| Another alternative would be to use a square wave - that way the transistors are either on or off, so don't dissapate much power.
The problem with this is that the pump motor will not run wonderfully well on a square wave. It'll tend to consume more power, but not push more power into the shaft. This can only mean that the pump gets hot instead!
That's easily, cuz things don't get so hot, but doesn't work very well.
AidanII
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