Posted on January 21, 2019 David Sherman
Electromechanical relays are switches used to control high power electrical devices. They turn a small amount of power into a much larger amount. These relays use an electrical supply in order to perform a mechanical action, hence the name. Moving parts are used to connect contacts within the relay. Electromechanical relays are most commonly used to control a single circuit using a low power signal or to control multiple circuits with a single signal.
Electromechanical relays are made up of moveable armatures, moveable and stationary contacts, springs, electromagnetic coils, and wire that wraps around the coil. The armature is used to open and close the contacts. The spring is attached to the armature and moves it back to the armature’s original position. When energy is supplied to the coil, an electromagnetic field is produced. The moveable contact moves towards the stationary contact, and the relay switches on.
When a current flows through an electrical conductor, a magnetic field forms. When the flow increases, so does the strength of the magnetic field. The magnetic field produced exerts mechanical forces on magnetic objects. This relationship is the basis of electronic devices and can be described mathematically as B= μoI/2πr.
Electromechanical relays are commonly used in devices that are turned on and off. They can be used in something simple like a hairdryer, or more complicated like a vehicle. A few things must be considered when selecting relays. For example, it’s important to know whether the contact will be normally closed or normally open. Because the maximum amount of voltage the relay can handle and the amount of current needed are usually set amounts, it matters if the relays natural state is closed or open.
Share
