TWO-WIRED LED LIGHT ADJUSTING SYSTEM

• US 20110148326A1
• Filed: 12/22/2010
• Published: 06/23/2011
• Est. Priority Date: 12/22/2009
• Status: Active Grant

• Current Assignee: Weltrend Semiconductor Inc.
• Original Assignee: Weltrend Semiconductor Inc.
• Inventors: Lo, Chiu-Lang, Wang, Shih-Chieh, Su, Pu-Ju, Tsai, Yu-Huan
• Granted Patent: US 8,324,821 B2
• Time in Patent Office: Days
• US Class Current: 315/307
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/31 Phase-control circuits

Abstract

A two-wired LED light adjusting system, for controlling the luminance adjustment for a LED lamp module. The light adjusting circuit includes a phase modulating circuit, a LED driving circuit and a controller. The phase modulating circuit generates a phase modulating voltage. The controller detects the phase modulating voltage of various waveforms. When the controller detects the phase modulating voltage of different waveforms, the controller controls the LED driving circuit to enable the LED lamp module to emit light of different luminance according to waveforms of the phase modulating voltage.

Claims

1. A two-wired LED (Light-Emitting Diode) light adjusting system for adjusting light of an LED lamp module, comprising:

a phase modulating circuit, coupled to an alternating current (AC) power source, for generating a phase modulating voltage, wherein the phase modulating circuit partially restrains AC power received from the AC power source for a waveform of the phase modulating voltage to comprise a non-conduction angle;

a rectifying circuit, coupled to the phase modulating circuit and the AC power source for rectifying the phase modulating voltage so as to generate a DC (direct current) voltage;

an LED driving circuit, coupled to the LED lamp module and the rectifying circuit, for driving the LED lamp module according to the DC voltage; and

a controller, coupled between the phase modulating circuit and the LED driving circuit, for controlling the LED driving circuit to drive the LED lamp module according to the non-conduction angle of the waveform of the phase modulating voltage.

2. The two-wired LED light adjusting system of claim 1, wherein the phase modulating circuit comprises a first switch, a second switch and a third switch.

3. The two-wired LED light adjusting system of claim 2, wherein when the first switch, the second switch and the third switch are all turned on, the phase modulating voltage generated by the phase modulating circuit is a first sine wave.

4. The two-wired LED light adjusting system of claim 3, wherein when the phase modulating voltage is the first sine wave, the controller controls the LED driving circuit to drive the LED lamp module to generate a first luminance.

5. The two-wired LED light adjusting system of claim 2, wherein when the third switch is not turned on and the first switch and the second switch are turned on, the phase modulating voltage generated by the phase modulating circuit is a second sine wave, and 0-90 degrees of phase of the second sine wave comprises the non-conduction angle.

6. The two-wired LED light adjusting system of claim 5, wherein when the phase modulating voltage is the second sine wave, the controller controls the LED driving circuit to drive the LED lamp module to generate a second luminance.

7. The two-wired LED light adjusting system of claim 2, wherein when the first switch is not turned on, and the second and the third switch are turned on, the phase modulating voltage generated by the phase modulating circuit is a third sine wave, and 180-270 degrees of phase of the third sine wave comprises the non-conduction angle.

8. The two-wired LED light adjusting system of claim 7, wherein when the phase modulating voltage is the third sine wave, the controller controls the LED driving circuit to drive the LED lamp module to generate a third luminance.

9. The two-wired LED light adjusting system of claim 2, wherein when the second switch is not turned on, the phase modulating voltage generated by the phase modulating circuit is a fourth sine wave, and each of 0-90 degrees and 180-270 degrees of phase of the fourth sine wave comprises the non-conduction angle.

10. The two-wired LED light adjusting system of claim 9, wherein when the phase modulating voltage is the fourth sine wave, the controller controls the LED driving circuit to turn off the LED lamp module.