Induction Disc Type Relay (Shaded Pole Structure)

Hi I am Md Irfan Ahmed. Welcome to our YouTube Channel Basic electrical. About this video:- It consists of an aluminium disc which is free to rotate in an air gap of an electromagnet.The part of pole face of each pole is shaded with the help of copper band or ring.This is called shading ring.The total flux φ produced due to the alternating current split into two fluxes displaced in time and space due to the shading ring.            Due to the alternating flux, e.m.f gets induced in the shading ring.This e.m.f drives the currents causing the flux to exist in shaded portion.This flux lags behind the flux in the unshaded portion by angle ∝.  Let                             φs = Flux in shaded portion                                   φu = Flux in unshaded portion                                   Es = E.M.F. induced in the disc due to φs                                   Eu = E.M.F. induced in the disc due to φu                                   Is = Induced current due to Es                                   Iu = Induced current due to Eu                Eu lags behind φu by 90° while Es lags behind φs by 90°.The current Is lags Es by small angle β while Iu lags Eu by small angle β.This angle is generally neglected and Is and Iu are assumed to be in phase with Es and Eu respectively, in practice.The phasor diagram is shown in the figure below.             As proved in the previous section, neglecting It we get,                                     T ∝ φs φu sin ∝                     (where   T = Torque ) Telegram channel Basic Electrical https://t.me/basic_Electrical Instagram Channel Basic Electrical https://instagram.com/basicelectrical?igshid=12c91l0e47pfo If anyone wants to donate me some amount for my work, then details given below. Phonepe- 8294759336 Google Pay- 8294759336 @BasicElectricals