Re: cheap 200A AC to DC power supply?

Arlet a écrit :
Fred Bartoli wrote:

Arlet a écrit :
Tony wrote:

If you can insulate the Peltier elements, it would generally be easier
to provide 170VDC at 17A. If the insulation is REALLY good, you could
just rectify and filter the 120VAC, or preferably work up a PFC front
end to provide both regulation and an input current waveform that
doesn't trip out every breaker you connect it to .... or else rethink
the project or the budget.
The filter needs to be pretty good, otherwise the quickly fluctuating
temperatures cause mechanical stresses which severly reduce the
lifespan of the Peltier elements.

That's bollocks. You'll have to have a huge LF ripple to kill your TECs.
Any decently (read not completly screwed) designed PWM supply will give
you as long a lifespan as a DC battery.

That's what I mean. You'll need a real supply, not just a rectifier and
a few big caps.


Even that will do unless you have a so small cap that the ripple is more than 5-10%.
The pb associated with ripple are:
- loss of cooling efficiency
- if your ripple is too low in frequency WRT thermal inertia, like when you're thermal cycling your TEC with a ON/OFF thermostat then you may reduce its life.


--
Thanks,
Fred.
.

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