Patent ID: 7082545

Claim:
A detector for detecting a wire connection with a personal computer, the detector comprising: a plug for connecting the detector to the personal computer through a cable; a battery power supply which outputs a predetermined constant electrical potential; and a Micro Control Unit which receives a specific electrical potential from the personal computer through the plug and cable, and receives the constant electrical potential from the battery power supply, wherein the Micro Control Unit comprises: a CPU and peripheral circuit which receives the constant electrical potential from the battery power supply, wherein the CPU and peripheral circuit is operated by electrical potential supplied from the battery power supply; a USB function circuit which receives the specific electrical potential from the personal computer, wherein the USB function circuit is on-off controlled by the CPU and peripheral circuit, wherein the USB function circuit is operated by only electrical potential supplied from the personal computer; and a detection circuit which detects a voltage level of the specific electrical potential from the personal computer and outputs an electrical potential to the CPU and peripheral circuit based on the detected voltage level.