Scott Dorsey wrote:

Steve wrote:


Hi Gang,
In the past, when converting equipment from 400 Hz power to 60 Hz power,
I've replace the transformer(s), and increased the size of the filter caps.
That was many moons ago.



This is the smart thing to do IF you don't care about keeping the equipment
original.



These days, it seems like it'd be fairly easy to build something like a
switching power
supply but using a fixed frequency at 400 Hz instead. Has anyone done this
yet, and if so, I'd sure be intersted in the details.



There are switching converters out there. The problem is that if you use
a square wave at 400 Hz, you get all kinds of harmonic trash, so you either
need to use a class B or better stage and suffer extreme inefficiency, or
use a "modified sine" inverter configuration. I don't think it would be
too hard to hack up some of the cheap truckstop 12V-120V inverters to
produce 400 Hz, though.
--scott



I modified a 140 watt unit using information I got from some where.
Only two capacitors had to be changed.
It worked well until I tried to run a motor from it :-(.

No I don't remember the details of the modification, but the new units
would probably be different anyway.

Bill K7NOM