Circuit Description - Casio EV-2500B Service Manual & Parts List

POWER SUPPLY
CP105
Q110
D100 C137
R107
MA141K 33K B6800p
C140
Q101
CH470p
2SD1819A-R
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

T100
LC12U-35
2
2SD1819A-R
Q111
1
2SD1119-R
9
R115
100
6
CP106
GND
Figure 1
Voltage
4.50 ± 0.02 V
25.9 ~ 31.3 V
10.0 ~ 12.0 V
–8.0 ~ –7.0 V
–18.4 ~ –16.0 V
Table 1
— 4 —
D158 MA143A
R160
3
68
C146
4 OPEN
D156 MA141K
1
L101
3
5
2 CP112
100u
D154 MA142WK
6
D152
MA142WK
7
D150
MA142WK
8
Function
Main voltage
Tuning voltage
Display voltage
Display voltage
Display voltage
L103
VCC2-3 (4.5 V)
100u
L102
VCC2-2 (4.5 V)
100u
VCC7 (25.9 ~ 31.3 V)
CP110
VCC6 (10.0 ~ 12.0 V)
CP111
VCC2-1 (4.5 V)
CP113
VEE1 (-8.0 ~ -7.0 V)
CP114
VEE2 (-18.4 ~ -16.0 V)
CP115