The EPRI Magnet Motor

Cross-section of the EPRI magnet motor, from US Patent 5,304,882.
Note the flat permanent magnets under the rotor pole-pairs, and the stator of typical
switched reluctance design, similar to the Takahashi Self-Generating Motor.

Permanent magnets in a switched reluctance motor

An early "significant patent" [Ref 1] for a switched reluctance motor with permanent magnets is US Patent 5,304,882 of 19 April 1994, issued to Thomas Lipo and Yuefeng Liao of the prestigious Electric Power Research Institute (EPRI). According to the Wikipedia entry on EPRI, "The institute's research and development program spans every aspect of generation, environmental protection, power delivery, retail use, and power markets. EPRI provides services to more than 1000 energy-related organizations in 40 countries. It has more than 900 patents to its credit."

Was it ever built?

While this patent 5,304,882 claims many very important improvements over previous designs, (including "higher efficiency") I can find no evidence that the patented machine (shown above) was ever actually built — it seems to have been entirely a series of computer simulations. 

Free energy is implied

The most provocative claim was that the invention could produce between √2 and 2√2 times as much torque as a comparably-sized conventional machine having the same winding heat dissipation and degree of magnetic saturation. Since energy output is directly proportional to torque, through a given angle of rotation, this implies an energy output of more than 1.4 to 2.8 times that of the conventional machine for the same current (and hence presumably for the same energy input). Since a conventional switched reluctance motor can achieve 94% efficiency, this claim, supported by figures from the patent shown below, implies that this EPRI motor could quite easily deliver free energy, although nothing explicit was said about that.

Figures from US Patent 5,304,882, showing energy conversion loops of magnetic flux linkage (here labelled λ, but more usually ψ) vs stator coil current.

Note especially the parallelogram-shaped energy loops of Figures 8A and 8B, showing operation in the second
quadrant as well as the first, giving a much larger total energy output than could be achieved with an equivalent
conventional switched reluctance motor (represented by the smaller cross-hatched loops). 

Notable points

The following points about the EPRI motor are worth noting:

-  Although the patent is titled "Variable reluctance motors with permanent magnet excitation," the authors state that "...The essential feature is that the permanent magnets see a constant reluctance flux path at all times, that is, the total overlapping stator/rotor pole areas must remain constant." (My emphasis).

-  Figures 8A and 8B above strongly suggest that the motor is able to use current reversal to achieve magnetic repulsion as well as attraction.

-  Considering all of the major improvements claimed for their patented motor, it is surprising that EPRI apparently did not build any version of it as a physical prototype — at least no such prototype has been publicised, to my knowledge. It is also surprising that more than twenty years later, manufacturers still seem uninterested in incorporating permanent magnets into their commercially available switched reluctance motors in this way, in order to achieve anything like the energy conversion loops shown above.

Are these energy conversion loops too obvious?

In two subsequent patents, also on variable reluctance machines incorporating permanent magnets, US Patent 5,672,925, and WO9418855, the same EPRI inventors did not provide any energy conversion loops, whereas by analogy with US Patent 5,304,882 they would have been expected.

On espacenet, I found one more associated patent from these inventors, US Patent 5,825,112. This patent does have the provocative large "two quadrant" energy conversion loops similar to those shown above, and again claims to produce torque of between √2 and 2√2 times that of a conventional motor. 

Curiously, I found on espacenet that I could easily see the mosaics (patent images) from the two patents that did not have any energy conversion loops, whereas I could not see the mosaics from those (US Patents 5,304,882 and 5,825,112) that did have them.

I've mentioned before that although espacenet remains my favourite site for patent searches, I do occasionally have a few problems with it, so I don't really think this is an attempt at suppression! (If it is, it's a very feeble one — the patent images are easily downloadable and visible in all cases from the "original document" tab on their patent webpages).

Questions

As usual, there are plenty of unanswered questions concerning this EPRI work, in particular the motor of US Patent 5,304,882. I'll confine myself to just a few important ones:—

(for EPRI):—

-  Was a physical prototype ever built? If not, why not, in view of all the claimed advantages? If it was, what were its test results?

-  Can any interpretation be put on the large parallelogram-shaped energy loops of Figures 8A and 8B, other than that they show over-unity energy output? If so, what?

-  Why were energy loops omitted for US Patent 5,672,925, and WO9418855?

(for switched-reluctance motor manufacturers):—

- Why are you apparently not interested in incorporating permanent magnets into your motors and controlling them in the way shown in this EPRI work, so that their energy loops can extend into the second as well as the first quadrant, to achieve the far better performance claimed by EPRI (and also by Yasunori Takahashi, with his "self-generating" motor of very similar design, which he explicitly claimed to be a free energy motor)?

Reference

1. T J E Miller, Electronic Control of Switched Reluctance Machines, Newnes, p32.

Stability of Permanent Magnets

Claims that magnets deliver energy by losing their strength

In the past, several magnet motor inventors have claimed that the permanent magnets in their machines deliver energy into those machines by losing their strength over time, i.e. that the magnets themselves are not stable, and so are a source of energy from that loss of strength. David Porter makes this claim at 1:04:20 in the video cited previously, at https://www.youtube.com/watch?v=PfEbCBcddQw 

Yasunori Takahashi made a similar claim, to Chris Tinsley, about his Self-Generating Motor:—

"I asked Mr. Takahashi about this scooter. Was it over-unity? Seemingly not. Apparently the magnets lose strength at about 3% per year, and Takahashi claims this to be the source of the energy. But he had a glint in his eye when he said it. When I said, "No, it isn't," he grinned."

Ref: "Chris Tinsley: Travels in the New Energy Age," Infinite Energy magazine Vol 1, No 5/6, 1996, p29.

Such claims imply that permanent magnets are "used up" as if they were, say, "a gallon of petrol or a torch battery" (we'll meet that expression again, below).

Ridiculous — in theory and practise

This is a ridiculous concept, both theoretically and practically, as will now be shown. Why some inventors have made such claims, which they must know will reduce their credibility, is yet another of the many unanswered questions that swirl around the subject of over-unity magnet motors.

Engineering Design Guide

There is some useful information on-line about magnet stability, e.g. at http://www.magnetsales.com/design/designg_frames/designg_2.htm However, I couldn't find what I was really looking for — the Engineering Design Guide for permanent magnets which I first found in my local Public Library, of all places. It was eliminated from there many years ago (but not before I had copied most of it). I don't have any way of identifying it now apart from its first page, reproduced above.

Quoting from page 11 of this Engineering Design Guide:—

"Stability of permanent magnets

The designer planning to use permanent magnets must be confident that each magnet will remain stable in its working environment, or that any changes will be predictable. When a fully magnetized magnet is removed from the magnetizer, the first immediate loss of magnetization continues on a logarithmic scale, subsequent periods of 10, 10², 10³, etc, times the interval over which the initial loss was measured resulting in equal changes. If the first rapid change is accelerated by stabilization after magnetization, then — assuming a fixed steady temperature — the magnet is likely to remain stable to within 0.01 per cent for many years.

The chief causes of magnetic instabilty are temperature changes, exposure to stray magnetic fields, and mechanical shock or vibration, although in each case the same underlying mechanism is responsible. When a magnet is fully magnetized, it is thermodynamically unstable with the least stable domains trying to return to a state of lower energy by domain boundary movement or reversals. If the magnet is subjected to stray magnetic fields, or if thermal agitation is increased by a rise in temperature, then these unstable domains are the first to revert to their equilibrium state, leading to a loss of magnetization in the magnet. If, after fully magnetizing, some flux reduction is deliberately brought about by the application of a small alternating field, the unstable domains are the ones which are affected and, since these have already relaxed, a subsequent increase in temperature will have a reduced effect. It follows that stabilization by alternating flux reduction is a good general insurance against further loss, but for the highest stability requirements, this should be followed by cycling through a temperature range slightly wider than that to which the magnet will be exposed in use. Similarly the magnet may be subjected to any other abnormal conditions it is likely to encounter (for example, excessive vibration) in order to minimize further losses from these causes before it is put into operation."

So, as long as a magnet is first subjected to any conditions tending to demagnetize it which are slightly in excess of those which it will encounter in use, it will remain stable indefinitely.


(BH)_max  or Energy Product calculation

Quoting again from the above Engineering Design Guide:—

"There is one particular working point on the demagnetization curve [of flux density B versus magnetizing force H] for which the product BH is a maximum. This maximum is referred to as (BH)_max and is a useful characteristic of the material. It has the dimensions of energy per unit volume (Jm^-3) and is sometimes called the energy product, although (BH)_max is actually numerically twice the available energy of the magnet. For this reason the use of this term is not recommended, particularly as a magnet is not used as a source of energy in the same way as, say, a gallon of petrol or a torch battery."

The amount of permanent magnetic material used in David Porter's or Yasunori Takahashi's motors has not been reported, but we can certainly say that the permanent magnets in the Kure Tekko motor must have weighed less than its total reported weight of 155 pounds, i.e. 70.307kg. If we (generously) use that figure, and (very generously) assume all magnets to have been samarium-cobalt with a density of 8250kg/m³, that would give a volume of 0.008522m³ for its total magnetic material.

At say 20MgOe = 159155 J/m³ for samarium-cobalt, that means the total available energy from the energy product of the Kure Tekko motor's magnets would be very generously estimated at ½ × 0.008522 × 159155 = 678.16 joules.

We also have a reported power output for the Kure Tekko motor of 45 hp = 33556.5 watts. So if energy was really being taken from the magnets themselves to run it, then at full power it would have exhausted itself in about two-hundredths of a second!

The Takahashi "Self-Generating Motor"

Primary References:—

Infinite Energy magazine No 5-6, 1996, pp28-29, 35 and 36-37.

Japanese patent JPS2002291228 (A)

Fig 1  Sciex scooter with Takahashi Self Generating Motor

In 1994 in London, Yasunori Takahashi, Director of Research and Development at Sciex (UK) Ltd, demonstrated the first version of an electric motor scooter incorporating his permanent magnet Self Generating Motor (SGM). An article in the September 1994 issue of the British Broadcasting Company’s Top Gear magazine noted the impressive performance of the scooter. It was also demonstrated to a Senior Engineer at Nissan’s European Technical Center who remarked “If it checks out in our own tests, it has huge implications for everything which uses a motor — it could revolutionise the world.”

Chris Tinsley — investigation

In November 1995 Takahashi allowed Infinite Energy Contributing Editor, electrical engineer Chris Tinsley, an impromptu test ride of a later version of the scooter, shown in Figure 1 above.

Tinsley reported that after 25 minutes of riding under conditions which would have flattened much larger batteries (his intention was to flatten the batteries if possible) the small scooter batteries remained fully charged, as measured by his own voltmeter; the brakes were hot, and the motor was barely warm.  He was also shown a video of a Takahashi motor driving an alternator powering lamps estimated at about 120 watts, with no external energy input. Tinsley wrote an interesting report [Ref 1] and he managed to obtain some very provocative data from Takahashi’s company Sciex (UK) Ltd [Ref 2]. Some of the product literature claimed that at constant speed travelling the Self Generating Motor would deliver sufficient free energy not only to propel the scooter, but also to provide battery charging as necessary.

Fig 2  Takahashi Self Generating Motor and controller,
including dimension drawings.
Image from Infinite Energy magazine No 5-6, 1996, p37.

Fig 3  Images from patent JPS 2002291228.
Note the flat permanent magnets underneath the rotor poles,
and the stator similar to that of a switched reluctance motor.

Magnetic Power Inc. — problems

In mid 1996 the Takahashi scooter was shipped to Magnetic Power Inc., in the USA. After problems with customs clearance, it was eventually tried out, and its batteries were quickly flattened.

About a year and a half after that, the following advertisement appeared in Infinite Energy magazine:—

“For sale. Sciex scooter with Takahashi motor. Used only for test purposes. It failed to confirm his claims.  Accelerates rather well (possibly due to ultracapacitors). Otherwise standard electric scooter from Taiwan. $2,000 invested. Make offer. Magnetic Power, Inc. 707-829-9391.” [Ref 3]

Questions

As usual, there are questions begging for answers. For example:

-  What was the outcome of the tests which Nissan planned to do?

-  Where are the scooters now? (i.e. the original, and the one tested in the UK and the USA).

-  Has the motor and controller of either scooter been studied in detail by an independent competent investigator? If so, what was found?

-  What was the official reason for the difficulties with clearing the scooter through US customs? (Bearing in mind that the delay could have allowed some technical dirty trick to have been played — for example substitution of the motor, and/or damage to the controller).

-  Why was the advertisement to sell the scooter placed in Infinite Energy magazine — a very unusual forum for vehicle sales? And why did it need to underline the failure of the scooter to confirm Takahashi’s claims? (Admirable honesty in advertising, but a cynic might be forgiven for thinking that the main purpose of the advertisement was to discredit Takahashi, rather than to sell the scooter).

-  What has happened to Takahashi today? He seems to be keeping an extremely low profile. And what were/are his comments on these developments? This touches on one more question which Infinite Energy themselves asked:— [Ref 4]

-  Why would someone of Takahashi’s background [Ref 5] get involved in something like this if it were fraudulent? What would be the point?

Chris Tinsley — dead

It is certain that Chris Tinsley would not have left questions like these unanswered. But he could not pursue them, because he died suddenly on October 1, 1997. (See http://perpetualmotion21.blogspot.com/2015/08/harassment-and-premature-deaths-1989_22.html).

So we have been left, for many years, with a very unsatisfactory situation. The completely different performances of the scooter in the UK and the USA remain unexplained; the engineer best placed to look further into that died before he could do any further investigation, and the scooter motor's inventor has disappeared, at least from public view.

As seems de rigueur in such cases, claims have appeared for and against Takahashi, such as the usual unproven accusations of fraud, in the (surprisingly easily found) email exchange here.

This leads to a final question, which again I cannot answer — has any other credible investigator made any progress in following up on the Takahashi Self Generating Motor?

References

1. Infinite Energy magazine No 5-6 p28-30.
2. Infinite Energy magazine No 5-6 p35-37. Also see T. E. Bearden’s article in this issue p38-55, which contains some disinformation.
3.  Infinite Energy magazine No 17 p91.
4.  Infinite Energy magazine No 10 p57.
5. See the Curriculum Vitæ for Yasunori Takahashi in Infinite Energy magazine No 5-6 p35, which shows for example that in 1983 he resigned from his position as General Manager for Research and Development for Sony Corporation, to found his own company, Sciex (UK) Ltd. He holds many patents in advanced electrical technology. (I have already posted Takahashi's CV here).

The Galtech Carousel Motor/Generator

Primary references:—

Lightworks video "Free Energy — The Race to Zero Point"

US Pat 5625241

Also see http://blog.go-here.nl/4831


More electrical power claimed to be delivered than used

Here are two screenshots from the 2008 Lightworks video "Free Energy — The Race to Zero Point."  The first one shows an Energy Research Corporation advertisement. Its introduction states "In controlled laboratory tests, the ERC's new motor/generator technology delivers more electrical power than it uses. This incredible breakthrough could one day make your electric bill a thing of the past."

The second screenshot shows a closeup of this "carousel" motor/generator, invented by Russell R. Chapman, Harold E. Ewing and principal inventor David R. Porter of Galtech Semiconductor Materials Corporation. It was claimed to be particularly suitable for high speed/high frequency operation.

Energy Research Corporation was a wholly owned subsidiary of Galtech Semiconductor Materials Corporation, which was itself renamed Real Data Inc. in 2013.

This full video has been posted at https://www.youtube.com/watch?v=PfEbCBcddQw. The section concerning David Porter and the carousel motor/generator starts at 59:54.

A strange claim

I don't propose to comment on the Galtech carousel motor/generator in detail. I'll just note one very strange claim made by David Porter, that it takes energy from an ongoing loss of strength of the permanent magnets incorporated in it.

Porter is not the only inventor to make such a claim. I'll examine it more closely in the post after next.

Repulsion Motor UAER — Drum vs Disc Part II

Disc design modelling, without repelling stator magnets

Fig 3a  Disc-design model

Figure 3a shows one of my early models of a toroidal electromagnet plus permanent magnet, as would be used in a disc-design UAER motor. The pole pieces on the electromagnet core (grey) are each 96 × 60 × 6, with 0.5mm airgaps to the 96 × 60 × 16 NdFeB35 magnet (blue). So the magnet has the same surface dimensions and total thickness as the magnet pair used before in the drum design. The electromagnet coil (transparent red) has a 4927.5 mm² current injection plane (solid red) which in this model delivers the same constant square-wave excitation pulse of 16400 amp-turns while the magnet is being vertically displaced from 0 to 96mm, as before.

The magnet is first attracted in to the unenergized core, until there is zero vertical displacement, as shown. The electromagnet is then energized as noted above, to repel the magnet out from the core.

Once again, only forces in the vertical Z-direction are relevant to the analysis.

Fig 3b   Modelling results, square-wave excitation

Results

Figure 3b shows graphed results from this modelling.

The total energy gained is 55.581 joules, without any added stator magnets. This is a worthwhile improvement over the drum design, with or without stator magnets added to the latter. Admittedly the toroidal electromagnet core has a somewhat larger cross-section than the core of the drum design electromagnet, but the total volume of steel is much the same between the two options. They also have exactly the same total permanent magnet volumes, and excitations.

So, at least from the work done so far, it seems that the disc design of the UAER motor is preferable to the drum design.

Further modelling

Fig 4   Modelling results, half-sinewave excitation

I have done quite a lot more modelling of versions of this design. Figure 4 shows graphed results from the same model as shown in Figure 3a except for a reduced-length permanent magnet, but with the excitation now a half-sinewave, with details as noted on the graph (red curve). This modelling was done for comparison with some real-world experiments, which I may discuss in future posts.

Fig 5   An experimental toroidal electromagnet I built in 2009