Go Down

Topic: Connect external power supply (Read 451 times) previous topic - next topic

Kevintosh

Hello,

I want to supply 12 V to an device. I want to control the power supply over an relay.
Which parts do I have to order to connect a normal 12 V power supply to the bread board or directly to the relay?

Thanks in advance.

Kevintosh

DVDdoug

Does the relay have a 12V coil?  If the relay requires more than 5V or more than 40mA, here is a transistor-driver circuit.

Some relays have a low-current 5V coil and they can be driven directly by the Arduino.   In that case, you only need a "backwards" diode across the relay coil to kill the back-EMF (high voltage kick) when the relay is switched-off.


Go Up