Figure 5-19.--Plotters transfer switchboard.
lever-operated spring return or spring return rotary
circuit 81JS. Any of the remaining jackboxes, JS3
through JS10, may be connected to one of the five
switches are provided at all calling stations. Buzzers,
sound-powered circuits by simply closing the associated
horns, bells, and drop-type annunciators are installed at
the associated called stations. Buzzers are used in low
noise level spaces. Horns are used in high noise level
CALL AND SIGNAL
spaces, and bells are used in other spaces. Annunciators
are provided at all stations where two or more similar
audible signals are required.
Call and signal circuits used in conjunction with a
ship's sound-powered telephone system provide the
To use the circuit, the caller operates a switch at the
means of calling and signaling between stations of the
calling station, which in turn energizes the audible
various sound-powered telephone circuits. The call and
and/or visual signal devices located at the called
signal circuits are designated E, EM, and MJ.
CIRCUIT E - SOUND-POWERED
Circuit E is divided into the following functional
1E-Cruising and miscellaneous
Circuit E provides a means of signaling between
sound-powered telephone stations, where not more than
six stations are to be called by the calling station. The
circuit operates on 120-volt, 60-Hz, single-phase power,
which is usually supplied by the main IC switchboard.
Watertight and nonwatertight push buttons and