The Ossie motor

[futuristic]

Hi after looking at your scope shots for some minutes they don't look so bizare any more. 

What we see here is induced voltage which seems to be visible only when FET is conducting.
Depending on the hall position you were catching certain part of the sinus wave of induced voltage.

Pulse from the battery is so small that is not even visible. You said it's 2mA and induced sine wave shows approx 70mA of induced AC current.

If you get your motor to max rpm and then quickly replace FET with just wire, you should see on the scope complete sinus wave and not only a part of it like now.

Anyway I think you have something really amazing there. 

To get full wave on the resistor I would suggest to try putting schottky diode in reverse direction to FET, because its internal diode doesn't seem to work?

Any way great work!

Frenky

[futuristic]

For this type of results we should have smiley like this one: 

http://i133.photobucket.com/albums/q79/ComicsReader/bow.gif

[futuristic]

BTW if I didn't say it specifically.

I think that it should be fairly easy to make you motor to selfrun from a capacitor.
Because with 70mA:2mA current ratio it just can't get any better.

Frenky

[woopy]

HeHe

thanks Frenky

but now goind to bed and night will connect all the good ideas hopefully

good luck at all

Laurent

[captainpecan]

Hi after looking at your scope shots for some minutes they don't look so bizare any more. 

What we see here is induced voltage which seems to be visible only when FET is conducting.
Depending on the hall position you were catching certain part of the sinus wave of induced voltage.

Pulse from the battery is so small that is not even visible. You said it's 2mA and induced sine wave shows approx 70mA of induced AC current.

If you get your motor to max rpm and then quickly replace FET with just wire, you should see on the scope complete sinus wave and not only a part of it like now.

Anyway I think you have something really amazing there. 

To get full wave on the resistor I would suggest to try putting schottky diode in reverse direction to FET, because its internal diode doesn't seem to work?

Any way great work!

Frenky

I'm usually fairly good at reading the scope traces, but this one is a bit over my head I think.  It's just not really making sense to me yet.  I'm still waiting for my scope to show up so I can get some more hands on to learn it better.  But how are you reading the 70ma current coming out from that scope shot?  I'm not saying your wrong, I'm just saying I don't understand it.  2ma going in and 70ma coming back out is making think something may be a bit weird with the calculations.  I hope I'm wrong, but that's a 35 times increase, or course only if the voltage was exactly the same, but you know what I mean.  Even if the voltage coming out was only 1 volt, it's way over power than what is going in.  Maybe we should take a couple more close looks here, and make sure it is being read right.

@woopy,  is there any chance you have a DPDT switch you can hook up at that fet.  If you hook one set of poles to a shorting wire, and other to the fet, you could easily just flip the switch to see the difference in scope traces.

Either way, great work!  It's nice to see a group of builders, moving along from hands on experience than just kicking all theories around.