NAVEDTRA 14187A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES MODULE 15- PRINCIPLES OF SYNCHROS, SERVOS, AND GYROS Flashcards
Which name is given to a variety of rotary, electromechanical, position-sensing devices?
Synchro
Which principle does a synchro run on?
Electromagnetic induction
Synchros are used primarily for the rapid and accurate transmission of what between equipment and stations?
Information
What are the two general classifications of synchro systems?
Torque and Control
Which type of synchros are used in systems that are designed to move heavy loads such as gun directors, radar antennas, and missile launchers?
Control
Which two broad categories can the synchros used in the Navy be grouped into?
Military standard and Prestandard Navy
How many symbols meet the standard military specifications for schematic diagrams of synchros and synchro connections?
Five
When a symbol is used on a schematic, it will be accompanied by the military abbreviation of one of how many synchro functional classifications?
Eight
What are the two common types of synchro rotors in use?
Salient-pole and Drum/Wound
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?
Stator
What is a measure of how much load a machine can turn?
Torque
Which unit of measurement are torque synchro measurements in?
Ounce-inches
What is the measurement of work?
Foot-pounds
The strength of the magnetic field produced by what determines the torque?
Stator
Military standard and Navy prestandard synchros are designed to operate on either 115 volts or how many volts?
26
Synchros used in shipboard equipment are designed predominately for how many volts?
115
How many volts do most aircraft synchros operate on?
26
Which frequency are synchros designed to operate on?
60 or 400 Hz
What is the most widely used frequency for airborne equipment?
400 Hz
Standard synchros are designed to withstand surrounding temperatures ranging from -67 degrees F to what at the terminal board?
+257 degrees F
Prestandard synchros operate in a range of -13 degrees F to what temperature?
185 degrees F
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?
1,200
Low-speed prestandard synchros must be capable of continuous operation for how many hours at 300 rpm without a load?
500
Low-speed prestandard synchros must be capable of continuous operation for 1,500 hours at what RPM without a load?
1200
Which type of transmitter converts the angular position of its rotor (mechanical input) into an electrical output signal?
Synchro torque
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?
2.2:1
What stator voltages are measured, reference is always made to what voltages instead of to a single coil’s voltage?
Terminal-to-terminal
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?
Damping
What are two types of damping methods?
Electrical and Mechanical
Which condition exists when both transmitter and receiver rotors in a synchro system are on zero or displaced from zero by the same angle?
Correspondence
What is the angle called through which a transmitter rotor is mechanically rotated?
Signal
What is necessary to determine the actual position of the synchros rotor?
Labeling
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?
Control
What is a control synchro device accurately governing some type of power amplifying device used for moving heavy equipment?
Control transformer
Which Control Transformer (CT) windings are considered to be the primary windings?
Stator
Which type of simple system should the synchro capacitor never be used in?
Transmitter-receiver
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?
Multispeed
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?
Tri-speed
What is the reference point for alignment of all synchro units?
Electrical Zero
What is the most accurate method of zeroing a synchro?
AC voltmeter
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?
0.1 volt
How many conditions must exist for a control transformer (CT) to be on electrical zero?
Two
What is perhaps tile (the?) fastest method of zeroing synchros?
Electrical lock
What are used primarily for quickly locating a defective synchro?
Synchro testers
Which method is used in synchro receivers to prevent the rotor from oscillating or spinning?
Damping
What is a low voltage used in multispeed synchro systems that contain CTs to prevent false synchronizations?
Stickoff voltage
Which signal lights are used to aid maintenance personnel in locating synchro trouble quickly?
Trouble indicators
