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GriffinRU
RC-Monster Aluminum
 
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Posts: 748
Join Date: Oct 2005
08.26.2006, 09:27 AM

Quote:
Originally Posted by thesteve
I don't think the voltage limit of the mosfets is the problem with supporting 6S in the ESC. Mosfets will keep operating just fine at higher voltages until they fail - and when they do fail you'll know cause you'll smell that lovely electronics smell. Without having one of the controllers to look at I believe the problem with higher voltages is simply a function of how fets work, in general you need/want a higher voltage on the gate(the on/off pin if you will). To get this higher voltage pretty much all ESCs have a voltage charge pump(booster) So even though you may have a 6 cell nimh pack connected the ESC is turning the fets on and off with 12 or more volts. I am guessing the charge pump in the Quarks isn't high enough to keep the gate voltage higher then the input voltage, and as a result the fets will not turn on properly.
The ESC above appears to have 36 fets (6 per phase) which is a very solid design. Even the Schulze U-Force which is a very good controller only has 18 fets in it(3 per phase)
Also the fets they are using are quite good - rated at 28 amps in real world conditions.
And this story about FET's and high voltage based on?
And do not blame fet's control if you not sure how it works...

Artur
   
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