that larger physical battery size will be able to capture more energy.

Now this all requires a significant investment in batteries, and the higher voltage most likely means you’d have to redesign your entire circuit as well, so it’s not a small step to take, but apparently needed if you want to see any serious results.

For my next motor, I’m looking at using 8x 12V 35aH flooded lead-acid batteries, 4 for running, 4 for charging, for a total of 48V, which will set me back about $500… ouch…

Note: Julian Perry told me he didn’t find a relation between battery voltage and CoP, and that using a higher voltage battery on the same coil would even result in lower CoP due to more current consumption, so higher voltage should probably go hand in hand with larger, higher resistance coils, which is what Adams also did.


In an old Bedini interview we hear him mention that LiFePO4 batteries are the future, and it’s true that these batteries have some interesting characteristics, like a smaller form factor and a very low impedance.

However, they are also about 5x the price of a lead-acid battery with the same capacity!!

Paul Babcock and Mike Clarke successfully use lead-acid, and Julian achieved CoP > 1 with both lead-acid and LiFePO4 batteries, but achieved his highest CoP values with 18Ah LiFePO4’s.

So I think lead-acid would be the economical place to start, and once you see success with those and find a jar of money somewhere, then you can consider giving LiFePO4 a try.


In my original Adams Motor design, I had only one battery which was running the motor, and which I also tried to recharge from the flyback at the same time, as I tried to keep the circuit as simple as possible.

Now the thing is that a battery can only really do one of those at a time, and if you do what I did, the ions will just be sloshing around, and the battery won’t be charged efficiently.

Note: battery swapping is essential. I can’t stress that enough.

Paul Babcock

As you can see in the quote above, it seems like you’re going to need a second battery bank which will be charging while the first bank is running the motor.

Paul then has a circuit that will swap the run and charge battery around in the circuit every 3 minutes or so, but unfortunately he did not want to disclose his circuit during the presentation.

There is also a battery switching board for sale by Energy Bat Labs for a whopping $600, which actually uses 3 battery banks, where 1 bank is “resting, and switches based on voltage levels instead of time.

Example of battery swapping circuit

If you search really well, you might come across some circuit diagrams like the one above, which I haven’t tested myself.

But if you want to simply switch batteries after a certain period of time, like in Paul Babcock’s situation, the following video has a potential answer for you!

It uses a 12V 4-Pole Double-Throw latching relay, the Panasonic SP4-DC12V, driven by an Arduino for the timing and a tiny circuit to determine whether to SET or to RESET the relay.

Another key thing to consider when using relays is to make sure you turn the motor OFF while the relay switches, or else current will still be flowing, thus creating arcs inside the relay, which will eventually cause the contacts to burn out.

I turn the motor off by utilizing the ENABLE pin on my MOSFET gate driver IC.

In my latest video I show how I implemented battery swapping:

You can find the schematics, wiring diagram, and Arduino code for the battery swapper in the description of the video.


A small addition to the battery story is that you might want to add 500-1000uF of capacitance right after the run batteries in your circuit, as they will be able to provide energy to your pulses much faster than the batteries alone could muster.

It also seems that once you have a system that charges faster than it runs down, there might be a point where batteries could be replaced by capacitors altogether, but I don’t know of anyone who has reached that point yet.

Duty cycle: 25-35%

In a pulse motor you obviously pulse the coils, but for how long?

Adams recommends a sweet spot for the duty cycle of 25-35%, with the lower range being more energy efficient, while the higher end gives you some more torque.

Going higher than 35% will waste unnecessary power.

One easy way to achieve this is by using a photo-interruptor and a timing disk attached to the shaft.

Generator: on the shaft

In Adams’ manual, he shows a motor generator system where there are 2 drive coils and 4 generator coils placed around the periphery, which I replicated, and which wasn’t very effective at all at generating power.

My Adams Pulse Motor Generator replication

However, in the British Adams / Aspden patent they write the following:

If the object is to generate electricity by operating in generator mode then one could design a machine having additional windings on the stator for delivering electrical power output. However, it seems preferable to regard the machine as a motor and maximize its efficiency in that capacity whilst using a mechanical coupling to an alternator of conventional design for the electrical power generation function.

R. Adams & H. Aspden, UK Patent GB 2,282,708, Electrical Motor Generator (1995)

Paul Babcock recommended the same thing: use the pulse motor as a motor, and attach a conventional generator to the shaft for electrical power output instead of fabricating your own, probably very inefficient, generator coils.

Mechanical construction: precision is key

When it comes to pulse motors, everyone seems hung up on the electronics, but then I see some motors made out of wood sawed and drilled by hand, a bend curtain rod as a shaft, and cheap bearings full of grease…

Such a build just isn’t going to work.

I understand that not everyone has the tools, skills, and funds to build a high-quality machine, but the reality is that the mechanical aspects of these motors need to be spot on, and made of high quality, precision made parts, or else the losses will be tremendous and you’ll never achieve the results you’re looking for.


When it comes to bearings, we want as little friction as possible (so no thick grease inside), and we want to make sure they are non-magnetic.

The bearing type of choice for me has been full-ceramic bearings, which are very low friction, non-magnetic, waterproof, need no grease or other lubricants, and promise a much longer lifespan compared to conventional ball-bearings.

They are usually more expensive, unless you get then off of AliExpress.

I can highly recommend the brand Fushi, which sells through AliExpress, and who make precision ceramic bearings in many sizes for competitive prices.


Your shaft also needs to be very straight and also non-magnetic, so either 316 stainless steel or aluminium.

I tried ordering stainless steel shafts in the past, but they ended up being a different type of steel and so were actually magnetic.

Mike Clarke had the same thing happen to him, and he only found out after he epoxied his expensive rotor to the shaft!!

That’s why I’m mainly using hardened aluminium precision shafts, and when you go up to 20mm and up, a hollow shaft might be a great option, as it is lighter and stronger than a solid shaft.

Balanced rotor

During all my research into pulse motors, I’ve hardly ever heard anyone discuss the importance of balancing the rotor, which is a crucial step in the construction of any type of rotating machinery.

It was observed that average power loss due to unbalance is of 0.11watt/gm.mm unbalance. This can amount to 2.75 kw if there is unbalance of 50 gm at a radius of 500 mm.

M. Bulsara, Energy loss due to unbalance in rotor–shaft system (2016)

The above quote from a 2016 research paper shows that just 50 grams of unbalance on a 1 meter diameter rotor can result in 2.75 kilowatt (!!) of power loss due to vibration, which is a huge amount!

In this video I’m showing how to dynamically balance a Tesla Turbine rotor using Tesla’s own balancing patent

And the faster a rotor spins, the more important a good balance is, as the centrifugal forces grow tremendously with speed, excarcerbating the vibrations, and pulse motors tend to go FAST!

At certain speeds, your system will hit a resonance point, where the vibrations can become truly destructive.

Unfortunately, proper balancing is not exactly super easy, as you’ll have to deal with both static imbalance and dynamic imbalance, which are very clearly explained in the video below.

Dynamic imbalance becomes more important the wider your rotor is, so luckily for most pulse motors out there with relatively flat rotor disks you can focus primarily on balancing your rotor statically, which is fairly easy to do.

In the video below you see how someone statically balances a motorcycle wheel, mainly to give you an idea about what a simple balancing setup looks like.

Below is a brief description of the static balancing process.

Static balancing was the primary method for balancing before more sophisticated machines became available that could dynamically measure imbalance in rotating parts. Static balancing can be accomplished by placing a part on knife edges [or some low-friction bearings]; the part will usually rotate until the heaviest side rests at the bottom. Material can either be removed from the heavy side, or added to the opposite side to try and correct the imbalance. This process is repeated until the part can rest at any angle without turning.

Static balancing is more suited for non-critical machines where a rough balancing process is adequate e.g. car wheels are usually statically balanced and weights are added to the wheel rim to compensate for imbalances. High speed rotating equipment will typically have to be dynamically balanced, or else excessive vibration could lead to failure and/or damage.


As you can read above, a dynamically balanced rotor is ideal, but even just a static balance will already reduce your power loss due to vibration significantly, and will put you way ahead of 99% of the other pulse motor builders.

Since I’m planning on building a fairly wide and powerful rotor, I’m considering to let a professional balancing company balance it for me, for which I was quoted €300… ouch again.

Rotor weight

In Mike Clarke’s presentation he describes how he casted his rotor from epoxy, and that it’s so heavy you need two adult men to lift it.

This is not an ideal situation in my eyes, as more mass means more energy required to make it spin, so any non-functional weight should be kept to a minimum, like the inside of the rotor.

Robert Adams used a lightweight HDPE foam filler in his rotors to keep them as light as possible.

Magnets resin bonded to paxolin disk, then rest of rotor filled with HDPE foam

I plan to 3D print my rotor, and use thicker walls, but a mere 20% infill to keep the structural weight down as much as possible.

Closing thoughts

A lot of pulse motor design considerations were discussed in this article, some easier and cheaper than others, but all important in their own way.

At the very least, I hope this article gave you some food for thought on how to take your pulse motor to the next level.

And if I said anything stupid or if I missed some important points, please let me know in the comments below so I can amend the article.

Finally, be sure to check out the Paul Babcock and Mike Clarke ESTC presentations!

Robert Adams Pulsed Electric Motor Generator

Robert Adams Pulsed Electric Motor Generator: Theory & Tips

In 1975 the Chairman of the New Zealand Institute of Electrical Engineers, Robert Adams, filed for a patent on a new type of highly efficient motor / generator that utilized the power of permanent magnets.

However, his patent was denied, and he was subsequently pressured by the prime minister and several large companies to keep his invention to himself.

After 20 years of this, Adams, now in his seventies, felt he didn’t have much to lose, and so he decided to publish his invention in a 1994 edition of Nexus Magazine.

Since then, thousands of experimenters around the world have replicated Adams’ revolutionary device, some with incredible results.

Unfortunately, there is a lot of confusion and misinformation out there about the Adams Motor, which I aim to clear up in this article by mainly referring to the inventor’s own words.

What makes the Adams Motor so special?

In short, the Adams motor uses only a small amount of power to rotate permanent magnets, it then recaptures some of this power to keep its supply battery (partially) charged, and then uses generator coils to extract additional useful power to run loads.

These claims might seem ridiculous to some readers, but I have a working model running in my shed that does just this, and I only studied this stuff for two weeks before I built it!

It’s not rocket science, you just need an open mind and learn why it works, without violating any established laws of physics.

Now on to the detailed answer 🙂

But first, a short detour, as I need to clarify the term “back EMF” before we can continue, since even Robert Adams himself does not always use it in the clearest way.

Back EMF 101

It is important to know that there are 3 types of electromotive force, or EMF, present in an Adams Motor circuit:

  1. Supply EMF
    The voltage supplied by a power supply or a battery.
  2. Counter EMF
    A voltage induced in a motor coil by a moving magnet, opposing the supply voltage.
  3. Flyback EMF
    A high voltage spike produced by a collapsing magnetic field.

As you can see I did not use the term “back EMF” in the list above, as some people use that term for #2, while others use it for #3 in the list, or both!

This is the source of a lot of confusion and misunderstanding.

That is why I use the wording from the 1954 Basic Electricity manual, which was used to teach army cadets about electricity and electric motors:

Counter EMF

Here is an excerpt from that excellent book:

In a DC motor, as the armature rotates, the armature coils cut the magnetic field, inducing a voltage or electromotive force in these coils. Since this induced voltage opposes the applied terminal voltage, it is called the “counter electromotive force”, or “counter-emf.”

There you have it; counter EMF is induced in a coil when a magnet passes by, and is in opposite direction to the supply voltage.

Counter EMF is displayed as a battery opposing the source voltage

It continues:

This counter-emf depends on the same factors as the generated emf in a generator–the speed and direction of rotation, and the field strength. The stronger the field and the faster the rotating speed, the larger will be the counter-emf.

An electric motor is at the same time a generator, and the generator output of a motor is the counter EMF.

Now here comes the really interesting part that was an eye-opener for me:

What actually moves the armature current through the armature coils is the difference between the voltage applied to the motor (Ea) minus the counter-emf (Ec).

Ohm’s Law states that

current = voltage / resistance

But for DC motors, this is changed to

current = (supply voltage - counter EMF) / resistance

Since counter EMF increases as the motor speeds up, this explains why the current draw of an electric motor decreases with speed, which is further explained in the next section:

The internal resistance of the armature of a DC motor is very low, usually less than one ohm [10-20 ohm in an Adams motor]. If this resistance were all that limited the armature current, this current would be very high… However, the counter-emf is in opposition to the applied voltage and limits the value of the armature current that can flow.

And from another source:

As the motor turns faster and faster, the [counter] emf grows, always opposing the driving emf, and reduces the voltage across the coil and the amount of current it draws… if there is no mechanical load on the motor, it will increase its angular velocity ω until the [counter] emf is nearly equal to the driving emf. Then the motor uses only enough energy to overcome friction.

Lumen Learning

Soooo, long story short: if you want to use the least amount of current to spin a rotor, you let it run at maximum speed, without a mechanical load, to maximize counter EMF.

Robert Adams had this to say about it:

For efficient running the [counter] E.M.F. must be nearly equal to the applied E.M.F.

So what then is the flyback EMF that others sometimes mistakenly call “back EMF”?

Well, when current flows through a coil, this current establishes a magnetic field around the coil.

If you then suddenly disconnect the coil, there will no longer be any current flowing to support the magnetic field, and so it rapidly collapses in on itself.

And we know that a changing magnetic field induces a voltage, and the formula it follows is

Voltage = Inductance / Rate of change of current

In other words, the faster you cut off the supply current, the higher the resulting voltage spike.

In a regular DC motor, this high voltage flyback EMF is being diverted using a flyback diode to protect the windings, essentially wasting this energy.

In an Adams Motor, the flyback EMF is instead “captured” in a capacitor, and then used to (partially) recharge the supply battery.

I hope it is now clear what the difference is between the three types of EMF present in an Adams Motor.

For more information on counter EMF, and how you can engineer an electric motor that does not generate any counter EMF, I highly recommend you check out Peter Lindemann’s brilliant Electric Motor Secrets presentations.

Features and advantages

In his publication “The Adams Pulsed Motor Generator Manual“, Adams mentions a long list of features and advantages of his device.

I will now quote these and add comments where needed.

It overcomes back EMF, which is the big problem in all conventional machines

In this case, back EMF refers to counter EMF.

Adams mentioned that “as Lenz’s Law states, the induced [counter] EMF is in such a direction as to oppose the rotation which is producing it.”

This is called Lenz drag, and results in wasted power.

An Adams Motor is pulsed at the exact right time so the Lenz drag is cancelled out, allowing the rotor to keep spinning freely.

It, in turn, (due to its unique design) harnesses the effect of back EMF, I.E., the collapsing magnetic field, thereby increasing torque and decreasing power input

In this case, back EMF refers to flyback EMF.

The flyback voltage spike pushes the magnet along, increasing torque.

The flyback EMF is also siphoned back to the supply battery, thereby decreasing net power input.

It does not require a separate motor in the motor/generator mode to produce electrical output energy

It utilizes one common rotor which runs the machine and generates output power

Conventional machines need drive coils around the entire rotor circumference to pull it through its full range of motion, while an Adams Motor only needs two or even just one drive coil.

This leaves room to place generator coils around the same rotor, removing the need for a second generator rotor.

All it’s rotor poles are of similar polarity, I.E., all south going or all north going

Traditional electric motors use an alternating north-south magnet configuration, while in an Adams Motor all magnetic pole faces are of the same polarity.

It’s drive (stator) winding and pole requirements are small

While you are not restricted to using any particular wire gauge, there are in fact a couple of guidelines you should follow to create optimal drive coils, which I’ll discuss later.

The air gap is not critical

Whether the gap between the coil core and the rotor magnet is 1mm or 2mm is not super important, “however reduction will increase torque and also increase input power in proportion.”

It requires no cooling fan

The motor and switching circuit run cool (~40º), because they use only a very small amount of current, applied during brief pulses.

The machine does not require constant current power input

The motor is ideally pulsed with a 25% duty cycle, which means no current flows for 75% of the time, while conventional electric motors have a current flowing continuously.

The unique design of the machine is such that:
a. It feeds energy back into its battery supply
b. There is virtually zero magnetic drag
c. It’s temperature, under full load conditions, is less than half that of any conventional machine
d. Regarding mechanical switching mode, the “tapered star contactor disc” which the inventor conceived, is a means of governing and/or altering the duty cycle, which, in turn, gives an automatic means of varying speed, current, and torque

A lot to unpack here.

The high voltage flyback EMF is fed back to the supply battery, allowing it to (partially) recharge.

Magnetic drag is nullified by a perfectly timed pulse.

The small amount of current in the system allows the motor to run cooler.

Duty cycle is used to adjust speed, current, and torque of the motor.

The machine, in high efficiency mode, I.E., beyond unity, is producing energy from space, viz., (electrostatic scalar potential)

This claim is a questionable one for several reasons.

First of all, the term “beyond unity” or “overunity” will immediately disqualify this invention in the minds of many, since nothing can be more than 100% efficient, and neither is the Adams Motor.

A better term to use would be “Coefficient of Performance” or “COP”, as this compares power input from the power supply with power output by the device.

Since some rotational energy comes from the permanent rotor magnets being attracted to the iron coil cores, energy which is not coming from the power supply, a properly constructed Adams Motor can actually achieve a COP > 1.

Since this energy comes from the magnets, the claim that energy is produced “from space” seems to be incorrect.

The vague term “electrostatic scalar potential” also seems to be unnecessary to explain the functioning of this device.

Contrary to conventional machines, the slower the speed, the greater the efficiency, the greater the torque, the lower the input power

This statement confuses me a little, as in conventional machines it is in fact the case that slower speed equals higher torque, but also higher current draw in proportion.

I did notice that my most efficient Adams Motor ran at a slower speed, and used much less power, but I haven’t yet been able to measure if it had in fact greater torque.

As there is no power factor loss in the machine there are constant power and torque characteristics (machine in resonance mode)

Adams writes “there is no power factor loss because the Adams machine runs in a state of resonance.”

The phase angle of the voltage and current in a series resonant circuit is zero at the resonant frequency, and if phase angle is zero, power factor is unity, see: https://www.electronics-tutorials.ws/accircuits/series-resonance.html

As there is no change in the direction of supply energy there are no eddy current or hysteresis losses sustained

This same claim is made in a patent of another pulsed motor, called the Keppe Motor, and explains the reasoning behind it in a bit more detail:

“Zero hysteresis, since the feeding current is a direct and pulsed current, so there is no polarity alternation of the source. Minimized eddy currents, because… the magnetic fields created inside the coil –both during power supply and back energy supply are parallel to the body of the motor, thus yielding close-to-zero induced currents.”

The machine, in all modes of operation, is self-protective from any likely adverse conditions occurring; therefore no protective ancillary devices are required

Can be run without a load without running itself to destruction, due to the self-regulating effects of counter EMF vs speed.

High speeds with their attendant problems are not necessary

Even a slowly spinning permanent magnet rotor is able to generate power, and the flyback EMF which recharges the source battery is also not dependent on rotational speed.

The machine can be electrically loaded simultaneously with a further increase in output energy of upwards from 50% to beyond 100% without overload or heating above its normal operating temperature

Adding properly designed generator coils to the Adams Motor allows extra power to be extracted, without much additional current draw.

The machine lends itself admirably to simple and inexpensive speed control

All you need to do is tweak the pulse duration.

How does it work?

Now that we know why this motor is so special, let’s look at how it actually works.

In his patent application, Adams describes his devices as follows:

…a direct current electric motor… which draws current only when the most effective use can be made of it, thus allowing the motor to run very efficiently.

Robert Adams, provisional patent application

The following series of drawings from Robert Adams’ patent application show a full cycle of the motor, which will help explain how it works:

Different stages of drive pulse vs rotor rotation

Here is what Robert Adams had to say about these drawings (I will highlight some important parts in bold):

Figures 1 to 4 show, in diagrammatic form, a motor according to the present invention, the rotor being at a different stage of its revolution in each of the various figures, and

Figures 1a to 4a [the bottom left corner of each drawing] show a representation of the current flow in each of the stages shown in Figures 1 to 4.

The drawings show a form of motor according to the invention which has a rotor [A] comprising four permanent magnets, 1 to 4, and a stator [B] comprising of two coil windings. The motor can be operated when the coil windings are connected to an appropriate DC voltage source.

The voltage source can be a bench power supply, but most often rechargeable lead-acid batteries are used.

The rotor magnets can be of any type, but Adams said that “there will be much disappointment to a lot of people out there to learn that magnet energy product does not govern efficiency in any way whatsoever.”

Stronger magnets require more input power to achieve the same amount of rotation, and so efficiency remains the same, although torque increases.

So to start, build a 12-24V device, and use lower strength ferrite magnets before upgrading to higher voltages and neodymium magnets.

The supply of current to the windings is controlled by a current controller shown diagrammatically in the drawings as a switch [S]. The current controller is operated in synchronism with the rotation of the rotor [A], so that current is supplied to the stator windings [B] only when the magnets 1 to 4 have just past their central point of alignment with the stator windings.

While Robert Adams himself preferred to use a brush commutator as his current controller, he also included drawings for transistor switches triggered by, for example, photo interrupters, Hall sensors, or trigger windings.

I’ve seen many websites mention that you should only use MOSFETs for switching, as their internal body diode will create a path for the “back EMF” to flow back to the battery. This is WRONG, and another clear example of people not understanding the concept of counter EMF! You do NOT want the counter EMF to flow that way, you only want the flyback EMF to flow that way. None of Robert Adams’ drawings show MOSFETs, only regular transistors, although he does mention MOSFETs in an 2001 article written on his website.

As is shown in Figure 1 the stator windings are activated to produce a north magnetic pole adjacent the ends of the rotor magnet, 1 & 3. As indicated in Figure 1a, this is the point at which the current is first permitted to pass through the windings. Thus there is a magnetic field repulsion established between the stator and the rotor which causes the rotor to rotate in the direction indicated by the arrow. The magnetic repulsion is commenced when the rotor is at a small angle x degrees past the point of alignment with the stator windings.

Then, as shown in Figure 2, the current is maintained in the stator windings until the rotor has moved to an angle of y degrees past the point of alignment with the stator windings. Then at this point the current controller [S] cuts off the supply of current to the windings [B]. The resulting collapsing magnetic field now reverses magnetic polarity attracting on-coming rotor poles, thereby stator windings are pulsed again repeating the cycle.

You see that pulse timing is everything in this motor, in order to maximize the effect of the repulsion and attraction forces.

You need a way to precisely control the start time of the pulse, as well as its duty cycle, or your results will most likely not be very impressive.

This is why I decided to use a microcontroller to have direct control over the pulse timing and duty cycle.

Also, another force that is acting on the rotor, mentioned in another text, is the attraction of the approaching rotor magnet to the iron cores of the drive coils.

This attraction normally results in drag when the rotor magnets moves past the coils, but since that is the exact time the coils are pulsed, this nullifies the drag on the rotor, allowing it to continue to spin freely!

Figure 3 shows the motor with the rotor [A] having just past the position shown in Figure 2 and there is no supply electric current remaining in the stator windings [B]. The rotor is continuing to rotate under its angular momentum. This continues until the position shown in Figure 4 is reached. The pole 1 of the rotor is now at an angle of z degrees passed its point of alignment… Thus the pole 4 of the rotor [A] has almost reached the position of the pole 1 in Figure 1. In other words, the current controller [S] is just about to allow current to flow through the stator windings once more.

The cycle is then repeated, four times for each revolution of the rotor [A].

You’ll want the rotor to have a decent amount of mass, in order for it to act as a flywheel to maintain its angular momentum when the pulse is OFF.

Sooo, now that you know how the Adams Motor works, you can see why this motor is so efficient, as current is only applied “when the most effective use can be made of it”, just like when pushing someone on a swing, instead of being applied continuously, as in a regular DC motor.

But here is the biggest secret of this motor, in the words of Adams:

In all, the machine benefits from [three] different force actions per revolution and paying a minuscule toll fee for only one.

…the rotor magnet is mutually attracted to the stator (gets away without paying for that)

…from the repulsion pulse of the stator at point ‘x‘.

…the rotor is given a further pulse from the collapsing field (a few degrees after point ‘x‘)

Adams Update


Now, the collapsing field is harnessed not just to give the rotor a boost, but also to recharge the supply battery, as Adams depicts in the following drawing (be sure to read the notes!):

Adams motor battery recharging

All that seems to be needed is a diode and a capacitor!

(Still trying to figure out exactly how the above circuit works)

It’s an exceptionally ingenious device, yet no laws of physics are being broken.

Coil resistance

Now, there is one more aspect of the drive coils that needs our attention:

Wind stators with a resistance in the range of ten to twenty ohms each for a small model.

Robert Adams, The Revelation of the Century

It might seem crazy to the average electrical engineer to wind stator coils with such high resistance, but Adams said that using stator coils of low resistance is the main reason many experimenters see lousy results:

The cardinal mistake being made here is that most of these experimenters are concerned about I2R losses!

IceStuff Adams Motor Guide

Our goal is an efficient motor, and so we want to draw as little current as possible, and so a higher resistance coil makes sense.

But less current equals a weaker magnetic field, and we need a strong magnetic field to achieve the greatest possible torque and RPM…

So what’s the solution?

Magnetomotive force (MMF) is measured in Ampere-Turns, which is based on the following observations:

  1. If the current is increased and the number of turns remains the same, the magnetic field strength is increased.
  2. If the number of turns of a coil is increased and the current remains the same, the magnetic field strength is increased.

Based on #2 above, we can see that if less current flows because our drive coil has a higher resistance, then we’d need to increase the number of turns to achieve our desired magnetic field strength.

A few turns of thin wire on the left, many turns of thick wire on the right, identical resistance

A 10 Ω coil with many turns of thick wire will establish a much stronger magnetic field for the same amount of current draw than a 10 Ω coil with few turns of thin wire, and will result in a much stronger flyback EMF from the collapsing magnetic field, which we can use to (partially) recharge our battery.

So while the high-ohm drive coils suggested by Adams will reduce current draw, they also force you to use more copper, resulting in more energy being available to be recaptured.

Now this is all absolutely within the current laws of Physics.

But once I state it as “more energy being available” now that we have more copper involved, some people will start to feel uncomfortable.

“Where does this additional energy come from?!”

Not sure, but it is exactly what the well established Ampere-Turns rule predicts, so it shouldn’t be news to any electrical engineer.

It seems that only Joseph Newman, who became batshit crazy, but who had some brilliant original thoughts earlier in his life, has an explanation for it in his book “The Energy Machine of Joseph Newman“.

He postulates that:

Energy input to make a magnet has absolutely nothing to do with energy within a magnetic field — catalytic effect only.

Joseph Newman, The Energy Machine of Joseph Newman


The facts further demonstrated that the strength of the magnetic field was observed to increase as more atoms within the material became aligned!

Joseph Newman, The Energy Machine of Joseph Newman

So Newman says that the more atoms you can align, the stronger the magnetic field, and you only need a relatively small input current to achieve this, as it is purely a catalyst to force atoms into alignment.

From this it follows that having more copper in a coil gives us more atoms to align, and thus a stronger magnetic field results.

This is why his motor was HUGE, and had 90.000 (!!) turns of 5-gauge copper wire!

Was Newman correct?

I don’t know, but his is the only explanation I’ve found so far that makes any logical sense, and which completely fits the experimental evidence.

In our Adams motor, we don’t need an infinitely strong magnetic field.

It should just be strong enough to overcome the attraction of the rotor magnet to the stator core, and ideally provide enough flyback EMF to recharge our battery.

So we can use much, MUCH smaller coils than in the Newman motor 🙂

I’ve found that using 0.35 mm copper wire works very well, and based on some forum posts, this is also what Adams preferred to use for his low voltage machines, while he supposedly used 0.5 mm wire on his high power ones.


We have discussed the Adams “motor” in detail, but wasn’t there also a “generator” part to it?

There is indeed!

Luckily the generator is a lot simpler than the motor bit, although there are still a few things to keep in mind.

Here are some quotes by Robert Adams pertaining to the generator coils:

Ideal cores can be built cheaply and quickly by dismantling a spare power or audio transformer and utilizing the “I” section laminations, obtain winding former to fit same and it is ready for winding. Turns and gauge will depend on what voltage and current you choose. Remember, at this stage, you should only be building a demonstration model, so to speak.

After a few changes, corrections, and/or general modifications you will be ready to put a mechanical and/or electrical load on the machine. For an electrical load it is suggested you firstly wire up a bank of 6 – 12 LEDs. If everything is go, then switch over to torch lamps. Later on with a bigger machine – car lamps, or maybe household lamps and a mechanical load simultaneously.

Robert Adams – The Adams Pulsed Motor Generator Manual, p.27

Adams clearly mentions here that he uses laminated cores for his generator coils, which makes sense, as these minimize eddy currents.

I plan to try these Dayton Audio crossover coils as generator coils, as they already have laminated cores.

We read before that Adams mentioned:

It does not require a separate motor in the motor/generator mode to produce electrical output energy

It utilizes one common rotor which runs the machine and generates output power

Robert Adams

In the drawing below, we see 2 slim drive coils, spaced 180º apart, and 4 fatter generator coils, spaced 90º apart, all placed around a single rotor.

Adams Motor Generator Setup
4 rotatable “fat” generator coils directly hooked up to a load and ammeter

Actual dimensions

The drawing notes mention a 1/2 scale, but what paper size was used?

New Zealand uses ISO standards, so it could realistically be either A4 or A3.

I started out by assuming it was A4, but the measurements were all a bit odd and random.

Then I read somewhere that Adams preferred to use 3/4 inch (20mm) magnets, and 0.35 mm wire.

When I scaled the image to A3, the magnets were indeed 10mm wide, and at a 1/2 scale, that means in actuality they were 20mm!

Since it would be easier to get the direct measurements instead of having to multiply everything by 2, I scaled the image again to an A2 size (which is 2x A3), and did the same for the other technical drawings from the manual.

Now I could directly read the dimensions of all the parts by drawing over them, and this is what I found:

Rotor: 20 cm diameter, 2 cm thick, very light materials used, tiny amount of spacing between rotor and stators.

Magnets: 20x20x80 mm magnets with N poles facing out, and rounded edges. This 4:1 length to width ratio for the magnets supports the hypothesis that Adams used Alnico magnets in this particular design:

Typical open circuit Alnico 5 applications require a long magnetic length to pole surface ratio (usually 4:1 or greater) to insure good magnetic performance.

Adams Magnetic Products

Drive coils: 20 mm wide, 30 mm long, 10 mm solid iron core. If Adams used 0.35 mm wire, the coil would end up being ~10 Ohm, which is what he recommends, so this further solidifies these dimensions.

Generator coils: 30 mm wide, 30 mm long, 20 mm core with 15 mm of laminated core sticking out the back. ~15 Ohm if 0.35 mm wire is used, however, this resistance value seems unreasonably high, so you might want to experiment with generator coils with much thicker wire and lower ohmic resistance.

Shaft: 10 mm brass shaft, with 8mm ends for bearings (measurements differ slightly per drawing, so this is my best guess).

Structure: ~50 cm wide.

Switch: A custom star wheel commutator disk, 50mm wide.

A few additional things stand out from the drawing:

  1. The drive coil cores are 1/2 the width of the rotor magnet, while the generator cores have the same width as the rotor magnet
  2. The generator cores stick out about 50% further than the end of the coil
  3. The generator coils can be rotated around the rotor between 25º and 45º for finding the point of maximum power generation
  4. A switch to turn the current flow from the generator coils ON or OFF

Now, point #2 above requires some additional explanation.

Heel end slug

A core sticking out the back of a coil is called a “heel end slug”, and was used in relays like the GPO Relay 3000 to create a slower release.

A heel end slug affects the collapse of the magnetic field when the energising current is switched off. The collapsing field cuts the slug to produce an eddy current which in turn has its own magnetic field which opposes the collapse. ie It assists the field and attempts to maintain it around the complete magnetic circuit and therefore holds the armature in… The relay becomes practically normal to operate but slow to release.

Dean Forest Railway Telecoms

In the case of a generator coil, its function is slightly different, yet significant.

When a rotor magnet approaches a generator coil, the coil effectively turns into an electromagnet, with a North and a South pole, and a neutral zone in the middle.

If we add a heel end by making the core longer than the coil, the neutral zone will still be in the middle of the core, and so will have moved further up the coil.

Left, a regular generator coil. Right, a generator coil with a 50% heel end.

The result?

A heel ended generator coil will produce a much higher voltage for 2 reasons:

  1. More coil windings are exposed to the same magnetic polarity
  2. Higher inductance due to the additional iron

While this is a plausible explanation, Robert Adams never actually mentions this requirement, and it could just be that having the laminations stick out the back made it easier for him to mount the generator coils, as they have a bolt through them in the drawing.

Switching the generator coils

While the drawing appears to show a regular switch, Robert Adams may in fact have used a more advanced switching mechanism, as he used the same symbol in other drawings to represent various commutation methods.

Some experimenters claim that by precisely switching the generator coils, just like we did with the drive coils, magnetic drag can be minimized, and power output maximized.

Surprisingly, the output coils are switched Off for most of the time.

This sounds mad but it most definitely isn’t mad.

With the output coils disconnected, the approaching rotor magnets generate a voltage in the output coil windings but no current can flow.

As no current is flowing, no magnetic field is generated and so the rotor magnets just pull directly towards the output coil iron cores.

The maximum output coil voltage is when the rotor magnets are aligned with the output coil cores.

At that instant the output switch is closed and a strong pulse of current is drawn off and then the switch is opened again, cutting off the output current.

The output switch is closed for only three degrees or so of the rotor’s rotation and it is off again for the next eighty seven degrees, but the opening of the switch has a major effect.

The switch being opened cuts off the current flowing in the output coils and that causes a major reverse voltage spike causing a major magnetic field which pushes the rotor on its way.

That voltage spike is rectified and passed back to the battery.

Patrick J. Kelly

Keep in mind that again, Robert Adams himself never mentioned the need to switch the generator coils to achieve his results.

In fact, it seems that a lot of people are convinced they need to try all sorts of esoteric “low-drag” generator coil setups, while Adams managed to make his motor so efficient that he could achieve his results with any old generator, as is evidenced from this excerpt from his UK patent GB2282708A:

It seems preferable to regard the machine as a motor and maximize its efficiency in that capacity whilst using a mechanical coupling to an alternator of conventional design for the electrical power generation function.

Robert Adams & Harold Aspden – Patent GB2282708A, p. 24

The MOTOR is the invention.

However, the generator does have a clear function in demonstrating the peculiar properties of this device, as mentioned in the same patent:

The machine is able to demonstrate the excess power delivery from the ferromagnetic system by virtue of electrical power generation charging a battery at a greater rate than a supply battery is discharged.

Robert Adams & Harold Aspden – Patent GB2282708A, p. 19

So this is how Adams tried to prove his motor displayed power in excess of that supplied by the source battery: by charging a second battery from the generator output at a rate faster than the source battery was discharged.

Source of excess energy

So where does this “excess energy” come from?

We’ll let Robert Adams describe it in his own words:

There is massive trapped energy in many natural materials, especially metals. Latent magnetic energy is ever present in these materials and this energy I describe within the structures of electric motors is found to play an important role together with that of the energy harnessed from the small air gap between the rotor and stator sections; this applies to both motors and generators alike.

Power source applied to electric motors expands the ever present covert electromagnetic flux of the metal materials, i.e., the iron core and copper windings. It is not the impressed energy applied to the motor that creates the inductive field, as taught in universities and colleges alike; the magnetic flux field “already” exists in its natural state within the stator system; the application of energy into the system simply “expands” the natural latent inherent inductive energy residing therein.

This expanded inductive energy, in conjunction with the energy harnessed at the air gap between the rotor and stators, provides the driving power of the motor.

Robert Adams – Applied Modern 20th Century Aether Science

When Adams talks about “the energy in the air gap”, he means energy from the aether, or what quantum physicists nowadays call the zero-point field, which he strongly believed in.

As proof of this excess energy flowing into his air gap, he refers to a simple but fascinating experiment, both in his UK patent and in his book The Revelation of the Century, from The Principles of Electromagnetism (1955) by E.B. Moullin.

The first thing to remember is this:

The flux density in the gap represents the mechanically available energy.

Next, here’s what you do:

Take some transformer E laminations and wind a primary and a small secondary onto the middle as shown above in Fig. 1.

Use a variable AC power supply to adjust the input power supplied to the primary.

Use strips of cardboard or plastic between the E and I laminations to simulate an “air gap” of various thicknesses.

Now you want to measure both the amps that go into the primary, as well as the voltage in the secondary / search coil.

Each time you increase the gap by placing another strip of material in between, you adjust the power supply so that the voltage in the secondary remains the same, which means the flux density, or magnetic field strength on “the other side of the gap” remains constant, and thus the mechanical energy available remains constant.

Now here comes the kicker: if you plot the input current versus the gap size, you’ll clearly see it curves down!

Remember, we kept the voltage across the gap the same, so the same mechanical power is present, yet we need less and less current to establish that same amount of mechanical power the larger the gap becomes!

So where is that additional energy coming from?!

All we know is that it is clearly NOT coming from our power supply 🙂

This is why your air gap should not be too small, as that will limit this excess gap energy from being harnessed.

Adams mentions in several places that ideally the gap should be 1 to 1.25mm wide.

Replication tips

In this article you learned several things to keep in mind when trying to replicate this device, but Robert Adams was also kind enough to leave us a list of recommendations in his book The Revelation of the Century.

Some of his tips only apply if you use brush commutation, so I highlighted the parts I feel are most important, regardless of commutation method.


  1. Use only pure iron for the stator/drive windings, not laminated steel core.
  2. Wind stators with a resistance in the range of ten to twenty ohms each for a small model.
  3. For 2) above, use voltages of between 12 and 36.
  4. For small machine make contactor star disk one inch maximum diameter.
  5. Keep wiring short and of low resistance.
  6. For small machine install fuse/holder 500m.a. to 1 amp.
  7. Install switch for convenience and safety.
  8. Use small bearings. Do not use sealed bearings as these are pre-packed with a dense grease which causes severe drag.
  9. Use only silver contacts for pulse switch.
  10. If using high-energy-product magnets, vibration becomes a serious problem if constructional materials and design are faulty.
  11. Air gap is not critical; however reduction will increase torque and also increase input power in proportion.
  12. For higher speed, lower current, series-connected stators recommended.
  13. a) If machine stator windings are of low resistance and drawing high current at higher input voltage, it is advisable to install a switching transistor which will completely eliminate sparking at points.

    b) On calculating input power, however, the transistor switch burden must be subtracted from total input.
  14. a) Points tuning and pressure are vitally important; experiment will indicate optimum settings.

    b) If, however, all electronic switching process is preferred, i.e., using photo, magnetic, hall effect, etc., then the above in a) is completely eliminated.
  15. If constructing a large model involving large super-power magnets, note the following:- The greater the magnetic energy product, the greater the power required to drive the machine, the greater the torque, the greater the vibration problem, greater copper content, greater cost etc.

Further tips were given by Adams, and again, I highlight the important points:

If contemplating the construction of a proving machine – note as follows :

1) Don’t purchase expensive powerful ‘neodymium’ or ‘samarium cobalt’ magnets without first having experience with cheap easy-to-get ‘alnico’ magnets, for if you commence with powerful magnets you will find yourself facing powerful problems. Using powerful magnets will not prove anything beyond what alnico will do. However, given this, if you feel you MUST choose powerful magnets, for whatever your reasons, take heed -great care is required in the handling of them to preclude personal injury.

2) For a proving machine do not use less than 10 ohms each for two stators at 180 degrees apart; recommend series mode for first attempt. Don’t be concerned about start windings initially and, remember, what can be achieved MICROscopically can be achieved MACROscopically and so I strongly suggest – walk before you run.

3) Should you experience any difficulty in designing and constructing the tapered disc contactor (machining, etc.) then use electronic switching, i.e. photo, Hall effect, or inductor effect, with switching current transistor, etc. The machine, correctly constructed, should still deliver a minimum 107% efficiency. The charging effect will, of course, be lost, and the input current to supply the electronic switching will raise the total input quite steeply. The point to be made here is that in using electronic switching, in a larger machine, the degree of loss due to this use of electronic switching is negligible.
However, for those who are seeking greater efficiency figures, it is advised to stay with the tapered disc contactor method and build a small wattage unit, i.e. 0.25 to 1 watt. This is the area of power rating within which you will gain quicker and better results which, in turn, will provide the necessary experience for designing and building a larger unit.

Once again the inventor cannot stress the importance enough, for those who wish to construct a successful device, to start at the bottom rung and listen to what the device is saying to you as you go along.

The above statements make it really clear that for the best results, don’t use transistors, but use a brush commutator instead.

Only once you’ve achieved good results with the contactor disk should you progress to transistors or other means of switching.

Other pulsed motors

Was Robert Adams the only person who thought about pulsing a motor?

Not really, although it seems he was the first!

Adams invented his pulsed electric motor generator in 1970, filed for a patent in 1975, but didn’t publish his work publicly until 1994.

Joseph Newman

Then there is the infamous Joseph Newman, who developed a pulsed motor of gigantic proportions to prove his theory and patent claims were valid.

Joseph Newman Motor
Joseph Newman standing next to his enormous motor / generator

Newman filed for a US patent titled “Energy Generation System Having Higher Energy Output Than Input” in 1980, and released a book titled “The Energy Machine of Joseph Newman” in 1984, in which he explains the theory behind his motor/generator in detail.

The general idea is that he pulsed a coil consisting of 90.000 turns of thick 5-gauge wire with just 9V (6 1.5V AA batteries), which then generated a very strong magnetic field, which in turn spun the heavy permanent magnet rotor around, and generated huge flyback currents when the pulse ceased, which he then used to power loads.

Newman was not granted a patent, so he went to court, grew more and more frustrated over the years, and slowly went crazy.

I recommend you watch this documentary to find out what happened exactly.

John Bedini

Newman, amongst others, inspired John Bedini, who successfully replicated the Newman motor, developed his own pulsed motors, and published his theories in a 1984 book titled “Bedini’s Free Energy Generator“.

But while Newman used a massive amount of copper in order to create a VERY strong magnetic field, the Bedini motor only needed a magnetic field strong enough to offset the attraction of the rotor magnet to the stator core, which is why the Bedini motor is a LOT smaller.

John Bedini motor
John Bedini next to one of his pulsed motors

In 2001, John Bedini filed for a patent titled “Device and method for utilizing a monopole motor to create back EMF to charge batteries“, which was granted in 2003.

He helped a 10-year old girl create one of his motors for a school science project, and this circuit turned into the most replicated motor in the alternative energy community, called the Bedini SG (SG stands for School Girl).

So while Newman and Bedini published their ideas before Robert Adams did, we see that Adams already filed a patent years before that.

Lutec 1000

In 1999, the Australian duo Lou Brits and John Christie from the company Lutec, filed for a patent titled “System for controlling a rotary device“.

If you read the patent, you’ll soon find out that they use the exact same methods Robert Adams used, and Adams made it very clear he felt they were stealing his ideas.

Lutec 1000 motor prototype
Image on the Lutec home page of their latest prototype, before the site went offline

There has been a lot of controversy around the Lutec 1000 motor, and the Australian Sceptics Society ripped them apart in their article “Free Energy? Not From Lutec“.

Keppe Motor

The last pulsed motor I want to discuss is a very interesting one, as it is the only one discussed here that has actually been implemented into a consumer product!

It is called the Keppe Motor.

The Keppe Motor is a highly efficient motor that uses the principle of electromagnetic resonance to optimize its efficiency. It was developed by three researchers, Carlos Cesar Soós, Alexandre Frascari and Roberto Heitor Frascari, based on the discoveries of the scientist Norberto da Rocha Keppe, set forth in his book “The New Physics Derived From A Disinverted Metaphysics,” first published in France, 1996.

Keppe Motor Website

While their explanation of how the motor works seems a bit odd and metaphysical from time to time, the fact of the matter is that you can buy a table fan from their website which is just as powerful as a store-bought fan, but uses up to 80% less power to run and doesn’t heat up!

Keppe motor table fan
The Keppe motor table fan

They also achieve this by pulsing the motor at the exact right time, although the details differ slightly from the Adams motor, as Adams used rotor magnets of identical polarity, while the Keppe motor uses both North and South poles.

In their FAQ they explain how the Keppe motor works:

Electric motors transform electric energy into mechanical energy, and electric generators do the opposite, i.e., transform mechanical energy into electric energy. The Keppe Motor comprises a motor feature (electricity being transformed into mechanical energy) and a generator feature (mechanical energy being transformed into electricity) in balance at the point of resonance of the system.

System’s highest efficiency is reached when the resonance between the two components of action (motor feature) and complementation (generator feature) takes place. The resonant point of this system includes the electric power supply (domestic grid or battery) and the load on the shaft.

The Keppe Motor contains a magnetic rotor with permanent magnets which rotates inside the stator coils. When the magnet is set in motion by the supply voltage applied to the coil (motor feature), it creates additional voltage in the coil terminals (generator feature), increasing the magnetic energy stored in it. This energy enters in resonance with the power grid’s energy through pulses of varying intervals determined by the Keppe Motor itself and this is the nature of its high efficiency. As consequence, one of the best advantages of the Keppe Motor is that it runs cold, which is an indication of its high efficiency and guarantee of durability.

Nevertheless, for all this to occur, it is not enough to make a motor with a different design – you must also change the power supply, otherwise, resonance cannot be achieved.

The best way to reach resonance is to let the motor interrupt its own power supply according to its own structure, without interfering with its operation. Because of that, the typical and necessary power supply of the Keppe Motor is PDC (Pulsed Direct Current), the only supply that allows the system to reach resonance. Depending on the motor design and parameters, such as wire gauge, presence or absence of an iron core, type of magnet, coil inductance, etc., the entire system will automatically search for its point of resonance for the load and voltage specified. At this point the electrical current decreases to the minimum necessary to perform the desired work. This minimum is always lower than that required by conventional direct or alternating current to perform the same task.

The Keppe team was granted a US patent in 2013, titled “Electromagnetic motor and equipment to generate work torque“.

Closing thoughts

This article was meant to clear up some confusion that exists among experimenters attempting to replicate Robert Adams’ device.

The idea was to use the words of Adams himself to explain what he was and wasn’t trying to do, and I hope you gained some clarity from this.

I also urge you to study the other pulsed motors I discussed in this article, as certain patterns will become clear to you, and a lot can be learned from them.

Especially study the Bedini motor, as there is a lot of educational material available for that one.

As for me, I’ve been working for months on perfecting my own Adams Motor / Generator replication (follow my progress on YouTube).

Right now, I’ve settled on a final design for the drive coils and drive circuit (check out my Arduino Pulsed Motor Driver on Github), and am now going to add the generator coils.

Once everything is working as advertised, I will create a PCB and make plans and kits available through this website.

My goal is to have this ready halfway through 2021.

Are you working on an Adams motor replication? Shoot me an email at [email protected], because I’d love to hear how it’s going!

P.S. My presentation about the Adams Motor at the 2021 Energy Science & Technology Conference is OUT NOW! It contains a lot of research that has never before been shared, and goes way beyond the information in this article, so check it out today: https://emediapress.com/shop/the-robert-adams-pulsed-electric-motor-generator/ref/12/

P.S.S Also check out my new and very detailed Pulse Motor Generator Design Considerations article