eddy current brakes

EDDY CURRENT BRAKES

PRESENTED BY:M.PRIYA VANDANA P.V.SAI PRIYA

CONTENTS: Introduction of Eddy Current. Introduction of Eddy Current

Brake.Working Principle. Types of Eddy Current Brakes. Advantages and Disadvantages. Applications. Conclusion.

WHAT IS A BRAKE?

EDDY CURRENT:

An Eddy Current is a Swirling current set up in a Conductor in response to a Change in Magnetic Field.

EDDY CURRENT : CONDUCTOR FLUCTUATING MAGNETIC FIELD

VOLTAGE

CURRENT

EDDY CURRENT

EDDY CURRENT BRAKES: It is a device used to slow a moving

object by creating eddy currents.

Braking action is made by Varying the Strength of the Magnetic Field.

A Braking Force is possible when an electric current is passed through the Electromagnets.

EDDY CURRENT BRAKES:

WORKING PRINCIPLE:

Eddy Current brake is based on Two basic Principles of Electromagnetics,which are

Faraday’s Law

Lenz Law

FARADAY’S LAW: It states that change in magnetic flux

induces an EMF in the circuit.

LENZ LAW:“ An induced EMF always gives rise to

a current whose magnetic field opposes the original change in magnetic flux”

WORKING: Electromagnets produce Primary

magnetic field from supplied current which in turn produces eddy current.

Eddy Current produces secondary magnetic field which opposes the primary field.

Opposing magnetic field reduces the Velocity

WORKING:

Circular Eddy current Brakes.

Linear Eddy Current Brakes.

TYPES OF EDDY CURRENTS

CIRCULAR EDDY CURRENT BRAKES: Brake assembly is Circular in Shape.

Consists of disc(magnetic material) placed between the poles.

Conductor coils are wound on the poles and when the disc rotates through the magnetic field creates Eddy Currents.

CIRCULAR EDDY CURRENT BRAKES:

LINEAR EDDY CURRENT BRAKES: The Linear Eddy Current Brake

Consists of a magnetic yoke with Electric coils placed along the rail.

This magnet is kept at a distance of 7m from the rail.

When the magnet is along the rail it generates the eddy

currents.

LINEAR EDDY CURRENT BRAKES:

LINEAR EDDY CURRENT BRAKES:

ADVANTAGES: No wear or Tear. No Noise or Smell. Adjustable Brake Force. Uses Electromagnetic force instead of

Friction. Low maintenance. Light weight.

DISADVANTAGES:

Breaking Force diminishes as Speed diminishes.

Very Tough Design and Simulation. No ability to hold load in Standstill

position. Acts like a Governor to reduce the

Speed. We cannot Use it for Low speed

Vehicles.

APPLICATIONS: In high speed trains. In roller coaster for braking and smooth

functioning. It is also used in vehicles but still not widely

used.

CONCLUSION:We can make Use of Opposing tendency of eddy current to control the speed of High Speed Vehicles without any Wear and Tear.