Orban OPTIMOD 8685, Руководство по эксплуатации

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6-12
TECHNICAL DATA ORBAN MODEL 8685
During system initialization, the SC520 queries the DSP hardware about its opera-
tional status and will display an error message on-screen if the DSP fails to initialize
normally. Please note any such messages and be ready to report them to Orban Cus-
tomer Service.
The DSP chips are located on the DSP board—see the drawings starting on page 6-
61. IC801 is a local switching-type voltage regulator on the DSP board that derives
the +3.3 V supply for the DSP chips from the +RAW unregulated system voltage,
while IC802 creates a +1.2 V regulated supply from +RAW.
Power Supply
Warning! Hazardous voltages are present in the power supplies when connected to
the AC line. Several parts, including the heat sink, are hot to the AC power line. Ex-
cept for servicing, do not remove the insulating shield from the power supply.
There are two redundant power supplies connected to a power supply supervi-
sor/distribution board. Via power supply supervisory ICs U1, U2, U3, and U7, the
power supply supervisor monitors each supply’s output for fault conditions, includ-
ing undervoltage and overvoltage. If one supply fails, the power supply supervisor
will automatically choose the good supply to power the 8685’s circuitry. MOSFETs
Q1-8 switch the supplies. These transistors have very low “on” resistance to mini-
mize heating and power loss.
Each of the two redundant power supplies is a modular switching supply to mini-
mize heat buildup and power consumption. They convert an AC line voltage input
to +15, –15, and +5 volts. All other supply voltages are derived from these three
voltages via local regulation. The supply accepts inputs from 95 to 264 VAC, 50 – 60
Hz.
The only fuses in your Optimod are 2.5A 20mm Quick Acting HBC fuses mounted on
the power supplies’ circuit boards. Because the supplies’ outputs are automatically
current-limited, the fuse will usually open only if the power supply fails.
Be sure to
disconnect your Optimod from AC power before replacing the fuse!
Because of safety and EMI suppression requirements for the power sup-
plies, there are no user-serviceable parts in them and we do not provide
documentation for these supplies at the component level. In case of fail-
ure, replace the entire bad supply with an Orban-supplied replacement (Orban part
number 29270.000.01.1), which ensures that your Optimod will continue to meet all
regulatory requirements for safety and emissions.
The output of the power supply is monitored by the power-indicator LED circuit,
which causes the power LED to flash according to a preset code to diagnose prob-
lems with the various power supplies in the 8685. See step (2.B) on page 4-9.