Switching Relays – A know how

A relay will be defined as a switch and is an electrically operated switch. Switches are typically used to close or open the circuit manually. Relays are used wherever it’s necessary to manage a circuit by a separate low-power signal. Many relays use an electromagnet to operate a switch. The advantage of switching relays is that it takes a bit of power to control the relay coil, but the relay itself accustoms motors, heaters, lamps or AC circuits that themselves will draw plenty additional power.

Types of Switching Relays:

Although many alternative forms of relays are present, their operating is same. The most common forms of relays utilized in ATE applications are:

electrical contacts

Electromechanical relays

They are made of a coil, an armature mechanism and electrical contacts. Electromechanical relays have a mechanically movable contact, an electromagnet, switching points and spring switching.

Reed relays

Reed relays have physical contact that is automatically motivated to open or close a path.

Solid state relays

SSRs are created employing a photo-sensitive MOSFET device with an LED to actuate the device.

FET switche

They use a series of CMOS transistors in Implementation of the switch.

Choosing the correct Switching Relay:

They are available in variety of factors, styles, and technologies. Depending on your application, just one relay type is also appropriate. By understanding the strengths and weaknesses of the various relays we must be able to choose the one that’s best suited to the task at hand.

Electromechanical relays support a wide range of signal characteristics, from low voltage/current to high voltage/current and from DC to GHz frequencies. The reed relays mechanical period is additionally much higher than an electromechanical relays. Solid state relays don’t seem to be as strong as electromechanical relays. FET switches are most frequently employed in electronic device configurations for higher speed, low voltage applications.


Electromechanical relays offer an honest resolution, though they need limitations in package size, switch speed, and mechanical lifespan. Reed relays improve on package size, density, and speed however is less strong in things wherever surge currents may be present. SSRs are a nice alternative to mechanical relays have higher path resistances and don’t seem to isolate between the contacts. FET switches offer a quick, low-priced answer but have the limitation of solely operating with low voltages. For any application, contemplating all of the system parameters before selection of a given relay.