A colleague of mine, is attempting to start and stop a very small 5VDC electric motor with from a 5V low current output on an interface card.
He has produced a circuit using a small signal BS107 MOSFET, which I have uploaded a picture of, it can be seen here
As far as my understanding of MOSFETS as switches is concerned I cannot see any reason why this would not work, and it does indeed work on another application to drive a sounder.
The Transistor appears to work perfectly with no load connected, however, when the motor is connected, the result is with the transistor gate pulled to 0V the motor runs slowly and when pulled up to 5V it runs quickly, again indicating that the circuit is switching.
Any advice on why this is not simply starting and stopping the motor when applying 5V/0V respectively to the gate would be appreciated.
Thanks in advance for any advice on this.
Michael Wagstaffe BEng Hons EngTech MIET