V G wrote:
> I don't care about efficiency, since it doesn't
> consume much power anyway, and it will get power from a computer
> power supply (12V rail or wahtever).

You can use a relay to switch between 3.3V, 5 V, 12V outputs when
doing PID. To cool a drink quickly you would use 12V, to maintain the
temperature you would switch between 0V - 3.3V.
--=20
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