EPSON Stylus Photo 750

Revision A

2.2.2.2 Reset Circuit

Reset circuit consists of reset/timer IC(IC8) and peripheral elements. The reset/timer IC prevents the CPU from running away, which is caused by the unstable voltage(+5VDC line voltage is less than +4.3V) in the logic line during the power ON/OFF operation. Also, IC sends the reset signal to the CPU and gate array when +42VDC line voltage is less than +35.5V.

 

 

IC 1

 

 

 

 

 

C90A05

 

 

 

 

 

/RES

 

 

 

IC 8

 

B1

 

 

 

RTC-9810

 

10

 

 

+42

VIN

/VDT

29

/NMI

 

 

VDD

FRST

3

24

MRES

 

 

 

 

/RST

2

25

/RESET

 

 

 

 

VBK

CE

 

 

 

 

GND

SCLK

 

 

IC 2

 

 

 

E05B588

 

 

 

 

 

 

 

DATA

 

 

 

Figure 2-5. Reset Circuit

Operating Principles

Operating Principles of Electric Circuit

33

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Image 38
Epson Photo750 manual Reset Circuit