Ask about IGBT and Power Mosfet. In dire need of help!!!


Joined Jul 17, 2007
Thank you very much SgtWookie, my objective is actually very simple. I'm using complementary darlington pair to drive the coil with AC sine wave. However, I need a tens of kHz bandwidth, of course hundreds of kHz would be even better. The problem I encounter is I don't know how to kill the kickback voltage effectively. There are ways I find to kill DC kickback voltage but I can't find any circuit that can do it bidirectionally. Also I can't afford to use relays or other slow circuits.
OK, you know that Darlington pairs are generally rather slow, right? The propagation delay from one transistor to another is cumulative, but there is also the saturation aspect - and it's difficult to predict how long it will take for a transistor to come out of saturation.

Why don't you tell us what you're really trying to accomplish? Simply driving a coil at 10s of kHz really doesn't say a lot.

Zener diodes might accomplish the function you're looking for. They'll have to be pretty high Wattage though, and have good heatsinks.