What does NO mean in cars?

[LeAdeline]

The symbol for normally open is NO, corresponding to the first letter O of the English word 'open'. Contacts that remain open when not energized are called normally open contacts. The symbol for normally closed is NC, corresponding to the first letter C of the English word 'close'. Contacts that remain closed when not energized are called normally closed contacts. Meaning of NO in cars: Whether normally open or normally closed, both refer to their original state. Once energized, their states reverse. Normally open contacts will close, and normally closed contacts will open. Working principle: Relays rely on the magnetic force generated by the coil to operate the switch. The coil acts like a large inductor, producing a significant back electromotive force during energization and de-energization. Diodes and capacitors are installed to absorb this interference and prevent damage to other circuit components. Simply put, this is an anti-interference measure.