Circuit Operation; Power Supply - Circuit Types; Power Supply Operation - Epson FX-880 Service Manual

Operating Principles

Circuit Operation

Power Supply – Circuit Types
The FX-1180 and FX-880 printers can be powered by any of three power supply boards: the C229 PSB
board (120 V), the C229 PSE board (230 V), or the C229 PSH board (UPS). The output of these boards
supplies the DC current necessary to drive the printer control circuits and the printer drive mechanism.
Though all three boards provide the same output, their primary circuitry differs.
The input voltages and fuse ratings for these boards are shown in the following table.
Board
C229 PSB
C229 PSE
C229 PSH

Power Supply Operation

The table below describes the two power supply output voltages and lists their applications.
Table 3. Power Supply Output Voltages and Applications
Output Voltage (DC)
+5 V 5%
+35 V 6%
The power supply circuit consists of a line filter, a ZC-RCC (Zero-Cross Ringing Choke Converter)
switching circuit, and a 5 V chopper regulator IC. When AC power enters the printer from an external
power source, the line filter circuit removes high-frequency noise. The AC voltage then undergoes full
wave rectification and is smoothed to produce direct current. The voltage is then fed through the
switching circuit and a secondary smoothing circuit to produce a stepped down +35 VDC voltage;
feedback ensures stable output. A second, additional output at +5 VDC is produced by a chopper
regulator IC which draws from the 35 V supply.
2-12
Table 2. Power Supply Boards
Input Voltage Input Frequency Range
85 to 138 VAC 49.5 to 60.5 Hz
187 to 276 VAC 49.5 to 60.5 Hz
85 to 276 VAC 49.5 to 60.5 Hz
Rated Output Current
0.7 A
0.8 A
Fuse F1 Rating
4 A / 125 V, 250 V
T2.0 A / 250 V
T4.0 A / 250 V
Applications
Main control board
logic circuitry
Sensors
Control panel LEDs
Printhead drive
CR motor drive
PF motor drive
EPSON FX-880/FX-1180 Service Manual