
What are switches?
Many people think they understand what a relay is. In electrical engineering the meaning of a switch or relay is much more complex, as there are actually 58 symbols used to represent different types.
The word "switch", even in everyday usage, has many different meanings. Switching something on and off is one thing, but you can also switch it over to another way of working. Switching can be done manually, remotely (using relays), or electrically (using timers or sensors).
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Switches
Contacts can be found on switches in one or more groups. Each switch will be connected to a circuit externally, and will either be "closed (on)" or "open (off)”. In either case, spring tensioning is usually used to secure them. The most common toggle switches will lock into either positi...