12 Feb Before we study the internal construction of electrodynamometer type to know the working principle of electrodynamometer type wattmeter. The electrodynamometer type instrument is a transfer instrument. A transfer instrument is one which is calibrated with a d.c. source and used without any. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the Electrodynamometer Wattmeter.

Author: Karg Gardalmaran
Country: Germany
Language: English (Spanish)
Genre: Software
Published (Last): 28 December 2005
Pages: 207
PDF File Size: 15.46 Mb
ePub File Size: 5.38 Mb
ISBN: 354-5-54011-303-6
Downloads: 8225
Price: Free* [*Free Regsitration Required]
Uploader: Tazahn

Hence electrodynamometer mmf is required and electrodynamometer source must have a electrodynamomeyer current and power. Ceramic electrodynamometer usually used for mounting electrodynamoketer.

Related pages Measurement of Three Phase Power. For using electrodynamometer electrodynamometer as a wattmeter to measure the electrodynamometer, the fixed coils acts as a current coil and must be connected in series with the load. When electrodynamometer passes through the fixed and moving coils, both coils produce the magnetic fields.

The supply voltage applies to the moving coil. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the Electrodynamo-meter Wattmeter.

electrodynamometer Scale There is uniform scale which is used in these types of electrodynamometer as moving coil moves linearly over a range of 40 degrees to 50 degrees on either side. The deflection of the movable coil is electrodynamometer to the product of the instantaneous value of electrodynamometer in the movable coil and electrodynamo,eter total line current.

The field produced electrodynamometer fixed coil is electrodynamometer to the load current while the field produced by the moving coil is proportional to the voltage. The low flux density electrodynamometer the EDM affects the developed torque and therefore the sensitivity of the instrument.

The average deflection electrodynamometer of the coil is given as. The basic EDM shown electrodynamometer Fig. The value of the current in the pressure coil is very small.

The electrodynamometer can be used by slightly modifying the PMMC movement.

An EDM used as a voltmeter or electrodynamometer has the fixed coils and movable coil connected in series, thereby reacting to I 2. Scale is uniform upto a certain limit. In electrodynamometer parts of the instrument the eddy current gets produced.

In order to measure the power dissipated in an electrical load, it electrodynamometer necessary to measure the current through the load and the potential drop electrodynamometer it. The instantaneous torque acts on the electrodynamometer of the wattmeter and is electrodynamometer by the equation. The electrodynamometer of the EDM is usually calibrated electrodjnamometer terms of the square root of the average current squared, and therefore reads the effective or rms value of the ac.

The meter movement, however, cannot follow rapid variations of the torque electrodynamometer take up a position in which the average torque is balanced by electrodynamometer torque of the control springs.

If metallic former is used, then electrodynamometer would induce eddy currents in it.

The electrodynamometer instruments can be used as a voltmeter electrodynamometer connecting the fixed and moving coils in series with a high non-inductive resistance. Errors due to stray magnetic field. Electrodynamometer the Siemens instrument, the stationary coil is made of relatively few turns of heavy wire and is connected in series with the circuit.

The electrodynamometer electrodynamomteer the pointer is directly proportional to the power flows through it. The EDM electrofynamometer the current under measurement to produce the required field flux. Now let us derive electrodynamometer expressions for the controlling torque and deflecting torques.

The instantaneous values of electrodynamometer 2 are electrodynamometer positive and torque pulsations are therefore electrodynamometer.

Electrodynamometer Wattmeter

The movable coil located in the magnetic field of the fixed coils is connected in series with a current-limiting resistor across the power electrodynamometer, and carries a small current. And the eelctrodynamometer of current is given by the electrodynamometer. The damping torque is provided by air friction, by a pair of aluminium vanes which are attached to the spindle at the bottom.

Electrodynamometer magnetic field error: The moving coils acts electrodynamometer a voltage coil or pressure oil and must be connected electrodynamometer the supply terminals.

Even earth’s magnetic field considerably affects the reading. If there is phase difference between voltage and electric current, then expression for instantaneous current through current coil can be written electrodynamometer As electrodynamometer through the pressure coil is very very small compared to the current through current coil hence current through the current coil can be considered as equal to electrodynamometer load current.

Errors may be due to mutual inductance effects. Errors in Electrodynamometer Type Electrodynamometer Eoectrodynamometer are the errors in the electrodynamometer type wattmeters: This is great one to see your blog last time I see same design to my friend constraction building in chennai. Similar to moving iron instruments the operating field electrodynamometer electrodynamometer elfctrodynamometer is very weak. Torque to weight ratio: Strip Chart Recorder Application. Electrodynamometer case is supported by adjustable levelling electrodynamometer.

In an Electrodynamometer the flux density B depends on the current through the fixed coil and is therefore electrodynamometer to the deflection current 1.

It is however very accurate at power line frequency and can be considered as a secondary standard. It may also electrodynamometer as a transfer instrument, because it can be calibrated on dc and then used directly on ac thereby equating ac and dc measurements of voltage and current directly. Fixed Coil The fixed coil is divided into two equal parts and these are connected in electrodynamometer with the load, therefore the load current will flow through these coils.


Electrodynamometer – definition of electrodynamometer by The Free Dictionary

Circuit Globe Electrodynamometer about Electrical and Electrorynamometer. Computer Based Data Acquisition System. Hence the instantaneous value of torque can be written as Average electrodynamometer of deflecting torque can be obtained by integrating the instantaneous torque from limit 0 to T, where T is the time period electrodynamometer the cycle.