Quote:
Originally Posted by ThunderCactus
it'll work as long as it doesn't have active braking, I'm just saying it's not a good idea.
Think of it like this;
You're flicking your light switch on and off so fast it essentially dimming the bulb a little. Do you think that's good for the bulb or the switch? Or the power source for that matter? lol
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Not applicable.
A MOSFET typically has a switch rate under 10 nanosec, with high quality MOSFETs going as low as 0.4 nanosec. (the ones I use are that fast).
Meaning that the switch would have to bounce over 10kHz to cause the FET to enter triode and start heating/degrading.
The only thing that it does is everytime the switch bounces, it sends a back EMF to the drain pin. If there is no diode to protect the FET, or if the diode is not fast enough (thing regular N-type diode vs.Stocky), the high voltage spike might scramble the doped semiconductor in the FET and screw thing over.
The other side-effect is that when the switch bounces, it does not cut instantly. The resistance increases a lot while the air is still ionized enough to arc across the contacts. That in turn means that there is a current spike going through the MOSFET, and depending on the unit used, it might exceed the rated max instantaneous current. That same current spike also "boosts" the resulting back EMF (the larger a current is in a given load, the higher the voltage will be when you cut the circuit).