[Milsurplus] Design for a cheap 400Hz power supply

Richard Brunner [email protected]
Sun, 29 Sep 2002 11:58:45 -0400


Yes!  I bought, inexpensively, a solid-state 24-32 vdc to 115 volt 400 cycle
2500 va inverter, intending to convert it to 800 cycles.   Well, Avionic
Instruments Inc. wants $250 for the instruction book and schematic, so
conversion is academic.  It's complicated, with 40 power transistors and a
driver board with no visible adjustments.  However, it works fine; I loaded
it to 900 Watts, and the output voltage didn't move a hair.  This is fine
for the PRC-47, (400 cycle) but not good for the TBW. (800 cycle)  The
output transformer sings a bit at 800 cycles, and when the cooling fan comes
on it sounds like a shop vacuum, but is less noisy than the 800-1 rotary
inverter.

Richard Brunner, AA1P