Electrical ramsey

A DC motor is reversed by

• Reversing the armature leads or field windings

• Reversing the armature and field windings

• Connecting the field in series the armature

• Connecting the fields in parallel with the armature

The choice of motor running over current protection is based off the motors full load current obtained by the

• NEC table

• Armature readings

• Wire ampacity table

• Motor name plate

In a casual inspection of a DC motor, you notice new grooves cut in its commutator just down to the mica. The first thing you do ( aside from the normal safety procedures) is

• Immediately take the motor out of service and replace it

• Hand stone the commutator

• Log the problem and have the commutator replaced as scheduled maintenance

• Inspect the brushes for dirt, defects, and wear, then clean and replace as necessary

You observe a DC motor with a ticking sound that corresponds with a discolored commutator bar rotating under the brushes. You log the error and suggest that there is

• An open commutator bar connection

• A bearing ready to fail

• Poor coupling alignment

• Brush rigging not on electrical neutral

When greasing a motor, the worse thing over greasing does is

• Cause a fire hazard

• Unbalance the motor armature

• Break down winding insulation

• Causing the bearing to run hotter then normal

The type of electronic component that isolates the stages inside a microprocessor from those outside the microprocessor is the

• Buffer

• Bus

• Ram

• Rom

To represent a varying DC voltage from. O to 8 volts on LED display one of the main components would be

• AD/A converter

• An A/D converter

• A serial to parallel converter

• A series in parallel out register

If the transistor in the diagram at left were shorted emitter to collector what would be the current through RL be?

• .05 mA

• 5mA

• 50mA

• 0 Amps

When adjusting the gain on a armature current loop amplifier at left, the response to a step input command should be adjusted until it is similar to

• Wave a

• Wave b

• Wave c

• Input

I’m the circuit at left with v in = -1 because, what would be the output of the diode shorted?

• 0v

• .7v

• 10v

• 50v