Power supply apparatus, image forming apparatus having the same, and method thereof

摘要

A power supply apparatus capable of outputting a predetermined voltage or a predetermined electrical current selectively is provided, including a voltage level setter to determine an output level of a voltage or an electrical current according to an external signal, a constant voltage feedback unit to correct an output value of the voltage level setter so as to output a constant voltage of the output level to a load terminal, a constant current feedback unit to maintain the external signal constantly and correct an output value of the voltage level setter so as to output a constant current of the output level to the load terminal, a switch to connect the voltage level setter with the constant voltage feedback unit or the constant current feedback unit selectively, and a controller to control the switch to output the constant voltage or the constant current selectively according to a state of the load terminal.

主权项

1. A power supply apparatus capable of outputting a predetermined voltage or a predetermined electrical current selectively, the power supply apparatus comprising:
a voltage level setter to determine an output level of a voltage or an electrical current according to an external signal; a constant voltage feedback unit to correct an output value of the voltage level setter so as to output a constant voltage of the output level to a load terminal; a constant current feedback unit to maintain the external signal constantly and correct an output value of the voltage level setter so as to output a constant current of the output level to the load terminal; a switch to connect the voltage level setter with the constant voltage feedback unit or the constant current feedback unit selectively; and a controller to control the switch to output the constant voltage or the constant current selectively according to a state of the load terminal, wherein the constant voltage feedback unit is electrically connected between a first side terminal of the load terminal from which an input current is output and the switch, and the constant current feedback unit is electrically connected between a second side terminal of the load terminal to which a current is input and the switch, and wherein the controller selects the constant voltage feedback unit or the constant current feedback unit for controlling the switch.