Power Supply Circuit Operating Principle - Epson Stylus Photo 1390 Service Manual

EPSON Stylus Photo 1390/1400/1410

2.3.1 Power Supply Circuit Operating Principle

The power supply circuit board of this product is the C589 PSB.
Basic circuit structure
Flyback switching system
+42VDC and +3.3VDC are supplied to the Printer Mechanism and Control
Board
The following indicates the applications of the voltages generated in this power supply
circuit.
Table 2-9. Supplied Power
Voltage
+42VDC • CR Motor
• PF Motor
Rated output current: 0.45A
• PG Motor
• ASF Motor
• Pump Motor
• Head drive voltage
+3.3VDC • Logic sensor circuit
• Sensor circuit
Rated output current: 0.5A
• Nozzle selection circuit (on the Printhead)
• Interface control circuit
OPERATING PRINCIPLES
Applications
Electrical Circuit Operating Principles
The following is a block diagram of the power supply circuit.
Separate-excited
Simulated Resonance
Flyback Converter
Over Current Limitation
Over Voltage Limitation
Secondary Power
Supply SW function
Low Power mode
C51, C52
Smoothing
Circuit
D51
TRANS: T1
QF1
Main Switching
Circuit
Over Current
Filter Circuit
Protection
F1, TH1 C1, FL1
AC Input
Figure 2-13. Power Supply Circuit Block Diagram
Revision B
F51
Fuse for LPS +42VDC
IC51
+3.3V Chopper
+3.3VDC
Circuit
+5VDC
PSC Signal
ESAVE
Full Wave
Smoothing
Rectifier
Circuit
Circuit
D11, D12, C11
D13, D14
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