DUGAS, JASON A. (JSC-EP) (NASA) wrote:
> I have seen very little discussion in the amateur community for HV Switch
> Mode Power supplies in conjunction with RF amplifiers. With the increased
> difficulty of finding 60Hz 2400VAC transformers as well as the light-weight
> advantages of using switch mode power supplies, I'm surprised there has been
> no discussion thus far for homebrewing these for amateur use.
>
> Jason
> KB5URQ
There was a design for one several years ago in QEX (the ARRL's
technical journal). There are also some corrections to it. I can't
recall the power rating, but it was about 2 kW - too small for what I
wanted.
I'd like to have a go at designing one, as long as someone else was
paying for the time and blown devices!!
If you design SMPS's for a living, or have a lot of experience in
designing them, I suspect moving to high power/ high voltage would not
be too hard, although you would obviously have to watch the insulation
problems on the HV side. But to me at least, the design of SMPS's is a
"black art" and not something I'd like take lightly at high voltage high
power.
There seems (to me anyway) a problem that if a fault develops on one,
the protection circuits shut the unit down. So once its shut down, you
can't debug it. Remove the protection circuits and you have a whole host
of blown devices.
I know people with far less electronics knowledge than myself (i.e. they
have no formal training) who manage to fix PC power supplies. Personally
I would not attempt it, and neither would I for units that would cost a
lot more to replace.
There are a lot of SMPSs that take mains in and produce 48 or perhaps
more at a couple of amps. The rated input/isolation on these is usually
several kV. You could stack these in parallel on the input, but series
on the output. But unless you could get the devices cheap (which I
doubt), the cost would be very high.
--
David Kirkby,
G8WRB
Please check out http://www.g8wrb.org/
of if you live in Essex http://www.southminster-branch-line.org.uk/
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