A power relay is a switch that uses an electromagnet to move an armature. The armature is the moving part of the switch and is surrounded by a frame. When the relay is powered, the coil draws the armature to the coil, where it is energized and pulled into contact. The armature is then returned to its original position by a spring.

The power relay is usually powered by a battery. The armature, a movable arm made of iron, attracts the electromagnet. It is held in place by a spring. The armature is then pulled in the direction of the coil, reaching a contact and closing the circuit. The opposite occurs when the armature is released.

One common problem with high-voltage power relays is arcing. Arcing occurs when the contacts of the relay are open at the same time, causing a high amount of heat in the device. This in turn decreases the lifespan of the relay. One common way to troubleshoot a power relay is to use a multimeter and use its continuity feature.

There are many uses for a power relay. They can be used to protect devices from noise and to give a signal when the voltage changes. A wide range of different relay types and styles is available.