22–8 THE COUNTER-ELECTROMOTIVE FORCE MOTOR CONTROLLER The counter-emf controller, shown in Figure 22–22, is a commonly used method for the automatic acceleration of a DC motor. First, the line switch is closed. When the start button is pressed, relay coil M is energized. This control circuit remains energized because the sealing contacts are closed, as […]
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Direct current fundamentals
Starters and speed controllers : the counter-electromotive force motor controller and the voltage drop acceleration controller (lockout acceleration).
22–8 THE COUNTER-ELECTROMOTIVE FORCE MOTOR CONTROLLER The counter-emf controller, shown in Figure 22–22, is a commonly used method for the automatic acceleration of a DC motor. First, the line switch is closed. When the start button is pressed, relay coil M is energized. This control circuit remains energized because the sealing contacts are closed, as […]
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Dc motors: speed control of dc motors, reversal of rotation, power losses, permanent-magnet motors and summary of dc motors
21–8 SPEED CONTROL OF DC MOTORS Not all electric motors are suited to have their speed controlled with smooth acceleration or deceleration. DC motors do have this ability. Speed is easily controlled in shunt motors by placing a rheostat in series with the shunt field, thereby varying the current and, consequently, the flux, as shown […]
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Dc motors: speed control of dc motors, reversal of rotation, power losses, permanent-magnet motors and summary of dc motors
21–8 SPEED CONTROL OF DC MOTORS Not all electric motors are suited to have their speed controlled with smooth acceleration or deceleration. DC motors do have this ability. Speed is easily controlled in shunt motors by placing a rheostat in series with the shunt field, thereby varying the current and, consequently, the flux, as shown […]
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Starters and speed controllers : starters for series motors, drum controllers and magnetic controllers.
22–5 STARTERS FOR SERIES MOTORS Series motors require a special type of manual starting rheostat called a series motor starter. These starting rheostats serve the same purpose as the three- and four- terminal manual starting rheostats used with shunt and compound motors, which is to limit the surge of starting current and to accelerate the […]
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Starters and speed controllers : starters for series motors, drum controllers and magnetic controllers.
22–5 STARTERS FOR SERIES MOTORS Series motors require a special type of manual starting rheostat called a series motor starter. These starting rheostats serve the same purpose as the three- and four- terminal manual starting rheostats used with shunt and compound motors, which is to limit the surge of starting current and to accelerate the […]
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Starters and speed controllers : trends in motor control, the need for reduced-voltage starting, manual starters and manual speed controllers.
Starters and Speed Controllers 22–1 TRENDS IN MOTOR CONTROL Until recently, DC motors have been the only choice for applications where accurate control over wide speed ranges and load positioning were required. To satisfy these demands, industry developed a great variety of controllers. In the infancy of motor technology, manual control boxes were built. Later […]
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Starters and speed controllers : trends in motor control, the need for reduced-voltage starting, manual starters and manual speed controllers.
Starters and Speed Controllers 22–1 TRENDS IN MOTOR CONTROL Until recently, DC motors have been the only choice for applications where accurate control over wide speed ranges and load positioning were required. To satisfy these demands, industry developed a great variety of controllers. In the infancy of motor technology, manual control boxes were built. Later […]
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Dc motors: field distortion and the need for interpoles, the shunt motor, the series motor and the compound motor.
21–4 FIELD DISTORTION AND THE NEED FOR INTERPOLES In our study of generators we learned of a concept known as armature reaction (Section 19–4), which results in a distortion of the magnetic field. This distortion causes the neutral plane to shift forward (with respect to the direction of rotation). In electric motors, as in generators, […]
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Dc motors: field distortion and the need for interpoles, the shunt motor, the series motor and the compound motor.
21–4 FIELD DISTORTION AND THE NEED FOR INTERPOLES In our study of generators we learned of a concept known as armature reaction (Section 19–4), which results in a distortion of the magnetic field. This distortion causes the neutral plane to shift forward (with respect to the direction of rotation). In electric motors, as in generators, […]
Continue reading…