Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Q. In the magnetic circuit shown in Figure the center leg has the same cross-sectional area as each of the outer legs. The coil has 400 turns. The permeability of iron may
A voltage signal generated by a sensor conditioning circuit varies from -0.5V to +0.5V . The signal from the sensor is to be connected to the analog to digital converter which onl
What is ammeter An ammeter is an instrument used to calculate current and must be connected in series with the circuit.
Consider and obtain the values for R S , R 2 , R 1 , and R D . Apply the rule-of-thumb dc design procedure outlined in this section for a JFET with V P = 3V, I DSS = 20 mA, and a
Q. How does current flow through the channel of a JFET after pinch off? It is seen that above the pinch off voltage at a constant value of VDS (saturation drain current, ID inc
In second technique, a concentrator expander (CE) is used near cluster of users and another one at exchange end as demonstrated in figure. Only a few junction lines are run between
Hall Effect experiment: Prob. Write short note on Hall Effect and its applications. What properties of a semiconductor are determined from a Hall Effect experiment? Sol.
Faraday's Law Faraday's laws of electromagnetic induction state: i) An induced e.m.f is setup when the magnetic field linking that circuit changes ii) The magnitude of
dfsdf
Write a short note on dispersion shifted and dispersion flatted fibers? The dispersion features of a fiber is display below: The overall dispersion is the sum of materi
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd