Circuit for realizing intelligent LED dimming and color modulation based on single DC-DC dimming chip

Abstract

The invention discloses a circuit for realizing intelligent LED dimming and color modulation based on a single DC-DC dimming chip, which comprises a single-chip microcomputer, a dimming chip and a color modulation module, and is characterized in that the single-chip microcomputer is connected with an external pulse signal and calculates a color temperature signal and a brightness signal, and the single-chip microcomputer outputs the color temperature signal and the brightness signal; the dimming chip is electrically connected with the single-chip microcomputer and receives a brightness signal. The color modulation module is electrically connected with the single-chip microcomputer and receives a color temperature signal. Brightness adjustment and color temperature adjustment of an LED can be achieved through a single DC-DC dimming chip, the PCB space and related circuits are saved, PCB miniaturization design is facilitated, peripheral circuits are reduced, the stability of a circuit system is improved, brightness and color temperature are synchronously adjusted through complementary PWM signals, and the lighting effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of LED adjustment circuits, and specifically to a circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip. Background Art

[0002] As a new type of light source, LEDs have the characteristics of energy saving, environmental protection, and high efficiency, and are currently widely used in various lighting fields. Common household LED lights usually have the function of adjusting color temperature and brightness to meet different lighting needs. In related technologies, a DC-DC dimming chip is commonly used to change the color temperature or brightness of LED lights. Existing color adjustment / dimming chips can only perform color adjustment or dimming. If both color adjustment and dimming are required, an additional set of chips needs to be added, and the additional chips occupy more PCB space, which is not conducive to miniaturized design. Summary of the Invention

[0003] The purpose of the present invention is to provide a circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip, including a single-chip microcomputer, the single-chip microcomputer is connected to an external pulse signal and calculates a color temperature signal and a brightness signal, and the single-chip microcomputer outputs the color temperature signal and the brightness signal;

[0005] A dimming chip, the dimming chip is electrically connected to the single-chip microcomputer and receives the brightness signal;

[0006] A color adjustment module, the color adjustment module is electrically connected to the single-chip microcomputer and receives the color temperature signal.

[0007] Further, the color adjustment module includes a first optocoupler and a second optocoupler, the first optocoupler and the second optocoupler isolate two color temperature signals, and further includes a first MOS transistor and a second MOS transistor, the first MOS transistor and the second MOS transistor serve as the negative electrodes of the LEDs.

[0008] Further, the color adjustment module includes a third MOS transistor, a fourth MOS transistor, and a triode, the third MOS transistor and the triode are electrically connected to the single-chip microcomputer, and the fourth MOS transistor is electrically connected to the triode.

[0009] Compared with the prior art, the beneficial effects of the present invention are: The brightness adjustment and color temperature adjustment of the LED can be realized through a single DC-DC dimming chip, saving PCB space and related circuits, being conducive to the miniaturized design of the PCB, reducing the peripheral circuit, improving the stability of the circuit system, and synchronously adjusting the brightness and color temperature through complementary PWM signals, with good lighting effects. Brief Description of the Drawings

[0010] Figure 1 The circuit diagram of the first embodiment of the present invention;

[0011] Figure 2 The circuit diagram of the second embodiment of the present invention. Specific implementation manners

[0012] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0013] Embodiment 1

[0014] Please refer to Figure 1 , the present invention provides a technical solution: a circuit for realizing intelligent LED dimming and color mixing based on a single DC-DC dimming chip, including a single-chip microcomputer (U1), the single-chip microcomputer is connected to an external pulse signal and calculates a color temperature signal and a brightness signal, and the single-chip microcomputer outputs the color temperature signal and the brightness signal;

[0015] A dimming chip (U2), the dimming chip is electrically connected to the single-chip microcomputer and receives the brightness signal;

[0016] A color mixing module, the color mixing module is electrically connected to the single-chip microcomputer and receives the color temperature signal.

[0017] In this embodiment, the dimming chip is a DC-DC, and the dimming chip converts the input DC voltage into another DC voltage, and the power output by the dimming chip serves as the positive electrode of the LED.

[0018] In this embodiment, the color mixing module includes a first optocoupler and a second optocoupler, the first optocoupler and the second optocoupler isolate two color temperature signals, and further includes a first MOS transistor and a second MOS transistor, and the first MOS transistor and the second MOS transistor serve as the negative electrode of the LED.

[0019] 1 DC-DC dimming chip adjusts the brightness through 1 PWM signal, and then through the complementary manner of 2 PWM signals, one for white light and the other for yellow light, is isolated to the DC-DC side through the first optocoupler and the second optocoupler, and the first MOS transistor and the second MOS transistor are driven to realize the dimming and color mixing function

[0020] The single-chip microcomputer receives an external pulse signal (such as PWM, button input or wireless communication signal), and analyzes and generates a color temperature signal (white / yellow light ratio) and a brightness signal (PWM duty cycle) through a built-in algorithm;

[0021] The dimming chip adopts a constant-current control type chip. The input voltage range covers 5 - 60 VDC. It outputs to drive the positive electrode of the LED. The output current is adjusted through the brightness signal (accuracy ±3%). It supports 65,536 levels of grayscale dimming. The dimming chip integrates an over-temperature protection function. When the temperature exceeds the limit, the current is automatically reduced or cut off.

[0022] The first optocoupler (white light channel) isolates the color temperature signal from the second optocoupler (yellow light channel) to prevent mutual interference between the two MOS transistor drive circuits.

[0023] The first MOS transistor and the second MOS transistor serve as the negative switches of the white light / yellow light LEDs respectively. The current ratio of the two channels is dynamically adjusted through complementary PWM signals (such as 60% duty cycle for white light + 40% for yellow light) to achieve continuous color temperature adjustment from 2700K to 6500K.

[0024] The following two PWM signals output by the single-chip microcomputer (U1) are complementary (cold light duty cycle + warm light duty cycle = 100%) to avoid color temperature jumps. The response times of the first optocoupler and the second optocoupler need to match the PWM frequency (1 - 5 kHz) to prevent signal delay from causing flickering of the mixed light.

[0025] N-channel MOS transistors with low on-resistance (Rds < 50 mΩ) are selected, which support high-frequency switching (>100 kHz) to reduce power consumption and heat generation.

[0026] The input power supply (such as 12 VDC) is divided into two paths through an isolation transformer: one path supplies power to the single-chip microcomputer (U1) (5 V), and the other path supplies power to the dimming chip and the LEDs (adjustable from 12 - 36 V).

[0027] An inductor (such as 22 μH) and a capacitor (100 μF) are connected in series at the output end of the dimming chip to suppress high-frequency ripples and improve the stability of constant current.

[0028] The dimming chip is built-in with over-current protection (such as a 3A threshold), and an external fuse (such as 2A) is used as secondary protection, achieving high-precision coordinated control of the LED brightness and color temperature.

[0029] Embodiment 2

[0030] Please refer to Figure 2 This invention provides a technical solution: A circuit for realizing intelligent LED dimming and color mixing based on a single DC-DC dimming chip, including a single-chip microcomputer (U1). The single-chip microcomputer (U1) is the secondary of the switching power supply. The single-chip microcomputer is connected to an external pulse signal and calculates the color temperature signal and the brightness signal. The single-chip microcomputer outputs the color temperature signal and the brightness signal, and adjusts the brightness through the upper PEM signal.

[0031] A dimming chip (U2), which is electrically connected to the single-chip microcomputer and receives the brightness signal.

[0032] A color - adjustment module, which is electrically connected to a single - chip microcomputer and receives a color temperature signal.

[0033] The color - adjustment module includes a third MOS transistor, a fourth MOS transistor, and a triode. The third MOS transistor and the triode are electrically connected to the single - chip microcomputer, and the fourth MOS transistor is electrically connected to the triode.

[0034] The PWM signal below is used for brightness adjustment through a DC - DC dimming chip, and then directly drives the third MOS transistor through the PWM signal. And this PWM signal also passes through a triode (NPN) for inverting amplification to drive the fourth MOS transistor. Through this operation, two complementary PWM signals are output to drive the third MOS transistor and the fourth MOS transistor to achieve the function of dimming and color adjustment.

[0035] The third MOS transistor is an N - channel MOS transistor, directly connected to the PWM of the color temperature signal of the single - chip microcomputer to control the white - light LED circuit. The triode is an NPN - type triode, used for level conversion and drive amplification, connected to the complementary PWM signal of the single - chip microcomputer, driving the fourth MOS transistor to control the warm - light LED circuit, and driving its gate voltage by the triode.

[0036] When the single - chip microcomputer outputs a high level of white - light PWM, the third MOS transistor conducts, and the LED emits white light.

[0037] The complementary PWM signal drives the fourth MOS transistor to conduct through the triode, and the yellow - light LED lights up.

[0038] By adjusting the duty cycles of the two PWM signals (such as the duty cycle of white light is 60% and the duty cycle of yellow light is 40%), the mixed - color - temperature adjustment is realized. The optocoupler isolation is omitted, the circuit is more concise, and the scheme of using the triode to drive the third MOS transistor and the fourth MOS transistor enhances the anti - interference ability and is applicable to high - noise environments.

[0039] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip, characterized in that: include: A single chip microcomputer, wherein the single chip microcomputer is connected to an external pulse signal and calculates a color temperature signal and a brightness signal, and the single chip microcomputer outputs the color temperature signal and the brightness signal; A dimming chip, the dimming chip is electrically connected to the single-chip computer and receives a brightness signal; A color adjustment module is electrically connected to the single chip computer and receives a color temperature signal.

2. According to claim 1, a circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip, characterized in that: The dimming chip is a DC-DC, and the dimming chip converts the input DC voltage into another DC voltage, and the power output by the dimming chip serves as the positive electrode of the LED.

3. According to claim 1, a circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip, characterized in that: The single chip computer is electrically connected to a power source.

4. According to claim 1, a circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip, characterized in that: The color adjustment module includes a first optical coupler and a second optical coupler, and the first optical coupler and the second optical coupler isolate two color temperature signals.

5. The circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip according to claim 4, characterized in that: It also includes a first MOS tube and a second MOS tube, and the first MOS tube and the second MOS tube serve as the cathode of the LED.

6. The circuit for realizing intelligent LED dimming and color adjustment based on a single DC-DC dimming chip according to claim 1, characterized in that: The color adjustment module includes a third MOS tube, a fourth MOS tube, and a triode. The third MOS tube and the triode are electrically connected to the single chip computer, and the fourth MOS tube is electrically connected to the triode.

Images