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Rev. A
11
Load Detection Circuit
Load detection circuit is shown on Figure S-9. The output current is detected by current
transformer CT1AX. I t lowers 1000 times of output current for CPU detection. The current
signal generated from CT1AX flows through a full-bridge rectifier and R3AX to convert to
a voltage signal (0~ 5 Volts). Then CPU can receive output current value of the UPS.
11.1 At line/ boost/ buck mode: The current value multiplies output voltage to get output
VA value.
11.2 At battery mode: Because the power factor of step wave is approximately equal to 1,
the current value multiplies 120V (230V) output voltage to get output Watt value.
Figure S- 9 Load Detection Circuit
Summary of Contents for EP450 series
Page 2: ...Page 1 of 26 Rev A UNINTERRUPTIBLE POWER SYSTEM SPECIFICATION EP450 650 850 Series ...
Page 9: ...Page 8 of 26 Rev A Figure S 2 Control Power Circuit CH1 C15 å GND Figure W 1 Cold Start ...
Page 11: ...Page 10 of 26 Rev A Figure S 3 B Charger Control Circuit ...
Page 18: ...Page 17 of 26 Rev A Figure S 6 CPU Control Circuit ...
Page 26: ...Page 25 of 26 Rev A Figure W 7 Battery Mode Examination Flowchart ...
Page 27: ...Page 26 of 26 Rev A Figure W 8 Line Mode Examination Flowchart ...