The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit. Since the moving coil carries a current proportional to the voltage, it is called the pressure coil or voltage coil or simply called p. The fixed coils or field coils are connected in series with the load and so carry. For more details about electrodynamometer type wattmeter click here. The fixed coils or field coils arc connected in series with the load and so carry the current in the circuit. We will discuss electrodynamometer type wattmeter working principle and its construction. Electrodynamometer type wattmeter in general, a watt meter is used to. This is a online courseware website for sns college students through this website student can access their materials. The torque on the moving coil was proportional to the product of current and voltage, and therefore to the instantaneous power. The fixed current coils are wound with a few turns of a relatively large conductor. At zero power factor, corresponding to a purely reactive load, both wattmeters will again have the same wattage indication but with the opposite signs, so that their algebraic sum will yield zero power absorbed, as it should. The traditional form of wattmeter is called as dynamometer wattmeter.
Thus circuit voltage is impressed across the pc and cc carries the circuit current. The current coils of the two wattmeters are connected in series on any two lines and the third line on which no wattmeter is connected. In electrodynamometer type wattmeter, moving coil works as pressure coil. A electro dynamometer wattmeter is used for the measurement for d. Electrodynamometer electrodynamics type instruments. The two wattmeter is used for the power measurement in the 3 phase system, irrespective of whether the load is balanced or unbalanced, star or delta connected. Electrodynamometer type wattmeter construction and working. 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.
The scale of the wattmeter illustrated in figure 2 is read directly only when the range switches are set to 1 a and 120 v. Now the pressure coil is split into two parts one is purely inductive another is purely resistive as shown in the diagram by resistor and inductor. An electrodynamometer wattmeter have two types of coils. Electrodynamic instrument a measuring instrument whose operation is based on. 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. Electrodynamometer type instruments download as powerpoint presentation. Electrodynamic wattmeter article about electrodynamic. Construction of electrodynamometer wattmeter fixed coils the fixed coils carry the current of the circuit.
Classification, absolute and secondary instruments, indicating instruments, control, balancing and damping, constructional details, characteristics, errors in measurement, ammeters, voltmeters. Pdf implementation of a digital wattmeter on fpga researchgate. Dynamometer type wattmeter construction and working. Electrodynamometer type, induction type, single phase and three phase wattmeter, compensation, energymeters. En8592 notes wastewater engineering regulation 2017. Week 03 electrodynamometer as wattmeter ece2 3t 201415. It is based on the principle that mechanical force exists between two current carrying conductors. The fixed coil is connected in series to the circuit whose power consumption is to be calculated. 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. It is important to avoid excessive current flow in the voltage and current coils of a wattmeter. Electrodynamometer wattmeter pdf and can moves freely. Electrodynamometer type instruments pdf the electrodynamometer type instrument is a transfer instrument. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamo meter wattmeter. 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.
Key item description 1 carry strap for carrying or hanging the instrument. Wattmeter are illustrated in figure 21, and the functions of these elements are described in table 21. A transfer instrument is one which is calibrated with a d. The transition from a negative to a positive value occurs. The dynamometer wattmeter works on the motor principle. To see other topics in basic electrical and electronics engineering click here. As shown in the above figure, the wattmeter has two sets of coils. Electrodynamic instrument article about electrodynamic. The general circuit diagram of single phase electrodynamometer power factor meter is given below. This device is available in a purely electronic form too which is known as digital wattmeter. Also, on analog wattmeters, the potential coil carries a needle that moves over a scale to indicate.
The traditional analog wattmeter is an electrodynamic instrument. Measurement of threephase power with the 2wattmeter. It includes instructions for troubleshooting, testing, and repairing of the me82u, and replacing maintenance parts. Wattmeter electric power is measured by means of a wattmeter. This explains electrodynamometer type wattmeter construction and working principle of electrodynamometer type. Power factor meters electrodynamometer type power factor. Electrodynamometer wattmeter pdf electrodynamometer wattmeter consists of two coils, pressure coil pc and current coil cc.
Hence moving coil is connected across the voltage and. Click here to download the pdf of this topic 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 these wattmeters, the field produced by the currentcarrying moving coil tries to come in line with the field produced by the currentcarrying fixed coil, and a deflecting torque is exerted on the moving system. Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter. As shown in figure 318, it consists of a pair of fixed coils, known as current coils, and a moving coil, called the voltage potential coil. Dynamometer type wattmeter working your electrical guide. The scale of the electrodynamometer wattmeter is therefore uniform. Electrodynamometer type wattmeter working principle. Before we study the internal construction of electrodynamometer wattmeter, it very essential to know the principle of working of electrodynamometer type wattmeter. They are used as wattmeters, voltmeters and with some modification as power factor meters and frequency meters. The two coils are connected in different circuits for measurement of power. For the love of physics walter lewin may 16, 2011 duration. Pressure coil is connected across the circuit whose power is to be measured and current coil is connected in series.
Electrodynamometer types of instruments are used as a. If the coils are connected so that a value of current proportional to the load voltage flows in one, and a value of current proportional to the load current. Wattmeter design chapter 8 dc metering circuits pdf version. Therefore this fixed coil is often called current coil cc. Single phase electrodynamometer type wattmeter the instrument used to measure active power p drawn by a load or circuit is called watt meter. A dynamometer type wattmeter is most commonly employed for measurement of power in a. Electrodynamometer wattmeters a media to get all datas. Pdf on oct 1, 2016, slami saadi and others published. Electrical and electronics measurements and instrumentation kelm. Electrodynamometer type instruments alternating current. Dynamometer wattmeter electrical engineering assignment.
Electrodynamometer type wattmeter 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. These instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Power in an electric circuit is the product multiplication of voltage and current, so any meter designed to measure power must account for both of these variables. Electrodynamometer wattmeter consists of two coils, pressure coil pc and current coil cc. Week 03 electrodynamometer as wattmeter ece2 3t 201415 free download as pdf file. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamometer wattmeter. Electrodynamometer type wattmeter electrical study app.
The supply voltage is equal to the voltage across the pressure coil. Electrodynamometer type instruments free download as powerpoint presentation. Wattmeter design dc metering circuits electronics textbook. Download the pdf of this topic electrodynamometer type wattmeter. Wastewater engineering notes en8592 pdf free download. This is one of the advantages of this type ofmeter. It uses for measuring the power of both the ac and dc circuits. The traditional wattmeter was an electrodynamometer instrument with a rotating potential coil of many turns and a fixed current coil of a small number of turns. The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils. Electrodynamometer wattmeters these instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Electrodynamic type instruments are similar to the pmmctype elements except that the an electrodynamometer for use as a wattmeter is shown in fig. Dynamometer type wattmeter engineering notes dynamometer type wattmeter.
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