Since all of my pelt chiller parts are either hand/home-made or way out of warranty, I am planning on 'modifying' one of the vpc controllers I have. If it works out as planned I'll be able to 'control' a lot more than 200 watts. I measured the output of the vpc and found that in fact it is always putting out a slight amount of power and when the threshold is hit the power jumps as does the frequency. So I guess it (the vpc) is a combination of pwm and 'Yo_Duh's power sharing circuit '...don't really know but it has been totally reliable for some time now. I am going to add several high power mosfets, additional cooling area, and a higher AMP circuit breaker to the controller. I think that the logic is all low level and it simply triggers the onboard mosfets...if this is so then much higher amp loads can be handled with adequate cooling (large sheets of plate aluminum). The vpc circuit is potted so I cannot see what is inside and makes it tick but the mosfets and fuse(circuit breaker) are accessable which will allow me to add a couple of jumpers and see what I can do to up the power handling.
wj
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