Dynamometer this instrument is suitable for the measurement of direct and alternating current, voltage and power. Jan 09, 2020 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 fieldit experiences a mechanical force and due to this mechanical force deflection of conductor takes place. Electrostatic type wattmeter is useful in measuring very small powers in dielectric circuits. A wattmeter, measures electric power of the given an electric apparatus or circuit. 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.
The signals which vary in discrete steps and have only finite number of values in any given range are digital signals and the associated devices are digital instruments. We are manufacturing a supreme range of dynamometer portable type watt meter. Wattmeters these instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Electro dynamometer type wattmeter polytechnic hub. Extension of range of wattmeter using instrument transformers. Electro dynamometer type wattmeter to living the current flowing through moving coil a high resistance is connected in series with the moving coil and its circuit is made pure resistive. For example, in using an electrodynamic wattmeter on direct current, two readings are taken, the direction of current flow through the instrument being reversed.
In an electrodynamic instrument the operating field is produced by another fixed coil and not by permanent magnet. Electrical measurements lab manual pdf em lab manual pdf. The most important use of the dynamometer principle is in the wattmeter. Since the moving coil carries a current proportional to the voltage, it is called the pressure coil or voltage coil or simply called p. A dynamometer type wattmeter with its voltage coil connected across the load side of the instrument reads 250 w. Dynamometer type moving coil instruments in this instrument the permanent magnet is replaced by one or two fixed coils which carry current to be measured or a current proportional to the voltage to be measured and which are connected either in series or parallel with the moving coil. The current coil of the wattmeter is connected to one phase, and the pressure coil is connected to the other phase of the line. The construction of a dynamometer instrument to some extent resembles the pmmc instrument. The eddy current dynamometer is a type of chassis dynamometer.
Although electrical service to residential buildings in the usa are exclusively by single phase circuits, electrical. It uses for measuring the power of both the ac and dc circuits. Constructional details of dynamometer 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. 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 fieldit experiences a mechanical force and due this mechanical force deflection of conductor takes place. Working forces are small as compared to moving iron type instruments. Dynamometer type wattmeter engineering notes dynamometer type wattmeter. Sep 30, 2019 dynamometer and moving iron type 1ph and 3ph meters frequency meters. The torque of the instrument is dependent upon the magnetic field strengths of.
A simplest form of an absorption type dynamometer is a prony brake dynamometer. Construction of dynamometer type wattmeter, dynamometer type wattmeter working principle. It consists of two wooden blocks around a pulley fixed to the shaft of an engine, whose power is required to be measured. A wattmeter is generally used for checking on the power supply of. Meters, double element and three element dynamometer wattmeter, errors and compensations, measurement of unknown resistance, method of measuring low, measurement of inductance, ballistic.
Calibration of electrodynamometer type instruments are highly affected by the changing the supply voltage frequency. Calculating and measuring power in three phase circuits. Electrodynamometer type instruments download as powerpoint presentation. Dynamometer type threephase wattmeter a dynamometer type threephase wattmeter consists of two separate wattmeter movements mounted together in one case with the two moving coils mounted on the same spindle. 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. So the expression for the torque can be written as.
Induction type wattmeter, watthour meter, and dynamometer type power factor. It is based on the principle that mechanical force exists between two current carrying conductors. A dynamometer consists of an absorption or absorberdriver unit, and usually includes a means for measuring torque and rotational speed. The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit. The dynamometer type wattmeter is one kind of dynamometer type instrument. Dynamometer type wattmeter construction and working. Wattmeter working principle construction types of wattmeter dynamometer type wattmeter induction wattmeter working principle uses of wattmeter. The product of current and voltage directly gives power, in the case of the dc measurement by dynamometer type wattmeter. That is, the instrument measures the twisting motionand the subsequent powergenerated by the wheels of an automobile.
Construction and working principle of electrodynamometer type wattmeter. 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. A dynamometer type dynamometer type instrument, electro dynamometer type instrument. This coil is known as voltage coil or pressure coil and its terminals are marked as common and voltage. The fixed coil is splitted into two equal parts, which are placed parallel to each other. This type of wattmeter is free from errors due to waveform, frequency, eddy current and low power factors. Electrodynamic or dynamometer instruments in an electrodynamic instrument the operating field is produced by another fixed coil and not by permanent magnet.
Example 1022 a dynamometer type wattmeter with its voltage. 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. Dynamometer type wattmeter electrical technology youtube. 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. Introduction the generation and transmission of electricity is commonly accomplished by means of three phase circuits. The fixed coils or field coils arc connected in series with the load and so carry the current in the circuit. We know that instantaneous torque in electrodynamic type instruments is directly. The two fixed coils are aircored to avoid hysteresis effects when used on ac. A dynamometer type threephase wattmeter consists of two separate wattmeter movements mounted together in one case with the two moving coils mounted on the same spindle.
Study of ammeter, voltmeter and wattmeter connections. A dynamometer type wattmeter primarily consists of two coils called fixed coil and moving coil. In electrodynamometer type wattmeter, moving coil works as pressure coil. This device is available in a purely electronic form too which is known as digital wattmeter. This instrument can be used as an ammeter or as voltmeter but is generally used as a wattmeter. Power is measured by means of an electrodynamometer instrument that has similarities to a pmmc instrument. Feb 20, 2018 in this video you will learn about how a wattmeter workand its construction. 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. There are two current coils and two pressure coils.
Mr sk patidar sir genique education is an educational organization that is committed to providing the best learning experience of. The rotor is coupled to the engine or other equipment under test and is free to rotate at whatever speed is required for the test. Dynamometer type threephase wattmeter a media to get all. Electrodynamic type instruments are similar to the pmmctype elements except that the an electrodynamometer for use as a wattmeter is shown in fig. The dynamometer wattmeter works on the motor principle. May 15, 2018 disadvantages of electrodynamic type power factor meters. Dynamometer type wattmeter and its deflecting torque. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power. Dynamometer type wattmeter working your electrical guide. Power factor meter working principle the basic working principle of power factor meter is similar to that of dynamometer type wattmeter i. So we can say that the deflecting torque is directly proportional to the power delivered to the load. The electrical measurements notes pdf em notes pdf book starts with the topics covering control and damping torques, design considerations type of p. Dynamometer instruments tend to be more expensive than other types of ammeters and voltmeters. Construction of electrodynamometer wattmeter fixed coils.
The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils. A dynamometer type wattmeter responds to the a average value of the active power. Calculating and measuring power in three phase circuits 1. The blocks are clamped by means of two bolts and nuts. Electrostatic type wattmeter for small amount of a. The dynamometer instrument can also be employed as a voltmeter or ammeter. Nov 30, 2014 this principle is used in this type of wattmeter. Reactive power measurement in balanced threephase circuit the single wattmeter method is used for measuring the power of the balanced threephase circuit. The principle of operation of an induction wattmeter is same as that of induction ammeters and voltmeters i. Dynamometer type wattmeter works on very simple principle and this principle we know that instantaneous torque in electrodynamic type. We make your testing easy engine dynamometers an engine dynamometer is a device used to test an engine that has been removed from a vehicle, ship, generator, or various other pieces of equipment.
If two coils are connected such hence an electrodynamic instrument, when connected as shown in. A dynamometer or dyno for short, is a device for simultaneously measuring the torque and rotational speed rpm of an engine, motor or other rotating prime mover so that its instantaneous power may be calculated, and usually displayed by the dynamometer itself as kw or bhp. Wattmeter types diy electrical electronics projects. The traditional form of wattmeter is called as dynamometer wattmeter. Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter.
We connect the current coil in series with the circuit. This is one of the advantages of this type ofmeter. Sep 30, 2019 the electrical measurements notes pdf em notes pdf book starts with the topics covering control and damping torques, design considerations type of p. Dynamometer wattmeter electrical engineering assignment. An absorption unit consists of some type of rotor in a housing. Dynamometer type wattmeter construction and working principle. May 07, 2019 so the expression for the torque can be written as. A dynamometer type wattmeter is most commonly employed for measurement of power in a. The motor used for this purpose is called a wattmeter, and the instrument that can be applied as a wattmeter is known as a dynamometer, or sometimes as an electrodynamic instrument. Jun 08, 2019 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 deflection of conductor takes place. Dynamometer type wattmeter working principle electrodynamometer. Nov 29, 2014 the traditional form of wattmeter is called as dynamometer wattmeter. The dynamometer type wattmeter can also measure alternating power. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamo meter wattmeter.
A wattmeter is used to measure the voltage in an electronic circuit. If the load voltage be 200 v, what power is being taken by load. However, it is much more convenient to have an instrument that indicates power directly. 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. Pdf electrical measurements pdf notes em notes 2019 sw. This is a online courseware website for sns college students through this website student can access their materials. Jul, 2016 a dynamometer type wattmeter is most commonly employed for measurement of power in a.
These are provided to assist the user in formulating acceptance criteria, determining applications, and for periodic recalibration of the instrument. The two coils are connected in different circuits for measurement of power. Wattmeter working principle construction types of wattmeter. This page describes the basic working principle and construction of electrodynamometer wattmeter.
As the input value changes, the moving system or pointer exhibits a smooth continuous motion. Electrical measurements pdf notes em pdf notes smartzworld. Power factor meters electrodynamometer type power factor. Electrodynamic or dynamometer instruments electrical. Dynamometer type wattmeter working principle electrical a2z. They are quite costly as compared to other instruments. To understand the basic construction of a dynamometer instrument. The working principle elevtrodynamometer the electrodynamometer wattmeter is very simple and easy. The following figure shows the dynamometer wattmeter for measuring the power.
Induction type wattmeter engineering notes induction type wattmeter. Dec 24, 2019 dynamometer type wattmeter works electrodynmaic very elecfrodynamic principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic fieldit experiences a mechanical force and due to this mechanical force deflection of conductor takes place. Single phase dynamometer wattmeter, lpf and upf, double element and three element dynamometer wattmeter. As shown in the above figure, the wattmeter has two sets of coils. Electrodynamometer type wattmeter construction and working. How we can determine short circuiting current any plant and for example a plant which power generation is 415 volts and plant load is 500 kw. Dynamometer type wattmeter works electrodynmaic very elecfrodynamic principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic fieldit experiences a mechanical force and due to this mechanical force deflection of conductor takes place. As the deflecting torque is very small it is not a commercial wattmeter. Jul, 2016 the principle of operation of an induction wattmeter is same as that of induction ammeters and voltmeters i. Disadvantages of electrodynamic type power factor meters. We use the highestgrade basic components and maintain rigorous norms of quality to manufacture these in our stateoftheart facilities. Mcq on measuring instruments 4 how engineering works. This type of dynamometer consists of an iron core or disc which rotates inside a magnetic field.
1500 794 340 904 124 1195 79 1499 164 239 62 270 880 372 613 327 957 399 576 1309 493 335 1327 529 705 146 417 1351 864 873 583 719 887 706 315 1110 333