I'm making an h-bridge from a bunch of old z44n mosfets I've got lying around, I want to use them as switches for a 12v supply but arduino only outputs 5v logic levels and I think to make a mosfet work the gate voltage has to be the same as the source, is there a way i can use either op amps or 2n2222 transistors to drive the mosfet from arduino by perhaps applying the 12v supply to the gate through a transistor or an op amp or is there another way which doesn't involve buying new logic level transistors?
Oddwired:
I think to make a mosfet work the gate voltage has to be the same as the source.
That's how you turn a mosfet "off".
To turn these mosfets fully "on", you need ~10volt between source and gate.
For grounded source, connect a ~1k resistor between 12volt and gate.
Use a small NPN transistor (2N2222) to switch the gate to ground.
Problem is that the mosfet is "normally on", and the transistor actively turns it off.
A second transistor could fix that.
Maybe better to use a $1 logic fet.
Leo..