A 9V relay is an electromagnetic switch that uses a small 9-volt electrical signal (like from a dashboard button) to control a much larger, separate high-current circuit, allowing you to safely operate accessories like lights, motors without overloading the low-current switch or wiring. It works by energizing a coil, which creates a magnetic field that pulls contacts to complete the high-current circuit, effectively acting as a remote, heavy-duty switch.�
This relay can be used to switch High power (whether AC or DC) to a load by driving the relay coil with a far much lower voltage and current. When Current flows through the relay coil, It makes or breaks its contacts through electromagnetic induction. A relay contacts comprises of the Normally-Open (NO) and Normally Closed (NC) contacts. These refer to the state of the relay contacts when the relay coil is not energized. When driving a relay coil from a digital output or transistor, always connect a diode in reverse bias across the coil of the relay in other to avoid the resulting back-emf that appears across the coil of the relay when its turned off from damaging the digital device or transistor.
It can control small motors, incandescent lamps, indicator lights, low-power power supplies, intelligent instrumentation and various solenoid valves, etc. It can also be used as a pusher for high-power electromagnetic contactors.
