On Wed, 28 Mar 2012 15:07:03 +0100, "N_Cook" put
finger to keyboard and composed:

Under therrmistor control. If at power up the DC voltage is too low to start
the fan can you always rely on the fan starting at some point with a slowly
increasing voltage or does it depend on the make/design of fan ?

FWIW, here is an article that shows the innards of a typical
thermistor controlled CPU fan:
http://www.pavouk.org/hw/fan/en_fan4wire.html

- Franc Zabkar
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