Oki OKIOFFICE 84 Service Manual page 415

A3.3.1 048 POW (120V/230V) Circuit Diagram
IMPORTANT:
Oki Data Corporation recommends that maintenance of the Power supply unit (MPW1446 (230V)/MPW1546 (120V))
be performed by replacement of a unit, not by replacement of components.
Therefore,
1) circuit descriptions in this section are for reference.
2) orders for components of the power supply unit cannot always be accepted.
Functions of unit:
The circuit generates the following direct currents (DC) based on the alternating current,
AC 120 V +6%, -15%
AC 230 V +15%, -14%
1. Low-voltage power supply circuit
This circuit generates the following voltages.
Output Voltage Output Voltage
+5 V Logic circuit supply voltage (IC, LSI), and high-voltage source voltage
-8 V CIS (contact image sensor)
+24 V Send motor, drum motor, fan drive, flash memory, CIS, and clutch
2. Input ratings
l
Voltage : AC 120 V+6%, -15% (AC 102 V to 127 V) ; AC 230 V+15%, -14% (AC 198 V to 264 V)
l
Frequency : 50 Hz/60 Hz +/-2%
3. Output ratings
Pin No. Rated
CN-003 Voltage
2, 3 +5V
8 +26V
1 +24V
9 -8V
CN3-12 +5VS
4. Block diagram
Figure A3.3.1 shows a block diagram.
* The information contained herein can change without notice owing to product and/or technical improvements.
Service Guide OKIOFFICE 84
Chapter A Board Descriptions
Rated Current
Current Range
1.2A 0.2 to 3.9A
1.3A 0 to 1.3A
1.0A 0-0.2A
0.1A 0 to 0.1A
20mA 15 to 50mA
Voltage Output
Range Ripple
+4.9~5.3V 100 mV
+26~+40V 500 mV
+22.8~+25. 50mV
2V
-6.5~-12V 100 mV
+5.0~5.4V 100 mA
Page: 247
Output
Noise
250 mVP-P
-----
100mV
250 mV
250 mVA