Read Sharp ER-A490 (serv.man2) Service Manual online
<Dot display>
Fig. 9-6
IMPORTANT:
The CKDC6 lines are not high voltage resistive ports. Damage may
occur to the CKDC6 if lines are shorted carelessly when using oscillo-
scope probes.
occur to the CKDC6 if lines are shorted carelessly when using oscillo-
scope probes.
•
Dot matrix tube
A 4-bit binary output signals (ST0-ST3) from CDKC6 are converted
into the digit drive signal (DG0-DG11) in the M66004FP.
A 4-bit binary output signals (ST0-ST3) from CDKC6 are converted
into the digit drive signal (DG0-DG11) in the M66004FP.
<Dot display control>
The CKDC6 controls the character segment (5 x 7) and the indicator
of the dot display by using the controller (M66004FP) for dot display
control.
of the dot display by using the controller (M66004FP) for dot display
control.
1
M66004FP/Dot display control signal
Signal
name
Contents
Pin/Remark
DSO
Serial data output signal
for M66004FP
for M66004FP
C-MOS pin
DSCK
Serial shift clock output
signal for M66004FP
signal for M66004FP
C-MOS pin.
Requires to be pulled up
Requires to be pulled up
DCS
Chip select output signal
for M66004FP
for M66004FP
C-MOS pin
10. Power supply circuit
Fig. 10-1
+24V:
Printer, solenoid power
+5V:
VCC (Logic power)
VBAT:
Battery charge
–32V:
Display tube power
VF1, VF2:
Display tube power (AC)
VRAM:
Battery back-uped power
VCKDC:
CKDC-6 Back-up power
VCH:
Fiscal memory unit
11. Switching regulator circuit
ENST
ST0~ST3
19.1µ s
DGn
"h" th digit
display
DGn+1
Display off
D0~D35
"h" th didit display pattern
(h+1) th didit display pattern
17.2µ s
(h+1) th digit display
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
D16
D17
D18
D19
D20
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
D31
D32
D33
D34
D35
: Indicator
VBAT
Power
trans.
trans.
DC-DC
Converter
circuit
Battery
circuit
circuit
VRAM
+5V
-32V
VF1/VF2
VF1/VF2
F1
F2
Switching
regulator
(STR2124)
+24V
+
-
~
~
VCKDC
VCH
30
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