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. an electrodynamometer for use as a wattmeter is shown in Fig. Wattmeter: Perhaps the most important use of the electrodynamometer is for the wattmeter. electrodynamometer (plural electrodynamometers). An instrument, having a fixed and a moveable coil, that measures the power flowing in an electric circuit;.

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Multi Channel Data Acquisition System. The EDM electrodynamomrter consumes some power for the maintenance of its magnetic fieldbut this is usually small compared to the load power.

Electrodynamometer Type Wattmeter

The traditional analog wattmeter is an electrodynamic instrument. To get accurate results, these errors must be minimized. The potential coil has, as a general rule, a high-value resistor connected in series with it to reduce the current that flows through it.

Hnec metal parts should be kept as minimum as possible. The instantaneous torque acts on the pointer of the wattmeter and is given by the equation.

The moving coil is mounted on an aluminium spindle. This is probably due to the fact that a glass cylinder surrounds the mechanism, and protects it from dirt and mechanical damage.


Electrodynamometer | Basic EDM as a Voltmeter –

This particularly affects low power e. Related pages Measurement of Three Phase Power. The necessary field required for the operation of the instrument is produced by the fixed coils.

Leave a Reply Cancel reply Your email address will not be published. By using this site, you agree to the Terms of Use and Privacy Policy. The frequency error can be reduced by having equal time constants for both fixed and moving coil circuits.

The two circuits of a wattmeter can be damaged by excessive current. With some little modifications, electrodhnamometer can be used as a wattmeter for the power measurements. A uniform field is obtained near the center of coil due to division of coil in two sections. Wikimedia Commons has media related to Wattmeters.

Wattmeter – Wikipedia

The damping torque is provided by air friction, by a pair of aluminium vanes electrodynamomteer are attached to the spindle at the bottom. It is air cored.

The addition of a series multiplier converts the basic EDM into a voltmeter [Fig. Electronic wattmeters are used for direct, small power measurements or for power measurements electrodynamoometer frequencies beyond the range of electrodynamometer-type instruments. The deflection of the pointer is directly proportional to the power flows through it.


December Learn how and when to remove this template message. Stray magnetic field error: Diode detectors are either directly connected to the source, or used with a sampling system that diverts only a portion of the RF power elecyrodynamometer the detector.

The EDM movement is extensively used to measure power, both dc and ac, for any waveform of voltage and current. If the pressure coil is purely resistive, then their current is in phase with the voltage. Simple electrodynamometsr may be calibrated to meet specified accuracy only for sinusoidal waveforms. Retrieved from ” https: Now let us derive the expressions for the controlling torque and deflecting torques. The coils are usually varnished.

Damping is provided by aluminium air vanes moving in a sector shaped chamber. This makes the system heavy reducing torque to weight ratio.

electrocynamometer An instrument which measures electrical energy in watt hours electricity meter or energy analyser is essentially a wattmeter which accumulates or averages readings. The construction of moving coil is made light as well as rigid.