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SWITCH—(1) A device used to connect, disconnect, or change the connections in an electrical circuit [1].
(2) A device used to open or close a circuit [3].
SYMMETRICAL MULTIVIBRATOR—A circuit that generates square waves [18].
SYMPTOM ELABORATION—Using built-in indicating instruments or other aids to define equipment
malfunction [16].
SYMPTOM RECOGNITION—Recognition of a situation in equipment operation that is not normal [16].
SYNCHRO—A small motorlike analog device that operates like a variable transformer and is used
primarily for the rapid and accurate transmission of data among equipments and stations [15].
SYNCHRO CAPACITOR—A unit containing three delta-connected capacitors. The synchro capacitor is
used in synchro systems to increase the system's accuracy by cancelling or reducing the phase shift
introduced by synchro inductance [15].
SYNCHRONIZER—A circuit that supplies timing signals to other radar components [18].
SYNCHRONIZING NETWORK—A circuit, also called a crossover or switching network, used in
servosystems to sense how far the load is from the point of correspondence; it then functions to switch
the appropriate signal into control [15].
SYNCHRONOUS—A type of teletypewriter operation where both transmitter and receiver operate
continuously [17].
SYNCHRONOUS MOTOR—An ac motor whose rotor is activated by dc. It is characterized by constant
speed and requires squirrel-cage windings or some other method to be self-starting [5].
SYNCHRONOUS ORBIT—An orbit in which the satellite moves or rotates at the same speed as the earth
[17].
SYNCHRONOUS SPEED—The speed at which the rotating field in an ac motor revolves. This speed is a
function of the number of poles in the field and the frequency of the applied voltage [5].
SYNCHRONOUS TUNING—In a klystron amplifier, a method of tuning that tunes all the resonant
cavities to the same frequency. High gain is achieved, but the bandwidth is narrow [11].
SYNCHRO SYSTEM—Two or more synchros interconnected electrically. The system is used to transmit
data among equipments and stations [15].
SYNCHRO TESTER—A synchro receiver with a calibrated dial. This receiver is used primarily for
locating defective synchros. It can also be used for zeroing synchros [15].
SYSTEM—A combination of sets, units, assemblies, subassemblies, and parts joined together to form a
specific operational function or several functions [17].
TACHOMETER—(1) A small ac or dc generator, sometimes referred to as a rate generator, that converts
its shaft speed into an electrical output. The tachometer is frequently used in servosystems to sense the
velocity of a load [15]. (2) An instrument that measures the rate at which a shaft is turning [16].
TANK CIRCUIT—A tuned circuit used to temporarily store energy. Also referred to as a parallel-resonant
circuit [9].
