by Doug Coulter » Mon Jun 27, 2011 9:04 pm
That sounds good. Yeah, we should just do a separate one for "high power, high regulation", I think. It'll necessarily be bigger to support the opamp and larger output caps, no need to make the simple one big -- more useful as is, and the small disc caps on this model are fine, standard and gettable forever. The "blue block" caps are only required when the current demand is high and the ripple needs to be really low. That model would just be a simple doubler anyway to get the output current as good as possible, since some phototubes really eat the power in the divider chain.
My large ones are "only" about 4 megs - at 2kv (tops, usually use less volts) that's about a watt, but it seems like more when you see how hot the socket full of R's gets.
I have built one of those already, and it works great, I just have to pop the box top and see what I did and write it down. Closing that loop was slightly tricky due to the delay (phase shift) in the CCFL and output filter. The bench model I put a 10 turn pot on and it's real reproducible and nicely stiff for things like that. I scored about 100 of those nice 10t pots surplus....so I have a supply of them that won't break the bank.
The diotech diodes are .55" body and need about .65" hole spacing unless we want to stand them on end (not that I haven't forced them into narrower spacings, but it looks ugly). Keeping them flat is good from a noise standpoint so they don't act like antennas for the 50kz on them and radiate it all over the place. We'll want to fashion a box for this anyway, metal for shielding, they're real noise makers. Or find something off the shelf. I've been known to use metal flashing tape to make a plastic box act like a metal one re shielding.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.