The string of diodes will be very lossy. If these diode losses can be also tallied then it is ok.
I prefer a more elegant method such as a transistor or mosfet saturating switch (one for each half wave) whose turn on is triggered by either rotation angle using a cam or precise voltage level of the waveform.
I can work up a circuit for this if needed.
Also a reed switch properly placed and timing magnets on the shaft will also work, but will need careful adjustment. This could also have very low losses.
Edit: Now that I think about it a bit more, the diodes cannot work as they will conduct right through the peak of the waveform. According to Smudge, current must only flow at 45 thru 135 and 225 thru 315. No conduction allowed during remaining phase angles. Diodes alone will only provide a large crossover distortion around zero and 180 degrees of phase angle.
Smudge: How about using the excess energy to provide a push to the PM rotor at the appropriate time so no shaft input power required outside of a kick start? This would require storing the excess energy in a capacitor or inductor and releasing it to push the rotor during one of the available times when you are not extracting. Or would this prevent the operation that you have proposed? Maybe something to try after the initial proposal shows signs of working.
« Last Edit: 2014-09-15, 14:48:24 by ION »
---------------------------
"Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy
|