Rarely are these familiar examples good for learning but a 3 way switch is an excellent example of using normally open and normally closed switches.
Normally open relay contact symbol.
Changeover contact this is the changeover contact of a relay that is closed or connected with one terminal known as normally closed terminal when the relay is deactivated the other terminal.
In other words when voltage is applied to the relay contactor terminals this contact closes.
Now let s go through a real world example of normally open and normally closed contacts that we are all familiar with.
The contacts open when the relay activates to break the circuit.
The following is a description of the four basic types of time delay relay contacts.
The relay are switching devices activated by signals.
Relay symbols and electromagnets.
Relays and contactors have two types of contacts each suited for different applications.
First we have the normally open timed closed notc contact.
Of these contact forms the following are particularly common.
Most of the time a small voltage or current is used to switch other voltages or higher currents that may be electromechanical or fully electronic type.
Form a contacts make contacts are normally open contacts.
Normally open no contacts allow current when the relay or contactor is energized.
It is the contact of relay that is in closed position when there is no power supplied.