Epson PC AX Technical Manual page 34

PRINCIPLES OF OPERATION REV.B
(Reference)
Resistor R5 and R6 have two following functions
1) To be equal the voltage of the resistor R5 in e12 to that of the resistor
R6 in C13.
2) To use up the electric charge as soon as the switch is turned off.
C12
C13
RS
30K
R6
30K
FIGURE
2-2-7.
FUNCTIONS OF RESISTOR RS AND R6
2.2.2 Secondary circuit
2.2.2.1 -SV and -12V Circuit
When an electromotive force which is in the direction of 1 is produced in the
transformer Tl, tbe series voltage regulator 21 and 22 are supplied with the
power reference through RC2 and L4.
When an electromotive force which is in the direction of 2 was produced at the
transformer Tl, the power reference is supplied from L4.
*
R17 is for capacitor discharge.
*
D14 and D13 is for series voltage regulator protection.
014
- 12 V0.3 A -1 2 V
-sv
- S VO.3A
C37
J;
630V
R 17
0.01
lW •
200
AN 79MOS
~, ~~ ~l~
013 00 47
06'="C--I~"':'::'-'-4'--""'::"'=-+-"
+
C23
2SV
100
)JPC7812H
or
HA17812P
,..........-.,
(2) 8
GNO
FIGURE 2-2-8. -SV AND -12V SUPPLY CIRCUIT
2-6