Relays are a switch responsible for opening and closing circuits in an electromechanical or electronic format. Relays will control one circuit through the open and closing of contacts throughout the circuit. The relay contact remains open under the No value and when the relay is not energized it can be an NC value. Relays are used for smaller circuits along a switch circuit and they are often used with solenoids or smaller motors which draw low amps.
Relays are not typically used for controlling larger power generation because the large voltages can often require extra controls to properly change circuits. Most types of general purpose relays will operate under AC or DC current and it most common for control currents to range from 2A-30A. Relays operating in this range are often the most economical choice for control and they can be added into a wide range of switch configurations.
Solid state relays are much more commonly used with a DC power source. These relays include an input circuit, control circuit and output circuit. The various circuits perform functions along the electromechanical relay that will activate and deactivate the relay through the input circuit. There is a dropout voltage in the relay that will regulate this drop out value.
The type of power that operates a relay and the lifespan of a relay will often depend on the applications it is used for and the mechanical life rating on a relay. The rating in mechanical life is the number of openings and closings that a contact can perform through the electrical circuit. Most relays are rated at around 1 million operations before they need to be replaced.
If you are interested in learning more about Relays and what would be the best fit for your business, contact us today.
For nearly half a century, Swartz Engineering has been at the forefront of industry safety. They are a family-owned company specializing in power distribution for the electrical industry. They are the leading manufacturer of Type 76 DC relays. It is the most widely accepted protective overcurrent device used in the transit industry today.