Specifications

5/9/13 888-2857-001 4-9
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
Platinum VAX-C Series
Figure 4-3 Low Voltage Power Supply Block Diagram
4.4.5 Battery Backup Option
The battery backup board interfaces directly to the LVPS board. Three Lithium-ion cells
are used in a series arrangement and provide 9.6 volts at 1200mAh, 12WHr rated. The
battery backup assembly consists of a battery backup circuit board with three Lithium-
ion cells permanently attached; it also includes a custom battery charging circuit and
protection circuitry. The batteries and circuit board are sold as a unit when replacement
batteries are required.
The battery backup assembly part number is 971-0051-012G.
The battery backup supplies the LVPS board with +6.4V to 10.8V at 20A maximum. It
is mounted directly to the LVPS board. A block diagram of the battery backup assembly
is shown in Figure 4-4.
The battery backup assembly specifications are as follows.
• Recharge time for the fully discharged battery pack is two to three hours. The
charge cycle starts and stops based on the battery pack output voltage.
• Under the optimum battery condition, this battery backup option is capable
of one minute of operation of the modulator portion of the VAX-C
transmitter following an ac power failure. This is accomplished by keeping
Cr
DC3
DC2
DC1
Ideal
Diode
Qc
+24VM
p
+12VIN
n
Qd
+12VOSC
+24V
+12V
+5V
12V
Qb
Vbat
Qa
DC
12V,0.25A
DC5V
DC612V
+12V,3.5A
DC
DC
+24V,1.2A
DC612V
DC612V
+5V,12A
Timers&
Driver
1Min
32Mins
n
n
DC
Vs
3CellsLiIon
+12V,12.5A
DC
GND
AC2
AC
ACLine
Filter
AC1
10.8Vnom.
1.2AHr
13WHr
20Apk
1.5A
610.8V
DataLine