Circuit Indicator.
A pocket compass, decomposition apparatus, galvanometer or other device
for indicating the condition of a wire, whether carrying a current or
not, and, if carrying one, its direction, and sometimes roughly
indicating its strength.
Circuit, Internal.
The portion of an electric circuit included within the generator.
Circuit, Line.
The portion of a circuit embracing the main line or conductor, as in a
telegraph circuit the line carried on the poles; distinguished from the
local circuit (see Circuit, Local,) in telegraphy.
Circuit, Local.
In telegraphy, a short circuit with local generator or battery included,
contained within the limits of the office or station and operated by a
relay, q. v. This was the original local circuit; the term is applicable
to any similar arrangement in other systems. Referring to the cut, the
main line circuit includes the main battery, E, Key, P, Relay, R, ground
plates, G, G1. The relay magnet opens and closes the local circuit with
its local battery, L, and sounder magnet, H, with its armature, B. The
minor parts, such as switches, are omitted.
Fig. 90. LOCAL CIRCUIT OF TELEGRAPH SYSTEM.
Circuit, Local Battery.
A local circuit worked by and including a local battery in its course.