Saturday 25 June 2016

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!

Saturday 11 June 2016

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).