MOSFET Switching Experiments

Low voltage power mosfets offer an excellent set of operational parameters which make them suitable for low power coilguns. Ease of use arises from a voltage control characteristic which means that, in many cases, the device can be driven directly from simple triggering circuit. In fact, many mosfets are now manufactured specifically for use with TTL (5V) level gate drive.

It is also possible to get devices with extremely low on resistance - of the order of 10m. Mosets can also withstand peak pulsed currents several times their continuous rating. If a larger current capacity is needed then mosfets can easily be paralleled since they have a positive resistance temperature coefficient.

Fig 1 illustrates the three measurements which are made in this investigation.

Fig 1. Basic measurements during mosfet operation.

Results:

Switching