Singapore GST will increase from 8% to 9%

(Effective from Jan 1, 2024)

Electgo: Your trusted Source for Electrical Components in Singapore

An Authorized Supplier Offering a Comprehensive Range of Electrical Component Categories

October 17, 2019

Relay | What is a relay, its function, types and relay wiring

What is a Relay

If you are from the electronics field, this word must be prevalent and if you are not, let us tell you all about it!

Relays are the switches that aim at closing and opening the circuits electronically as well as electromechanically. It controls the opening and closing of the circuit contacts of an electronic circuit. When the relay contact is open (NO), the relay isn’t energized with the open contact. However, if it is closed (NC), the relay isn’t energized given the closed contact. However, when energy (electricity or charge) is supplied, the states are prone to change.

Relays are normally used in the control panels, manufacturing, and building automation to control the power along with switching the smaller current values in a control circuit. However, the supply of amplifying effect can help control the large amperes and voltages because if low voltage is applied to the relay coil, a large voltage can be switched by the contacts.

If preventive relays are being used, it can detect overcurrent, overload, undercurrent, and reverse current to ensure the protection of electronic equipment. Last but not the least; it is used to heat the elements, switch on audible alarms, switch the starting coils, and pilot the lights.

Relay Types

In addition to the electromechanical and electromagnetic relay, there is a wide variety of relays with different working principles; principles of operation and polarity.

Electrothermal Relay Electromechanical Relay Solid State Relay Hybrid Relay
When two different material gets in contact, a bimetallic strip is formed, and when it is energized, it bends. This bending allows the users to make contact connections When different mechanical parts are connected on the basis of the electromagnet, a contact connection is established The relay uses semiconductor devices to make a connection to ensure the effectiveness, efficiency, and easiness of the switching speed. This is commonly used for two reasons; a faster-switching process and durability It is the name given to the solid-state and electromechanical relays

Relay Products

Relay Types As Per The Polarity

These relays are identical to electromechanical relays except for the presence of an electromagnet and a permanent magnet. With this relay, the armature movement is based on the input polarity applied to the coal and is commonly applicable in telegraphical purposes

There are no polarities in this relay, and it executes no change with the alteration of the input signal

We all are aware of the TV remotes on which we can press one button to make a function, relays work similarly to that. Relays are used to eliminate the direct link of users with electronic equipment to protect them from expected high voltages.  If the vast industries are focused, they are using the bigger capacity relays to optimize the motors and pumps' operation.

The common purpose of relays can be understood by analyzing the headlight turn-on. The headlight switching button can be found on the car dashboard, and if moved, they supply a small value of current to the coil which results in the contactor switching on. Then, the relay comes into action by controlling the high-power load (headlights). There are many other common examples of relays from our daily life.

Everyone has a fridge at their home and relays control the equipment responsible for working and production of cold temperatures. Traffic lights are another application of relays where they are used as the switching component. The movement and direction of automatic garage doors are also utilizing the relays for optimal switching contacts.

It is safe to state that relays are responsible for energizing the electronic equipment and working on their functioning to ensure optimal operation. These have eased our lives by bringing in automation factors along with the safe and smooth running of electronic equipment. This means that there are no threats involved regarding the high voltage as there will be no contact at the time of an electronic breakdown.

Relay Function

We have added the relay diagram in the section below to ensure a clear understanding of relay wiring and relay circuits along with their working.

The diagram sheds focus on the internal section of the relay in the circuit. There is an iron core delimited with the control coin. The power source connects with an electromagnet through load contacts and a control switch. When energy is supplied to the circuit through the control coil, magnetic fields intensify given the commencement of energizing. This way, upper contact arms get attracted by the lower fixed arm which closes the contacts leading to the short circuit. However, if the relay was de-energized, an open circuit is created with the opposite movement of the contact.

Once the coil current goes off, a movable armature is forced back to the initial position, and the force is equal to half of the magnetic force and electric strength. The main reasons behind this force include gravity and spring.

The relays perform two basic functions, such as high voltage application and low voltage application. In the case of high voltage, arcing is reduced while in the low voltage applications, overall circuit noise is reduced to a minimum.

Relay Wiring

These relay diagrams focus on the wiring configuration in a 2-pole relay circuit. One is the square, and the other one is round, but their functioning is similar to each other. The coil wire will connect to pin 2 and pin seven on the socket for the wiring.
In the diagram given below, L1 (hot) goes to the closed switch which signifies the current application until the switch is open. The L1 will be hot to the START switch, and when the switch is pressed, L1 leads to Master Control Ray and supplies the charge.
Relay Wiring
Now, release the START button, and the current will start flowing around the open START switch. To switch off the light, we press the STOP button, and it will de-energize the coil. Once the STOP button is let off, the START button will be depressed, and this is what the relay circuit is all about!

If you are in need of an Omron relay, you can get in touch with us at Electgo to buy Omron relays at relatively lower prices. If you sign in to our website, you will be provided with a discount. We are the best choice because we have an in-house team of engineers who are best at providing technical support to our clients. Once you buy the relay from us, we will also provide the relay datasheet for the provision of information.

Free ebook - Introduction Guide to Relays & Contactors