Hello all. I want to switch a relay 12v dc by mega8. Does somebody know what kind of buffer I should use? Very thank you.
http://www.electronics-tutorials.ws/transistor/tran_4.html You use a transistor as switch. I'm sure someone going to pop up and say use a mosfet. plain old 2n2222 will work with a diode across the coil of the relay.
How much coil current thru the relay? 2N2222(A) or similar NPN might suffice. N-Channel MOSFET might be needed.