single phase
The run winding is made of relatively _ wire. It is placed in the _ of the stator core
Large, bottom
Permanent magnet motors have – efficiency, then wound field motors.
Higher
The commutative compound motor connection means that the fields of the series and shunt field windings
Add
A device that converts electrical input into mechanical output is called
Motor
A compound motor has _ field windings
Series and shunt
The start and run warnings are connected in _
Parallel
What type of motor must never be operated under a no load condition
Series
When the field winding of a DC motor is connected in parallel with the armature, the motor is called a _ motor
Shunt
The compound motor connection is rarely used is the
Differential
What type of motor can develop extremely high starting torque?
Shunt
A _ is used to disconnect the start windings from the circuit
Centrifugal switch
Some DC server motors have square wave input voltage. To vary the motor speed, the on and off time ratio of the square wave is varied. This is called – modulation.
Pulse – width
The speed regulation of a DC motor is proportional to the
Armature resistance
Brushless DC motors that require very smooth operation, such as grinders that produce a finished surface are powered by _ waves
Sign
Most converters that supply power to brushless DC motors, produce a _ wave
Trapezoidal
The direction of rotation, for the motor is determined by the _ of the rotating magnetic field, created by the run and start windings
Direction of rotation
What is the name of the protective device that is connected in series with the shunt field and found on most large compound DC motors
Field loss relay
When full voltage is applied to the armature and reduced current flow through the shunt field, the motor operates at.
Over speed
Small, permanent, magnet motors that have lightweight rotors are often used as
Servo motors
Repulsion motors are commonly wound for _ , _, or _ poles
4,6,8
A _ is a device that exhibits a change of resistance with a change of temperature
Thermistor
The speed regulation of a DC motor is proportional to the
Strength of the magnetic pole pieces
Because the rotor of a servo disc motor is made from copper laminated onto a fiberglass disk, the motor is also called a _ motor
Printed circuit
Torque is a force that tends to cause
Rotation
When the AC begins to decrease from its peak value back towards zero, the magnetic field of the pole piece begins to _
Collapse