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

Cmos processes, CMOS processes: The low-performance "lateral" bipolar ...

CMOS processes: The low-performance "lateral" bipolar transistors occasionally employed in CMOS processes are sometimes designed symmetrically, i.e., with no distinction betwe

Interrupt signals - pins and signals , Interrupt Signals There are five...

Interrupt Signals There are five  interrupt  signals in 8085 microprocessor.  These  signals  are used to inter rut the  current  program  under  execution and  transfer the ex

Electrical machine -i, What are the causes of sparking in the commutator? E...

What are the causes of sparking in the commutator? Explain the methods to reduce the sparking in the commutator?

Explain how conduction takes place in insulators, With the help of energy b...

With the help of energy bands explain how conduction takes place in insulators. Insulators: Substance as wood, glass, that do not permit the passage of current through them

Call instructions, Call Instructions Call instruction are used to call ...

Call Instructions Call instruction are used to call a  subroutine program in assembly language  procedure and functions are called  subroutines. There are two types  of calls i

What do you mean by circuit analysis techniques, What do you mean by Circui...

What do you mean by Circuit Analysis Techniques?   One simplifying technique often used in complex circuit problems is that of breaking the circuit into pieces of manageable

Define the second group of 32 ascii character codes, Define the second grou...

Define the second group of 32 ASCII character codes? The second group of 32 ASCII character codes include various punctuation symbols, special characters, and the numeric digit

Describe the basic types of number systems, Q. Describe the basic types of ...

Q. Describe the basic types of Number Systems? Probably the largest stumbling block most beginning programmers encounter when attempting to learn assembly language is the commo

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