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159 Cards in this Set
- Front
- Back
Relay Motor controllers perform what key function? |
High Circuit Isolation |
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The following circuit is nothing more than a ____________ |
Emitter follower circuit |
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The current to the motor is amplified by the _____________ |
Driver |
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A loaded DC motor produces __________ |
Less CEMF |
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How is acceleration or deceleration symbolized? |
a |
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When plotting velocity and distance traveled, what would the graph look like for a fixed velocity over time? |
Straight line increasing over time |
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What is not a popular motion sensor used in industry? |
Photo Induction |
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In measuring RPM on a spinning shaft, the distance between the sensing edge is ___________
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Unimportant |
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A closed loop motor system regulates motor speed by ______________ |
Comparing feedback information with a base speed |
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What is the force that turns the shaft of a Prime Mover called? |
Torque |
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In a PID controller the D stands for ________ |
Derivate |
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The output of the proportional control signal is the input to the ________ |
Summing amplifier |
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A PID controller is operating properly when the output of he PID circuitry has a/an _______ and reaches the set point value. |
Constant DC level, PWM and controller output
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The PID controller input is the error signal from the __________ |
Window Decoder |
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The __________ control reaches the set point value but degrades rise time |
PI |
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With a PID control system, if the process variable changes due to the loading or unloading condition, the motor will __________ |
Be regulated back to the set point value |
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A closed loop motor system regulates motor speed by ____________ |
Comparing feedback information with a base speed |
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What type of digital position sensor uses four sensors? |
Code |
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Which is usually undesirable and is also controlled in a DC motor? |
Large currents |
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The series and parallel starters change ______, _________, ________________. |
Resistance, current to the motor, and voltage applied to the motor |
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What are the major components of a feedback system? |
Driver, PWM, Motor, and Voltage Source |
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The current to a motor is amplified by the __________ |
Driver |
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The relationship between voltage and speed of the motor is that as voltage increases, speed ___________ |
Increases |
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As the load is increased on a motor, current __________ |
Increases |
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An electronic feedback system utilizes a ___________ in place of a human operator. |
Comparator |
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What types of feedback are used in closed loop motor systems to regulate speed? |
Source current, CEMF and External RPM sensors |
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What factors would affect a motor's speed, if a closed loop feedback system were not implimented? |
Physical loading temp, source voltage |
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What is the weight that one horsepower can lift one foot in one second? |
550 |
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The __________ is the actual operating parameter or actual measured value. |
Process variable |
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Stabilization is reached as the ________ reduces the overshoot of the signal. |
Derivative control mode |
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What is the condition which indicates that the values of a circuit have settled and tend to remain constant? |
Steady-state |
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Which control system provides a fast rise time, minimal overshoot, and quick response to outside influences? |
PID |
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In a PID controller, the D stands for _________
|
Derivative |
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With a PID controller, integral action takes place anytime there is a deviation between the _____________ and process variable. |
Set point |
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What does the "P" in PID stand for? |
Proportional |
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What does the "I" in PID stand for? |
Integer |
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If the input to the controlling circuitry is bad and the motor is producing an output, what is the valid problem? |
Sensing Circuitry Malfunction |
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What can a technician do to troubleshoot a signal path with a signal that is too low for an oscilliscope to read? |
Inject a signal with a function or signal generator. |
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How many complete stator cycles does it take to produce one complete revolution of a stepper rotor that has a step of 9 degrees? |
10 |
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What causes a torque up - torque down action? |
One phase energized sequence |
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What disadvantage does a stepper motor have with two stator coils energized at once? |
Twice the current is drawn from the power supply |
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What is the primary difference between a 1¢ and 2¢ full step generator? |
Input data signal "ON" duration |
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How are BLDC motors characteristically different from their conventional permanent magnet DC motor counterparts? |
The BLDC is used in applications that require smaller dimensions. |
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What part is used in AC motors only? |
Squirrel cage |
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What induces current in the rotor of an induction motor? |
Stator magnetic field |
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What induces a rotor magnetic field in an induction motor? |
Rotor current |
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What level of voltage is produced in an AC generator when the armature movement is perpendicular to the strator field? |
Maximum |
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In a revolving field AC generator, DC from a seperate source is passed through the __________ via the slip rings and brushes. |
Field windings on the rotor |
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To isolate the controlling circuitry, one must check the output from the circuit and the ________ |
Input to the circuit |
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Human error in troubleshooting could be related to _________, _________, ___________, |
Input signals, motor parameters, equipment setup |
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Localization is used to __________ |
Determine which stage or section contains the fault |
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The process of determining the bad component in a particular stage or section as _________ |
Isolation |
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During signal injection, the generated signal should _________ |
Be as small as possible to prevent circuit damage |
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The square wave signal from the speed detector is changed to a voltage by the ___________ |
F/V Converter |
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In most cases, system fault localization will require either __________ or ___________ to narrow the problem to a specific circuit or stage |
Signal tracing, signal injection |
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A system block diagram will help a troubleshooter seperate the system into _________ |
Stages |
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What is the term used to describe the number of degrees that a stepper motor rotates for each input pulse? |
Step |
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If a stepper mode operates in the step mode but does not operate in the run mode, what is the probable faulted area? |
Oscillator circuit |
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Given the following stepper motor with a coil activation sequence of QA → QD. What direction will the rotor rotate? |
Clockwise |
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A two phase full step generator is __________ to a single phase generator |
Nearly identical |
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What is the following circuit called? |
Ramp up - Ramp down |
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What the relationship of torque to acceleration? |
Directly proportional |
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What is the basic purpose of a photodiode array of an optical sensor? |
Convert light to data |
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What principle of magnetism do motors operate on? |
Attraction and repulsion |
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In a delta connected alternator, the line voltage equals the ____________ |
Phase voltage |
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A closed loop feedback system utilizes motor output to create a __________ |
Control signal |
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Which component is faulty if the input to the motor checks out fine and the motor does not run? |
Bad motor |
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What term is used to describe the highest PPS that a stepper motor can use? |
SR |
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Which circuit in a stepper motor system develops the power necessary to energize the stators? |
Driver |
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Why is the BLDC easier to examine and repair than a conventional DC motor? |
The electric windings do not rotate. |
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A device that has a spinning shaft and uses electricity as the input or output is called ___________ |
Rotating machinery |
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How does an incremental motor operate? |
The shaft rotates a specific distance for each input |
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What type of power is produced by a generator? |
AC or DC |
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What term is used to describe speed in a motor or generator? |
RPM |
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What best describes torque? |
A twisting action |
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CEMF and speed are ______ |
Proportional |
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One horsepower is the power rate according to _____________ |
33,000 ft-lb/min |
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Electrical power is defined in terms of ___________ |
Watts |
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What principal of magnetism do motors operate on? |
Attraction and repulsion |
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What principal of magnetism allows a generator to power its own stator windings and still generate an output voltage? |
Retentivity |
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What is the primary difference between a DC motor and a DC generator? |
The power to the rotor is replaced in a generator with a load. |
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A DC motor operates using what? |
Direct Current, DC Voltage, The principal that electric energy produces mechanical energy. |
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How many types of compound motors are there? |
2 |
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When a schematic diagram shows a field coil, you instantly know that the motor is what type? |
Electromagnet |
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Where is the shunt field coil placed in parallel with a series field motor in a schematic? |
There is not shunt field coil in series field motor |
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In a shunt field motor, output power is equal to __________ |
Speed x torque x (0.1047) |
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How is CEMF related to torque? |
Inversely proportional |
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If motor speed increases but the applied voltage remains constant, the only thing unaffected is ____________ |
Field current |
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In a series motor, how many paths are there for a current? |
1 |
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Starting current of a DC series field motor is ________ than an equivalent DC shunt field motor. |
Higher |
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If a series field motor is loaded, what happens to the electrical input power? |
Remains the same |
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Opposing series and shunt fields cause a DC compound motor to __________ |
Lose armature magnetic field |
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Which type of compound motor is common in small DC motors? |
Short shunt |
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Which type of compound motor is pictured? |
Long shunt |
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PWM stands for __________ |
Pulse width modulation |
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Sinusoids are generally examined by the conduction angle and the ____________ |
Firing angle |
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The instant a signal turns "ON" is determined by the _____________ |
Firing angle |
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By controlling the firing angle, the _________, ____________, __________ is also effected |
RPM of the motor, average voltage, conduction angle |
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What signal is the output of a pulse width modulator? |
Varying width pulse |
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What determines the period (or time) between output pulses? |
Input clock pulses or triggers |
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The ____________ determines the width of the pulse width modulated signal. |
Amplitude of the DC input. |
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In the experiment, when the motor speed control is increased from 30 to 40, the positive pulse ___________ |
Increased in length |
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Synchronous speed is the same as ___________ |
Stator field speed |
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During disassembly, which part of the motor is most fragile and easily damaged? |
Stator windings |
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An overloaded motor will most likely display which symptom? |
Overheated |
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An open stator will usually cause what? |
Failure to start |
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The megger is used for testing _______ and the clamp on meter is used for ____________ |
Insulation deterioration, stator current |
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What is a common frequency of the ac supply voltage to a synchro system? |
60 |
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What is a common phase of the AC supply voltage to a synchro system? |
Single |
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In a torque synchro system, which component has a rotor with rotational position driven by electrical voltage and phase? |
TR |
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What is the biggest difference between torque systems components and control synchro systems components? |
Current requirements |
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Which system component is most like a torque receiver? |
Control transformer |
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The term ____________ means, the axis of rotation of the gyro wheel tends to remain in a fixed direction in space if no forces are applied. |
Rigidity |
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What stabalized platform is mostly mechanical and is susceptible to errors? |
Gimbalized INS |
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What stabalized platform requires up to 4 hours to allign? |
Gimbalized INS |
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The AC induction motor uses what type of motor? |
Squirrel cage |
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Slip speed is __________ |
The difference between stator field RPM and shaft RPM |
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An AC motor is typically described as a one, two, or three _________ motor. |
Phase |
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Strator field rotation is also called _______ |
Synchronous speed |
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What is slipspeed? |
Synchronous speed - shaft speed |
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Given the following circuit, what type of motor is this? |
Split inductive motor |
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Given the following circuit, what type of motor is it? |
Split capacitive start motor |
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Always _________ and tag out the circuit prior to performing any maintenance on electrical wiring, motors or loads. |
De-energize |
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What troubleshooting stage allows the technician to locate the most difficult and hidden problems of a motor? |
Performance test |
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What defect is normally found when measuring air gap? |
Bearing wear |
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What type of connection is shown? |
WYE |
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How many wires are used for a 3, WYE alternator? |
4 |
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Two basic components of a synchro are the stator and the ___________ |
Rotor |
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The purpose of a synchro system is to transfer ______________ |
Angular information |
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A CT synchro is a control _________ |
Transolver |
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The mechanical movement of a synchro produces a voltage that represents ____________ |
Angular information |
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What is the function of the torque differential transmitter? |
Provides rotational correction to the torque receiver |
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While flying on a heading of 110°, another aircraft is detected on a heading of 120° How much correction is applied to the radar tracking by the torque differential transmitter in this situation? |
10° |
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The torque differential transmitter always adjusts a synchro system according to ___________ |
The current compass heading |
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What is the symbol for a control differential transmitter? |
CDX |
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What is this? |
A control transformer |
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What is the symptom of a shorted receiver stator winding? |
The receiver rotor locks up on the good windings |
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When troubleshooting a synchro system, how is a multimeter used? |
Measuring resistance |
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A shorted stator winding on a transmitter affects what devices? |
Single receiver, transformer |
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What gyro property causes the gyro to remain in a fixed position? |
Rigidity |
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What factors determine the rigidity of a gyro? |
Rotor speed, rotor weight and rotor shape |
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What gyro characteristically provides the basis of the operation of a rate gyro |
Precession |
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What type of accelerometer is designed to provide an output signal in digital form? |
Pulse |
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What does an AC motor need as an electrical input signal? |
Sinusoidal waveform, alternating current (AC) |
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What type of AC motor is used for large horse power or special applications? |
Synchronous |
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The three stages of AC motor troubleshooting process are ____________ |
Visual inspection, operational check, performance test |
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What defect is normally found when measuring air gaps? |
Bearing wear |
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What type of 3 connection can also power single phase appliances? |
WYE |
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How many wires are used for a 3, WYE alternator? |
4 |
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How many stator windings does this synchro have? |
3 |
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The two classifications of synchros are control synchros and _________________ |
Torque synchros |
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(T/F) A torque differential transmitter must be used on every synchro system. |
False |
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What is the function of the torque differential transmitter? |
Provides rotational correction to the torque receiver |
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The torque differential transmitter always adjusts a synchro system according to ___________ |
The current compass reading |
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What is this? |
Torque differential transmitter |
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When synchronized, what is the output from a control transformer? |
Out of phase |
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Which device in the control synchro system performs the same function as the torque transmitter? |
Control transmitter |
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The fuse is open that supplies power to the synchro system. What is the most likely defect in the system? |
Shorted rotor |
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How are components isolated for troubleshooting in a synchro system? |
Flipping switches, disconnecting cables, and desoldering |