Centralion 400VA, Service Manual, Page: 5 / 33

B. Block Diagram
The Block diagram of Blazer series (refer to Figure S-1) is divided into the following
parts:
a)
Main relay (MAIN-RY):
To switch the UPS between line and battery mode. Its mechanical action also affect
the UPS power loss time.
b)
Booster Relay(BOOST-RY):
At line mode, this is a switch used to increase UPS output voltage 18% when the
commercial line source is under voltage.
Relay OFF : line voltage is normal
Relay ON : line voltage is under voltage.
c)
Buck Relay:
At line mode, this is a switch used to decrease UPS output voltage 15% when the
commercial line source is over voltage.
Relay OFF : line voltage is normal
Relay ON : line voltage is over voltage.
d)
Main Transformer(MAIN TX) :
The Main transformer has three functions:
1.
Inverter Transformer
Provides inverter voltage to UPS output. It performs a push-pull transformer when
UPS at battery mode.
2.
Booster/Buck
Thus the output voltage at booster mode is given by (Boost Relay ON) :
V
OUT
= V
IN
* 1.18
The Buck relay is ON when the line voltage is over voltage. It can reduce output
voltage by:
V
OUT
= 0.85 V
IN
3.
Charger :
The Main transformer has a charger coil (TXC) to supply an adequate voltage to
charger circuit.
e)
Line Sense
To process the attenuated signal (including input voltage and zero crossing) from rectifier
and send the results to CPU.
b)
CPU (NEC µPD78F9116A)
The Central Process Unit
c)
Electricity Switch
It controls the 5 Volts and 12 Volts DC supplies. +5Volts and +12Volts Control Power
Generator:
P5Volts (generated from 7805 regulator) and +12Volts DC power supply
d)
Charger:
The source for the Charger comes from the charger coil (TXC) of the Main
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