Patent ID: 8115457

Claim:
A circuit, comprising: a control circuit coupled to an input of a power converter, the control circuit coupled to detect whether an electrical energy source is coupled to an input of the power converter; and a switch coupled to the control circuit and coupled to the input of the power converter, the control circuit coupled to drive the switch in a first operating mode when the electrical energy source is coupled to the input of the power converter, the control circuit coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input of the power converter, wherein a capacitance coupled between input terminals of the input of the power converter is discharged through the switch to a threshold voltage in less than a maximum period of time from when the electrical power source is uncoupled from the input terminals of the power converter, and wherein the control circuit is coupled to drive the switch to have a high average impedance in the first operating mode.