Toshiba 4560, Service Manual

Page: 240 / 369

Nov. 1997 © TOSHIBA 15 - 1 4560/4570 POWER
15. POWER STABILIZING CIRCUIT
15.1 Power Circuit
This power circuit has the following 3 DC outputs.
DC output Rating Main load
5V 5V±5% LED eraser array, LCD, LED, logic IC power supplies
24VA – C, K, L 24V±10% Motors, clutches, high-voltage transformer, scanning motor
24VD – J 24V±10% RADF, optional sorter, main switch
15.2 Description of Operation
When the main switch on the copier is turned ON, AC power is supplied to the switching power supply,
and then the 5V power supply for the logic ICs, and the 24VD – J DC power supply for the RADF and
sorter are turned ON. At this time, if the door switch is ON (closed), the 24VA – C, K, L DC voltages are
turned ON.
Each of these power circuit is provided with overcurrent protection fuses (excluding 5V) and an overcurrent
protection unit is provided in the circuit to protect the copier’s power circuit in case of an overload or a
power output short.
When these functions are in operation, remove the cause of the overload or short. When a fuse has
blown, replace the fuse. Or, when overcurrent protection in the circuit is in operation, turn the main switch
OFF then ON again to enable circuit operation.
The power circuit is also provided with an overvoltage protection function. This function prevents the
power supply from being turned ON to protect electrical components if two different voltages short. If this
happens, remove the cause of the short, and turn the main switch OFF then ON again to enable circuit
operation.