Samlexpower SAM-1500C-12 Owner's manual - Section 2 |
6 | SAMLEX AMERICA INC.
SECTION 2 |
Features, Applications &
Principle of Operation
!
caution!
Certaindevices(fewexamplesgivenbelow)maymalfunctionwhenpoweredfromModi-
fiedSineWave.Checkwiththemanufacturerofthedeviceforsuitabilityofpowering
withModifiedSineWave:
• Devicesutilizingzerovoltagecrossingfortimingcontrol:Someclocksusedinconsumer
electronic items (will not keep accurate time)
• DevicesusingmodulationofRFsignalsonAClinesduringzerocrossinge.g.X-10System
for Home Automation
• DevicesutilizingTriacbasedphasecontrolfortransformerlessvoltagestepdowne.g.:
• Smallbatterychargersforhandtools,flashlights,night-lights,shaversetc.
• Variablemotorspeedcontrolinhandtools
• Lightdimmers
• Temperaturecontrollerse.g.:
• TemperatureControlledElectricBlankets
• Devicesusinghighcapacitancebasedvoltagemultipliersforgeneratinghighvoltage
(will create very high surge currents) e.g.:
• PhotographicStrobeLights
• LaserPrinters
meaSurinG moDifieD Sine-WaVe VoLtaGe WitH
a “true rmS” VoLtmeter
Asmentionedabove,ModifiedSineWavevoltageisatypeofsquarewavethathasan
RMS(RootMeanSquare)valueof115VAC.Ageneral-purposeACvoltmeteriscalibrated
toaccuratelymeasuretheRMSvalueofaPureSineWaveandNOTofaModifiedSine
Wave.Ifthisgeneral-purposevoltmeterisusedtomeasureModifiedSinewavevoltage,it
will indicate a lower value (96 VAC to 104 VAC). for accurately measuring the voltage of a
ModifiedSineWave,useavoltmeterwhichisdesignedtomeasure“TrueRMSValues”like
fluke 87, fluke 8060A, fluke 77 / 99, beckman 4410 etc.
principLe of operation anD cHarGinG aLGoritHm - Battery cHarGer
The battery charger is a 2 Stage, Switched Mode Design using fly back Topology.
120VACfromtheACInputisrectifiedtohighvoltageDCofaround170VDC,whichis
thenconvertedtohighfrequencypulsesusingMOSFETSwitchandthensteppeddown
throughswitchingtransformer.Thetransformedvoltageisrectifiedandfiltered.Asample
of the output voltage is used as feedback signal for the drive circuit for the switching
Mosfet to achieve desired voltage regulation of 13.8 VDC using Pulse Width Modulation
(PWM).Itisdesignedtoprovidemaximumchargingcurrentof15A.