Generators
Motors
Principles
Misc
Math
100
The component of a DC generator that converts the armature AC into DC is the
Commutator
100
Series field windings are connected in series with the armature. They are wound with turns of fairly wire.
Many, Large
100
Two factors that determine Torque
1.) Strength of the magnetic field of the pole pieces
2.) Strength of the magnetic field of the armature
100
Most converters that supply power to DC motors produce a what wave
Trapezoidal
100
A square wave voltage varies between 0v and 12v. The positive pulses are 50 us wide and there is a 50 us gap between them. What is the DC average of the waveform?
6 volts
200
The position at which the windings are parallel to the lines of flux and there is no induced voltage is the
Nuetral Plane
200
The servomotor which has a fiberglass and copper rotor is the
ServoDisc Motor
200
What was the first motor to be invented? DC or AC motors?
DC
200
What limits the amount of current flow through the armature when power is first applied to the motor?
Armature Resistance
200
A square wave voltage varies between 0v and 12v. The positive pulses are 25 us wide and there is a 75 us gap between them. What is the DC average of the waveform?
3 Volts
300
Out of the whole 360 degree rotation, at which point of the rotation is the voltage at its maximum?
At 90 Degree's
300
In shunt motors, the full load speed normally stays within how many percents of the no load speed?
10%
300
DC Generators operate on the principle of
Magnetic Induction
300
In a compound generator, the setting of the amount of currents in the series and shunt field winding's determines the
Compounding
300
What is the efficiency of a motor that has an output power of 415.15 watts and an input power of 1800 watts?
23.064 %
400
What is a DC generator that uses a permanent magnet as it's field is referred to as
Magneto
400
Between Series, Shunt, and Compound Motors, which of these has the most drastic speed curves?
Series
400
What operates on the principle of repulsion and attraction of magnetism?
DC motors
400
When a DC machine is used as a motor, what function does the commutator perform?
Keeps the correct direction of current flow through the armature
400
What is the efficiency of a motor that has an output power of 359.572w and an input power of 156w?
76%
500
The resistance of the equalizer should not exceed what?
20% of the resistance of the series field winding of the smallest paralleled generator.
500
Because the rotor of a ServoDisc motor is made from copper laminated onto a fiberglass disk, the motor is also called a
Printed Circuit
500
What are Brushes used for in DC Generators?
Brushes are used to carry the current from the loop to the outside circuit.
500
Brushless DC motors that require very smooth operation such as grinders that produce a finished surface are powered by what waves
Sine
500
What is the efficiency of a motor that has an input power of 3360 watts and an output power of 2118.64 watts?
63.055%