ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Figure 4-11. Power Supply Circuit Card Adjustment Locations (Sheet 2 of 2)
(1)
Set BATTERY and VEHICLE circuit breakers
d. PS Troubleshooting Subroutine No. 1 - Input
CB1 and CB2 to OFF.
Power Short and Continuitv Checks. This subroutine
checks the circuits that carry the + 24v input power
(2)
If 0 to + 40V input power source still indi-
ahead of the main relay K1. The power supply runs on
cates greater than 1 amp, the short remains:
+ 24V from either the vehicle battery at 3J4 or the
replace filter FL1.
backup battery at 3J2. The normal mode of operation is
to use only the vehicle power through filter FL1,
(3)
If short is removed, check from filter FL1-1 to
vehicle circuit breaker CB2, and power diode CR2 to
ground for + 5V.
the main relay K1. When the system draws more ower
(4)
If + 5V is not present, replace filter FL1.
than the normal path can supply (60 to 100 amps, or if
the normal path is intermpted, sequence monitor cir-
(5)
Set PSTS INPUT POWER UUT circuit
cuit card assembly A5 will turn on controlled rectifier
breaker to OFF.
CR3. This allows the backup battery to maintain a
continuous flow of power to the system, When control-
(6)
Set INPUT POWER PSTS circuit breaker to
led rectifier CR3 is turned on to connect backup power
OFF.
to the main relay Kl, it will stay on as long as a current
Set 0 to + 40V input power source to off.
(7)
flows through it, The flow of current from the backup
battery is sensed by a change in inductance of T1. This
(8)
Remove battery char er circuit card assembly
is done to keep the battery charger off while CR3 is
A7 (paragraph 4-19b(7)) far enough to discon-
conducting. Controlled rectifier CR3 will stop conduct-
nect connector A7P1. Leave transistors A706
ing and turn off when the vehicle voltage recovers
and A7Q7 installed. Secure circuit card with
enough to support the total load. When CR3 is not
one screw.
conducting, the battery charger will keep the backup
battery at + 28V, Power diode CR2 keeps backup
(9)
Set PSTS INPUT POWER PSTS circuit
power from flowing out 3J4 to the vehicle if the vehicle
breaker to ON.
battery is low or if the vehicle starter is engaged. FL1
(lo)
Set INPUT POWER UUT circuit breaker to
removes 40 kHz ripple that would otherwise be placed
ON.
on the vehicle battery. Perform subroutine no. 1 as
follows:
(11)
Set 0 to + 40V input power source to on.
4-120
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