Bleeder circuit for use in a power supply

摘要

A bleeder circuit for use in a power supply of a lighting system includes a first terminal to be coupled to a first input of the power supply. A second terminal is to be coupled to a second input of the power supply. An edge detection circuit is coupled between the first and second terminals of the bleeder circuit. The edge detection circuit is coupled to output an edge detection signal in response to an input signal between the first and second inputs. A variable current circuit is coupled to the edge detection circuit and coupled between the first and second terminals of the bleeder circuit. The variable current circuit is coupled to conduct a bleeder current between the first and second terminals of the bleeder circuit in response to the edge detection signal.

主权项

1. A bleeder circuit for use in a power supply of a lighting system, comprising:
a first terminal to be coupled to a first input of the power supply; a second terminal to be coupled to a second input of the power supply; an edge detection circuit coupled between the first and second terminals of the bleeder circuit, the edge detection circuit coupled to output an edge detection signal indicating a high frequency transition in an input signal between the first and second inputs, wherein the edge detection circuit comprises a high pass filter coupled between the first and second terminals of the bleeder circuit, wherein the high pass filter includes an output coupled to generate the edge detection signal indicating the high frequency transition in the input signal between the first and second inputs of the power supply; and a variable current circuit coupled to the edge detection circuit and coupled between the first and second terminals of the bleeder circuit, the variable current circuit coupled to conduct a bleeder current between the first and second terminals of the bleeder circuit in response to the edge detection signal, wherein the variable current circuit is coupled to continue conducting the bleeder current between the first and second terminals of the bleeder circuit until an end of a half line cycle of the input signal.