my rad fan is 450 W if that helps

alistair

PS i dont see the point in a pwm controlled fan, I would concentrate
in a more sophisticated temperature interpretation, ie a PID
controller... monitor rate of temp change to that fan can keep on top
of things...

but you know, my experience of the fans in real life is that they
come on, cool the van down and go off.... seem to work fine :)

On 25-Apr-10, at 2:07 AM, Tom Hargrave wrote:

Interesting - we use a PWM controller in our stir plate design. It
uses a 12
VDC supply but I don't know if it would handle the current drawn by
the fan
motor.

The ideal solution would be a PWM controller that changes the fan speed
based on coolant temperature - ours does not do that but one could be
designed that does.

Tom
www.stir-plate.com