C294Psb / C294Pse Board; Electric Circuit - Epson LX-300+ Service Manual

LX-300+/1170
Table 2-14. Main Elements
Elements Location
RISC C33208 CPU, QFP 128 pin
• Outside clock 19.66 MHz/
Inside clock 39.32 MHz
CPU
IC3
• 8KBRAM built-in
(C294 MAIN)
• Various DMA
• A/D converter
Approximately 21000 gates, QFP 160 pin
• Bit manipulation
• Clock control
*
G/A
IC6 • interface control (IEEE1284/Type-B I/F)
(C294 MAIN)
• Input Buffer control
• Motor control
• Head control
CPU:
RISC C33208 CPU, QFP 128 pin
• Outside clock 19.66 MHz/
Inside clock 39.32 MHz
• 8KBRAM built-in
• Various DMA
CPU/GateArray
• A/D converter
IC3
(C294 MAIN-B)
Approximately 21000 gates, QFP 160 pin
• Bit manipulation
• Clock control
• interface control (IEEE1284/Type-B I/F)
• Input Buffer control
• Motor control
• Head control
4M / 8Mbit, DIP 40 / 42 pin
PROM IC7 • Stores firmware
• CG
1/2/4M bit switching method, SPJ package 40 pin
DRAM IC8
• Various buffer, work area
AT93C46, 1kbit, SOP 8pin
EEPROM IC5
• Stores default value and various parameter
Operating Principles
Function
Electrical Circuit Operating Principles
Table 2-14. Main Elements
Elements Location
M62030 (SANYO), 8 pin
RESET IC IC4
• CPU and G/A reset
CR Motor Driver IC9 LB1847 (SANYO)
PF Motor Driver IC10 LB1847 (SANYO)
Serial I/F
IC2 HIN202CBN or equivalent
Transceiver
BA033 (ROHM) or equivalent
Regulator IC IC11
• Generates 3.3V logic voltage
PD494 or equivalent
• 95V rated voltage circuit
Regulator IC IC12
• Detects over voltage (over 150V) and sends OFF
Thermistor TH1 Measures temperature of the motor driver.

2.3.2 C294PSB / C294PSE Board

LX-300+/1170 generates power supply by a power supply boards: eather C294PSB (100V)
or C294PSE (200V) depending on local supplied voltage. The table below shows the power
supply boards input voltage specifications.
Table 2-15. Power Supply Boards Input Voltage Specifications
Circuit
C294PSB
C294PSE

2.3.2.1 Electric Circuit

The power supply board supplies two types of power for control circuit and driving
mechanism. The table below shows output voltage and its use.
Function
signal to the power supply boards.
Input voltage Fuse specification
99 - 132VAC ULTSC-2.5A-NI
198 - 264VAC HT 1.25A
Revision C
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