That module has a transistor and diode built-in, from the photo.
Thus it just needs 5V power for the relay coil, ground and a logic signal. The 3-pin
connector seems to be labelled +, -, S.
The screw terminals are the relay contacts.
That module has a transistor and diode built-in, from the photo.
Thus it just needs 5V power for the relay coil, ground and a logic signal. The 3-pin
connector seems to be labelled +, -, S.
The screw terminals are the relay contacts.