Introduction to Low-Voltage Electrical Appliances Commonly Used in Induction Heaters

Low-voltage electrical appliances mainly include: low-voltage switching appliances, contactors, relays, fuses, master control appliances, etc.

Switching appliances refer to electrical devices used to connect or disconnect current in one or several circuits. A switching appliance can perform one or two operations. It is one of the most common and earliest used electrical appliances, with commonly used ones including knife switches, isolating switches, load switches, combination switches, circuit breakers, etc.

A contactor is a non-manually operated mechanical switching device with only one initial position, which can connect, carry, or disconnect current under normal conditions. Contactors cannot cut off short-circuit current, but they can frequently connect or disconnect AC and DC circuits and can realize remote control. They have low-voltage release protection function, as well as characteristics such as large control capacity, strong overload capacity, long service life, simple structure, and low price.

An electrical relay is a component that, when the input circuit controlling the component meets specified conditions, will produce a predetermined jump in one or more of its output circuits. Electrical relays generally control the main circuit through contactors or other electrical appliances, so the rated current of relay contacts is relatively small (5-10A), without arc-extinguishing devices, but with high action accuracy. It is also an electrical appliance for automatic and remote control. Widely used in automatic control systems, remote control systems, measurement and control systems, power protection systems, and communication systems, it plays roles in control, detection, protection, and regulation. It is one of the most basic components in electrical devices.

A fuse is defined as: when the current exceeds the specified value for a sufficient length of time, it operates by fusing one or more specially designed and corresponding components. A fuse is a protective electrical appliance, and the fuse element is a fuse wire or fuse link.

Master control appliances, in control systems, are used as switching appliances to close or open control circuits to issue commands or serve as program control. They are generally used to control contactors, relays, or other electrical circuits, thereby connecting or disconnecting the circuit to realize automatic control of power transmission systems or production processes.