An automatic transfer switch is an electrical device composed of one or more transfer switch devices and other necessary devices, used to monitor power circuits (such as voltage loss, overvoltage, undervoltage, phase loss, frequency deviation, etc.), and automatically convert one or more load circuits from one power source to another. In the electrical industry, it is also known as a "dual power automatic transfer switch" or "dual power switch.".

Conversion switch, also known as combination switch, is a switching device that plays an important role in circuits. The operation mode of the switching switch is usually a flat operation with left and right rotation, which is different from the up and down flat operation of the knife switch. By rotating the switch handle, the contacts will move from one position to another, thereby transmitting signals or power in the circuit to different paths.