Specifications

Maxiva UAX
October 17, 2013
4‐13
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
4.3.12 BatteryBackup,UPS(FutureOption)
ThisUPSversionofbatterybackupboard(971‐0051‐012G)willrequireuseofthelowvoltagePSboard971‐0051‐
011G.
Note
Current versions of the low voltage PS board (971-0035-007) use battery backup board assembly (971-
0035-003G ).
TheUPS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cu
stombatterycharging
circuitandprotectioncircuitry.Thebatteriesandcircuitboardaresoldasaunitwhenreplacementbatteriesare
required.
Thebat
terybackupassemblypartnumberis971‐0051‐012G.
Theb
attery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4‐9.
Thebat
tery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UAXtransmitterfollowinganacpowerfailure.Thisisaccomplishedbykeeping
the+24V,+12V,+12Vosc,+5V,and‐12Vpowersupplyinterfaceboarddcoutputsenergizedforoneminute
f
ollowingapowerfailure.Duringthistimethe PAassemblyisnotpowered.
• ItkeepstheoscillatorcircuitsandtheinternalGPSreceiveroperatingforanadditionalfifteenminutesfollow‐
ingth
eoneminutemodulatorbackupoperation.Itaccomplishesthisbyde‐energizingallbutthe+12Vosc
powersupplyoutputs.
• Duringthelastfifteenminutesofbatter ybackupoperation,thebatterybackupmaintainspowertothe
10MHzand1PPSInputcircuitryontheSignalProcessingboardandtheFPGA,OCXOandGPScircuitryonthe
PFRU.Bypoweringthesecircuitsthemodulatorcanmaintainthe10MHzOCXOdisciplineloopwhenthe
t
ransmitterlosespower.TheOCXOcantakethreeminutestostabilizefromacoldstartandthediscipline
loopitselfcantak eanhourtoreachthemaximumprecision;havingthedisciplineloopactiveduringapower
outageenablestheUAXtransmittertoreturntoairfasterwithgreaterfrequencyaccuracy.

Figure 4-9 Battery Backup Block Diagram