SRD Power Relay - PCB Type: 3~48VDC
A power relay is a switch which uses an electromagnetic coil in order to close or open a circuit. Power relays also contain an armature, a spring and one or several contacts. If the power relay is designed to normally be open, when power is applied, the electromagnet attracts the armature, which is then pulled in the coil’s direction until it reaches a contact, therefore closing the circuit. If the relay is designed to be normally closed, the electromagnetic coil pulls the armature away from the contact, therefore opening the circuit.
These power relay units are very commonly used in many DIY circuit projects. Each unit has five leads which can be easily soldered on PCBs.