Electromechanical meters, Electrical Engineering

Assignment Help:

Electromechanical Meters

Electromechanical energy meters are based on the Ferraris Principle (see note in the margin). The working of these meters is explained.

Working of Electromechanical Meters

The meters have a revolving metallic disc mounted on jewel bearings or magnetic suspension bearings. The display is cyclometer or mechanical counters and accuracy is classically 1% or 2% (class 1.0 or 2.0). They  cater  to  limited  tariffs  applicable  majorly  to  1-phase  or  3- phase direct connected segment (whole current meters).The electromechanical induction meter operates through counting the revolutions of the disc that rotates at a speed proportional to the power consumed. 

The number of revolutions is, therefore, proportional to the energy usage.  The metallic  disc is acted upon through three magnetic fields,  one  proportional  to the voltage,  the other  to the current  and  a third  constant  field  supplied  by  a  permanent   magnet.  One  of  the varying  fields  induces  currents  in  the  metallic  disc,  that  are  then acted upon through the other varying field to produce a torque.

This  results  in  the  torque  being  proportional  to  the  product  of  the current  and voltage,  that is power.  As the metallic disc rotates through the permanent magnetic field, eddy currents are again produced that dissipate energy (because the disc has some resistance) and act to slow the rotation. This drag is proportional to the rotation speed. The equilibrium among the applied torque and the drag results within a speed proportional to the power. The rotating disc in this category of meter is, actually,  an  electric  motor  of  a category  known as  a reluctance  motor  or  eddy current motor. It consumes a little amount of power, classically around 2 W.


Related Discussions:- Electromechanical meters

What is meant by blanking, a. Explain the following terms: (6) (i) Persi...

a. Explain the following terms: (6) (i) Persistence of vision (ii) Flicker in motion pictures b. What is meant by blanking? What is the need of blanking pulses? Compare th

Jfet amplifier, i want to know the all the three jfet in present and future...

i want to know the all the three jfet in present and future use and desing for each component

Show binary to octal conversion, Q. Show Binary to Octal Conversion? It...

Q. Show Binary to Octal Conversion? It is simple to convert from an integer binary number to octal. This is accomplished by: Break the binary number into 3-bit secti

What are the various flags used in 8085, The various flags are: - Sign flag...

The various flags are: - Sign flag,  Axillary flag, Zero flag, Parity flag, Carry flag.

Gis applications in management of power distribution systems, GIS Applicati...

GIS Applications in Management of Power Distribution Systems: a.)        Inventory of existing network. b.)        Easy access to network details. c.)        Easy access

Sbb instruction , SBB Instruction This  instruction is used to subtrac...

SBB Instruction This  instruction is used to subtract the contents of register  or memory  location  with carry  flag from accumulation. The results  of operations is stored

Decoder - introduction to microprocessors , Decoder A decoder is  logic...

Decoder A decoder is  logic  circuit  that energizes a particular  output line for each  combination of input  signal. Fig   shown  the block  diagram  logic diagram  and fu

Explain indexed addressing in 8051, Probelm: (a) Explain indexed addre...

Probelm: (a) Explain indexed addressing in 8051. (b) How does the 8051 distinguish between a byte address and a bit address? (c) How do open-loop and closed loop appli

Design a matching network of balanced stubs, A certain cellular telephone a...

A certain cellular telephone antenna has an input impedance at f=1.0 GHz modeled by a shunt R-C combination, with R=200Ω and C=2.0pF. Because of manufacturing restrictions, you can

Show the storage layout of digital system, Q. Show the Storage Layout of di...

Q. Show the Storage Layout of digital system? The IEEE floating point numbers have three basic components: the sign, the exponent, and the mantissa. A mantissa is composed of t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd