Dynamometer type wattmeter works on very simple principle and this principle we know that instantaneous torque in electrodynamic type. A transfer instrument is one which is calibrated with a d. It measures direct and alternating current with accuracies of from 0. Apr 26, 2019 electrodynamometer type wattmeter therefore in circuit were power is quite high, current transformer shall be used for the measurement of power. Dynamometer type wattmeter working your electrical guide. Examples of such instruments are voltmeter, ammeter and wattmeter etc. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power. The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils or sets of coils, one fixed and the other movable. The electrodynamometer wattmeter has two types of coils.
If you dont see any interesting for you, use our search form on bottom v. Electrodynamometer instruments are widely used as an ammeter, voltmeter and wattmeter. Also, on analog wattmeters, the potential coil carries a needle that moves over a scale to indicate. Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter dynamometer type wattmeter works on very simple principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due to this. In an electrodynamic instrument the operating field is produced by another fixed coil and not by permanent magnet. The traditional analog wattmeter is an electrodynamic instrument. Therefore this fixed coil is often called current coil cc.
The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit. This instrument can be used as an ammeter or as voltmeter but is generally used as a wattmeter. Sep 21, 2019 the electrodynamometer type instrument is a transfer instrument. Apr 24, 2018 electrodynamometer instruments are widely used as an ammeter, voltmeter and wattmeter. For example, in using an electrodynamic wattmeter on direct current. In this post we will be discussing the torque equation in. Dynamometer type wattmeter construction and working principle. Other articles where electrodynamic ammeter is discussed. The fixed coils or field coils arc connected in series with the load and so carry the current in the circuit. For example, in using an electrodynamic wattmeter on direct current, two readings are taken, the direction of current flow through the instrument being reversed. Electrodynamometer type wattmeter in general, a watt meter is used to measure the electric power of a circuit, or sometime it also measures the rate of energy transferred from one circuit to another circuit. Dec 30, 2018 measurement of three phase power using two wattmeter method by raman sir duration. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on youtube.
Electrodynamometer type instruments download as powerpoint presentation. Construction of dynamometer type wattmeter, dynamometer type wattmeter working. Earlier these fixed coils are designed to carry the current of about 100 amperes but now the modern wattmeter are designed to carry current of about 20 amperes in order to save power. Given the two wattmeter readings from the twowattmeter method used on a threephase balanced load, it is possible to find the tangent of the phase impedance angle as times the ratio of the difference between the two wattmeter readings and their sum, based on equation 4. In order to derive these expressions let us consider the circuit diagram given below. Measurement of three phase power using two wattmeter method by raman sir duration. It consists of a measuring transducer, which converts the quantity being measured into an alternating or direct current, and a measuring mechanism of an electrodynamic system. It consists of a pair of fixed coils, known as current coils, and a movable coil known as the potential coil. Measurement of threephase power with the 2wattmeter. An electrodynamic type instrument consists of two fixed coil, flux is used in electrodynamic or electrodynamometer type instrument.
This means that the torque in electrodynamometer instruments must have a finite value and unidirectional for ac and dc quantity unlike pmmc instruments. Dynamometer type wattmeter works on very simple principle and this principle can be stated as when any electric current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due this mechanical force deflection of conductor takes place. On this page you can read or download electrodynamic wattmeter in pdf format. For highpower measurements, a calorimeter directly measures heat produced by rf power. Dec 10, 2015 on this page you can read or download electrodynamic wattmeter in pdf format. The traditional form of wattmeter is called as dynamometer wattmeter. Electrodynamic instrument article about electrodynamic. Electrodynamic wattmeter article about electrodynamic. To provide magnetic shielding, normally electrodynamic type instrument is enclosed in a high permeability alloy. Electrodynamometer definition of electrodynamometer by. Electrodynamic wattmeter pdf the working principle of the electrodynamometer wattmeter is very simple disturbs the main magnetic field of the electrodynamic wattmeter. The dynamometer wattmeter works on the motor principle.
An electrodynamic type instrument consists of two fixed coil, a moving coil, control spring, damping device and magnetic shielding arrangement. Mar 12, 2020 dynamometer type wattmeter works on very simple principle and this principle can be stated as electridynamometer any electric current carrying conductor is placed inside a magnetic fieldit experiences a mechanical force and due this mechanical force deflection of conductor takes place. Given the two wattmeter readings from the two wattmeter method used on a threephase balanced load, it is possible to find the tangent of the phase impedance angle as times the ratio of the difference between the two wattmeter readings and their sum, based on equation 4. In the thermal ammeter, used primarily to measure alternating current with accuracies of from 0. The following figure shows the dynamometer wattmeter for measuring the power. Since the moving coil carries a current proportional to the voltage, it is called the pressure coil or voltage coil or simply called p. Electrodynamometer type wattmeter in general, a watt meter is used to measure the wattmster power of a circuit, or sometime it also measures the rate of energy transferred from one circuit to another circuit.
Nov 29, 2014 the traditional form of wattmeter is called as dynamometer wattmeter. An electrodynamometer wattmeter have two types of coils. Dynamometer type wattmeter works on very simple principle and this principle. If two coils are connected such that, current proportional to the load voltage, flows through one coil and current proportional to the load current, flows through another coil, the meter can be calibrated directly in watts. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamometer wattmeter. When the wattmeter is connected in the circuit to measure a. Electrodynamometer type wattmeter when a moving coil that is free to rotate is kept under the influence of a current carrying conductor, then automatically a mechanical force will be applied to the moving coil, and this force will make a little deflection of the moving coil. Moving coil is connected across the supply voltage. Click here to download the pdf of this topic electrodynamometer type wattmeter.
The two coils are connected in different circuits for measurement of power. Construction of electrodynamometer wattmeter fixed coils. A wattmeter is used to measure the voltage in an electronic circuit. Electrodynamic wattmeter the electrodynamic wattmeter is used to measure power taken from ac or dc power sources. Power factor meters electrodynamometer type power factor. Measurement of threephase power with the 2wattmeter method. We know that instantaneous torque in electrodynamic type. Wattmeters these instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters.
Electrodynamometer type wattmeter electrical study app by. The movement of the needle is the result of a vector product between the magnetic fields of two coils, one carries the voltage and one carries the load current, producing a torque. Construction and working principle of electrodynamometer type wattmeter. Dynamometer type wattmeter construction and working. As shown in the above figure, the wattmeter has two sets of coils. Electrodynamic or dynamometer instruments electrical. Understanding the effect of inductance of voltage coil moving coil on the wattmeter readings. Jun 08, 2019 before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter dynamometer type wattmeter works on very simple principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due to this mechanical force. Electrodynamic type instrument electrical concepts. Following are the advantages of electrodynamometer type wattmeters and they sattmeter written as follows. Electrodynamic type instruments are similar to the pmmctype elements except that the an electrodynamometer for use as a wattmeter is shown in fig. Dec 24, 2019 electrodynamic type wattmeter pdf the wattmeter is an instrument for measuring the electric power in watts of any given circuit.
Dynamometer type wattmeter works on very simple principle and this principle we know that. It uses for measuring the power of both the ac and dc circuits. May 15, 2018 before we introduce various types of power factor meters it is very essential to understand what are the needs of power factor meter. This instrument can measure ac as well as dc quantities. Standard electrodynamic wattmeter and acdc transfer instrument. The dynamometertype wattmeter automatically compensates for the power factor error of the circuit under test. This device is available in a purely electronic form too which is known as digital wattmeter. Dec 10, 2015 on this page you can read or download electrodynamic wattmeter advantages in pdf format. As the deflecting torque is very small it is not a commercial wattmeter. Electrodynamometer type wattmeter therefore in circuit were power is quite high, current transformer shall be used for the measurement of power.
Nov 03, 2019 for example, in using an electrodynamic wattmeter on direct current, two readings are taken, the direction of current flow through the instrument being reversed. Jan 22, 20 the movement of the needle is the result of a vector product between the magnetic fields of two coils, one carries the voltage and one carries the load current, producing a torque. The device consists of a pair of fixed coils, known as current coils, and a movable coil known as the potential coil the current coils are connected in series with the circuit, while the potential coil is connected in parallel. These instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Wattmeter types diy electrical electronics projects. May 07, 2020 for example, in using an electrodynamic wattmeter on direct current, two readings are taken, the direction of current flow through the instrument being reversed. Dynamometer type wattmeter electrical technology youtube.
Electrodynamometer type wattmeter construction and working. Why we do not directly calculate power factor in an ac circuit just by dividing the power with product of current and voltage because these readings can. Originally only a tool of professionals there are now many different types of the device available that are both cheap and easy to use and available for home use. Dynamometer type wattmeter works on very simple principle and this principle can be stated as electridynamometer any electric current carrying conductor is placed inside a magnetic fieldit experiences a mechanical force and due this mechanical force deflection of conductor takes place. Fixed coil is provided for the sake of production of magnetic field. Aug 22, 2018 electrodynamic type instruments are similar to the pmmctype elements except that the an electrodynamometer for use as a wattmeter is shown in fig. We know that instantaneous torque in electro dynamic type. Before we introduce various types of power factor meters it is very essential to understand what are the needs of power factor meter. Electrodynamometer definition is an ammeter or galvanometer in which the torque due to the reaction between two coils in series with each other is balanced by a spiral spring.
It indicates only the instantaneous power resulting. Electrodynamic or dynamometer instruments in an electrodynamic instrument the operating field is produced by another fixed coil and not by permanent magnet. Electromagnetic wattmeters are used for measurement of. Electric power is measured by means of a wattmeter. Compositecoil electrodynamic instruments nist page.
Electrodynamometer type wattmeter in general, a watt meter is used to. A repulsive force exists on a plate placed in an electric field. The electrodynamic ammeter uses a moving coil rotating in the field produced by a fixed coil. We know that instantaneous torque in electrodynamic type instruments is directly proportional to the product of instantaneous values of currents flowing through both the coils and the rate of change of flux linked with the circuit. Electrodynamic type wattmeter pdf the wattmeter is an instrument for measuring the electric power in watts of any given circuit. Electrodynamic type instrument electrical concepts working of induction type wattmeter.
The fixed coil is connected in series to the circuit whose power consumption is to be calculated. This principle is used in moving iron attraction type instrument. The electrodynamometer type instrument is a transfer instrument. These coils are called the current coils of electrodynamometer type wattmeter. The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils. An electrodynamic instrument connected as a wattmeter, with the main current flowing through the fixed coil, and a small current proportional to the voltage flowing through the movable coil.
Apr 24, 2018 an electrodynamometer wattmeter have two types of coils. Electrostatic type wattmeter is useful in measuring very small powers in dielectric circuits. Electrodynamometer wattmeter construction electrical concepts. Electrodynamic instrument a measuring instrument whose operation is based on the mechanical interaction between two conductors in which an electric current is present. On this page you can read or download electrodynamic wattmeter advantages in pdf format.
1431 87 1078 1117 1521 255 119 1321 167 1547 1088 119 1428 1004 200 720 1024 151 1090 376 1298 758 1549 1178 162 1131 1092 212 765 1289 137 544 934 1352 782 549 1440 12 1075 533 1432