B. Power Supply CircuitThe copier’s DC power supply provides eight DC outputs: 38 VU, 24 VU, 24 VR, 24VA2, 24 VH, 24 VA1, 12 VU, and 5 VR.Its AC power supply consists of the following: a. AC direct input line without a switch;b. input line through a power switch (SW1); and c. input line through both power switch(SW1) and door switch (SW2).When the power switch (SW1) is turned ON, each power supply circuit is suppliedwith AC power for DC outputs; the input lines are switched for the 5 VR, 12VU, and24VA1 power supply circuits by the remote signal (RMT) from the DC controller PCB.When the power switch (SW1) is turned ON, power is supplied to each power supplycircuit through the line that goes through the power switch (SW1; b) to activate themicroprocessor on the DC controller PCB. Then, the microprocessor on the DCcontroller PCB causes the remote signal (RMT) to go ‘1’ to turn ON the relay (RL401),switching the AC input line to the AC direct input line (a).When the power is turned OFF, the 38VU, 24VU, 24VR, 12VA2, and 24VH circuitsturn OFF; however, other DC power supply circuits remain ON to continue to provide theDC controller PCB with DC power, thereby rotating the fans for a specific period of time(about 15 min).Thereafter, the DC controller PCB causes the remote signal (RMT) to go ‘0’ to cut offthe AC circuit, thereby automatically cutting off the AC input to the DC power supplyPCB.You must disconnect the power plug before working on the DC controller PCB (forreplacement, for example).Reference:The tolerances for DC voltage are as follows:• +38VU +10%, –7%• +24VU +10%, –7%• +24VU ±2%• +24VA2 +10%, –7%• +24VH +10%, –7%• +5VR ±4%• +12VU +10%, –7%• +24VU +10%, –20%The above, however, assumes that the AC input accuracy is ±10%.COPYRIGHT © 1997 CANON INC. CANON NP6045 REV. 1 MAR. 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 7 EXTERNALS/AUXILIARY MECHANISMS7-9Caution:
