Confirming the Delayed Lenz Effect

[conradelektro]

@Gyula:

Using the current limitation feature of the laboratory power supply is a very good idea, I will do that when testing the Hall sensors with the transistor H-bridge. My power supply shuts off at 3 A any way, but I will trim it down to 500 mA which the selected P-channel MOSFETS should support easily.

I could do some more tests with a diode across the coil (see the attached scope shots):

It seems that the spikes (no diode across the coil) have a beneficial effect on the turning ring magnet. The spikes seem to pull briefly the S-pole of the ring magnet  towards the coil core and such seem to accelerate the ring magnet. Once the spikes are eliminated by the diode this "help" goes away and the spin rate drops by 30%.

Moving the Hall sensor can not compensate for the "loss of the spikes". With spikes the turn rate is about 110 Hz, with the diode across the coil the turn rate drops to about 70 Hz (13.5 Volt supply Voltage, 15 mA average power draw).

Remarks:

- When the transistor switches on (triggered by the Hall sensor) the coil pushes away the N-pole of the ring magnet.

- It looks like there never was a reverse breakdown of the diode in my initial tests (the LED also did not break down, they are sturdier than one thinks, like the 2N6111 which survives 140 Volt spikes).

- Any way, the reverse breakdown Voltage of LEDs and Diodes was news for me (I never really understood the implications of this value), I learned something.

- I always wondered why the Bedini circuit (and similar ones for monopole rotors) work so well with spinning ring or ball magnets (which are in effect N S N S rotors). May be the spikes are the explanation. The spikes seem to help the other pole to pass the drive coil. But I might be wrong.

Greetings, Conrad

[synchro1]

@Quote from Conradelektro:

" I always wondered why the Bedini circuit (and similar ones for monopole rotors) work so well with spinning ring or ball magnets (which are in effect N S N S rotors). May be the spikes are the explanation. The spikes seem to help the other pole to pass the drive coil. But I might be wrong".

A simple reed switch dosen't need any help letting the other pole pass the coil. I think the bifilar Bedini trigger coil generates a base transister charge from both N and S poles.

Bedini's N S circuits are designed for single wire coils. I don't think his bifilar needs any extra help to run a N S array. I don't think Bedini discovered that, I believe it had to be shown to him. The bifilar is ambivilant about a pole face. The approaching  "Magnet Pole" causes an opposite pole to appear in the bifilar. This pole is reinforced by the power pulse. This makes The two pulse SSG a hi torque power hog, compared to the monopole reed switch that pays double the money! The (JonnyDavro, Gadgetmall) 12 volt relay inductor causes the kind of pulse width modification that retards that uneeded second pulse and allows us to maximize economy. Like an Ozzie motor pulse trimmer. Input can be turned down to under a hundred millivolts to power a hi speed spinner. I have to short around the inductor to start my neo sphere, it inhibits the performance so much. Once it gets going you can pick up with it and speed up for practically nothing.

"Skipping" from from spikes may help explain the sudden bursts of speed. Also, very high speed causes the bifilar to generate coil capacitance, which induces resistance to change in current direction in the coil. This results in bifilar air core "Lenz Delay".

The real benifit of Bedini's circuit is the primary flyback. After ""Lenz Drag" is circumvented, our bemf harvest yields a tiny yet proud gain.

Two Hall effect transisters is a bad idea!

[MileHigh]

Conrad:

My compliments on your setup and your nice clean scope captures and showing your schematic.  Also, showing were you put both contacts of your scope probe is very important and everybody should do that.

It seems that the spikes (no diode across the coil) have a beneficial effect on the turning ring magnet. The spikes seem to pull briefly the S-pole of the ring magnet  towards the coil core and such seem to accelerate the ring magnet. Once the spikes are eliminated by the diode this "help" goes away and the spin rate drops by 30%.

You almost have it there but the logic is inversed.  What's happening is that when you have the spikes, let's call that the "normal" speed.  So there is no beneficial effect to the spikes.  When you add the diode, the speed is being reduced.  In other words adding the diode causes drag on the rotor and slows it down.  So with the spikes is the normal rotor speed and adding the diode causes a detrimental effect on the rotor speed.

This is all shown in the lower left scope trace that that looks like a square wave.  The voltage is near-zero when the transistor is switched on and this is what you would expect.  When the transistor switches off the voltage is about -14 volts.  This shows that when the transistor switches off the coil is continuously discharging it's stored energy through the diode.  For example, if the voltage across the diode is normally one volt and your power supply voltage is 13 volts, then the scope trace will always display -14 volts when the transistor is switched off.

Notice how you arrive at that voltage:  If the power supply is set to 13 volts, with your probe connections that will measure -13 volts.  If current is flowing through the diode, then the diode causes another voltage drop of one volt to give you a scope reading of -14 volts.  Notice that you never see any EMF waveform induced in the coil like in your upper-left scope capture.  Since you don't see an EMF waveform in the coil, that's telling you that the coil is actively discharging energy into the diode during the entire transistor off time.

That means that current is continuously flowing through the coil.  Current is increasing in the coil when the transistor is on, and decreasing in the coil when the transistor is off but it never reaches zero.  With respect to your rotor, the rotor gets a push when the transistor is on to make it spin faster.  When the transistor is off, the coil does not "shut off" and therefore it creates a pull on the rotor to slow it down.  Assume that the transistor switches on at top-dead-center.  That starts the push.  After a certain rotation angle if the coil does not switch off, the push all of a sudden becomes a pull because the rotor magnet polarity has changed.  So with the diode you get an undesirable pull on the rotor that slows it down.

Synchro:

When you are talking about pulse motor circuits and bifilar coils you have to be specific.  Just making general comments won't work.  I am assuming that when you say "bifilar coil" you are talking about two separate coils wound around the same bobbin.  I am also assuming that they will not be made to work in self-cancellation mode because that makes no sense.  So you have four terminals for the two separate wires that make up the bifilar coil.  How do you connect each one of those four terminals into a pulse motor circuit?  Can you draw a schematic because that's 1000 times better than a verbal description.

You state:

I don't think his bifilar needs any extra help to run a N S array. I don't think Bedini discovered that, I believe it had to be shown to him. The bifilar is ambivilant about a pole face. The approaching  "Magnet Pole" causes an opposite pole to appear in the bifilar. This pole is reinforced by the power pulse.

I have no idea what means because I don't even know how you wire a bifilar coil into a pulse motor.  If you want to clarify your statements and show a schematic and even add a timing diagram, even if it is a hand-drawn sketch, then people will have a much better chance of understanding you.

MileHigh

[MileHigh]

Conrad:

I always wondered why the Bedini circuit (and similar ones for monopole rotors) work so well with spinning ring or ball magnets (which are in effect N S N S rotors). May be the spikes are the explanation. The spikes seem to help the other pole to pass the drive coil. But I might be wrong.

There is a very simple explanation for this.

Suppose that you have a pulse motor with a rotor with four poles, all North facing out.  When the rotor magnets fly by the drive coil the coil switches on after top-dead-center to give the rotor a positive push.

Now, what happens if you turn two of the rotor magnets around so that the rotor magnets are N-S-N-S facing out?

The answer is that the North magnets will give you the same results - the coil energizes after top-dead-center to give the rotor a positive push.  The South magnets will cause the coil to energize before top-dead-center to give the coil a positive pull.  The pull will stop at top-dead-center, which is what you want.

To understand this more just look at the transistor triggering waveform from the pick-up coil for a North-out and for a South-out spinning rotor magnet.

MileHigh

[hoptoad]

Hi Conrad, A coil of many turns is not required, I got acceleration under load and short circuit using
a small coil of 270 turns with 7 mH and only 0.8 Ohms resistance.

I simply used the correct amount of capacitance so that the unloaded coil presented a fairly large Lenz drag
to the motor, then when the load is added or the output shorted the Lenz drag is reduced and so the motor speeds up the rotor.
There may be some resonant kick back to the rotor, but mainly it speeds up because the actual load is reduced by adding the
electrical load or short circuit.

Look at the scope shots.  http://www.youtube.com/watch?v=iFWin-crxQY

By winding many turns the resonant frequency of the coil is reduced into the range of operation of the motor generator, without adding a capacitor, same effect
but my way has less resistance.

If the effect is so unique and unusual, then how come i can do it with the small coil I used and how come i can do the transformer thing as well.

It is a frequency induced restriction of the maximum current and a reduction in Lenz drag when a load is added.

The "prime mover" I used was a universal motor powered by DC from a boost converter, the motor was designed for 240 volts but I used only 20 to 35 volts. 

We can see the effect is obvious with resonant systems. The electrical load reduces the total system loading by altering the parameters of the
circuit. The load on the supply is reduced, that is why the rotor speeds up when it is a generator and why the input reduces with a transformer.

http://www.youtube.com/watch?v=WRzQ_CO9vnw

Here's more with a regular transformer.

Input reduction under load effects ect..  http://www.youtube.com/watch?v=Zxde9qga79c

Same transformer lighting a globe efficiently with full rated voltage. http://www.youtube.com/watch?v=7pzqxQwxVGA

This is a normal effect, i see no reason why it shouldn't happen if the conditions are made to allow it to happen.

Normal generators/transformers are designed to be efficient and power loads when they are added with full voltage and power,
so they don't show the effects of a poorly designed and used generator or transformer.

All reactive power is just applied power not yet used, it doesn't come from anywhere but the supply.

Cheers

Indeed  .... KneeDeep