Harris DX 25U, Техническое руководство

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SUMMARY: When AC power fails while the transmitter is
operating, the current power level, and digital power output
data, are stored in the power level latch (U40) and in the
up-down counters, which operate from a memory back-up
supply (+5B supply). Within a few tenths of a second after
power returns, a “Turn-on Command” is generated by the local
(Controller) supply regulator fault logic to start the step-start
and turn-on sequence. This request is generated after regulators
on various boards are up to normal voltage and all “Supply
Fault” (undervoltage) logic signals are cleared. The “Supply Fault” signals also generate a Type 1 Fault induced
“OFF” command, but a five-second delay in the Controller
supply fault circuit inhibits this command so it is not latched.
The Controller “Supply Fault-L” signal also causes a “Data
Clear-L” which clears the data latches on the Analog Input
Board. When the Data Clear goes HIGH after the five-second
delay, the low-to-high transition generates a “Data Strobe” pulse
to latch digital power data.
COMPONENT FUNCTION/DESCRIPTION
BT1, BT2, BT3 Battery holders for three 1.5 Volt AA cells, for optional long-term battery back-up for +5B
supply. (DO NOT USE RECHARGEABLE BATTERIES).
DS1 Red LED illuminates if one or more voltage regulators provides a Fault Alert (+5, +15 and -
15 V supplies fail).
F3 Pr8 Volt unregulated supply if +5 V supply short circuit failure occurs.
F1 Pr22 Volt unregulated supply if +15 V supply short circuit failure occurs.
F2 Protects -22 Volt unregulated supply if -15 V supply short circuit failure occurs.
S1 Depress S4 for Fast Power Set; may be used when initially setting Low, Medium and High
power levels if an extended power failure or internal memory reset has cleared power setting
information.
S2 In PA Off position, provides PA Off logic signal to modulation encoder to turn all PA
modules off without turning off +230 Volt high voltage supply.
Table P-1. Controller Board A38, Controls & Indicators
TEST POINT FUNCTION/DESCRIPTION
TP2 Test point for reg5 V.
TP3 Test point for reg15 V.
TP7 Test point for regulated -15 V.
TP6 Test point for +5B memory back-up supply voltage.
TP8 Ground.
TP1 Ground.
TP5 Ground.
TP4 Ground.
Table P-2. Controller Board A38, Test Points
DX-25U
P-20 888-2297-002 Rev. S: 05-02-97
WARNING: Disconnect primary power prior to servicing.