Epson C117001-N - DFX 5000+ B/W Dot-matrix Printer Service Manual page 52

The power supply board converts the AC voltage to the DC voltages required to operate the
printer. The AC voltage is input to the AC inlet, and is supplied to the C117 power supply board
assembly via the power switch and fuse. l'hree switching regulator circuits convert the AC voltage
to the three DC voltages (+35 V,
The
power supply board contains two +35 VDC creation circuits. (Ike +35 VDC line is divided into
two sections.) One +35 VDC line supplies power to six of the nine printhead pins (pins 1,3,5, 7,8,
and 9); the other +35 VDC line supplies power to three of the nine printhead pins (pins 2,4, and 6)
and to the motors.
These switching regulator circuits perform voltage control and over-current limiting for each
voltage. They supply or cut the DC voltage based on the DRERR (Driver Error) signal from the
exceeded its duty cycle (the printhead temperature is too high).
The Cl17 power supply board assembly includes a cooling km that is driven by the +35 VDC. The
fan lowers the temperature of the circuit components, and is located under the carnage motor so
that it also lowers the carriage motor temperature.
To prevent a surge in the current, the power supply board cannot recover for approximately thee
minutes after the power is turned off. Therefore, after the printer is turned off, wait three minutes
before you turn it back on.
The specifications for the C117 power supply board assembly depend on the board type (120 V
Before using a different AC power supply, replace the fuse and power cord.
Voltage
V
+5 V (CN3)
+12 V (CN3)
-12 V (CN3)
Note: Before the power supply board outputs +35 VDC, it outputs +13 VDC to the printhead
drivers on the C117 MAIN board assembly. 'This procedure is a driver check to prevent
Rev. A
V, and +/-12 V) required to operate the printer.
+5
Rated Current
Cl Fan power for coding the CR motor
assembly and Cl 17 PNL bad ~w
operating voltages)
1.0 A
0.1 A voltage (serial interface conversion and
Type
0.1 A
Application
hold vda~
B optional
interface voltage supply)
2-13