Circuit Description - Casio EV-500C Service Manual & Parts List

POWER SUPPLY
Vcc1-1
CP100
D100 C137
R107
MA142WK 33 K B6800 p
C140
Q101
470 p
2SD1819A-R
GND
The power supply consists of a DC-DC converter and the associated circuit and supplies the voltages as shown
in Table 1.
Name
VCC2-1
VCC7
VCC6
VEE1
VEE2

CIRCUIT DESCRIPTION

2
LC12U-35
Q110 2SD1819A-R
Q111
1
2SD1119-R
9
R115
100
6
CP101
Voltage
4.50 ± 0.02 V
25.9 ~ 31.3 V
10.8 ~ 12.0 V
–8.5 ~ –7.5 V
–19.8 ~ –17.2 V
D158 MA143A
T100
R160
3
68
C146
(D: 180)
4 220 p
D156 MA142WK
5
D154 MA142WK
6
D152
MA142WK
7
D150
MA142WK
8
Figure 1
Function
Main voltage
Tuning voltage
Display voltage
Display voltage
Display voltage
Table 1
— 4 —
L102
Vcc2-2
330 u
Vcc7 (29.5 V)
CP110
Vcc6 (11 V)
CP111
Vcc2-1 (4.5 V)
L101
100 u
CP113
VEE1 (-7.5 V)
CP114
VEE2 (-18 V)
CP115
GND
(3.9 V)