Canon BJC-8500 Service Manual

Also see for BJC-8500: User manual

Contents

4.3 Power Supply SectionThe power supply section is a switching regulator that converts the input AC to thevarious DC voltages to be used on the printer, and supplies these DC voltages to thelogic board.4.3.1 Block diagram of power supply section4.3.2 Power supply section structure1) AC inletThe AC inlet incorporates a GND terminal. The input voltages are as follows:102V (120V -15%) to 264V (240V +10% )2) Internal circuitsProtective circuitsThe protective circuits protect the internal circuits from overvoltage input andeliminate electrical noise.The protective circuits are provided with a fuse. This fuse blows to protect theinternal circuits in the event of an overvoltage input.The fuse is installed in a fuse holder, and can be replaced if it blows due toovervoltage.Primary side circuitsThe primary side circuits rectify and smooth the input AC voltage. This voltage isthen converted by the DC/DC converter, and supplied through the switchingcircuit to the primary side of the transformer.Secondary side circuitsThe respective voltages are generated from the voltage at the transformer'ssecondary voltage. VH and VM are generated by the switching circuit, and VCC isgenerated by the constant voltage circuit.4-41BJC-8500Part 4: Technical ReferenceFigure 4-39 Block Diagram of Power Supply SectionRectifierandSmoothingCircuitVHVMVCCACInlet ProtectiveCircuitNoiseFilterOutputConnectorProtective Circuits Secondary Side CircuitsPrimary Side CircuitsLogic BoardConnected toPower CordSwitchingCircuitConstantVoltageCircuitTrans-formerRectifierandSmoothingCircuitRectifierandSmoothingCircuitSwitchCircuitJ802 J801