RELAYSBy

Chetan Goyal

Work carried out at

Submitted to

Department of Electronics and Communication Engineering

School of Engineering and Technology

Raffles University, Neemrana

CONTENT Company profile a). Introduction b).Work culture c).Company products d).Vision Introduction of Relays Basic design or operation Types of Relays Parts of Relays Applications Advantages of Relays History about Relays References

Company profile a).Introduction: Minda Furukawa Electric Pvt. Ltd. is a joint venture

between the Spark Minda, Ashok Minda and Furukawa of Japan. The joint venture is a 51:49 partnership .

The company develops and produces the entire range of wiring harness for four wheelers for its customers, and components related to wiring harness e.g. couplers, terminals, relay, junction box etc.

The plant is located at Bawal, Haryana and has all the state of the art machinery, testing and support facilities for making all types of wiring harness as per customer’s requirement.

b). Work cultureAlong with producing world class products, all

activities are geared towards innovation, reduction of costs and overheads to increase profitability. In order to achieve these lofty goals , Minda Furukawa believes that the human element is very important . Accordingly it places great emphasis on promoting the best practices in work culture and employee welfare .

Their motto is “We challenge Excellence with Team spirit”.

c). Company products

Door harness Engine harness

Steering Relay Terminal

d).VisionAimed at undertake technical innovation using modern

technology and skillsmanship. “Quality first”, devoted to customer and grow

holistically towards future. Focus on Quality CF, CS, & CD

Customer first

Customer safety

Customer delight Adopt new techniques.

Introduction to Relays Relays are switches that open and close circuits

electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. when a relay contact is normally open (NO), there is an open contact when the relay is not energized. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state.  Relays consist of an electromagnet and also a set of contacts. A relay is used when a circuit is to be controlled at a low power signal. Relays are often grouped together or with other components like fuses.

. Relays have two circuit: a control circuit and a load circuit.

Basic design or operation

A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron core, an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, and one or more sets of contacts. The armature is hinged to the yoke and mechanically linked to one or more sets of moving contacts. It is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay is closed, and the other set is open.

Types of Relays Basically, Relays are of two types either electromechanical or

solid state relays. Both accomplish the same result but the physical structure and functionality makes them different.

1. Electromechanical Relays(EMR) : In electromechanical relays contacts are open or closed by a magnetic force. Basic parts and functions of electromechanical relays include:

Frame Coil Armature Contacts 2. Solid State Relays(SSR): In solid state Relays there are no

contacts and switching is totally electronics. It consist of an input circuit a control circuit an output circuit

Parts of Relays

There are generally four parts in a relay. These are

1. Electromagnet: An electromagnet is a type of magnet which consist of wrapping of copper coil around a soft iron core in which magnetic field is produced due to flow of current through the coil.

2. Armature: A relays moving part. The armature opens and closes the contacts. An attached spring returns the armature to its original position.

Continue…..

3. Contacts: The conducting part of the switch that makes (closes) or breaks (opens) a circuit. ‘Closed state’ of contacts means electricity can flow between them, or ‘open state’ means contacts are separated and the switch is nonconducting.

4. Spring: Spring is attached to the armature of the relay which helps in returning the armature to its original position.

Applications Amplifying a digital signal, switching a large

amount of power with a small operating power.Detecting and isolating faults on transmission

and distribution lines by opening and closing circuit breakers.

Isolating the controlling circuit from the controlled circuit when the two are at different potentials.

In logic functions.Time delay functions.Used to control high voltage circuits with the

help of low voltage signals.

Advantages of RelaysUsed as a kind of safety switch to allow a

circuit with a small current through to switch on a circuit that will have a larger current flow through it.

Minimize the amount of damage to the system during a fault.

Small control signal controls a larger load current or voltage.

Decreased electrical noise when switching.Totally silent operation.Output resistance remains constant

regardless of amount of use.

History about Relays The relay was invented in 1835 by American

scientist Joseph Henry in order to improve his version of the electrical telegraph.

A simple device, which we now call a relay, was included in the original 1840 telegraph patent of Samuel Morse. The mechanism described acted as a digital amplifier, repeating the telegraph signal, and thus allowing signals to be propagated as far as desired. This overcame the problem of limited range of earlier telegraphy schemes.

Referenceshttp://www.galco.com/comp/prod/relay

.htmhttp://www.circuitstoday.com/working-

of-relaysExperience and view of Minda groupStudy of company profile

THANK YOU