Service manual

SERVICE MANUAL MASTER FILE
ENGLISH
Rev. A (1997/05/07)
2-4
.3 CIRCUIT OPERATION
.3.1 C229PSB/PSE Power Supply Circuit
This printer can be powered by either of two power supply boards: the C229PSB (120V) board or
the C229PSE (230V) board. The function of these two boards is the same , except for a difference
in the primary circuitry. The power supply outputs the DC current necessary to drive the printer
control circuit and drive the mechanism. The input voltages and fuse ratings for these boards are
as shown in the following table:
Table 2-1. Input Voltage and Fuse Rating
Board Input Voltage Fuse F1 Rating
C229PSB 85-138VAC 4A, 125V or 250V
C229PSE 187-276VAC T2.0AH, 250V
The power supply circuit outputs voltages used to drive the various control circuits and the
mechanism, as shown in the following table:
Table 2-2. Output Voltages and Applications
Output Voltage Applications
5V}• 5% 0.7A Logic lines
(Type-B I/F output is included.) Detectors
Panel Switches & LEDs
35V}• 6% 0.8A CR Motor
PF Motor
Printhead
The power supply circuit consists of the line filter circuit, ZC-RCC (Zero-Cross Ringing Choke
Converter) switching circuit and 5V chopper regulator IC. The AC voltage is first input to the line
filter circuit for higher harmonics absorption, then input to the switching circuit and transformed to
+35VDC. +5VDC is generated from +DC35V by the regulator IC. The over current / voltage
protection circuit is also designed on the board.
The power switch is set in the secondary circuit that is controlled by the signal PSC from the
control panel.
Line Filter
ZC-RCC Switching Regulator
AC Line
In p u t
+35V D C
+5VD C
PSC
- O ver C urrent protection
- O ver V oltage protection
R e g u la to r IC
Figure 2-4. Power Supply Circuit Block Diagram