Power Supply Circuitry - Canon NP6621 Service Manual

OPERATIONS AND TIMING
B. Power Supply Circuitry
The machine's power supply unit uses a single
main transformer (T101) to supply DC power.
AC power is supplied to the DC power supply
when the power switch (SW1) and the door switch
are turned ON.
Since DC power to the DC controller circuit will
be cut off in this condition, the machine is equipped
with a lithium battery (BAT301) to back up the RAM
(Q308) in the DC controller circuit.
DS1 PWSW
Q308
DC controller
3–102
BAT
301
Figure 3-502
COPYRIGHT © 1998 CANON INC.
Caution:
The AC power supply unit remains supplied
with voltage even when the power is OFF.
Reference:
The tolerances of the DC voltage are as follows:
• +30 V +10%, -5%
• +24 V ±5%
• +5V ±5%
However, the above stand when the AC input
inaccuracy is ±10%.
FU1
Power supply unit
CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
T101
DC Power
supply
unit
+30V
+24V
+5V