How does a relay control a high-power circuit?

A relay controls a high-power circuit by utilizing a low-power signal to activate an electromagnet. This operation is based on electromagnetic principles, where a small current flowing through the relay coil creates a magnetic field. This magnetic field then activates or closes the switch contacts in the high-power circuit, allowing or interrupting the flow of electricity without the need for direct physical interaction with high-voltage components.

This mechanism is particularly beneficial for controlling devices that require much higher currents than the signal to the relay can handle. As a result, relays offer a safe and efficient way to control large loads using smaller and safer control signals, like those from microcontrollers or switches. Additionally, it isolates the control circuit from the high-power circuit, enhancing safety and preventing damage to sensitive control devices.