1-4
By studying the simple synchro system, you can see that information can be transmitted over long
distances, from space to space, and from equipment to equipment.
In addition to supplying data by positioning dials and pointers, synchros are also used as control
devices in servo systems. When the synchro and the servo are combined, they work as a team to move
and position heavy loads. The methods used to accomplish this are covered in detail in the next chapter.
Q-1. What is the name given to a variety of rotary electromechanical, position sensing devices?
Q-2. What is the primary purpose of a synchro system?
SYNCHRO CLASSIFICATION
Synchros work in teams. Two or more synchros interconnected electrically form a synchro system.
There are two general classifications of synchro systems—TORQUE SYSTEMS AND CONTROL
SYSTEMS. Torque-synchro systems use torque synchros and control-synchro systems use control
synchros. The load dictates the type of synchro system, and thus the type of synchro.
Torque-synchro systems are classified "torque" because they are mainly concerned with the torque or
turning force required to move light loads such as dials, pointers, or similar indicators. The positioning of
these devices requires a relatively low amount of torque. Control synchros are used in systems that are
designed to move heavy loads such as gun directors, radar antennas, and missile launchers.
In addition to the two general classifications, synchros are grouped into seven basic functional
classes as shown in table 1-1. Four of these are the torque type and three are the control type. Each
synchro is described in the table by name, abbreviation, input, output, and the other synchro units that
may be connected to it. Generally, torque and control synchros may not be interchanged. The functional
operation of each of these seven synchros is covered later in this text.
