Wouter van Ooijen wrote:

> IIRC Peltier devices are heat pumps? If so their action is inherently
> slow due to thermal inertia, so you can PWM at a *very* low frequency,
> like N seconds on each minute. Easy in software, and would probably
> avoid the inefficiency Olin mentions.


The one I bought came with a warning NOT to use
PWM under 2kHz, apparently that produces too much
thermal stress. Very low frequencies (like you
mentioned) may be ok and are used in some cheap
car fridges, but a slowly ramping PWM at higher
than 2kHz will give the longest life, possibly
run from a nicely filtered buck converter even
better still always providing DC to the device.
-Roman

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