On Tue, Apr 17, 2012 at 5:32 AM, Jim Thomson <jim.thom@telus.net> wrote:
>
> ## any 2 x stage LC filter in a power supply these days is plane nuts. Any
> $$ spent on
> fixed and swing chokes is a complete waste of $$ imo. Even the resonant
> chokes used in the
> henry amps is a waste of effort.
This is just your opinion -- no facts presented.
> ## For XXX amount of $$$ spent, you are much better off to just buy the
> biggest hypersil
> C core xfmr you can get your hands on.....or an EI type with real low loss
> plates. Then use enough
> C to get the ripple down to at least 1% or less. Then you end up with
> superb regulation, both static and
> dynamic. On a 2 x GS35B 6m amp my buddy built, he tried using the bigger
> plate xfmr, and just changed the
> taps on it. With 5 kw CCS CXR out on 50.125 mhz, the B+ drops exactly 50
> vdc between RX and TX.
> Ripple is real low, like .3% with the 162 uf total C used. Ripple is zip
> on 120-240-360-480 hz.
> The combo of high C + a bigger plate xfmr will result in good V regulation.
> The low ripple is just the side effect of the high C...and amounts to a free
> lunch. And no, it wont cook your xfmr either.
Here's an opinion for you: 162 uF at 5 KV is asinine. I don't have
time to do the equation but I am pretty sure the stored energy is
somewhere between 5000 and 10000 Joules. Has your buddy had a plate
to grid arc yet? How long has this plasma generator been in
operation? I hope he's at least using a couple or three large oil
caps and has bleeder backup. I'd tell him to save the ridiculous
capacitance for his trunk speaker boomer--those things that rattle
windows when they go by outside.
Make sure he has his amp completely enclosed with screen over the vent
holes so bugs can't get in there between B+ and chassis.
73
Rob
K5UJ
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