Schematic diagram of two control lighting circuits

Schematic diagram of lighting control circuits in the two places is as follows:

Two control circuit principles:

Double-ground control is the abbreviation of double-ground control line in the circuit, and its principle is series connection first and then parallel connection. Disconnect the two wires and install a switch (such as "double-pole double-throw switch") to switch the two wires. This switch can also control the lights.

Generally, it is realized by two "single-pole double-throw switches" (commonly known as single-link double-control switches). There are two wires between the two "single-pole, double-throw switches": when the two switches are connected to the same wire, the circuit is connected and the light is on; When two switches are connected to different wires, the circuit is broken and the light goes out.

When there are many places to be controlled or the distance is too far, this circuit will waste electricity. Contactors can be used. Contactors are also needed for three-phase lighting and bidirectional control of motors.