Light source dimming control circuit
A technology of dimming control circuit and light source, applied in the direction of light source, electric light source, electroluminescence light source, etc., can solve the problem of inaccurate amplification of driving current of analog components
Active Publication Date: 2014-02-12
IML HONG KONG LTD
View PDF4 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Although the analog dimming mode can reduce the generation of electromagnetic interference, when the driving current becomes smaller, the characteristic error of the analog components will cause the inaccuracy of the driving current to be amplified
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
no. 1 example
[0043] According to the first embodiment, when the voltage level of the voltage signal V2 is higher than the voltage level of the voltage signal V3, the switch controller 130 keeps turning on the switch SW, and the voltage level of the reference voltage signal Vref is equal to the voltage level of the voltage signal V1 Therefore, the light source DL performs dimming by adjusting the continuous current I flowing through the resistor R1 (the current I is determined by the voltage level of the reference voltage signal Vref), that is The light source DL is dimmed in an analog dimming mode; and when the voltage level of the voltage signal V2 is lower than the voltage level of the voltage signal V3, the switch controller 130 alternately turns on and off the switches SW, and the voltage of the reference voltage signal Vref The level is fixed and the same as the voltage level of the voltage signal V3 to provide a fixed discontinuous current I. Therefore, the light source DL is dimmed b...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The present invention provides a light source dimming control circuit, which includes a voltage signal generator for generating a first voltage signal between a predetermined voltage level and a ground level; a reference voltage signal generator for generating a reference voltage signal at an output end according to the first voltage signal and a second voltage signal; a first switch with a first end coupled to an output end of a light source; a first resistor with a first end coupled to a second end of the first switch, and a second end coupled to a ground end; a switch controller coupled to the first switch and the voltage signal generator for controlling on / off states of the first switch according to a sawtooth signal and the first voltage signal; and a current controller for controlling current flowing through the first resistor according to the reference voltage signal. The light source dimming control circuit provided by the invention can be used for dimming a light source between an analog dimming mode and a pulse width modulation dimming mode.
Description
technical field [0001] The invention relates to a light source dimming control circuit, in particular to a light source dimming control circuit capable of dimming a light source between an analog dimming mode and a pulse width modulation dimming mode. Background technique [0002] With the advancement of related technologies, various light sources, such as light emitting diodes (LEDs) or cold cathode fluorescent lamps (CCFLs), are applied to various lighting devices to save power. The LED light source is a light source controlled by current, wherein the brightness of the LED light source is related to the magnitude of the driving current. In general, LED light sources can be dimmed according to a pulse width modulation method or an analog method. [0003] In the PWM dimming mode, a switch is alternately turned on and off according to the duty cycle of a PWM signal to generate a discontinuous current as the driving current of the LED light source. Although the pulse width m...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): H05B37/02
CPCH05B33/0824H05B45/44
Inventor 江永欣李怡玫
Owner IML HONG KONG LTD