I have a drive circuit for a 24V motor which I am trying to understand.
There seems to be some form of override circuit on the mosfet gate pin which I dont understand.
The logic for the motor comes in from the left, but there seems to be a BC337 which is over riding the logic circuit. But I am unsure under what conditions this circuit would ovoerride the Gate logic.

Any help would be appreciated.

 

Is this a circuit you came across or is it an actual unit you have?
If the latter , Do you know what piece of equipment it came from ?

 

without the rest of the circuit to understand the control scheme there is no point in making guesses. It may be a reasonable control scheme or it might be a safety shutdown system. Just seeing this fragment of circuit there is no way to tell.