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Clear-Com main stations, power supplies and certain remote stations each have
an auxiliary program input with its own volume control, which allows an
external audio source to be fed to the intercom system.
Visual Signal Circuitry (
call
lights), a standard feature on all main and remote
stations, allows the user to attract the attention of operators who have removed
their headsets.
Clear-Com manufactures a wide variety of both portable and fixed-installation
units. All are compatible with each other. Clear-Com intercom systems can also
interface with other communication systems and devices.
DESCRIPTION
The Clear-Com PS-704 is a single rack space, one- to four-channel intercom
power supply which can provide up to 1.2 amperes per channel to operate
Clear-Com beltpacks and remote stations. This power is supplied to any or all of
four channels, and will support up to 40 beltpacks or 10 speaker stations.
Clear-Com’s new fail-safe design automatically shuts down the power to a
channel when a short circuit or electronic overload is sensed on that channel. The
other channels continue to operate normally. Once the fault condition is
removed, the PS-704's fail-safe circuit will bring the power back up, even under
full load conditions. LED indicators signal a fault on any channel. A line-level
program input offers a master input level. Individual program selects, each with
its own send level, are provided for each channel. Use of a switching power
supply allows the PS-704 to operate with any AC line voltage from 100 volts to
240 volts AC at 50 Hz or 60 Hz. The metal chassis and extra-thick front panel
with integral rack ears maintains legendary Clear-Com ruggedness.
FAIL SAFE POWER
An intercom power supply has special needs that are not met by traditionally
designed power supplies. An intercom power supply must work in adverse
conditions such as low AC line voltage, momentary shorts on the DC power
lines to the stations, and excessive peak loads during “power-on”conditions. The
following features are incorporated into the PS-704’s power supply:
•
AUTOMATIC SHORT CIRCUIT PROTECTION:
The PS-704’s
internal power supply checks each channel for a short or current overload. If
it detects a short the power supply will shut down that channel. A short
duration short circuit will not cause the power supply to interrupt power.
•
AUTOMATIC OVERLOAD PROTECTION:
The PS-704’s internal
power supply senses the difference between shorts and overloads. If an
overload is detected the power supply will shut down that channel. An
overload lasting a short period will not cause the power supply to interrupt
power.
•
AUTOMATIC POWER RESTORE:
The PS-704’s internal power supply
senses the difference between short-term and long-term shorts and overload
conditions. After the first few times a short or overload occurs, the power
supply will try to restore power after only 0.5 seconds. If the short or
