Dynamometer type wattmeter construction and working principle. Physical construction of dynamometer same as the fixed coil unless the facts that is will rotating during the flowing of the current that flow inside it. Construction and working principle of electrodynamometer type wattmeter. It is based on the principle that mechanical force exists between two current carrying conductors. A dynamometer type wattmeter responds to the answer nakul pande. 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. If you have a basic watt meter, the display gives the instantaneous power used at that time. Working forces are small as compared to moving iron type instruments. Feb 20, 2018 in this video you will learn about how a wattmeter workand its construction. So far as i know there are only single phase and three segment connection. Electrodynamometer type wattmeter electrical study app by. As shown in the above figure, the wattmeter has two sets of coils. As the deflecting torque is very small it is not a commercial wattmeter. Three wattmeter method power measurement in an ac circuit is measured with the help of a wattmeter.
The electrodynamometer wattmeter has two types of coils. Voltage for testing produced by hand operated megger by rotation of crank in case of hand operated type, a battery is used for electronic tester. Combine different pdf documents or other files types like images and merge them into one pdf. Apr 08, 2018 the shape of scale of this instrument depends on the variation of dmdo i. This is a online courseware website for sns college students through this website student can access their materials. The dynamometer wattmeter works on the motor principle. An electrodynamometer type watt meter has two coils. Wattmeters these instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Dynamometer type wattmeter working your electrical guide.
Dynamometer type wattmeter working principle 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. It simultaneously measures the voltage and current values and multiplies them to give power in watts. It is important to avoid excessive current flow in the voltage and current coils of a wattmeter. So, it works for all operating systems including mac, windows, and linux. The fixed coils or field coils arc connected in series with the load and so carry the current in the circuit. The three main types are electrodynamic, electronic and digital.
Therefore, a power measurement in a dc circuit can be generally carried out using a voltmeter v and an ammeter a according to one of the arrangements shown in figure 39. Induction meter includes types such as induction voltmeters, induction ammeters and induction watthour meters. The average of the instantaneous voltage multiplied by the current is the true power. Principle of operation of the electrodynamic wattmeter. Dynamometer wattmeter working principle,construction. Wattmeter is an electric instrument which is used to measure the electric power of various electric circuits. Electric power is measured by means of a wattmeter. They are quite costly as compared to other instruments. Hi friends, in this article, i am discussing the dynamometer type wattmeter working principle and related information, if you are interested in it then you at the right place these are basically moving coil instruments. A simplified electronic wattmeter circuit is shown in figure 3. Jan 22, 20 the same principle applies to the induction energy meter, except that the movement is not limited by the spring but turns an aluminum disk constantly and racks up a counter mechanism. Dynamometer type wattmeter construction and working. The wattimeter has a rotating conductive disk which is crossing two magnetic flux, one is produced by coil connected to ac supply voltage and the other by a coil connected to ac current, as they are ac some eddy or foucault currents are produced.
By properly designing the fixed current coil and moving coil pressure coil,dmdo can be made to vary linearly over a range of 40 50 on either side of the zero mutual inductance as shown in figure below. The working principle of the electrodynamometer wattmeter is very simple and easy. This device is available in a purely electronic form too which is known as digital wattmeter. Electronic wattmeter a modern digital electronic wattmeter energy meter samples the voltage and current thousands of times a second. Nov 29, 2014 the traditional form of wattmeter is called as dynamometer wattmeter. Now let us look at constructional details of electrodynamometer type wattmeter. The principle of operation of an induction wattmeter is same as that of induction ammeters and voltmeters i. 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. The basic principle was laid out in an 1848 paper by wilhelm weber 18041891. The fixed coil is also called the current coil cc since it carries the load current or a fraction of it.
How to combine files into a pdf adobe acrobat dc tutorials. 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. Here, the current flows through the current coil from the source to the load. A dynamometer type wattmeter is most commonly employed for measurement of power in a. Measurement of threephase power with the 2wattmeter. Dynamometer wattmeter electrical engineering assignment. The traditional form of wattmeter is called as dynamometer wattmeter. This is one of the advantages of this type ofmeter. Top answer the movement of the needle is the result of a vector product between the magnetic fields of two coils, one carries the. It may refresh several times per second or maybe once every 5 seconds. The current coil having low resistance is connected in series with the load so that it carries the load current. Nov 30, 2015 an electrodynamometer type watt meter has two coils. The wattmeter is an instrument for measuring the electric power in watts of any given circuit. It is recommended to read before going to understand the torque equation.
When using the twowattmeter method, it is important to note that the reading of one wattmeter should be reversed if the power factor of the system is less than 0. What is the difference between an energy meter and wattmeter. Wattmeter working principle construction types of wattmeter. If you are already aware of constructional feature then you may proceed. 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. This page describes the basic working principle and construction of electrodynamometer wattmeter.
It consists of a pair of fixed coils, known as current coils, and a movable coil known as the potential coil. However, there is one difficulty in this type of connection. Electronic wattmeter electronic wattmeters are used for direct, small power measurements or for power measurements at frequencies beyond the range of electrodynamometer type instruments. Jul, 2016 a dynamometer type wattmeter is most commonly employed for measurement of power in a. 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. What is the working principle of wattmeter and energy meter. Simultaneously, watt readings using a standard commercially available analogue wattmeter were also taken. The fixed coils are made up of a few turns of a comparatively large conductor. May 15, 2018 disadvantages of electrodynamic type power factor meters. All articles of this app are totally based on practical experiences as well as a strong base of theoretical knowledge and is written in very simple and.
The same principle applies to the induction energy meter, except that the movement is not limited by the spring but turns an aluminum disk constantly and racks up a counter mechanism. Electrodynamometer type wattmeter construction and working. Like in the one wattmeter methord, where the wattmeter is connected in one phase, in the three wattmeter method, it is connected in all 3phases. Design and hardware implementation of a digital wattmeter. A wattmeter does a complex job, measuring the power flowing through an electrical circuit. Power factor meters electrodynamometer type power factor. Electrodynamometer introduction it have nonuniform scale it is sensitive to overloads and any mechanical impacts. The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit. We generally provide spring control with pneumatic damping in a dynamometer type wattmeter.
Apr 24, 2018 torque equation in electrodynamometer instruments. This app covers entire aspects of the subject, from basic engineering to advanced and modern topics related to electrical engineering and technology. Dynamometer type wattmeter and its deflecting torque. A wattmeter is an instrument which consists of two coils called current coil and potential coil. An electrodynamometer is an instrument used for measuring the electric power.
Aa magnet is used to brake the spinning of the disk through foucault induced currents, otherwise, it would speed up out of control. Choose from a variety of file types multiple pdf files, microsoft word documents, microsoft excel spreadsheets, microsoft powerpoint. Their working depends on the theory that the current carrying conductor placed in a magnetic field experiences a mechanical force. Measurement of threephase power with the 2wattmeter method. It may refresh several times per second or maybe once every 5 seconds depending on how sophisticated the monitoring circuit is. 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. Calibration of electrodynamometer type instruments are highly affected by the changing the supply voltage frequency. The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils. 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. Electrodynamometer instruments or electrodynamic instruments have fixed coil divided into two sections and a moving coil. This mechanical force deflects the pointer which is mounted on the calibrated scale. Single phase induction meters are very popular for domestic and industrial use because of its wide application as energy meter. Electrodynamometer by muhammad nur zakwan zainal on prezi.
We have used several lamps having watt ratings of 40, 60 and 100watt as loads and measured real power dissipated at those loads using our designed digital wattmeter. But in these instruments, the operating field is produced by the fixed coil instead of a permanent magnet. In such a case, the leads of one wattmeter may have to be reversed in order to get a positive reading. Wattmeter types diy electrical electronics projects.
The wattmeter is used to tune the stations antenna and to determine if the antenna and transmitter are working properly by allowing the measurement of the systems forward and reflected power. Electronic wattmeter a modern digital electronic wattmeterenergy meter samples the voltage and current thousands of times a second. Electronic wattmeter electronic wattmeters are used for direct, small power measurements or for power measurements at frequencies beyond the range of electrodynamometertype instruments. A repulsive force exists on a plate placed in an electric field. Sometimes it is not possible to have access of the neutral point in the star connection.
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. Power factor meter working principle the basic working principle of power factor meter is similar to that of dynamometer type wattmeter i. Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter. The two coils are connected in different circuits for measurement of power. The current coil, which is connected in series, is made up of thick wires of few turns and is divided into two identical parts as shown in the figure. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power. Megger working principle types history uses of megger. However, it differs from induction ammeter or voltmeter in so far that separate two coils are used to produced the rotating flux in place of one coil with phase split arrangement. Dynamometer type wattmeter electrical technology youtube. For the love of physics walter lewin may 16, 2011 duration. Apr 19, 2018 for the love of physics walter lewin may 16, 2011 duration.
42 998 1280 616 234 222 300 737 486 507 76 301 1460 859 1308 120 371 312 1449 481 1591 1292 819 1536 1248 99 11 578 372 208 382 1125 913 751 1186 1168 63 715