Electrodynamic Type Instrument – Construction and Working Principle

Electrodynamic type instrument is used for the measurement of AC and DC quantities unlike PMMC instrument which can only be used for the measurement of DC quantity. This type of instrument is known as Elctrodynamometer type instrument. Construction of Electrodynamic Type Instrument An electrodynamic type instrument consists of Two Fixed Coil, a Moving Coil, Control … Read more

Torque Equation in Electrodynamometer Instruments

Electrodynamometer Instruments are widely used as an ammeter, voltmeter and wattmeter. This instrument can measure AC as well as DC quantities. This means that the torque in electrodynamometer instruments must have a finite value and unidirectional for AC and DC quantity unlike PMMC instruments. In this post we will be discussing the torque equation in … Read more

Non-uniform Scale of Electrodynamometer Type Instrument

Unlike a PMMC instrument, the electrodynamometer type instrument has non-uniform scale. The non-uniform scale of this instrument can be explained by the equation of deflection. As we know that the deflection in electrodynamometer type ammeter and voltmeter is given as Ɵ = KI2dM/dƟ for ammeter and Ɵ = KV2dM/dƟ for voltmeter Therefore, if dM/dƟ is … Read more