Control Circuits TWO-WIRE CIRCUITS Control circuits are divided into two basic types: the two-wire and the three-wire. Figure 19–1 shows a simple two-wire control circuit. In this circuit, a simple switch is used to control the power applied to the coil of a motor starter. If the switch is open, there is no complete path […]
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Alternating current fundamentals
Control Circuits : Two-wire circuits , Three-wire circuits , Electrical symbols for pilot/control devices and Schematic and wiring diagrams.
Control Circuits TWO-WIRE CIRCUITS Control circuits are divided into two basic types: the two-wire and the three-wire. Figure 19–1 shows a simple two-wire control circuit. In this circuit, a simple switch is used to control the power applied to the coil of a motor starter. If the switch is open, there is no complete path […]
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Control Circuits : Wound-rotor motor control.
WOUND-ROTOR MOTOR CONTROL An automatic time-operated speed control for a wound-rotor motor is shown in Figure 19–20. In this circuit, the stator of the motor is connected to the line when M load contacts close. Resistors are connected to the rotor of the motor during starting. When the motor is first started, all resistors are […]
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Control Circuits : Wound-rotor motor control.
WOUND-ROTOR MOTOR CONTROL An automatic time-operated speed control for a wound-rotor motor is shown in Figure 19–20. In this circuit, the stator of the motor is connected to the line when M load contacts close. Resistors are connected to the rotor of the motor during starting. When the motor is first started, all resistors are […]
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Control Circuits : Interlocking , Jogging and Timers .
INTERLOCKING Interlocking is used to prevent some function from happening until some other function or action has occurred. A good example of interlocking is shown in the circuit in Figure 19–12. This circuit is a forward–reverse control. The two normally closed contacts labeled F and R are used to interlock the system. In this circuit, […]
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Control Circuits : Interlocking , Jogging and Timers .
INTERLOCKING Interlocking is used to prevent some function from happening until some other function or action has occurred. A good example of interlocking is shown in the circuit in Figure 19–12. This circuit is a forward–reverse control. The two normally closed contacts labeled F and R are used to interlock the system. In this circuit, […]
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Single-Phase Motors : Stepping motors.
STEPPING MOTORS Stepping motors are devices that convert electrical impulses into mechanical movement. Stepping motors differ from other types of dc or ac motors in that their output shaft moves through a specific angular rotation each time the motor receives a pulse. Each time a pulse is received, the motor shaft moves by a precise […]
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Single-Phase Motors : Stepping motors.
STEPPING MOTORS Stepping motors are devices that convert electrical impulses into mechanical movement. Stepping motors differ from other types of dc or ac motors in that their output shaft moves through a specific angular rotation each time the motor receives a pulse. Each time a pulse is received, the motor shaft moves by a precise […]
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Single-Phase Motors : Conductive and inductive compensation , Shaded-pole induction motor and Variablespeed motors .
CONDUCTIVE AND INDUCTIVE COMPENSATION AC motors larger than 1⁄2 horsepower (hp) are used to drive loads when a high starting torque is required. For these motors, there is excessive armature reaction under load. One method of overcoming the armature reaction is known as conductive compensation. In this method, an additional compensating winding is placed in […]
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Single-Phase Motors : Conductive and inductive compensation , Shaded-pole induction motor and Variablespeed motors .
CONDUCTIVE AND INDUCTIVE COMPENSATION AC motors larger than 1⁄2 horsepower (hp) are used to drive loads when a high starting torque is required. For these motors, there is excessive armature reaction under load. One method of overcoming the armature reaction is known as conductive compensation. In this method, an additional compensating winding is placed in […]
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