Protective Mechanisms - Canon iR1600 Service Manual

2.2 Protective Mechanisms

The power supply PCB is equipped with overcurrent/over-voltage protective mechanisms
that will automatically cut off the output voltage to prevent faults in the power supply cir-
cuitry otherwise caused by a fault in any of the loads (e.g., short-circuit).
When the overcurrent/over-voltage protective mechanism has gone ON, correct the fault
in the load, and turn on the power switch once again to reset the machine.
The circuitry is equipped with a fuse, which will blow to cut off the power in response to
an overcurrent in the AC line.
2.3 High-Voltage Power Supply Circuit
The high-voltage output circuit is built into the DC controller PCB. The ASIC on the DC
controller PCB sends the following commands for the generation of high voltage at such
times as needed:
• primary charging roller applica tion voltage (AC voltage + DC negative voltage)
• developing bias (AC voltage + DC negative voltage)
• transfer charging roller application voltage (DC positive voltage or DC negative voltage)
For the control of biases applied to each load, see "Image Formation System" in Chapter 5.
COPYRIGHT© 2002 CANON INC.
CHAPTER 8 EXTERNALS AND AUXILIARY CONTROL SYSTEM
2000 CANON iR1600/iR2000 REV.1 JAN. 2002
8-5