What type of circuit typically uses a relay for control?

Relays are typically utilized in low-power relay circuits to control larger loads while allowing a smaller control signal to operate them. This is particularly advantageous because it isolates the control circuit from the high-power circuit, thus enhancing safety and protecting sensitive components from damage. The relay acts as an intermediary switch that can be operated by a lower voltage or current, enabling control over devices that require significantly more power without direct manipulation of high-current circuits.

In applications requiring the operation of motors, lights, or other appliances that draw high current, using a low-power relay makes it feasible to automate these devices without risking exposure to high voltages or currents in the control circuitry. This aspect is crucial for various HVAC systems where safety and reliability are paramount.

While high-voltage circuits can also utilize relays, it is the low-power relay circuits that are designed with relays specifically to control the power transferring functions. In contrast, dangerous high-power circuits may not prioritize the same safety levels or component protection that low-power relays inherently deliver. Direct current circuits can use relays as well, but the classification of low-power relay circuits emphasizes the design and operational role of relays in facilitating control. High voltage applications might use relays but under specific designs often not associated with low-power operation