The relays are very important components of electric charge manipulation, since they guarantee the combination of logic in the control, as well as the separation of the power and command circuits. An important specification of relays is that the voltage of two terminals can be 5Vdc, 12Vdc or 24Vdc while at the same time the other three terminals can operate with 110Vdc or 220Vdc.
In this way, we can conclude that there is no physical contact between the drive terminals and the working terminals. This concept ensured the appearance of two circuits in an electrical panel:
– the control circuit, in which is the interface with the operator of the machine or device, operating with low currents and / or low voltages;
– the power circuit, in which the circuit where the loads to be driven are located, as well as the motors and heating resistors, among others. Boston Gear CSC131
Relays are rated as the simplest, are made by a housing with five terminals. Two terminals correspond to the excitation coil, the input is a terminal, and the terminals correspond to other two normally closed contacts, also called NF, and normally open, also known as NA, respectively.