Turn motor on for 5 seconds

Thread Starter


Joined May 13, 2014
I have a simple project which is to turn a 12v motor on after I press a pushbutton. I made the circuit work with an led, but when I replace the led with a motor circuit with transistor, the circuit stops working.



Joined Apr 11, 2010
What behavior do you observe? That is, what are the details of how it stops working.

Some observations of my own. There is no base resistor on the transistor. You need one to limit current and prevent magic smoke from occurring. This may be your problem.

Secondly, your push button is not debounced. Hence, each press will result in multiple clock inputs to the flip flop. It may not end in the desired state.

Also, I suspect that there is an unused NOR gate. It should have its inputs tied to ground and it's output left disconnected.