"west" writes:

Hello Steve,

Thanks for the interesting PS links. I'm not sure of their HT current
capabilities. I've been wanting to make a good bench HT, Fil, & Bias supply,
for a while now. I have a few ham radio PS that don't quite make it.. The
major drawback is that the Xfrs are only capable of 100ma. At times I could
use a little more that 400ma. Hopefully, someone reading this thread will
come up with a viable suggestion.

Cordially,
west

If you are willing to use transistors in your variable supply, along
with a fan and a big heatsink, it is quite easy to get 400mA up to
about 350V. For example, Hammond makes the 378CX, which is rated for
465mA of DC. You then use mosfets, which can easily handle the current
if you keep them cool. The B+ part of this schematic,

http://novatech-instr.com/PDF_files/ps_ss.pdf,

for example, is an exact copy of the GE 1-compactron PS, but done with
solid-state parts. Obviously, a lot of scaling needs to be done
(MPSA42 is only good to 300V). This particular one was done for 90v.

If you design it to cover 50-350 at 400mA, then you are going to burn
120watts worst case. That will require a fan, big heatsink and
several paralleled Fets, but it will work just fine.

I wasn't interested in spending that much on parts.

Steve
--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA