e-STUDIO2020C/2330C/2820C/2830C/3520C/3530C/4520C
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POWER SUPPLY UNIT
9 - 2
9.3
Operation of DC Output Circuits
1. Starting operation of the equipment
When the main switch of the equipment is turned ON, power starts supplying to all the lines only
when two covers (front cover and automatic duplexing unit) are closed.
2. Stopping operation of the equipment
When the main switch of the equipment is turned OFF, PER-DN signal is output after the
instantaneous outage insurance time (20 ms or more) elapses and then the supply of each voltage
stops. If the supply of voltage of the main switch line (+5.1 VS, +5.1 VA, +12 VA) stops earlier than
the 24 V line does, it may cause the damage of the electron device on each control circuit. To
prevent this, the supply of these voltages stops after the PWR-DN signal is output and the minimum
retaining time (50 ms) elapses.
3. Normal stopping (shifting to auto shut off mode)
When the [ON/OFF] button on the control panel is pressed for 1 second or more while the main
switch of the equipment is toggled ON, an auto shut off mode shifting signal (SYS-EN) is output and
then all lines for output voltage 5.1 VS are closed.
4. Normal starting (recovering from auto shut off mode)
When the [ON/OFF] button on the control panel is pressed for 1 second or more during the auto shut
off mode, an auto shut off mode recovery signal (PWR-SW) is output and then voltage starts
supplying to all the lines, if no error was detected.
5. Output protection
Each output system includes an overcurrent and overvoltage protection circuits (a fuse and internal
protection circuit). This is to prevent the defectives (damage or abnormal operation of the secondary
circuit) which may be caused by an overcurrent due to a short circuit or an overvoltage due to a
short circuit between different voltages. If the protection circuit is activated (except the case the fuse
is blown out), remove the causes such as short-circuit. Turn ON the power again 1 minute later to
clear the overcurrent protection.
6. State of the power supply
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Power OFF
The main power switch of the equipment is turned OFF. Since DC voltage is not supplied to each
board, the equipment is not operable.
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Normal state
The main power switch of the equipment is turned ON and DC voltage is supplied to each board.
When the cover of the equipment is closed, 24 V DC voltage is supplied and the equipment
enters into the ready/printing state.
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Sleep mode
Since 24V DC voltage is not supplied but 5 V DC voltage only, the equipment does not enter into
the ready state.
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Off mode
Only DC voltage and 5 VS are output from the power supply unit. The [POWER] button is
monitored and the LED of the main power switch is lit.