Canon NP6085 Service Manual page 212

3. OPERATIONS AND TIMING
B. Power Supply Circuit
1. Outline of Operation
The NP6085's power supply circuit generates
seven types of DC outputs: 38VU, 24VU, 24VR,
24VUN, 12VU1, 12VU2, and 5VR. The 12VU
power supply circuit 1 operates to turn ON/OFF
the power switch relay (RL3) at all times from
when the copier's power plug is connected until it
is disconnected.
The AC power supply may be (a) AC direct
input line through a relay unit; (b) input line
through RL3 on the relay unit PCB; or (c) input
line through RL3 and door switch relay RL4.
When the main switch is turned ON, the DC
controller PCB sends the main switch ON signal
( =0) to the DC power supply ON/OFF
MSWON
control latch PCB of the power supply PCB to
supply RL3 of the relay unit PCB with 12VU1 from
the power supply circuit relay drive 12VU power
supply circuit 1; AC power will reach the 24VU,
12VU2, 5VR power supply circuits through the
power supply circuit relay on the AC input line (b)
for distribution to the DC controller PCB.
At this time, the power supply circuit sends the
indirect power supply detection signal (AC1D=1)
to the DC controller PCB; the DC controller PCB,
in turn, sends the direct power supply signal
( =0) to turn ON the relay in the power
AC0ON
supply circuit to switch the AC input line to (a)/(b).
Then, the 12VU power supply circuit 2 sup-
plies 12VU2 to RL4 in the relay unit to turn ON the
relay; the AC power supply moves through the AC
input line (c) to reach the 38VU and 24VR power
supply circuits of the power supply circuit, and
each circuit supplies the DC controller PCB with
38VU and 24VR.
If the door switch (SW48) and the side tray
connection detecting switch (SW21; 100V model
only) are OFF (e.g., the front door or the side tray
has been separated from the copier), 12VU2
used to drive RL4 will be cut off so that the relay
will turn OFF to cut out the power to the AC input
line (c).
This condition will stop the output of the 24VR
and the 38VU power supply circuits. (The 230V
model, however, does not have SW21.)
At the same time, the DC controller PCB
sends the power unit remote signal (
to stop the 24VU power supply; 24VUN for error
detection for the SSR and the lamp regulator (AC
3-154
COPYRIGHT © 1996 CANON INC.
driver circuit also in the case of the 100V model),
however will remain.
If copying does not start for a specific period of
time after the DC controller PCB detects AC1D
and standby mode (energy saver, alarm, interme-
diate, error, jam, jam standby), the auto power-off
function will turn ON; the DC controller then sends
the power switch OFF signal (
OFF RL3 (except in energy saver mode) to stop
24VU, 24VR, and 38VU power supplies.
The DC controller PCB continues to supply DC
power, thereby rotating the fans for a specific peri-
od of time (about 15 min). Thereafter, the DC con-
troller PCB stops
relay of the power supply circuit and switches the
AC input line to (b) to stop all DC power supplies.
(However, this does not apply to 12VU for RL3.)
When the main switch is turned OFF manual-
ly, the DC controller PCB sends
the DC power supply ON/OFF control latch PCB
of the power supply PCB to cut off 12VU1 and
turn OFF RL3, thereby stopping the supplies of all
DC power supply circuits. (However, this does not
apply to 12VU 1 for RL3.)
The time before auto power-off may be varied
in user mode.
When an error is detected, the DC controller
PCB sends
to turn OFF RL3, thereby immediately stopping
AC power supplies.
Caution:
Be sure to disconnect the power plug
before handling the DC controller PCB
(e.g., for replacement).
Reference:
The DC voltage tolerances are as follows:
• +38VU ±5%
• +24VU ±5%
• +24VR 1%
• +24VUN ±5%
• +5VR ±1.5%
• +12VU ±5%
However, the above assumes that the AC
input inaccuracy is limited to ±10%.
=0)
REMOTE
CANON NP6085 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
PWOFF
=0 to turn OFF the
AC0ON
=0 to the power supply PCB
PWOFF
=0) to turn
=0 to
MSWON