US 8,710,755 B2 · Light emitting device power supply circuit, and light emitting device driver circuit and control method thereof

Abstract

The present invention discloses a light emitting device power supply circuit, a light emitting device driver circuit and a control method thereof. The light emitting device driver circuit is coupled to a tri-electrode AC switch (TRIAC) dimmer circuit, and it controls the brightness of a light emitting device circuit according a rectified dimming signal. The light emitting device driver circuit includes a power stage circuit and a light emitting device control circuit. The light emitting device control circuit generates a switch control signal. The power stage circuit operates at least one power switch thereof according to the switch control signal to generate a latching current for firing the TRIAC dimmer circuit, and the latching current is inputted to the light emitting device circuit.

Claims16

Dependent claims

A light emitting device driver circuit for driving a light emitting device circuit according to a rectified dimming signal, wherein the rectified dimming signal is generated from an AC input signal which passes through a tri-electrode AC switch (TRIAC) dimming circuit and a rectifier circuit, the light emitting device driver circuit comprising:

a power stage circuit coupled between the rectifier circuit and the light emitting device circuit, the power stage circuit operating at least one power switch therein according to a switch control signal to generate a latching current for firing the TRIAC dimming circuit, wherein the latching current flows through the light emitting device circuit;
and
a light emitting device control circuit coupled to the power stage circuit, the light emitting device control circuit generating the switch control signal according to a detection signal;
wherein the detection signal is generated according to the rectified dimming signal or a signal related to the rectified dimming signal, and the detection signal is generated when the rectified dimming signal changes from a neutral level to a predetermined level, and wherein the switch control signal turns ON the power switch continuously for a predetermined period.

1 more element

a power stage circuit coupled between the rectifier circuit and the light emitting device circuit, the power stage circuit operating at least one power switch therein according to a switch control signal to generate a latching current for firing the TRIAC dimming circuit, wherein the latching current flows through the light emitting device circuit;
and
a light emitting device control circuit coupled to the power stage circuit, the light emitting device control circuit generating the switch control signal according to a detection signal;
wherein the detection signal is generated according to at least one method below:
(1) by detecting the rectified dimming signal or a signal related to the rectified dimming signal, and the detection signal is generated when the rectified dimming signal is at a neutral level or below a predetermined level;
(2) by detecting an input or an output current flowing through the power stage circuit or a signal related to the input or the output current, and the detection signal is generated when the input or the output current is zero;
and
(3) by generating the detection signal with a frequency corresponding to a frequency of the AC input signal or the rectified dimming signal.

5 more elements

A light emitting device control method, comprising:

receiving a rectified dimming signal, which is generated from an AC input signal which passes through a tri-electrode AC switch (TRIAC) dimming circuit and a rectifier circuit;
generating a switch control signal according to a detection signal;
controlling at least one power switch of a power stage circuit according to the switch control signal to generate a latching current for firing the TRIAC dimming circuit;
and
inputting the latching current to the light emitting device;
wherein the detection signal is generated according to at least one method below:
(1) by detecting the rectified dimming signal or a signal related to the rectified dimming signal, and the detection signal is generated when the rectified dimming signal is at a neutral level or below a predetermined level;
(2) by detecting an input or an output current flowing through the power stage circuit or a signal related to the input or the output current, and the detection signal is generated when the input or the output current is zero;
and
(3) by generating the detection signal with a frequency corresponding to a frequency of the AC input signal or the rectified dimming signal.

7 more elements

A light emitting device power supply circuit, comprising:

a tri-electrode AC switch (TRIAC) dimming circuit for generating an AC dimming signal according to an AC input signal;
a rectifier circuit for generating a rectified dimming signal according to the AC dimming signal;
and
a light emitting device driver circuit for driving a light emitting device circuit according to the rectified dimming signal, the light emitting device driver circuit including:
a power stage circuit coupled between the rectifier circuit and the light emitting device circuit, the power stage circuit operating at least one power switch therein according to a switch control signal to generate a latching current for firing the TRIAC dimming circuit, wherein the latching current flows through the light emitting device circuit;
and
a light emitting device control circuit coupled to the power stage circuit, the light emitting device control circuit generating the switch control signal according to a detection signal;
wherein the detection signal is generated according to at least one method listed below:
(1) by detecting the rectified dimming signal or a signal related to the rectified dimming signal, and the detection signal is generated when the rectified dimming signal is at a neutral level or below a predetermined level;
(2) by detecting an input or an output current flowing through the power stage circuit or a signal related to the input or the output current, and the detection signal is generated when the input or the output current is zero;
and
(3) by generating the detection signal with a frequency corresponding to a frequency of the AC input signal or the rectified dimming signal.

9 more elements

Dependencies are inferred from the claim text.

Light emitting device power supply circuit, and light emitting device driver circuit and control method thereof

Life of this patent

Light emitting device power supply circuit, and light emitting device driver circuit and control method thereof

Life of this patent

Abstract

Claims16