How To Interface Relay With Arduino
A Relay is an electromagnetically operated switch. Relays are used to control a circuit. Many relays consist a coil, a yoke, and an armature. When a current is passed through the coil, a magnetic field is induced in the coil which moves the armature and relay start its switching function. A normal relay has NO(normally open), NC(normally connected), COM and coil pin within it. A Simple one channel relay is shown in below image Relay Required Components For designing a relay driver circuit you will need following components Relay 1N4007 Diode BC547 Silicon NPN transistor 10K Resistor Circuit Diagram A simple relay driver circuit is shown in below image. Here we use an NPN BC547 transistor to drive the relay.Base current ought to be a lot of enough to turn on a transistor. A diode 1N4007 use among the circuit to protect the transistor from damage due to back emf. When relay is in off state, COM pin of Relay Driver Circuit a relay is connected to NC(normally connect...