PWM driving an LM339

Hi,

I'm driving a mosfet H-bridge with an lm339 in a schematic somehow similar to this one http://letsmakerobots.com/node/18633 .

For current limiting, I thought about switching off the power (Vcc) on the lm339 whenever over current happens. Is it a good idea, or does the lm339 need some time when powered up to stabilize?

I don't want to bother the μC with over current limitating.

Thank you.

Personally, I'd be more inclined to disconnect the 3k3 resistor or to short out both right-most 1k2 resistors, which would result in all FETs turning off.

dougy83 said:

Personally, I'd be more inclined to disconnect the 3k3 resistor or to short out both right-most 1k2 resistors, which would result in all FETs turning off.

Click to expand...

Do you mean something like this ?
View attachment 68387

I think some resistor values had to be added for a such setup. But I don't know what you mean with shorting the 1.2k resistors. I guess this would set the reference voltage to 2.5V.