B. Power Supply CircuitThe machine’s DC power supply provides DC outputs: 38 VU, 24 VU, 24 VR, 24 VA1,24 VA2, 24 VH, 12 VU, and 5 VR.The AC power supply consists of (a) an AC direct input line without a switch, (b) aninput line by way of a power supply switch SW1, (c) an input line by way of power switchSW1 and door switch SW2, providing the DC power supply with DC AC power throughthree channels.When the power switch SW1 is turned on, each power supply circuit is provided withAC power to generate a DC output; the 5VR, 12VU, and 24VA1 power supply circuits arecontrolled so that the input lines are switched by the remote signal (RMT) from the DCcontroller PCB.When the power switch SW1 is turned on, each power supply circuit is provided withpower through the line which leads through the power switch SW1 (line b), therebyturning on the microprocessor on the DC controller PCB; thereafter, the microprocessoron the DC controller PCB causes the remote signal RMT to go ‘1’ turning on the relayRL401 so that the AC input line will switch to the AC direct input line (a).The 38VU, 24VU, 24VR, 24VA2, and 24VH circuits turn off when the power switchSW1 is turned off; other DC power circuits, however, remain on to continue to supply theDC controller PCB with DC power, thereby keeping the fans rotating for a specific periodof time (about 15 min); thereafter, the DC controller PCB causes the remote signal RMTto go ‘0’ to cut off the AC circuits, thereby automatically shutting off the AC inputs to theDC power supply circuits.Check to make sure that the power plug is disconnected always before working onthe DC controller, as for replacement.COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 7 EXTERNALS/AUXILIARY MECHANISMS7-10Caution:
