Ericsson GE 19B801507P1, Руководство по обслуживанию

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Pressing the PTT switch applies a ground to the anode of
diode CR15, reverse biasing the diode and removing the charge
path for C65. C65 discharges through R78 and the base emitter
junction of Q6, holding it on for approximately 25 millisec-
onds to allow the transmitter to come up to full power. When
the PTT switch is released diode CR15 is again forward biased
and begins to charge C65. Q6 remains off for approximately 25
milliseconds until the charge on C65 exceeds the threshold
point and allows Q6 to turn on. This action eliminates audio
pops and clicks heard over the speaker when the PTT switch is
operated.
MIC Audio
Operating the PTT switch applies a ground return to the
mic pre-amp, energizing the microphone. It also applies
ground to PTT inverters A3A- A3D which distribute PTT con-
trol throughout the charger and back to the radio through the
UDC connector. Contacts 1 & 2 and 8 & 9 of analog switch A9
close and contacts 3 & 5 and 6 & 10 open.
Mic audio is passed through buffer/amplifier A5/Q5, A9,
and audio delay circuit Q6. (The amount of delay is determined
by an RC network consisting of R78 and C65). Mic audio is
then coupled through C31, J6-2 (EXT MIC IN), and the UDC
connector to the radio for transmission.
DISPLAY FULL BOARD
The Display board provides the current status information
for the Vehicular Charger and radio. It contains the READY,
CHARGE, and TX LED status indicators and associated cir-
cuitry. The cathodes of DS2 and DS3 are at ground and turn on
when a positive voltage from the charge control circuit is ap-
plied.
READY indicator DS2 is controlled by A13 and turned on
when the battery is fully charged as indicated by a positive
voltage being applied from A13-10 through J7-7 to the anode
of DS2, turning DS2 on.
CHARGE indicator DS3 is controlled by BATT SET 2
transistor Q2. When the battery is being charged Q2 is turned
on, applying 13.8 Vdc from the battery input at J1-6 through
J7-6 to the anode of DS3, turning DS3 on.
TX indicator DS1 is controlled by the PTT switch. When
the microphone is keyed, PTT goes low, applying ground
through J7-8 to the cathode of DS1, turning DS1 on. The an-
ode is connected to the +13.8 Vdc input voltage bus through
J7-2.
EXTERNAL ANTENNA
An external antenna may be connected to the radio through
cable CA2 and the UDC connector. A TNC connector jack is
located on the bottom of the Vehicular Charger. Refer to the In-
stallation Manual for specific installation instructions.
INSTALLATION
Install the Vehicular Charger in a convenient place where it
will not interfere with the safe operation of the vehicle. Refer
to the Installation manual for specific installation instructions.
MAINTENANCE
The Maintenance section contains Disassembly instruc-
tions, Troubleshooting Procedures, and Adjustment Proce-
dures. A Test Adaptor may be constructed to facilitate servicing
the Vehicular Charger. The Test Adaptor is used to simulate ac-
tual battery pack conditions and to determine if the charger is
working properly. Simulations include cold battery pack, bat-
tery pack at room temperature, and a hot battery pack. Perti-
nent information is provided in a separate section at the end of
this manual.
DISASSEMBLY PROCEDURES
To Remove The Top Cover:
Remove the six Phillips head screws on the back of the
housing. (three at the top edge, two at the bottom corners,
and one in the center).
To Remove The Charge Board:
Remove the top cover.
Remove the four screws from the Charge board and four
screws from the heatsinks for Q1, Q3, and A12.
To Remove The Repeater Display Board:
Remove the top cover.
Remove the four screws securing the Display board to
the chassis.
ADJUSTMENT PROCEDURES
Test Equipment Required
1. Test Adaptor
2. Digital Voltmeter
Voltage Cutoff
1. Connect the Test Adaptor to TB-1.
2. Set switch S1 on Test Adaptor to position 2.]
3. Set S1 on Charge Board to “ON” to apply power to
the charging circuit.
4. Set R43 on Charge Board fully counter-clockwise
(CCW).
5. Connect the Digital Voltmeter to TP2, and set its
voltage at +9.5 V + 0.05 V by adjusting trimmer R4
on the Test Adaptor.
6. Verify that voltage on A13-6 e10 volts.
7. Slowly adjust R43 clockwise until the RDY indica-
tor just turns on.
+8 Volt Regulator
1. Connect the Digital Voltmeter to TP1, and set its
voltage at +8.0 V + 0.05 V by adjusting R5.
TROUBLESHOOTING PROCEDURES
A Troubleshooting Procedure is provided to assist the
service technician to rapidly isolate a fault in the equipment.
A table of Quick Checks and reference tables containing
typical voltage readings and pin status for various modes of
operation are provided as a troubleshooting aid.
Test Equipment Required
Multimeter
Test Adaptor
Procedures
1. Connect the Test Adaptor to TB1 on the Charge
Board.
2. Set S1 on the Test Adaptor to position 2.
3. Set S1 on the Charger Board to ON to power up the
charging circuit.
4. Adjust R4 on the Test Adaptor for +8.5 Vdc as
measured at TP2 on the Charge Board.
5. Set S1 on the Charge Board to OFF. Set S1 on the
Test Adaptor to position 1.
6. Set S1 on the Charge board to ON. Refer to Tables
1 and 2 and monitor the reference points listed.
Problem areas are identified by an indication other
than that listed in the tables.
7. Set S1 on the Charger Board to the OFF position.
Set S1 on the Test Adaptor to position 3.
8. Set S1 on the Charge Board to the ON position and
then back to the OFF position.
9. Disconnect the Test adaptor from TB1.
10. Set S1 on the Charge Board to the ON position.
This completes the operational checks of the
charger.
LBI-31864
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