Patent ID: 6061220
Filing Date: 2000-05-09
Classification: G06F,H04L

Abstract:
A power switching circuit provided in a main device to which external devices are connected via a network and which comprises a power supply circuit for supplying power; a physical connection control circuit for controlling the physical connection with the external devices; a voltage-reduction circuit, inserted between the power supply circuit and the physical connection control circuit, for reducing the voltage of the power supplied from the power supply circuit; and an internal circuit connected with the voltage-reduction circuit or the physical connection control circuit, andthe power switching circuit comprising the following elements for each external device:a first diode for transmitting the power from the main device to the network, and for preventing power from reversely flowing from the network to the main device;a second diode for transmitting power from the external device to the main device, and for preventing power from reversely flowing from the main device to the external device; anda port for physically connecting the main device and the external device, andwherein connection between the external devices is maintained regardless of the state of the power of the main device.