Figure 7-16.--Simplified system switching diagram.

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

troubleshooting.

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

adjustments on the preamplifiers and the amplifiers. The

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

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