초록 ▼

A dual mode external DC power supply system for supplying DC power to an electronic device and which operates under the control of the electronic device is provided. The disclosed embodiment of the power supply system includes a first input adapted to receive an input signal of unregulated DC power,

A dual mode external DC power supply system for supplying DC power to an electronic device and which operates under the control of the electronic device is provided. The disclosed embodiment of the power supply system includes a first input adapted to receive an input signal of unregulated DC power, a second input adapted to receive a control signal from the electronic device, and an output adapted to provide either a constant voltage DC output signal or a constant current DC output signal depending on the magnitude of the control signal. The control signal also determines the level of constant current delivered to the electronic device when the system is operating in the constant current mode. The disclosed embodiment of the DC power supply system includes a regulating circuit responsive for conditioning the input signal of unregulated DC power into a DC output signal, a voltage sensing circuit adapted to provide a first feedback signal to the regulating circuit, a current sensing circuit also adapted to provide a second feedback signal to the regulating circuit, and a switch responsive to the control signal, for operatively coupling the first feedback signal to the regulating circuit when the system is operating in the constant voltage mode and coupling the second feedback signal when the system is operating in the constant current mode.

대표청구항 ▼

[ What is claimed is:] [1.] An electronic system comprising:an external DC power supply system comprising:an AC to DC converter;a control signal input; anda regulating circuit coupled to the AC to DC converter and to the control signal input, the regulating circuit including a DC power output, and g

[ What is claimed is:] [1.] An electronic system comprising:an external DC power supply system comprising:an AC to DC converter;a control signal input; anda regulating circuit coupled to the AC to DC converter and to the control signal input, the regulating circuit including a DC power output, and generating a DC output signal at the DC power output in response to unregulated DC power from the AC to DC converter and a control signal from the control signal input, the regulating circuit including:a switching circuit coupled to the control signal input, for operating the regulating circuit in a constant voltage mode in the event a magnitude of the control signal is within a first prescribed range, and for operating the regulating circuit in a constant current mode in the event the magnitude of the control signal is within a second prescribed range, and for selecting a selected level of constant current, in the event the regulating circuit is being operated in the constant current mode, as a function of the magnitude of the control signal within the second prescribed range; anda portable electronic device comprising:a control signal output detachably coupled to the control signal input of the external DC power supply system, for providing the control signal to the control signal input; anda DC power input detachably coupled to the DC power output of the external DC power supply system.