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the equipment concerned with controlling the operation of an electrical device
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a low-voltage electrical device used for starting, speed regulation, reversing, and electric braking of DC and AC motors. It varies the electrical resistance in a control circuit and the connections in the power and excitation circuits of motors. Controllers are usually operated by means of a manual lever or a handwheel; servomotors are used for remote control.

Controllers are built as multistage flat, drum, or cam-operated contact switches. Flat controllers are mainly used where a large number of switching steps are required, as in the starting and regulation of electric motors up to 30–40 kilowatts (kW) in power. Drum controllers are used more often than other types for the direct control of DC motors up to 45 kW and AC motors up to 75 kW in power. As the drum is turned, segmented copper contacts touch fixed contacts, establishing different connections in the motor’s control circuits. For the control of high-powered electric motors where a large number of switching operations occur (up to 600 per hour), greater reliability is obtained with cam-operated controllers having rolling contacts, which provide greater wear resistance than sliding contacts.


Babikov, M. A. Elektricheskie apparaty, part 2. Moscow-Leningrad, 1956.
Chunikhin, A. A. Elektricheskie apparaty. Moscow, 1967.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(control systems)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


An electric device (or combination of devices) designed to initiate one or more functions of operation, such as starting, stopping, reversing, and speed changing, of the apparatus to which it is connected; operation may be manual or automatic.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.


A person authorized to provide air traffic control services. The term also refers to radar controllers employed either on air traffic or air defense duties.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved


Part of a computer, typically a separate circuit board, which allows the computer to use certain kinds of peripheral devices. A disk controller is used to connect hard disks and floppy disks, a network controller is used for Ethernet. Other controllers are: keyboard controller, interrupt controller and graphics controller.
This article is provided by FOLDOC - Free Online Dictionary of Computing (


(1) A device used to play video games. See video game controller.

(2) An electronic circuit board or system. In a computer, controllers contain the circuitry to run a peripheral device and are either contained in the chipset on the motherboard or on a plug-in expansion card. See control program and PC chipset.

Not As Much These Days
Although gamers may have a high-end graphics card that plugs into the computer's PCI Express bus, most peripheral control is in the chipset on the motherboard. See PC chipset.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The added key layout only applies to the first generation Elite Controller. The recently announced Microsoft controllers do not cover the support.
But in the case of the appointment of the six chairmen and five controller examinations, there was inordinate delay, they said.
The consequences of a wrong categorisation is problematic and may lead to controllers acting together to joint and numerous liabilities.
The control law implemented in an automatic controller can be of the following two types: continuous and switch.
Cluster-based distributed controllers are different from centralized controllers in that multiple distributed controller modules need to be run in a coordinated way so that they do not compete with each other.
Though overall employment of air traffic controllers is projected to decline by 3 percent from 2010 to 2020, the number of new controllers is expected to rise due to retirements of current controllers.
Standard features: Twin injection hydraulic cylinders, MJ20D-C controller with LCD, storage for 150 mold set-ups, self-diagnostics.
Each vertical bar indicates the highest large-IO READ throughput that can be supported by current controllers, host computer systems, and disks.
The eP Digital Controller measures 9.3" W x 4" D x 8.4" H and can be mounted on either the column or base of a machine.
Here, the controller output is proportional to the error or change in the process variable.
He also pointed out that your reunion agenda includes "sleeping in" and that many of you will have had a pretty good time this week, not only at scheduled events, but also at some of those late night meetings in the Controller Board Room--the bar.

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