Power Supply Unit - Oki ML420 Maintenance Manual

2.1.9 Power Supply Unit

This power supply unit is a switching power supply. This power supply unit supplies the +5VDC,
+40VDC.
SW
The uses of output voltages and signals are described below.
Voltage/signal
+5V
+40V
Various protective functions in the power supply unit:
(1) +40V overcurrent detection function
When an overcurrent has been detected, this function suspends switching and cuts off
all output.
This state in which all output is cut off is maintained.
Recovery takes place when the power supply is resumed about 30 seconds after turning
off the power switch.
Until the cause of the overcurrent is removed, even if the power supply is resumed this
function operates so that no +40V/+5V output occurs.
(2) +5V output overcurrent detection function
When an overcurrent has been detected, this function lowers the voltage for this output
only.
Voltage is restored when the cause of the overcurrent is removed.
(3) +40V and +5V output overvoltage detection function
When voltage rises above the standard value of +40V or +5V, this function suspends
switching and cuts off all output.
This state in which all output is cut off is maintained.
Recovery takes place when the power supply is resumed about 30 seconds after turning
off the power switch.
Until the cause of the overvoltage is removed, even if the power supply is resumed this
function operates so that no +40V/+5V output occurs.
42113931TH Rev.1
AC Fuse
Filter
circuit
Power supply Unit.
Use
Logic IC / LED drive / SENSOR drive
LF motor / SP motor drive / Printhead / FAN drive
Electric
current
circuit
SW
control
circuit
Oki Data CONFIDENTIAL
40V
+40VDC
circuit
5V
+5VDC
circuit
Alarm
ALM-P
circuit
Power
Save PSAVE-P
circuit
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