Epson LQ-510 - VDC Voltage Control Circuit

REV.-A
PRINCIPLES OF OPERATION
2.2.5 +24 VDC VOLTAGE CONTROL CIRCUIT
Figure 2-22 shows the + 24 VDC voltage control circuit. To maintain the correct voltage on the + 24 V line,
the main switching transistor goes off if the voltage exceeds 24 V. If excess voltage occurs, reverse current
flows through Zener diode ZD20, PC1 is activated, and the condition of the switching circuit is as shown
in Figure 2-23.
/
r
D4
C10
0.01
1
R8 ON -
-I-
+24V DC
GND
4
NOTE: Items in parentheses refer to the 220/240 V version.
Figure 2-22. +24 VDC Voltage Control Circuit
LQ-510
2-19