## Working Principle of Universal Motor

A universal motor is modified form of a DC motor and is widely used in home appliances like mixers and in machine tools. In this article I am discussing about working principle of universal motor.   If AC single phase supply is connected to a DC series motor, the motor gives circular rotation. During …

## Capacitor Start Capacitor Run Motor

A capacitor motor is also a split-phase induction motor. The starting winding has a capacitor in series with it. This is improved form of split phase motor. This type of motor was developed at the later stage. These motors have higher starting as well as running torque. This is the main advantage of capacitor motors …

## Split Phase Motor Working

Hi friends, in this article, I am explaining about “How does a split phase motor work?”.   It is provided with an auxiliary stator winding called starting winding in addition to main or running winding. These windings are placed in the stator slots. Both the windings are put in parallel. The purpose is to get …

## Vibrating Reed Mechanical Resonance Type Frequency Meter

The vibrating reed type frequency meters or mechanical resonance type frequency meter indicate the supply frequency of the circuit directly and are very much convenient for most practical purposes.   The vibrating reed frequency meter is a very simple instrument and has got an advantage of giving reading free from errors due to change in …

## Power Factor Meter

Thepower factor of a circuit can be found out from the wattmeter reading and voltmeter and ammeter readings suitably connected in the circuit.   Power factor = Wattmeter reading / (Voltmeter reading x ammeter reading).   Power factor = True Power / Apparent Power   This method involves mathematical calculations. Sometimes it is required to …

## Earth Tester Working Principle

Hi friends,   In this article, I am going to describe the earth tester working principle and method of earth resistance measurement by it. I hope you will find it informative and helpful.   The Resistance of the earth can be measured with the help of megger earth tester or earth megger. Earth Tester Working …

## Working Principle of Megger

The Megger insulation tester is an instrument used for measuring high resistances of the order of mega-ohms and for testing the insulation resistance. The instrument generates its EMF when the cranking handle is turned. It has two terminals marked ‘Line’ and ‘Earth’. The crank is turned at a moderate speed till a constant deflection of …

## Multimeter Working Principle

A multimeter is the most commonly used instrument by technicians and engineers in the laboratory, as well as other repair works. As it is clear from the name of this instrument, it can make many (multi) measurements with reasonable accuracies such as AC and DC voltages, currents, and resistances. In this article, I am discussing …

## Dynamometer Type Wattmeter Working

Hi friends, in this article, I am discussing the dynamometer type wattmeter working principle and related information, if you are interested in it then you at the right place. These are basically moving coil instruments. But in these instruments, the operating field is produced by the fixed coil instead of a permanent magnet. The instruments …

## Range Extension of Ammeters | Voltmeters

There is no fundamental difference in the operating principles of ammeters and voltmeters. Both are current operated devices (except electrostatic type voltmeters) i.e. deflecting torque is produced when current flows through their operating coils.   In an ammeter, the deflecting torque is produced by the current to be measured or by a definite fraction of …