> 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.
The primary side of a typical High Voltage AC/DC SMPS would be typical of
any other off-line converter. The secondary side could be implemented with
simple diode rectfication and a divider for the feedback through a typical
optical feedback. The 'black art' would be in the construction of the
magnetics. At these voltages and frequencies, core losses would be high and
there would be a tendency to arc across windings.
>
> 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.
This is true of circuits that use bootstrap windings to power the primary
side controller or other related circuitry (common in TV flybacks). This
supply would not need bootstrapping to achieve good efficiency.
>
> 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.
Only worth it if you're replacing obviously burned parts like snubber
resistors (a common malady).
>
> 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.
I doubt this would work even if you could get enough. The asynchronous
nature of the switching frequencies would create substantial noise
components, the transformers would break down quickly and the snubbers would
probably burn up.
Steve KT4FY
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