TM 11-6130-413-40
tween the soldered joint and the transistor.
(4) Set AUTO/MAN CHARGE No. 2 timer (M1) to
Use approximately the same length and dress of tran-
1 HR position.
sistor leads as used originally.
(5) Set ON-OFF switch (CB1) to ON position.
(6) Press POWER RESET switch (S5) momen-
3-10. Removal and Replacement
tarily
A formed, perforated sheet-metal removable cover,
(7) Set FUNCTION SELECT switch (S4) to
MANUAL DISCHARGE position.
nents of the Charger/analyzer. This cover is removed to
(8) Set 30V-3V switch (S3) to 30V position.
gain access to these components for maintenance. To
(9) Set DISCHARGE AMP-HR switch (S7) to
remove cover, remove hardware securing cover to the
0-17 position.
main chassis and lift off and set aside cover. Also note
(10) Set DISCHARGE AMP control (R15) initially
that the front and rear panels can be detached from
to 0 position.
the main chassis and swung down for servicing once
(11) Press START switch (S2) momentarily to ini-
the attaching screws are removed. Place cushioning
tiate operational cycle.
pads beneath panels to avoid damage to components.
(12) Slowly increase setting of DISCHARGE AMP
To replace cover or panels, reverse the removal proce-
control until unit goes into RESET. Note that trip-
dure.
point current is 24 amperes. If not, reset unit and ad-
just R73 and DISCHARGE AMP control until correct
3-11. Disassembly and Reassembly
trip-point is obtained. (Refer to paragraph 3-4 e for re-
Once the top cover is removed, all components are ac-
start procedures.)
cessible. The steps necessary to disassemble and reas-
(13) Set ON-OFF switch to OFF position and dis-
semble are obvious, and no special instructions are re-
connect equipment.
quired. However, certain procedures and precautions
c. Opertaional Amplifier Null Adjustments--
must be observed prior to, and during, reassembly.
operational amplifier stage U2 requires two null ad-
a. Make sure that all mating machine surfaces are
justments, set as follow: (Allow a 10-minute warm-up
absolutely clean.
period, then shut equipment off.)
b. Use thermal compound between all semiconduc-
(1) Turn on equipment as described in paragraph
tor and mounting surfaces.
b, steps (1) through (9), except remove F2.
c. Make sure that no hardware, such as nuts, bolts,
(2) Connect digital voltmeter between ground and
and washers, have fallen inside the equipment.
U2 pin 10 and adjust R64 for zero volts.
(3) Connect a 470 ohm resistor between pins 1 and
3-12. Parts Location
12 of U2 (figures 3-6). (Attach resistor across DIP
clip.)
placeable partsi of the equipment.
(4) Reconnect digital voltmeter between ground
and U2 pin 12 and adjust R47 for +100 millivolts.
3-13. Equipment Adjustments
(5) Shut down equipment by setting ON-OFF
switch to OFF position.
The following adjustments may be required after re-
(6) Disconnect resistor, digital voltmeter, ac and
placing a defective part or as a result of troubleshoot-
battery connections.
ing. The cover of the unit must be removed to gain ac-
d. Comparator Adjustment- If it is necessary to re-
cess to these adjustments located on circuit board Al.
place voltage regulator U23 (- 12V), check the voltage
a. Meter Zeroing Adjustments- Each of the front-
at U13, pin 4 with no battery connected and the unit
panel meters, M4 and M5, figure 5-1, has a mechani-
turned on (any mode). The voltage at this point meas-
cal zero adjustment screw located in the front of the
ured to ground should be -6.0 .1 volt. If it is out of
meter. With power off, adjust M4 for center-zero; ad-
this range, the trickle point will be incorrect and bat-
just MS for left-side zero.
teries may be damaged. Change R2C to correct the
b. Current Limit Adjustment- Potentiometer R73
voltage, by using the list below. Measure the - 12V
is adjusted to prevent the pass transistors from being
bus with a digital voltmeter and select the appropriate
damaged by excessive discharge currents, or by opera-
resistor,
tor error. Refer to figure 3-6 for location of R73. Con-
Voltage
Calculated Value Use
nect equipment to ac line and a known good battery
8,870 ohm
8,736 ohm
-11.5
(fully charged), then proceed as follows:
9,300 ohm
9,133 ohm
-11.75
(1) Set ON-OFF switch (CB1) to OFF position.
9,630 ohm
9,630 ohm
-12.00
10,000 ohm
9,927 ohmi
(2) Set AUTO-CHARGE No. 1 timer (M3) to 1 HR
-12.25
l0,500 ohm
10,320 ohm
-12.5
position.
(3) Set AUTO/MANUAL DISCHARGE timer (M2)
After changing the resistor, recheck the voltage at
to START position.
U13, pin 4 to be sure that it is correct.
3-9
