NAVEDTRA 14187A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES MODULE 15- PRINCIPLES OF SYNCHROS, SERVOS, AND GYROS

Question 1

Which name is given to a variety of rotary, electromechanical, position-sensing devices?

Answer 1

Synchro

Question 2

Which principle does a synchro run on?

Answer 2

Electromagnetic induction

Question 3

Synchros are used primarily for the rapid and accurate transmission of what between equipment and stations?

Answer 3

Information

Question 4

What are the two general classifications of synchro systems?

Answer 4

Torque and Control

Question 5

Which type of synchros are used in systems that are designed to move heavy loads such as gun directors, radar antennas, and missile launchers?

Answer 5

Control

Question 6

Which two broad categories can the synchros used in the Navy be grouped into?

Answer 6

Military standard and Prestandard Navy

Question 7

How many symbols meet the standard military specifications for schematic diagrams of synchros and synchro connections?

Answer 7

Five

Question 8

When a symbol is used on a schematic, it will be accompanied by the military abbreviation of one of how many synchro functional classifications?

Answer 8

Eight

Question 9

What are the two common types of synchro rotors in use?

Answer 9

Salient-pole and Drum/Wound

Question 10

Which part of a synchro is a cylindrical structure of slotted laminations on which three Y-connected coils are wound with their axes 120 degrees apart?

Answer 10

Stator

Question 11

What is a measure of how much load a machine can turn?

Answer 11

Torque

Question 12

Which unit of measurement are torque synchro measurements in?

Answer 12

Ounce-inches

Question 13

What is the measurement of work?

Answer 13

Foot-pounds

Question 14

The strength of the magnetic field produced by what determines the torque?

Answer 14

Stator

Question 15

Military standard and Navy prestandard synchros are designed to operate on either 115 volts or how many volts?

Answer 15

26

Question 16

Synchros used in shipboard equipment are designed predominately for how many volts?

Answer 16

115

Question 17

How many volts do most aircraft synchros operate on?

Answer 17

26

Question 18

Which frequency are synchros designed to operate on?

Answer 18

60 or 400 Hz

Question 19

What is the most widely used frequency for airborne equipment?

Answer 19

400 Hz

Question 20

Standard synchros are designed to withstand surrounding temperatures ranging from -67 degrees F to what at the terminal board?

Answer 20

+257 degrees F

Question 21

Prestandard synchros operate in a range of -13 degrees F to what temperature?

Answer 21

185 degrees F

Question 22

To meet military specifications, all standard synchros must be capable of continuous operation for 1,000 hours at how many revolutions per minute (rpm) without a load?

Answer 22

1,200

Question 23

Low-speed prestandard synchros must be capable of continuous operation for how many hours at 300 rpm without a load?

Answer 23

500

Question 24

Low-speed prestandard synchros must be capable of continuous operation for 1,500 hours at what RPM without a load?

Answer 24

1200

Question 25

Which type of transmitter converts the angular position of its rotor (mechanical input) into an electrical output signal?

Answer 25

Synchro torque

Question 26

The turns ratios in synchros may vary widely, depending on design and application, but there is commonly a stepdown of what between the rotor and a single coil?

Answer 26

2.2:1

Question 27

What stator voltages are measured, reference is always made to what voltages instead of to a single coil's voltage?

Answer 27

Terminal-to-terminal

Question 28

Synchro torque receivers, commonly called synchro receivers, are electrically identical to torque transmitters of the same size except for the addition of some form of what?

Answer 28

Damping

Question 29

What are two types of damping methods?

Answer 29

Electrical and Mechanical

Question 30

Which condition exists when both transmitter and receiver rotors in a synchro system are on zero or displaced from zero by the same angle?

Answer 30

Correspondence

Question 31

What is the angle called through which a transmitter rotor is mechanically rotated?

Answer 31

Signal

Question 32

What is necessary to determine the actual position of the synchros rotor?

Answer 32

Labeling

Question 33

When large amounts of power and a higher degree of accuracy are required, as in the movement of heavy radar antennas and gun turrets, torque synchro systems give way to the use of what type of synchros?

Answer 33

Control

Question 34

What is a control synchro device accurately governing some type of power amplifying device used for moving heavy equipment?

Answer 34

Control transformer

Question 35

Which Control Transformer (CT) windings are considered to be the primary windings?

Answer 35

Stator

Question 36

Which type of simple system should the synchro capacitor never be used in?

Answer 36

Transmitter-receiver

Question 37

Data that covers a wide range of values are handled very effectively and still maintain a high degree of accuracy in what type of synchro system?

Answer 37

Multispeed

Question 38

The advent of long-range missiles and high-speed aircraft has brought about the need for accurately transmitting very large quantities. This is best done by what type of synchro system?

Answer 38

Tri-speed

Question 39

What is the reference point for alignment of all synchro units?

Answer 39

Electrical Zero

Question 40

What is the most accurate method of zeroing a synchro?

Answer 40

AC voltmeter

Question 41

For the AC voltmeter method of zeroing a synchro to be as accurate as possible, an electronic or precision voltmeter having 0- to 250-volt and a 0- to 5- volt ranges should be used. On the low scale this meter should also be able to measure voltages as low as what?

Answer 41

0.1 volt

Question 42

How many conditions must exist for a control transformer (CT) to be on electrical zero?

Answer 42

Two

Question 43

What is perhaps tile (the?) fastest method of zeroing synchros?

Answer 43

Electrical lock

Question 44

What are used primarily for quickly locating a defective synchro?

Answer 44

Synchro testers

Question 45

Which method is used in synchro receivers to prevent the rotor from oscillating or spinning?

Answer 45

Damping

Question 46

What is a low voltage used in multispeed synchro systems that contain CTs to prevent false synchronizations?

Answer 46

Stickoff voltage

Question 47

Which signal lights are used to aid maintenance personnel in locating synchro trouble quickly?

Answer 47

Trouble indicators