Figure 7-16.--Simplified system switching diagram.
each microphone control station. These switches control
and for silent and remote testing of the amplifier
the relay power for each control station. They are also
channels and oscillator groups.
u s e d to isolate the control stations during
POWER AVAILABLE LAMP.-- This lamp, when
lit, indicates that power is available to the control rack
for operation of the system.
LOUDSPEAKER GROUP DISCONNECT
SWITCHES.-- There are six loudspeaker group
BLOWN-FUSE INDICATORS.-- There are
disconnect switches, one for each loudspeaker group.
combination fuse holders and blown-fuse indicators for
These switches control system output power to each
each amplifier oscillator power switch and for each
loudspeaker group. They are also used to isolate the
microphone control station switch.
loudspeaker groups during troubleshooting.
Primary power circuits are fused on both the high
VISUAL DISC SWITCH.-- This switch controls
and low sides. The switch controlling power to the
the output to the visual alarm indicators.
circuit, which a fuse protects, must be in the ON position
for the blown-fuse indicator to give an indication of a
TEST SWITCHES.-- The test switches consist of
fuse failure. For microphone control stations, the
the amplifier test switches, the amplifier oscillator test
microphone press-to-talk switch at the station must be
switches, and a meter test switch. The amplifier test
operated to give an indication of fuse failure.
switches are used when making system level
TEST METER.-- The test meter is used with the
amplifier oscillator test switches and the meter test
meter test switch for testing the output of the power
switch are used to test the output of the power supplies
supplies and for silent and remote testing of the