Bleeder circuit for use in a power supply

Patent metadata

Field	Value
Publication number	US-9210744-B2
Application number	US-201213449922-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Apr 18, 2012
Publication date	Dec 8, 2015
Grant date	Dec 8, 2015

Abstract

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.

First claim

What is claimed is:

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.

2. The bleeder circuit of claim 1 wherein the edge detection circuit comprises a capacitance and a resistance coupled between the first and second terminals of the bleeder circuit, wherein the edge detection signal is output from the resistance.

3. The bleeder circuit of claim 1 wherein the edge detection circuit comprises a capacitance and a resistance coupled between the first and second terminals of the bleeder circuit, wherein the resistance comprises a first resistor and a second resistor coupled between the capacitance and the second terminal, wherein the edge detection signal is output from a node between the first resistor and the second resistor.

4. The bleeder circuit of claim 1 wherein the variable current circuit comprises a current amplifier circuit having an input coupled to receive the edge detection signal, the current amplifier circuit coupled between the first and second terminals to conduct the bleeder current in response to the edge detection signal.

5. The bleeder circuit of claim 1 wherein the variable current circuit comprises a first transistor having a first terminal coupled to the first terminal of the bleeder circuit, a second terminal coupled to the second terminal of the bleeder circuit, and a control terminal coupled to be responsive to the edge detection signal.

6. The bleeder circuit of claim 1 wherein the variable current circuit comprises:
a first transistor having a first terminal coupled to the first terminal of the bleeder circuit, a second terminal coupled to the second terminal of the bleeder circuit, and a control terminal; and
a second transistor having a first terminal coupled to the first terminal of the first transistor, a second terminal coupled to the control terminal of the first transistor, and a control terminal coupled to receive the edge detection signal from the edge detection circuit.

7. The bleeder circuit of claim 6 wherein the first and second transistors are bipolar transistors, and wherein the first and second transistors are included in a Darlington pair coupled between the first and second terminals and coupled to be responsive to the edge detection signal.

8. The bleeder circuit of claim 1 wherein the variable current circuit comprises a switch having a first terminal coupled to the first terminal of the bleeder circuit, a second terminal coupled to the second terminal of the bleeder circuit, and a control terminal coupled to be responsive to the edge detection circuit.

9. The bleeder circuit of claim 1 further comprising a third resistor coupled to the variable current circuit and coupled between the first and second terminals of the bleeder circuit.

10. The bleeder circuit of claim 1 further comprising a rectifier circuit, wherein the rectifier circuit comprises:
a first diode coupled between the first input of the power supply and the first terminal of the bleeder circuit;
a second diode coupled between the second input of the power supply and the first terminal of the bleeder circuit;
a third diode coupled between the first input of the power supply and the second terminal of the bleeder circuit; and
a fourth diode coupled between the second input of the power supply and the second terminal of the bleeder circuit.

11. The bleeder circuit of claim 1 wherein the edge detection signal is a current, and wherein the bleeder current is an amplified representation of the edge detection signal.

12. The bleeder circuit of claim 1 wherein the input signal comprises an input voltage to be received by the power supply from a dimmer circuit.

13. 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;
a first edge detection circuit coupled between the first and second terminals of the bleeder circuit, the first edge detection coupled to output a first edge detection signal indicating a high frequency transition in an input signal between the first and second inputs of the power supply having a first polarity;
a first variable current circuit coupled to the first edge detection circuit and coupled between the first and second terminals of the bleeder circuit, the first variable current circuit coupled to conduct a first bleeder current in a first direction between the first and second terminals of the bleeder circuit in response to the first edge detection signal;
a second edge detection circuit coupled between the first and second terminals of the bleeder circuit, the second edge detection coupled to output a second edge detection signal indicating the high frequency transition in the input signal between the first and second inputs of the power supply having a second polarity; and
a second variable current circuit coupled to the second edge detection circuit and coupled between the first and second terminals of the bleeder circuit, the second variable current circuit coupled to conduct a second bleeder current in a second direction between the first and second terminals of the bleeder circuit in response to the second edge detection signal.

14. The bleeder circuit of claim 13 further comprising:
a first diode coupled to the first edge detection circuit and the first variable current circuit and coupled between the first and second terminals of the bleeder circuit, wherein the first diode is coupled to conduct the first bleeder current through the first variable current circuit in response to the input signal having the first polarity; and
a second diode coupled to the second edge detection circuit and the second variable current circuit and coupled between the first and second terminals of the bleeder circuit, wherein the second diode is coupled to conduct the second bleeder current through the second variable current circuit in response to the input signal having the second polarity.

15. The bleeder circuit of claim 13 wherein each one of the first and second edge detection circuits comprises a respective one of first and second high pass filters coupled between the first and second terminals of the bleeder circuit to generate a respective one of the first and second edge detection signals indicating the high frequency transition in the i

Assignees

• Del Carmen Jr Jose Requinton
• Angeles Christian Pura
• Power Integrations Inc

Inventors

• Del Carmen Jr Jose Requinton
• Angeles Christian Pura

Classifications

• H05B45/3575

  by means of dummy loads or bleeder circuits, e.g. for dimmers · CPC title

• H05B45/10 Primary

  Controlling the intensity of the light · CPC title

• H05B33/0815

  Electricity · mapped topic

• H05B33/0809 Primary

  Electricity · mapped topic

• H05B33/0845

  Electricity · mapped topic