BuyFindarrow_forward

Electric Motor Control

10th Edition
Herman
Publisher: CENGAGE L
ISBN: 9781133702818

Solutions

Chapter
Section
BuyFindarrow_forward

Electric Motor Control

10th Edition
Herman
Publisher: CENGAGE L
ISBN: 9781133702818
Chapter 46, Problem 1SQ
Textbook Problem
139 views

Why is this type of controller called a counter emf controller?

To determine

Explain the reason why direct current (DC) controller can be called as a counter emf controller.

Answer to Problem 1SQ

DC controller can be called as a counter emf controller because the counter emf of the armature is used for controlling the motor acceleration.

Explanation of Solution

In DC motor, the generated counter electromotive force is proportional to the speed of the motor for constant field. The counter emf can differ from the applied voltage only by armature drop.

DC controller can automatically adjust the starting time intervals, based upon the connected load. If heavy load is connected, it has more inertia to overcome; therefore, long time is required to generate the counter emf. When the DC motor starts, counter emf produced across the armature is very low. As the acceleration of motor increases, the counter emf increases. If the voltage value across the armature reaches a particular value, the starting resistance can be reduced at the correct time by actuating the relay. Therefore, the counter emf is mainly responsible to control the acceleration of motor.

Conclusion:

Thus, the DC controller can be called as a counter emf controller because the counter emf of the armature is used for controlling the motor acceleration.

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Additional Engineering Textbook Solutions

Find more solutions based on key concepts
Show solutions add
Obtain information about the Nuclear Regulatory Commission (NRC), which sets the standards for handling and oth...

Engineering Fundamentals: An Introduction to Engineering (MindTap Course List)

How many saw teeth should be engaged in the workpiece at any given time?

Precision Machining Technology (MindTap Course List)

What is a view?

A Guide to SQL

What is the primary purpose of a transfer case?

Automotive Technology: A Systems Approach (MindTap Course List)

List products for securing and tracking hardware and how each is used.

Enhanced Discovering Computers 2017 (Shelly Cashman Series) (MindTap Course List)

If your motherboard supports ECC DDR3 memory, can you substitute non-ECC DDR3 memory?

A+ Guide to Hardware (Standalone Book) (MindTap Course List)