Power Supply Circuit - Oki PACEMARK 4410 Service Manual

2.1.15 Power supply circuit

This switching type power supply circuit supplies the +5 VDC, ±12 VDC and +44 VDC.
SW FUSE
Noise filter
circuit
ACIN
The uses of output voltages and signals are described below.
Voltage/ signal
+5V
+12V
-12V
+44V
POW ALM-P
POW OFF-P
AC DOWN-P
POW DWN-P
POW ONRST-N
+44 V primary
switching circuit
Switching
control circuit
+5 V and ±12 V
primaty switching
circuit
AC input monitoring
circuit
Figure 2.19
Logic IC/ LED drive voltage
Logic IC drive voltage, option interface line voltage and LF motor locking
voltage
Option interface line voltage
Printhead, SP motor, LF motor, Other motors drive voltage
Output from the power supply circuit upon detection of an abnormal
temperature rise in the power supply circuit or an overcurrent of +44V.
The control unit suppresses the overcurrent by two-pass printing. If the
output does not change, the power supply circuit shuts off all DC output.
Output from the main PCB upon detection of an abnormality in the print head,
SP motor, LF motor, Other motor driver circuit, and shut all DC output off.
Output from the power supply circuit to the main PCB upon detection of no
AC input with the AC switch turned off. Then the main PCB outputs the
POWOFF-P signal to the power supply circuit to have the necessary
information written into EEPROM.
Output from the main PCB to the power supply circuit upon detection of no
host or operator access for approx. 10 min., to start the power-save mode.
In this mode, the power supply circuit cuts off 44V output.
Output from the power supply reset circuit to the main PCB. On receiving the
POWONRST-N signal, the main PCB prepares the main PCB RESET-N
signal and +5VDC.
Rectification and
smoothing circuit
Alarm control
circuit
Rectification and
regulating circuit
Rectification and
smoothing circuit
POWONREST
circuit
Use
33
+44V
POWALM-P
POWOFF-P
POWDWN-P
+5V
+12V
-12V
POWONRST-N
ACDOWN-P