Elevator lighting circuit

Nowadays, there are many high-rise residential buildings. Some of the lighting in the elevators is controlled centrally by the machine room, and some are controlled individually on each floor. If you forget to turn off
the lights, you will have to climb several more floors. Seems very inconvenient.
    This article introduces a simple and easy-to-implement circuit for lighting in the elevator room, which greatly facilitates
elevator maintenance work. The principle is as shown in the figure. Each layer has a normally closed button and
a normally open button. Composite buttons can also be used. As long as the normally open button is pressed every time, relay K
works, the contacts are closed, the lights on all floors are lit, and the relay works by itself. If
the normally closed button on any floor is disconnected, the relay will lose power, the contacts will be disconnected, and all lights will go out.
  It should be noted that the carrying capacity of relays and switches should be determined according to different loads.