What are electromechanical relays?
Electromechanical relays are a device used to create and break electrical connections. The relay usually uses a small voltage to control a higher voltage or higher current. Unlike some electronic switches, electromechanical relays electrically insulate control signals from switched signals. This relay is often used in vehicles to switch ignition, engines and lights to turn on and off the light. They are also used in factory equipment to control valves, pumps and engines. It opens and closes a set of electrical contacts connected to the spring fitting. If the relay is normally closed, its contacts are connected if the relay coil is not under voltage. When enough current passes through the coil, the anchor moves and disconnects, contacts while the coil is under voltage. The electromechanical relay with normally open contacts works in the contradictory.
as switches, electromechanical relays have a number of electrically separated contacts or poles that move when the coil isunder tension. Some relays have only one pole; Many of them have two and others can have four or more. Similarly, similar switches can be a relay with either one throw or double throw.
In a double throw relay, the Poles touch one set of contacts when the coil is not under voltage. They disconnect from this set and touch the second set as long as the coil is under tension. The relay with one throw has only one set of contacts to touch. Poles are either associated with this set of contacts or are disconnected and do not touch others.
Some electromechanical relays have coils that are designed to operate on the AC current (AC), while others use direct current (DC). The tension of the coil is often relatively low, from several volts to several hundred volts. However, relays can often switch much higher DC or AC voltage. Some can handle up to 15,000 volts and streams up to severalIk a thousand amperes. The coil is electrically insulated from switching contacts, so it is possible to work on DC while the other connects AC if necessary.
Electromechanical relay device usually has several disadvantages compared to the semiconductor switch of fixed state. It can be bulky and expensive and switch much slower than a semiconductor device. The relay control circuit insulates the relay from a solid state from the load -switched optoisulator. The switching device controls the light emitting light (LED) and the photodettector. Transistor, silicon -controlled rectifier (SCR) or triodes for AC (triac) switches the load electronically instead of mechanically.