1
The speed regulation of a DC motor is proportional to the
Resistance of the armature
Some DC servomotors have square wave input voltage. To vary the motor speed, the on and off time ratio of the square is varied, this is called
Pulse-width modulation
What limits the amount of current flow through the armature when power is first applied to the motor
Armature resistance
A force that tends to cause rotation is known as
Torque
The 3 basic types of starting relays are
Hot-wire relay
Current-relay
Solid state starting relay
Most converters that supply power to brushless DC moors produce a
Trapezoidal wave
Brushless DC motors that require very smooth operation such as grinders that produce a finished surface are powered by
Sin waves
When full voltage is applied to both the armature and the shunt field, the motor operates at
Base speed
What are the two main types of single phase multi speed motors?
Capacitor start- capacitor run
what are the three basic types of three phase motors?
Squirrel cage induction
Wound rotor induction
Synchronous
When full voltage is applied to the armature and reduced current flows through the shunt field, the motor operates at
Over speed
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
Permanent magnets have higher or lower efficiency than field wound motors
Higher
What are the 3 main types of repulsion type motors?
Repulsion motor
Repulsion start-induction run
Repulsion-induction motor
What speed do synchronous motors operate at
Synchronous speed
Because the rotor of a servodisc motor is made from copper laminated onto a fiberglass disk, the motor is also called a
Printed circuit motor
What type of motor can develop extremely high starting torque
Series
the motor that does not contain a wound armature, commutator, or brushes, is the
Brushless DC motor
The output voltage of the series generator is set when the load is
Connected
What type of motor can develop extremely high starting torque
Series
When reduced voltage is applied to the armature and full voltage is applied to the shunt field, the motor operates at
underspeed
A device that converts electrical input to mechanical output
Motor
The compound motor connection that is rarely used is the
The items that rides against the commutator to make electrical connection are
Brushes
Why are shaded pole induction motors popular?
Simplicity and long life