Patent ID: 7577855
Filing Date: 2009-08-18
Classification: H03K,H04L

Abstract:
1. A system for controlling power supplied by a power supply, comprising: an attachment device; and a circuit coupled to the supply and operable to be coupled to the attachment device, the circuit including a connector initially conducting power at a first power level to the attachment device, and a control coupled to the connector, the connector operable to provide a first signal to and receive a second signal from the attachment device, the attachment device producing state transitions of the second signal responsive to state transitions of the first signal, the control using the state transitions of the first and second signals to determine if the attachment device is authorized to receive power, the connector continuing to conduct power at the first power level to the attachment device if the control determines the attachment device is authorized to receive power, wherein the second signal states each comprise a corresponding voltage level and the attachment device is operable to regulate each voltage level of the second signal states to be within a predetermined voltage-level range.