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Author Topic: Confirming the Delayed Lenz Effect  (Read 869995 times)

conradelektro

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Re: Confirming the Delayed Lenz Effect
« Reply #1200 on: April 23, 2013, 11:55:12 AM »
Hi Conrad,

Would like to suggest two things.

One is using a diode D in series with the positive supply rail going to the H-bridge and connecting a puffer capacitor C across the supply rails of the H-bridge. (I modified your original schematic to show what I mean.) The reason for these small modifications is that the collapsing field of the coil in your original schematic goes back to the power supply and most probably dissipates across its inner resistance but inserting a diode prevents the 'flyback' pulse seeing the power supply and can only go into the puffer capacitor.

The second suggestion would be (after testing the first one) to use Schottky diodes in parallel with the built-in body diodes of all the 4 MOSFETs, (one diode for each MOSFET).

rgds,
Gyula

@Gyula:  the Diode in series with the poitive rail in front of the H-bridge and the electrolytic puffer capacitor as you indicated on my schematics really helped. As you said the spikes went back to my laboratory power supply.

First I only put the diode in the circuit and I saw the spikes on the scope (measured over the coil). Then I added a 4700 µF electrolytic puffer cap and I saw how it absorbed the spikes.

I still have to get a good Schottky Diode, at the moment I use a BYW29EX-200 (8A, 0.9 V forward Voltage). Since I use little power with the relay coil also a 1N4007 and a 1N4003 worked well.

Concerning your second suggestion (Schottky diodes in parallel with the built-in body diodes of all the 4 MOSFETs): My guess is that these Schottky Diodes should be able to conduct several Ampere?

The only Schottky Diode I could get easily from Farnell which allows 1A forward current and has 70 V reverse Voltage and 0.41 V forward Voltage is this one:

http://at.farnell.com/avago-technologies/hsms-2800-tr1g/diode-smd-schottky/dp/1056832RL

There seem to be a lot of Schottky Diodes for 100 V reverse Voltage and several Ampere forward current, but the forward Voltage will be 0.8 Volt.


I have the 1N5711 Schottky Diode with a very low forward Voltage of less than 0.4 Volt, but it is only for small signals (15 mA max, best for 1 mA or less).

I also have the BAT754C (200 mA, forward Voltage down to 0.2 Volt for very small signals).

Greetings, Conrad

gyulasun

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Re: Confirming the Delayed Lenz Effect
« Reply #1201 on: April 23, 2013, 12:13:36 PM »
Hi Conrad,

Thanks for the details, have you noticed any reducement in input current draw with this modification?

Diode type BYW29EX-200 are fast ones but due to the high forward current rating the voltage drop is close to a normal Si diode at the current levels your motor draws.

Will return with some diode types (Farnell is good for you or you have other order choices?)

Gyula

PS No need for high current diode types because the relay coil has its own 200-300 Ohm DC (plus its own inductive reactance) so even a some hundred mA rated diode would be good.

conradelektro

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Re: Confirming the Delayed Lenz Effect
« Reply #1202 on: April 23, 2013, 01:34:13 PM »
Hi Conrad,

Thanks for the details, have you noticed any reducement in input current draw with this modification?

Diode type BYW29EX-200 are fast ones but due to the high forward current rating the voltage drop is close to a normal Si diode at the current levels your motor draws.

Will return with some diode types (Farnell is good for you or you have other order choices?)

Gyula

PS No need for high current diode types because the relay coil has its own 200-300 Ohm DC (plus its own inductive reactance) so even a some hundred mA rated diode would be good.

@Gyula: Yes, the current draw of the circuit was reduced by a few mA (e.g. 18 mA instead of 20 mA) and the rpm went up by a few percent (e.g. 75 Hz instead of 70 Hz) for the same supply Voltage and current. Thank you for this very good suggestion, it made the circuit much safer for use with a laboratory power supply.

I would like that the circuit can handle up to 1 Amp current draw (e.g. 10 to 20 Watt) for future lower DC resistance coils.

At the moment I am building a new more solid mechanical set up with two drive coils and ball bearings which have an axle diameter of 5 mm (outer diameter 16 mm, a hint given by TinselKoala). See the attached circuit diagram and drive coil principle (at the right of the schematics). I want to reach more than 10.000 rpm (even if it means more power draw, e.g. 1 Watt to 2 Watt).

The new set up goes a bit in the direction of your suggestion to use both poles of a coil (although I am using two separate coils, as a start).

Farnell is good for me, also CONRAD. Mouser would cost me 20.-- Euro for shipping (instead of 5,40 Euro with Farnell and CONRAD).

Greetings, Conrad

gyulasun

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Re: Confirming the Delayed Lenz Effect
« Reply #1203 on: April 23, 2013, 07:00:15 PM »


The only Schottky Diode I could get easily from Farnell which allows 1A forward current and has 70 V reverse Voltage and 0.41 V forward Voltage is this one:

http://at.farnell.com/avago-technologies/hsms-2800-tr1g/diode-smd-schottky/dp/1056832RL




Hi Conrad,

Be careful with the above diode because the 1A forward current rating is valid for 1 usec pulse mode (from datasheet, page 2). But of course you may test them especially if paralleling them too...

I found these types, maybe the first would be good for your lower resistance coils and the second for the higher ones:

Schottky SB3100 100V 3A  VF=0.3V at 100mA  and 0.38V at 1A from Fig.2 data sheet:  http://www.micropik.com/PDF/SB350.pdf 
http://www.conrad.at/ce/de/product/160222/Schottky-Diode-SEMIKRON-Semikron-SB3100-Gehaeuseart-DO-201-IF-3-A-IFAV-3-A-URRM-100-V

Schottky RB160L-90TE25 90V 1A VF=360mV at 100mA and 0.6V typical at 1A  http://www.produktinfo.conrad.com/datenblaetter/125000-149999/140674-da-01-en-SCHOTTKY_DIODE_RB160L_90TE25_SOD_106.pdf
http://www.conrad.at/ce/de/product/140674/Schottky-Diode-ROHM-Semiconductor-RB160L-90TE25-Gehaeuseart-SOD-106-IF-1-A

It sounds good to me using 2 coils. In this case the input current draw will probably double for the same input voltage level if you are to compare it to the single coil case because the impedances of the coils will be in parallel i.e. the resultant impedance gets halved.

Just I am curious, whether you have taken a  scopeshot from the waveform across the coil after the modification (diode +cap)?

Thanks, Gyula

synchro1

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Re: Confirming the Delayed Lenz Effect
« Reply #1204 on: April 23, 2013, 08:37:50 PM »
One power coil counter wound in series wuth it's sister, would only need  one transistor. Like Mopozco's TROS motors.

conradelektro

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Re: Confirming the Delayed Lenz Effect
« Reply #1205 on: April 23, 2013, 09:34:43 PM »
@Gyula: thank you very much for looking up some Schottky Diodes, I ordered them. The scope shots over the drive coil with a diode and an electrolytic puffer capacitor look more or less like the ones from my Reply #1181 on: April 21, 2013, 10:48:15 PM. I will make more scope shots with my new setup which is almost finished.

I could put the two drive coils in series, then the power draw would drop. But it is more realistic to put them in parallel.

In this pulse motor http://www.youtube.com/watch?v=MEEjlYvZ5OM I put all drive coils in parallel.

In the attached pulse motor I had the toroid drive coils in series plus a resistor to adjust power draw (resistor values 5 Ohm to 50 Ohm). The toroid drive coils are of course the Steorn design. Strange enough, the toroids worked best in the depicted arrangement. But ordinary drive coils worked better. I could adjust the pulse width with two opto-gates, but it turned out that the pulse width was not very critical (neither for power draw nor for torque), therefore I switched to a Hall sensor (which is much simpler than opto-gates). I was very proud of the drive circuit (see the attached PDF-File).

I still have to try a sensor coil for my recent setup. I am a big fan of sensor coils, pulse width can be adjusted by distance from the passing magnets. Pulse timing can be adjusted by shifting the sensor coil in relation to the theoretically good position.

I built some pulse motors with Reed switches, but for me it looked like the Reed switches were difficult to control and only reliable at very low frequencies and very low power draw. One can build small things that turn slowly with very little power, but for more demanding situations Reed switches were not useful for me. For very low power applications I would now use the transistor 2SK170 or ALD110800 / ALD110900 and a sensor coil instead of a Reed switch, much cleaner.

@Synchro: I am aware of Mopozco's TROS motors, but I did not test them yet. I will try with my new setup (two drive coils). My main concern is not component count but low power draw and clean switching (for long duration tests, nothing should get hot or strained).

Greetings, Conrad

P.S.: my first setup will of course stay as it is for comparisons.

TinselKoala

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Re: Confirming the Delayed Lenz Effect
« Reply #1206 on: April 24, 2013, 08:19:26 AM »
@Conrad: That's a very nice pulse motor of the core effect kind. You have taken advantage of both poles of the rotor magnets, something Steorn didn't manage to do with their simplistic design, and you've also relieved a lot of bearing problems by making the "bump" caused by magnet-core interactions happen symmetrically aiding and in the plane of rotation, rather than radially and in opposition. Your physical layout has several advantages over the "Orbo" configuration. When I made "Orbette 2.0" I was interested in doing a precise replication of Steorn's motor performance, so my core-rotor geometry was set up like theirs, with some additional adjustability. The motor worked well with Hall sensor timing but I needed optical timing for various reasons, and wound up using 2 stacked USDigital optical encoders, one with large segments for pulse timing and the other with lots of tiny lines for data output-- rotor RPM and acceleration data.

Seeing your design is inspirational. I wish I had my lathe and mill here; I'd make one on your plan, to add to my collection. May do so anyway if I can figure out how to make the parts with the necessary precision.

It would be neat to compare the timing and dwell positions that worked best for your layout, comparing the regular coils and the toroidal core coils.
The regular core coils can be made to work in either attraction or repulsion, or in your design even both, depending on pulse polarity vs. rotor mag polarity, but the toroids should only work by core effect, and the polarity of the pulse to the toroids shouldn't matter.

ETA: I meant to also say that the optical commutator can be modified for dwell (pulse width) control very easily. Simply make another disk with the flags (or slots, or holes) , and stack and overlap them. Then your dwell can be controlled by the degree of overlap of the two discs.

conradelektro

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Re: Confirming the Delayed Lenz Effect
« Reply #1207 on: April 24, 2013, 09:09:13 AM »
@Conrad: That's a very nice pulse motor of the core effect kind. You have taken advantage of both poles of the rotor magnets, something Steorn didn't manage to do with their simplistic design, and you've also relieved a lot of bearing problems by making the "bump" caused by magnet-core interactions happen symmetrically aiding and in the plane of rotation, rather than radially and in opposition. Your physical layout has several advantages over the "Orbo" configuration. When I made "Orbette 2.0" I was interested in doing a precise replication of Steorn's motor performance, so my core-rotor geometry was set up like theirs, with some additional adjustability. The motor worked well with Hall sensor timing but I needed optical timing for various reasons, and wound up using 2 stacked USDigital optical encoders, one with large segments for pulse timing and the other with lots of tiny lines for data output-- rotor RPM and acceleration data.

Seeing your design is inspirational. I wish I had my lathe and mill here; I'd make one on your plan, to add to my collection. May do so anyway if I can figure out how to make the parts with the necessary precision.

It would be neat to compare the timing and dwell positions that worked best for your layout, comparing the regular coils and the toroidal core coils.
The regular core coils can be made to work in either attraction or repulsion, or in your design even both, depending on pulse polarity vs. rotor mag polarity, but the toroids should only work by core effect, and the polarity of the pulse to the toroids shouldn't matter.

ETA: I meant to also say that the optical commutator can be modified for dwell (pulse width) control very easily. Simply make another disk with the flags (or slots, or holes) , and stack and overlap them. Then your dwell can be controlled by the degree of overlap of the two discs.

@TinselKoala:

I built that Steorn replication thing in 2010 during the Steorn Hype. Yes, a magnet pulls itself towards the cores of the two Toroids and would get stuck between the two Toroids. A current pulse into the windings of the Toroids (no matter what polarity) frees the magnet, so that it can travel on. The torque depends on how strongly the magnet pulls itself toward the Toroid cores (strength of the magnet, size and material of the Toroid). Once the current pulse is strong enough to completely "mask" the Toroid core (so that the magnet is not slowed down when leaving the position in between the Toroids), the torque will not increase any more.

In contrast, with ordinary coils one can increase the torque by increasing the current theoretically ad infinitum, because the coil will pull and push the magnet depending on Watts fed into the coil (if the timing is right).

But I never did systematic comparisons. Once I saw the limitation of torque by the core effect of the Toroids I wandered on to other projects.

And I had mechanical problems with the ball bearings. I find it difficult to set ball bearings correctly. When turning the axle to fit into the centre of a ball bearing I either get the diameter too large or too small. If it is too large I ruin the ball bearing when hammering in the axle and when too small the axle rattles.

I found that the motor of a hard disk drive (the bigger the better) makes a good bearing for a disk which then carries magnets for a pulse motor. But balancing is a problem. A disk is a big thing which can produce a lot of force when tumbling.

Now I fiddle again with ball bearings for my latest attempt to make a fast "ring magnet spinner". The first version which I showed e.g. in my Reply #1194 on: April 22, 2013, 06:40:53 PM, has a rattling axle and it spins up to 9000 rpm with a maximum power draw of about 0.5 Watt. It spins at 2000 rpm with 0.1 Watt.

The thing I am building now is about the same but has two coils (the idea is derived from my Steorn replication, that is why I showed it although it is old news). See the attached photo, the ring magnet and the Hall sensor are not yet mounted. The drive circuit is shown in my Reply #1202 on: April 23, 2013, 01:34:13 PM. This time I got the axle right but the ball bearings I used seem to have some heavy grease in them, so they resist turning quite strongly. May be I can get the grease out by heating them up a bit. I will report how it goes. This latest design allows me to change ball bearings more easily, so I hope to succeed eventually. I have to look for these model helicopter bearings. I have a collection of ball bearings, but they are low quality and some are decades old.

The white coils I am using for this latest design are from 12 V relays and have 90 Ohm DC resistance, but I can also mount the 260 Ohm DC resistance coils from 24 V relays (as in the first spinner, see my Reply #1194).

The goal of this "ring magnet spinner" is to test various "Lenz free coils" (if they indeed exist, which I doubt). Success would be a fast "ring magnet spinner" that uses very little power. Torque should not be an issue with a "Lenz free generator coil".

Greetings, Conard

profitis

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Re: Confirming the Delayed Lenz Effect
« Reply #1208 on: April 24, 2013, 12:49:51 PM »
hey tinselkoala,kondralektro,ive often wondered what would happen if we used a steorn setup,using normal inductor coils instead of toroids,and simply short-circuit the coil as the magnet passes by,would this counter the magnetic attraction?any ideas?

ALVARO_CS

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Re: Confirming the Delayed Lenz Effect
« Reply #1209 on: April 24, 2013, 06:12:27 PM »
Hola conradelektro

I use to submerge the bearings some five minutes in acetone or in thinner to clean the grease.
After clean I use any light mineral oil eg. the one used to lubricate sewing machines.
About rotors, I prefer to use the ones that come in old video players, they act also as flywheels.

cheers


DeepCut

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Re: Confirming the Delayed Lenz Effect
« Reply #1210 on: April 24, 2013, 09:51:32 PM »
Hi all,

thought i'd drop in and see how it's going.

Nice to see this thread so active :) (just when i'm taking time off the bench !).

@TinselKoala - great to see you here pal :)

Great to see Conrad and Gyula developing Conrads (excellently built) motor.

@ synchro

I know MH can seem to be 'raining on our parade' at times, but he is well-educated in electronics and gives us lots of info and great ideas for testing. Please stop insulting him, he doesn't insult you. MH is like drugs, he should be used not abused ;+}

What a long discussion you've all had on polyfilar coils !

A few points.

1. I wound a straight-wound coil, 1LB of 0.28mm wire, tested it for AUL effects and it performed poorly. It did cause acceleration of the rotor and a decrease in input current but only very slight.
2. I rewound the same coil as a bifilar and the increase in acceleration was 4 times that of the straight-wound coil. The drop in input current was also 4 times as large. Perhaps, like induction, there is a quadratic relationship with capacitance at higher frequencies ? I don't know enough to formulate an answer to this.

So, regardless of classical electromagnetic properties, it is thebehaviour of the coil with regards to AUL effects that is important here, and a bifilar outperforms a monofilar. Hands down.

3. In the preceding discussion on induction you have all had, noone has mentioned another key influence on induction, namely, the physical dimensions of the coil. I wound 2LB of coil on a long former and got less inductance than 2LB of coil on a shorter, wider former. To maximise the inductance of your coil, it's length should be between 0.85 and 0.9 times it's radius.

A final thought, on the usefulness of AUL.

Supposing we build our own, standard generator, just a small one to power, say, a 1 watt bulb.

We power our generator, the bulb lights, hooray.

We then introduce a coil that strongly exhibits AUL effects.

This coil increases the rotor speed to beyond that of the setup with the 'normal' generator coils, it also decreases the input current.

Our rotor is now rotating at a higher speed, outputting more voltage, lighting the bulb more brightly than it was before, and all with less input current at the same voltage and therefore less input power.

That's a useful thing ?


All the best,

DC.




conradelektro

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Re: Confirming the Delayed Lenz Effect
« Reply #1211 on: April 24, 2013, 11:53:27 PM »
Hola conradelektro

I use to submerge the bearings some five minutes in acetone or in thinner to clean the grease.
After clean I use any light mineral oil eg. the one used to lubricate sewing machines.
About rotors, I prefer to use the ones that come in old video players, they act also as flywheels.

cheers

@ALVARO_CS: I will try the acetone treatment on my ball bearings, thank you for the suggestion. I have heard about the rotors from old video players. Old video players have become rare, but I will keep it in mind.


Hi all,

A final thought, on the usefulness of AUL.

Supposing we build our own, standard generator, just a small one to power, say, a 1 watt bulb.

We power our generator, the bulb lights, hooray.

We then introduce a coil that strongly exhibits AUL effects.

This coil increases the rotor speed to beyond that of the setup with the 'normal' generator coils, it also decreases the input current.

Our rotor is now rotating at a higher speed, outputting more voltage, lighting the bulb more brightly than it was before, and all with less input current at the same voltage and therefore less input power.

That's a useful thing ?

All the best,

DC.

@DC: A generator (which produces electricity) is generally not driven by an electric motor (which needs electricity). Usually a generator is driven by a Diesel engine, a water turbine or a wind wheel. Would the AUL effect speed up a Diesel engine or a water turbine or a wind wheel?


hey tinselkoala,kondralektro,ive often wondered what would happen if we used a steorn setup,using normal inductor coils instead of toroids,and simply short-circuit the coil as the magnet passes by,would this counter the magnetic attraction?any ideas?

@profits: I do not really know, but I suspect that shorting the coil while the magnet is passing the coil will cause a strong pull or drag on the magnet. Nothing beats a test, but it seems difficult to design a circuit which will do the driving and the shorting of the coil automatically (unless one uses a microprocessor to control each of the four MOSFETs in the H-bridge according to some program which uses the Hall sensor for timing).

Greetings, Conrad

gyulasun

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Re: Confirming the Delayed Lenz Effect
« Reply #1212 on: April 25, 2013, 12:32:25 AM »
Hi Conrad,

Some comments on sensor coil and reed switch:  yes, sensor coil can be small and handy and easy to explore its best position. Question is what you drive with it? say you drive the base-emitter of a bipolar transistor then I think a reed switch can also do that job in the same way when you use a few kOhm resistor in series with it which also serves as a base current injection to the transistor anyway so the current can be small via the reed. And you can find the same good position for the reed but I agree that many times a reed may need a separate control disk with small magnets on it to work reliable. On control disk I have referred to you already at a Bedini motor (zero force motor 2nd version, see second video link below) and he used reed switch, at rotor speed I estimate at least to be several thousand rpm. Of course a separate control disk needs some more job and material to build and anything you use is fine with me, :)



Would like to show you a video on Bedini's so called 'zero force motor'. It seems very simple, at least this first version he showed a few years ego at energetic forum (but later he deleted it). See this link http://www.youtube.com/watch?v=3kpDMMcNQxc someone uploaded it again.
You can see a rotor with some cylinder Neo magnets, all like poles out and the coil is positioned tangentionally to the rotor. He says it is a no Lenz, no backemf motor, a more advanced version of this can also be seen on youtube but it has a ring shape stator with coils on the ring, its link is here: http://www.youtube.com/watch?v=4TICXxP1jI4  Unfortunately, the very little info is what could be guessed from these videos, no further details have been given.

The coil position as shown in the first video above i.e. turning it sideways instead of the 'usual facing magnet' position was tested also by Naudin, you may have seen it in the right hand side scope shot here: http://jnaudin.free.fr/images/magconfig.gif  (and you can read about his findings in this link: http://jnaudin.free.fr/html/mromexp.htm )

So what I would suggest is first to explore what waveform your present ring magnet would induce with its changing poles in such sideway positioned coil (because the interesting waveform shown on the right hand side is always made by a single pole, (only the voltage polarity flips) either a N or S but not by suddenly changing poles your ring magnet presently has.
Probably the induced waveform you may see will be different from that.  I editied your earlier magnet-coil position drawing to show 2 coils tangentially fixed wrt the rotor magnet above and below it (on the left and the right hand side of the ring magnet) or I considered the two coils either at one side or both sides of the ring (in this latter case coil length may be an issue). I show you all this because both pole ends of the drive coils are utilized. The ON time should be figured out of course (probably 25% is good).

These are only suggestions, of course I do not mean in any way to 'influence' your own way what kind of setups or circuits you build.

rgds, Gyula

PS If there is a television and video repair service near to your location, you could inquire about faulty VCR heads  (I mean even rotors with some aging problem in their bearings) because they are replaced to new ones and the old one is not renewed) such rotors can still be very useful for tinkering.

gyulasun

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Re: Confirming the Delayed Lenz Effect
« Reply #1213 on: April 25, 2013, 01:02:49 AM »
Hi DeepCut,

On your few points:
1) it would be important to know that the 1LB coil you mention was present already physically in the setup but was not shorted when you measured the normal input current and RPM? or you measured the input current and RPM without the 1LB coil, logged those data and then you brought it into the setup and shorted it?
2) it would be good to know whether the same wire lenght (that the earlier 1LB coil had) was used to make the bifilar coil?
3) Yes I agree there is the so called Brooks coil shape which insures the biggest inductance to get from a given length of wire (you can google as Brooks coil to see the geometry ratio) but for generator coils the maximum or too high inductance coil is not always the best choice due to the increasing losses, for motor coils it could be a choice.

On your final thought:

if the answer to the question in the 1st point above is that the 1LB coil was not present first when you measured the input current and RPM and then introducing it and shorting it caused a decrease in input current with respect to the earlier input current, besides an increase in RPM, then yes it would be a useful thing. It is a question whether it could already give enough extra output for a possible looping to self run but the efficiency would certainly improve.

rgds, Gyula
« Last Edit: April 25, 2013, 11:04:00 AM by gyulasun »

profitis

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Re: Confirming the Delayed Lenz Effect
« Reply #1214 on: April 25, 2013, 01:14:03 AM »
thanx conradelektro.im more a electrochemist than electrician but im looking for evidence of a 2nd law thermodynamics violation amongst electromagnetic systems as i have found plenty evidence in electrochemical systems.could you or perhaps anybody else here tell me if you have ever verified(to yourselves) that the kickback energy on any coil inductor has ever been measured to be greater/larger than input energy?  Many thanks