Type of Relays: Electromechanical

Type of Relays: Electromechanical

General purpose relays are electromechanical switches, usually operated by electromagnetic coils. General-purpose relays work with AC or DC current and have universal voltages such as 12V, 24V, 48V, 120V and 230V. They can control currents of 2A-30A. These relays are economical, easy to replace, and allow multiple switch configurations.

The machine control relay is also operated by an electromagnetic coil. They are heavy-duty relays used to control starters and other industrial components. Although they are more expensive than general-purpose relays, they are generally more durable. Compared with general-purpose relays, the biggest advantage of machine control relays is that the functions of machine control relays can be expanded by adding accessories. Machine control relays have a variety of accessories to choose from, including additional poles, switchable contacts, transient suppression of electrical noise, latching control and timing accessories.

The reed relay is a small, compact, fast-operating switch design with one contact, normally open. The reed relay is sealed in a glass housing, which makes the contacts not affected by contaminants, smoke or moisture, can reliably switch, and can extend the life of the contacts. The ends of the contacts are usually plated with gold or other low-resistance materials to increase conductivity, and these ends are pulled together and closed with magnets. Reed relays can switch industrial components such as solenoids, contactors and starter motors. The reed relay consists of two reeds. When an electromagnetic force (such as an electromagnet or a coil) is applied, it creates a magnetic field in which the ends of the reed have opposite polarities. When the magnetic field is strong enough, the attractive force of the opposite pole overcomes the stiffness of the reed and attracts them together. After the magnetic force is removed, the reed will spring back to its original open position. Due to the short distance between the reeds, these relays work very quickly.