Making a back emf motor generator and load testing.

[Farmhand]

Hi Tommy, I'll watch the video now, maybe a misunderstanding, I don't think I said the motor coils would show a transformer effect to the generator coil, I said an oscillator with the third winding can output a (Edit: Transformer) effect voltage and a flyback voltage. I was saying that maybe the generator coil could collect the "back emf" from the motor coil magnetic field collapse without the "back emf"collection arrangement in use because the core is shared.


You would need to disconnect the back emf collection arrangement and scope the generator output before the bridge rectifier and remove the load resistor from the generator output capacitor so the voltage can climb from the spikes.  We should be seeing the sine wave and spikes. If the cap is climbing above the normal generator voltage then there is spikes doing it most likely.

Another way without scope is to get the motor running with back emf collection in place separate to the generator as you did and get a stable generator voltage on the generator cap with no load resistors, then remove the back emf collection arrangement and see if the generator cap voltage rises.

I can see spikes, are the spikes on the generator output when the back emf collection is in place ?

I think any spikes you see above the generator voltage on the generator output are "back emf"/magnetic field collapse spikes from the motor coils, which could be a problem if you want a stable generator output voltage. The capacitor will collect them if in place and they probably would not be seen if there is a load o the caps.

If the gen cap climbs up to a voltage the generator sine wave cannot charge the cap to then it must be spikes doing it.

Edited: I mistakenly wrote generator effect when I meant transformer effect above. I changed it.
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