How can I replace a MOSFET with a common transistor?

This is a flip-flop circuit that I want to use for a project. It calls for any N-Channel MOSFET, but I don't have one. Is it possible to replace it with a transistor, such as a 2N3904?

Picture of How can I replace a MOSFET with a common transistor?
sort by: active | newest | oldest
klee27x7 years ago
You've got the analogous parts figured out correctly. But I doubt that this exact circuit will work if you simply swap a transistor in place of the MOSFET. If you put a transistor there, it'll drop 0.6V or so. Then the base of the transistor on the left might not turn off, properly. There'll be a leak current through it's base that might throw off the circuit. You could get around that by adding a silicon diode between the emitter of the transistor on the left and ground. Then you'd also have to replace R1 with a much lower value, else your transistor on the right won't have enough base current to do anything. I'm not sure if the circuit will work with a transistor, at all. But a value of 1k would be worth a shot, rather than 1M. Also, the 2n3904 and 2n2222 transistors can only pass 150mA or so. You know that, right?
1up (author)  klee27x7 years ago
I couldn't get it to work, thanks though. You gave the best answer.
2n3904 would work if it is an rs flip flop even a timed rs
yes just use a 2n2222 transistor. a mosfet is supposed to change the voltage but a flip flop is supposed to switch so use a bipolar npn transistor of any sort
1up (author)  death defyer7 years ago
I'm assuming the base or the transistor goes to G, the collector to D, and emitter to S?