AI-5
STATOR—The stationary member of a synchro that consists of a cylindrical structure of slotted
laminations on which three Y-connected coils are wound with their axes 120 apart.
Depending on the type of synchro, the stator's functions are similar to the primary or
secondary windings of a transformer.
STEP-TRANSMISSION SYSTEM—A data transmission system that operates on direct
current. It consists of a step transmitter (rotary switch) and a step motor interconnected to
transmit data (information) between remote locations.
STICKOFF VOLTAGE—A low voltage used in multispeed synchro systems to prevent false
synchronizations.
SUMMING NETWORK—A combination of two or more parallel resistors used in servo
systems as error detectors. The output of the network is the algebraic sum of the inputs.
SYNCHRO—A small motorlike device that operates like a variable transformer and is used
primarily for the rapid and accurate transmission of data among equipments and stations.
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 phase shift introduced by synchro inductance.
SYNCHRO SYSTEM—Two or more synchros interconnected electrically. The system is used
to transmit data among equipments and stations.
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.
SYNCHRO TROUBLESHOOTING—The locating or diagnosing of synchro malfunctions or
breakdowns by means of systematic checking or analysis.
SYNCHRONIZING NETWORK—A circuit used in servo systems, also called a crossover or
switching network, to sense how far the load is from the point of correspondence and then
functions to switch the appropriate signal into control.
TACHOMETER—A small ac or dc generator, sometimes referred to as a rate generator, which
converts its shaft speed into an electrical output. The tachometer is frequently used in servo
systems to sense the velocity of a load.
TIME LAG—The delay in a servo system between the application of the input signal and the
actual movement of the load.
TORQUE—A measure of how much load a machine can turn. This measurement is expressed
either in ounce-inches for torque synchro systems or in pound-feet for heavy machinery.
TORQUE DIFFERENTIAL RECEIVER (TDR)—A type of differential synchro that takes
two electrical inputs, one to the rotor and one to the stator, and produces a mechanical
output. The output is the angular position of the rotor, which represents the algebraic sum or
difference of the two electrical inputs.
TORQUE DIFFERENTIAL SYNCHRO SYSTEM—A synchro system containing either a
TDX or a TDR. This system is used in application where it is necessary to compare two
signals, add or subtract the signals, and furnish an output proportional to the sum or
difference between the two signals.
