Quote:
Originally Posted by MadMax
There is one thing I found missing from that airsoft mech's article. DC motors are significant inductors. They are able to store some significant energy in establishing a magnetic field which means they can output a pretty high voltage when you disconnect them from a current supply. It may help to put a diode across the motor terminals opposite to the usual polarity applied by the external MOSFET cct. When you interrupt current flow through the MOSFET cct, the reverse biased diode provides an easy current path for the inductance current to dissapate throug so it won't fry the MOSFET. In normal operation, the reverse biased diode will not particapate and will appear to be an open cct so it will not affect the motors operation.
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I thought that the motors already had some king of protection, be it diode or capacitors....
Well that is a good thing to add. There is one integrated in the FET, but if it fries, must change the whole FET.
Thank you for pointhing that! I think that a 1W 50V diode should do the trick.