WY Series User
’
s Manual
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©
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7
Chapter 2 Basic Principle
The principle schematic diagram of WY Series Digital Constant Current &
Constant Voltage DC Power Supply is shown as follows:
AC/DC conversion
High-power regulator
Error correction network
Sampling and
filter for current
Analysis test for
electrical
quantities
CPU
Keys
LED display
RS232
communication
DC output
Power supply
Fig.2.1 Principle schematic diagram of WY series
The power source supplies electric energy to the high-power regulator via AC/DC
conversion. The power supply can switch the state between Constant Current (CC)
and Constant Voltage (CV) automatically with relevant indicator so as to get high
reliability.
When the instrument works in the
“
CONSTANT VOLTAGE
”
state, the
“
Error
Correction Network
”
receives and amplifies the error signals of electric bridge output.
And then, the amplified error signals control the high-power regulator to output the
preset voltage stably and light the indicator
“
CV
”
.
When the instrument works in the
“
CONSTANT CURRENT
”
state, the
“
Error
-Correction Network
”
compares the preset standard voltage with the voltage drop of
the sampling resistance, and then amplifies the error signal, the amplified error signals
control the high-power regulator to output the preset current stably, and light the
indicator
“
CC
”
.
The power supply is equipped with silicon controlled routine to control the
voltage drop of the high-power regulator so as to ensure the high efficiency of the
power supply.