AC tachogenerator DC tachogenerator The AC tachogenerator is use to measure speed only in one direction only. The DC tachogenerator is. A.C. Tachogenerator • 2. D.C. Tachogenerator; 6. CONSTRUCTION • An Armature is rotating type & this magnet is fixed type. • Armature is. The DC tachometer works on the principle that when the closed conductor moves in the The drag cup Tachogenerator generates the ripple free output voltage.

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Now as the field of the permanent field is fixed, the e.

Both of the latter two drawbacks are caused by the presence of the commutator in the d. The resistance is connected in series with the voltmeter for controlling the heavy current of the armature. Depends on the natures of the induced voltage the electrical tachometer is categorized tachogrnerator two types. The commutator collects current from armature conductors and converts internally induced a.

Quote of the day. Tachogenerators Chapter 9 – Electrical Instrumentation Signals.

The rotation induces the emf in the coil. Your email address will not be published. The DC tachometer works on the principle that when the closed conductor moves in the magnetic field, EMF induces in the conductor.

Leave a Reply Cancel reply Your email address will not be published. In measurement and control systems where directional indication is needed, tachogenerators provide an easy way to determine that. The relative motion induces the Gachogenerator in the coil which is placed between the constant magnetic field of the permanent magnet.


These variations are usually amply documented in the manufacturer data sheets and do not present a problem. Thus, the commutator and brushes are absent in AC tachometer generator.

The armature of the D.

Electrical Tachometer

Published under the terms and conditions of the Design Science License. Theoru the tachogenerator case the magnetic flux density B and the loop length l are constants, so the output voltage V o is proportional to the shaft angular velocity W, as required and a shown previously in eqn 1. The constant of proportionality K t is generally linear within a large dynamic range but does vary in relation to: The tachogenerator is a direct-type velocity transducer. The polarity of the induces voltage determines the direction of motion of the tavhogenerator.

The magnitude of the induces emf depends on the flux link with the conductor and the speed of the shaft. The electrical tachometer has more advantages over the mechanical tachometer. An electromechanical generator is a device capable of producing electrical power from mechanical energy, usually the turning of a shaft.

Tachogenerators are frequently used to measure the speeds of electric motors, engines, and the equipment they power: Permanent magnet, armature, commutator, brushes, variable resistor, and the moving coil voltmeter are the main parts of the DC tachometer generator.

This phenomena is therefore the same which gives rise to the back electromotive force b.

Tachogenerators | Electrical Instrumentation Signals | Electronics Textbook

The polarity of output voltage indicates the direction of rotation. The develops EMF is directly proportional to the speed of the shaft. The electrical tachometer converts tachogenetator angular velocity into an electrical voltage. The machine whose speed is to be measured is coupled with the shaft of the DC tachometer generator.


The equivalent circuit of a tachogenerator is also the dual of an electric motor and is shown in Figure Circuit Tschogenerator All about Electrical and Electronics. The commutator converts the alternating current of the armature coil to the direct current with the help of the brushes.

The rotor is made of the highly inductive material which has low inertia. The nonlinear relationship obtains between the output voltage and input speed when the rotor rotates at high speed. Advertise with Ads Link x Tachogenerators can also indicate the direction of rotation by the polarity of the output voltage.

D.C Tachogenerators – Instrumentation and Control Engineering

Figure 2 Tachogenerator equivalent circuit. By measuring the voltage produced by a tachogenerator, you can easily determine the rotational speed of whatever its mechanically attached to. The induces thdory is proportional to the speed of the rotation. It works on the principle of relative motion between the magnetic field and shaft of the coupled device.

The armature of the tachogenerator is coupled to the machine whose speed is to be measured. The magnitude of the induced emf is proportional to the shaft speed.