Solid state relays are switching relays that do not need the use of any mechanical parts. This usually gives them the benefit of having a lifespan longer than that of a common electromechanical relay. Although the magnitude of solid state relay is faster as compared to electromechanical relays, they do have some design stipulations. Solid state relays have taken the world by storm as it has revolutionized power distribution in every industry starting from agriculture-automation to aerospace. Starting from solid state relay basics to opto-isolators and opto-couplers, photodiodes, and PN junctions this article covers everything. Design of Solid-State Relay Solid state relays are typically designed by solid state relay manufacturer as a simple on-off switch with a power terminal and load terminal that switches when there is passing of an external control signal to the relay through another terminal. When this takes place, the switching happens very quickly, and the load is provided with power, usually by means of power-transistor. Solid state relays consist of multiple transistors that are parallelly aligned so that they can allow for a higher current flow potential, which can be rated into the 100s of amperes. AC switches needs at least two transistors because when the relay is in an off state one MOSFET cannot stop the current in both directions. When the sources of two transistors are connected, they are used to block current when it is in off state and when the control signal is switched on within the relay, they pass power. Working of a Solid-State Relay The difference between the switching mechanisms ultimately holds the real beauty of solid-state relays versus multi timer relay. Solid state relays generally use what the industry calls opto-isolators or opto-couplers. Opto-isolators in solid state relays are very much crucial as they are what separate the two or more circuits of the relay. Since to control very large voltage signals relays make use of small voltage signals, hence it becomes extremely important to keep these signals separated. The main beauty and revolutionary trait of opto-isolators is that there are no moving parts. For example, this circuit separation is made possible by an electro-magnetic field in electro-mechanical relays, which is also what is used to ultimately complete the large load circuit. Follow us on Twitter
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Meba Electric Co., Ltd is a professional manufacturer and supplier of highly designed and premium quality electrical appliances. We always focused on developing our capacity and increasing the efficiency to compete in the current market. Archives
April 2024
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