A Relay changes the point of an electric circuit from one point to another once the electric current passes through it. Relays, particularly the switching relays, offer primary protection to most of the electronic equipment.
Following are the 5 unique types of relays that you should be aware of:
- Electromagnetic Relays
There are mechanical, magnetic and electrical components in these types. They are also composed of mechanical contacts and an operating coil. When the supply system activates this mechanical coil, the mechanical contacts are either opened or closed. The types that fall under Electromagnetic relays are DC vs. AC relays, induction type relays, magnetic latching relays and attraction type electromagnetic relays.
All the above-mentioned sub-types of electromagnetic relays are used according to the power usage, type of operation or process, land size of the factory and other factors. There are types available for a small-scale industry to a large scale industry.
- Thermal Relay
This type of relay works on the heating effects – that is when the temperature rises from a particular limit. This directs the contacts to switch positions. They consist of temperature sensors and other control elements. The best examples are the thermal overload relays in this type.
- Solid State Relays
The solid state components are used to perform the operation of switching by not moving any of its parts. These are also known as switching relays. The power gain is comparatively higher requirement of control energy by the output power is lower. Reed relay coupled SSR, photo-coupled SSR, transformer coupled SSR and others are some of the examples that fall in this category.
- Reed Relay
This type of relay has two magnetic strips sealed in a glass tube. These relays are classified into subminiature, micro miniature and miniature relays on the basis of dimensions. Open type relays, hermetic and sealed relays are types based on its construction or appearance. High power types, intermediate, low and micro are different types based on its load operating range.
- Hybrid Relay
The composition of this relay is based on electronic components and electromagnetic relays. Rectification and other control functions are performed by the input part that contains the electronic circuit. Electromagnetic relay is included in the output part.
All these different types of relays are present in almost majority of the electrical and electronic circuits. This article deals with many types of relays that you think fits best your mode of operation.