5v 200ma trigger need to power 12V buzzer

[johnmikebolognone]

I have a temperature sensor that when the temperature is out of range, it will set a pin to +5v. I need to take that trigger and drive a 12Vbuzzer. Can someone help me design a simple way of using that trigger to drive the buzzer?

I was thinking to use an optocoupler to seperate the 5v side from the 12v of the circuit, but don't think i can run the higher amperage through the optocoupler.

I am a newbie, so speak slow...

[KMoffett]

This should serve your purpose, if the 5V and 12V supplies can share a common (-) ground. The Q1 MOSFET can be almost any one that can handle a 200mA current. The Diode D1 is not critical either.

Ken

[johnmikebolognone]

That works perfectly. Thanks!