[Milsurplus] Kluge conversion of 24 volt dynamotors to 12 volt

[boeing377 at aol.com]

I used this trick to try to make a 28 volt to 110 VAC 400 hz inverter run on 12 volts to power an APN 9 Loran A back in the 60s. It never really worked out, arcing, commutator pitting, rapid brush wear. Might have been due to my klugey technique in relocating the brush. Finally found a PE 109 14 volt rotary inverter which was used in a few C 47 transports that were 14 volt airplanes instead of 28 volts. That worked out perfectly. Odd that they would make some C 47s 14 volt, adds more weight in DC wiring I'd think. Anyone know the answer? 

73
AF6IM



You can actually make a 24 volt dynamotor run at approximately the original 
design RPM off of 12 volts by relocating the grounded brush 90 instead of 
180 degrees from the ungrounded one.  I did that with a DM-32 back in ancient 
times.  But it's a kluge. 


 


 


 

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