Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Question
Chapter 49, Problem 1SQ
To determine
Explain the reason for using magnetic brakes.
Expert Solution & Answer
Explanation of Solution
An electric brake also known as magnetic brake which consists of two friction surfaces or shoes that can be made to bear on a wheel on the motor shaft. Refer to Figure 49-1 in the textbook, the shoes are held by the spring tension on the wheel. Due to the friction between the wheel and shoes, the braking is achieved.
Magnetic brakes provide a smooth braking action and used for high inertia loads. Since these brakes apply and remove the braking pressure in either direction, it is recommended to use in cranes, hoists, elevators, and to increase the production of the industrial machinery. These magnetic brakes can limit the shock of braking.
Conclusion:
Thus, the reasons for using magnetic brakes are explained.
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Chapter 49 Solutions
Electric Motor Control
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- Explain regenerative braking in detail as applied to electric motivearrow_forwardConsider a loop of wire in a magnetic field below as well as the given commutators. The brushes of the commutators have a DC current passing through them and are connected to the wire loop. Solid Ring Commutator Half Ring Commutator Split Ring Commutator Part A The motor will work when the wire loop is connected to the [select all that apply] O split ring commutator O half ring commutator O solid ring commutator Submit Request Answer Part B For the commutators above, the most Torque would be produced by using the O solid ring commutator O half ring commutator O split ring commutatorarrow_forwardOne type of failure that's more common with 200 HP motors than with 10 HP motors is A. rotor bar failure.B. contactor failure.C. bearing failure. D. stator failures.arrow_forward
- QUESTION 1 When discussing motors with commutators and brushes, the neutral plane is: perpendicular to the magnetic field of the magnets, and alignment of the brushes should be along the neutral plane in order to minimize commutator sparking the conductor that allows current to return back to the source. the plane resulting in the maximum number of magnetic lines that will be cut when the motor is in rotation. parallel to the magnetic field of the magnets, and alignment of the brushes should be perpendicular to the neutral plane in order to minimize commutator sparkingarrow_forwardD1- Which DC motor's magnetic field gets stronger with an increase in mechanical load? a) series b) shunt c) compound d) "a" and "c", not "b" D2- The greater the mechanical load on a DC motor the faster it will turn. a) true b) false D3- Which of the following causes a DC shunt motor to automatically adjusts its input to take care of changes in mechanical load. a) the speed decreases with increases in load b) the cemf decreases with increases in load c) the supply current increases due to the decrease in cemf d) all of the abovearrow_forwardchoose the correct answerarrow_forward
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- I need answer within 30 minutes please with my best wishes MOarrow_forward(B)- Indicate whether the following statements are true or false and correct the false statements - In series d-c generator the field winding will be constructed from high number of turns and high cross-sectional area of wire. A de generator beyond critical resistance will generate maximum voltage In DC machines internal characteristics are plotted between E, vs load current 4- shunt generators are used in arc welding 5- Armature resistance control method is used for the below rated speed 4 +-arrow_forward1) answer the questions below. a) Does the slip increase as the load increases? What is the reason of this? b) What does it mean if the slippage is 0, 1, -1? Explain. c) Explain the effect of the capacitor on the operation of the asynchronous machine as a generator. d) Squirrel cage asynchronous motor, which has never been used before, will be operated as a generator at the first use. Does the machine work as a generator? Explain. e) How can we calculate the speed of the induction motor pro ed that the asynchronous motor driver keeps the slip value constant? Explain that you can adjust to different values.arrow_forward
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