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... 58. In order to achieve high accuracy, the slide wire of a potentiometer should be (a) as long as possible (b) as short as possible (c) neither too small not too large (d) very thick Ans: a 59. To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potent ...
... 58. In order to achieve high accuracy, the slide wire of a potentiometer should be (a) as long as possible (b) as short as possible (c) neither too small not too large (d) very thick Ans: a 59. To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potent ...
Wiring Manual | 2011
... the Moeller name that is being preserved. Our range of services also benefits from the alliance. The Moeller name will continue to exist as a product series designation. Recognizing the values transferred to Eaton, “Moeller ®Series” appears on former Moeller products, while the packaging features the ...
... the Moeller name that is being preserved. Our range of services also benefits from the alliance. The Moeller name will continue to exist as a product series designation. Recognizing the values transferred to Eaton, “Moeller ®Series” appears on former Moeller products, while the packaging features the ...
Reviewer 2 - Propeller`s Journal
... b. Brushes shifting out of place c. Rotating slip ring out of contact d. Excessive locked-rotor current Ans. A 20. Voltage failure of an AC generator may be caused by ___________. a. Failure of the exciter generator b. A tripped bus circuit breaker c. High mica segments on the stator bus bar d. Exce ...
... b. Brushes shifting out of place c. Rotating slip ring out of contact d. Excessive locked-rotor current Ans. A 20. Voltage failure of an AC generator may be caused by ___________. a. Failure of the exciter generator b. A tripped bus circuit breaker c. High mica segments on the stator bus bar d. Exce ...
- IEEE Mentor
... Attention is called to the possibility that implementation of this recommended practice may require use of subject matter covered by patent rights. By publication of this recommended practice, no position is taken with respect to the existence or validity of any patent rights in connection therewith ...
... Attention is called to the possibility that implementation of this recommended practice may require use of subject matter covered by patent rights. By publication of this recommended practice, no position is taken with respect to the existence or validity of any patent rights in connection therewith ...
Electrical Engineering Objective Type Questions
... 50. The voltage drop for which of the following types of brush can be expected to be least ? (a) Graphite brushes (b) Carbon brushes (c) Metal graphite brushes (d) None of the above Ans: c 51. The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the spee ...
... 50. The voltage drop for which of the following types of brush can be expected to be least ? (a) Graphite brushes (b) Carbon brushes (c) Metal graphite brushes (d) None of the above Ans: c 51. The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the spee ...
Warrior™ ST, Warrior™ AXP
... Do not clean this machine with a pressure washer. Do not operate this machine on ramps or inclines of more than a 2 percent gradient. Only use the brushes provided with the appliance or those specified in the instruction manual. The use of other brushes may impair safety. ...
... Do not clean this machine with a pressure washer. Do not operate this machine on ramps or inclines of more than a 2 percent gradient. Only use the brushes provided with the appliance or those specified in the instruction manual. The use of other brushes may impair safety. ...
Evaluation of Back-EMF Estimators for Sensorless Control of
... synchronous motors (PMSMs) have been widely used in various applications because of their advantageous features such as increased reliability and reduced cost. Various sensorless methods have been proposed. They can be classified into two groups: high frequency signal injection (HFSI) [1]-[4] and ba ...
... synchronous motors (PMSMs) have been widely used in various applications because of their advantageous features such as increased reliability and reduced cost. Various sensorless methods have been proposed. They can be classified into two groups: high frequency signal injection (HFSI) [1]-[4] and ba ...
GENERATOR PROTECTION
... A fault at or near the neutral shunts the high resistance that saves the stator from large currents with an internal ground fault A generator operating with an undetected ground fault near the neutral is a accident waiting to happen We can use 3rd Harmonic or Injection Techniques for complete ...
... A fault at or near the neutral shunts the high resistance that saves the stator from large currents with an internal ground fault A generator operating with an undetected ground fault near the neutral is a accident waiting to happen We can use 3rd Harmonic or Injection Techniques for complete ...
Commutator (electric)
A commutator is the moving part of a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine. The commutator is one component of a motor; there are also two or more stationary electrical contacts called ""brushes"" made of a soft conductor like carbon press against the commutator, making sliding contact with successive segments of the commutator as it rotates. The windings (coils of wire) on the armature are connected to the commutator segments. Commutators are used in direct current (DC) machines: dynamos (DC generators) and many DC motors as well as universal motors. In a motor the commutator applies electric current to the windings. By reversing the current direction in the rotating windings each half turn, a steady rotating force (torque) is produced. In a generator the commutator picks off the current generated in the windings, reversing the direction of the current with each half turn, serving as a mechanical rectifier to convert the alternating current from the windings to unidirectional direct current in the external load circuit. The first direct current commutator-type machine, the dynamo, was built by Hippolyte Pixii in 1832, based on a suggestion by André-Marie Ampère. Commutators are relatively inefficient, and also require periodic maintenance such as brush replacement. Therefore, commutated machines are declining in use, being replaced by alternating current (AC) machines, and in recent years by brushless DC motors which use semiconductor switches.