17 Jul Construction of Dynamometer type instruments: A dynamometer type Dynamometer type instrument, Electro Dynamometer type instrument. Electrodynamic type instruments are similar to the PMMC-type elements except that the .. an electrodynamometer for use as a wattmeter is shown in Fig. Electrodynamometer Type Instruments – Download as Powerpoint Presentation . ppt /.pptx), PDF File .pdf), Text File .txt) or view presentation slides online.

Author: Shasida Yozshurisar
Country: Liberia
Language: English (Spanish)
Genre: Travel
Published (Last): 3 July 2007
Pages: 287
PDF File Size: 17.51 Mb
ePub File Size: 4.52 Mb
ISBN: 221-2-77323-550-8
Downloads: 45390
Price: Free* [*Free Regsitration Required]
Uploader: Tugor

The below fig shows the construction of the electro-dynamometer type instrument. The fixed coils re usually air cored to avoid hysteresis, eddy currents and other errors when the instrument is used on A.

Electrical and Electronics Tutorials: Explanation of Dynamometer Type Instrument

Let the currents passing through fixed and moving coils be I 1 and I 2 respectively. It is wound either electrodynamometfr self electrodynamometer type instruments coil or else on a non-metallic former so as to prevent eddy currents. Majorly used Aluminium scaffolding equipment used for glass room design.

It is electrodynsmometer wound on a non magnetic metallic electrodynamometer type instruments. Light but rigid construction is used for the moving coil. Now the reason is very obvious of using two fixed coils instead of electrodynamometer type instruments, so that it can be constructed to carry considerable amount of electric current. For understanding the working principle, first ask yourself what will happen if we connect a PMMC instrument for the measurement of AC quantity?

Electrodynamometer type Instruments – Construction and Operation

It is air cored. Electrodynamometer type instruments coils are usually varnished and baked to form a solid assembly. Let I 1 and I 2 be the instantaneous values of currents in pressure and current coils respectively.

Connects Facebook Youtube Videos.

Electrodynamometer type Instruments – Construction and Operation

A suitable shunt is connected to these coils to limit current through them upto desired limit. Since the control is by springs, therefore. The magnetic filed in electrodynamic type instrument is very week of the order of 0. The necessary field required for the operation of the instrument is produced by the fixed coils. Errors caused electrodynamometer type instruments vibration of moving system. This type of instrument can be used either as an ammeter or as a voltmeter, but is generally used as a wattmeter.

This is great one to see your blog last time I see same design to my friend constraction building in electrodynamometer type instruments.

The controlling torque is provided by springs. If metal parts would have been used then it would weaken the field of the fixed coil. If there is phase difference between electrodynamometer type instruments and electric current, then expression for instantaneous current through current coil can be written as As current through the pressure coil electrodynamometer type instruments very very small compared to the current through current coil hence current through the current coil can be considered as equal to total load current.

In order to derive these expressions let us consider the circuit diagram given below: They are also used as a transfer instruments. Thus temperature compensating resistors can be used in the precise instrument to eliminate the temperature electrodynamometer type instruments.

To get accurate results, these errors must be minimized. Therefore can must electrodynamometer type instruments taken while handling them. The cases are son constructed as to remain stable over long periods of time. The moving coil is mounted on an aluminium spindle. Instead of a permanent magnet, the electrodynamometer type instrument uses the current under measurement to produce the necessary field flux. The eddy current interacts with the instrument current, to cause change in the deflecting torque, to cause error.

This requires the transfer type instrument to have same accuracy for both a. Due to this, mechanical force exists between the coils. The field produced by these instruments is very weak.

But there is something called inertia, you better know. It is also air cored.