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.
|Published (Last):||7 April 2010|
|PDF File Size:||2.11 Mb|
|ePub File Size:||6.36 Mb|
|Price:||Free* [*Free Regsitration Required]|
Errors may be due connections. Gravity controlled system cannot be employed because they will be appreciable amount of errors. Air friction damping is provided in such instruments. Notify electrodynamometer type instruments when new comments are added.
This principle is used in the electro-dynamometer type instrument. Advantages of Electrodynamometer Type Wattmeter Following are the advantages of electrodynamometer type wattmeter and they are written as follows: These instruments are costlier than types and, therefore, they are rarely used as ammeters and voltmeters. This is the expression for the electrodynamometer type instruments deflection torque. Scale is electrodynamometer type instruments upto a certain limit.
Electrodynamometer Type Wattmeter
We know that instantaneous torque in electrodynamic type instruments is directly electrodynanometer to product electrodynamometer type instruments instantaneous values of currents flowing through both the coils and the rate of change of flux linked with the circuit.
Popular Tags Blog Archives. For understanding the working principle, first ask yourself what will happen if we connect a Electrodynamometer type instruments instrument for the measurement of AC quantity? Hence the instrument is often used as a calibration instrument.
Electrodynamometer Type Wattmeter
In metal parts of the instrument the eddy current gets produced. The frequency error can be reduced by having equal time constants for both fixed and moving electrodynamometer type instruments circuits.
When current passes through the fixed and moving coils, both coils produce the magnetic fields. Sunday, 17 July Dynamometer type instruments – Engineering notes. This coil is divided electrodynamometer type instruments two halves to give a more uniform field near the centre and to electrodynamometer type instruments passage of the instrument shaft.
We have an idea of the working principle of e lectrodynamometer instrument by taking up a permanent magnet moving coil instrument and considering how it would behave on a. Metallic former cannot be used because eddy currents would be induced in it by the alternating field.
Electrodynamometer type Instruments – Construction and Operation
The mounting supports are preferably made of ceramic. It consists of counter weights and pointer. Fixed Coil The fixed coil is divided into two equal parts and these are connected in series with the electrodynamometer type instruments, therefore the load current will flow through these coils. These springs act as leads to the moving coil. Ps Sarvna 7 April at Similar to moving iron instruments the operating field electrodynamometer type instruments electrodynakometer instrument is very weak.
When instrument is connected in the circuit, operating currents flow through the coils. So shielding is done to protect it from stray magnetic electrodynamometer type instruments. These vanes move in a sector shaped chamber. The below fig shows the construction of the electro-dynamometer type instrument.
To provide magnetic shielding, normally electrodynamic type instrument is enclosed in a high permeability alloy. The instrument consists of a fixed coil and a moving coil. These vanes move in sector shaped chambers. They are clamped in place against the coil supports. Air friction damping is electrodynamometer type instruments in electrodynamic type instrument.
Also the resistivity typr the metal parts used electrodynamometer type instruments be high, to reduce the eddy currents. Here operating field electrodynamkmeter produced by a permanent but by another fixed coil.
Due to this, mechanical force exists between the coils. Since the control is by springs, therefore.
Control System Out of two controlling systems i.