Quote:
Originally Posted by BrianG
Wow! First of all, let me say you are tackling a complex project here!
When you say PNP/NPN, I assume you are familiar with bipolar transistors. Transistors are "current" driven, have a current gain (beta), and have a set collector to emitter voltage drop even at saturation. MOSFETs are voltage driven (they don't load down driving circuits) and their drain to source v drop is determined by the Rdson value and current flow. Think of them more like a faucet where the source is the water tank, the drain is the output, and the gate is the valve. Rough analogy, but sufficient. There are other differences, but you see what I mean - it's like comparing apples to oranges.
Aside from being N or P channel, are they enhancement or depletion types? I would think you would NEED enhancement types, but I dunno.
Sorry I can't help you any further on this as I've never really dealt too much with FETs at the design level.
The Quark 125 uses the same FET parts, just more of them. IIRC, they are the same on both sides.
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Thanks for the reply Brian. You're very knowledgeable and I was hoping you would chime in on this.
I like your analogy. It's a good one since DC Current only flows one way. I've often thought like that too.
I find myself switching back and forth between the two sets of data sheets comparing figures and I find no reference on either as being enhancement or depletion types.
I think I'm in the ball park on compatibility. The donor drive unit that gave up these bigger MOSFET's served as a controller for a 36 volt drive motor. The motor is brushless and is a 6.6kw unit. This was not a sensorless setup by any means. It pushed around a 9500 pound Industrial truck at 9mph.
The Controller these came out of has an extensive brain board that uses an encoder bearing in the motor to calculate timing. Based on encoder information, the controller knows motor speed and armature postion. Much like the Novak sensor based setups.
I want a high Amperage Car Controller that will do multipole motors! A HV setup that will do 36 volt reliably would be a dream come true.
