The electromechanical type energy meter, what we use in our domestic and industrial installation is single phase induction type watt hour meter. Although nowadays, the Electric Supply Companies, are replacing the conventional electromechanical type meters … Read more
Induction type wattmeter or simply induction wattmeter belongs to the family of induction type measuring instrument. Since the induction phenomenon can only happen in the alternating current system, this instrument only measures AC power. For … Read more
Constructional Details of Dynamometer Type Wattmeter This type of wattmeter is one variety of dynamometer type instruments. Here we use two coils in the instrument. One coil is the current coil. In dynamometer type wattmeter, … Read more
Construction Working Principle Deflecting Torque Construction of Repulsion Type Moving Iron Instrument One variation of moving iron instrument is repulsion type instrument. Here we keep the shaft of the moving system along the axis of … Read more
Construction of Attraction Type Moving Iron Instrument There are two types of moving iron instrument. One is the attraction type moving iron instrument. Another is repulsion type moving iron instrument. We will discuss in this … Read more
The working principle of the electrostatic type measuring instrument is quite simple. It depends on the attraction between two oppositely electrically charged plates. You know that as per Coulomb’s law there is always an attraction … Read more
Before going through the actual working principle of shaded pole type induction instrument we will examine what happens when we place one aluminum disc in between the poles of an electromagnet. The current through the … Read more
This is a variety of induction type instrument. The working principle of a Ferrari’s type instrument is similar to the working principle an induction motor. The core of the electromagnet has four projected pole faces, as … Read more
We use induction type instrument for AC measurement only. This is because the induction phenomenon only occurs in AC. An induction instrument has multiuse. For example, we use the instruments as ammeters, voltmeters, wattmeters, and … Read more
The basic working principle of a dynamometer type instrument is somewhat similar to the permanent magnet moving coil instrument. The only difference is that here instead of using permanent magnet we use a current carrying … Read more