CN201657436U - LED lamp light control device - Google Patents

Abstract

The utility model discloses an LED lighting control device, which comprises: a pulse width modulation generator, a power tube and an LED lighting device; the pulse width modulation generator is connected to the power tube; the power tube is connected to the LED lighting device; the pulse width modulation generator generates a pulse width modulation signal, and modulates the duty cycle of the LED lighting device through the power tube, thereby controlling the luminous brightness of the LED lighting device and realizing R, G, B mixed colors. The embodiment of the utility model can randomly realize infinitely many changes of light colors without software programming control, making it easy for non-professionals to grasp, and the circuit is concise, with few components and parts, saving costs.

Description

LED lighting control device

technical field

The utility model relates to the field of LED lighting, in particular to an LED lighting control device.

Background technique

With the development of light-emitting diode (LED) technology, people begin to use LED light-emitting devices as lighting and decorative lamps. When the LED lighting device is used as a decorative lamp, a single LED light is far from meeting people's aesthetic needs. Therefore, it is necessary for the LED lamp group to emit light of different colors, so that the decorative lamps change and look beautiful, giving people a visual sense. enjoy.

In the prior art, a 7-color transition or gradient circuit composed of a digital circuit (IC hardware) can be used to realize the color change and brightness change of the LED lamp, but the changing colors are only 7, and the colors are not rich enough.

Another technology to realize LED light transformation is to use computer programming software to realize thousands of color changes according to the program, but the programming is complicated and difficult for non-professionals to master, and the resulting software costs are also greatly increased.

Utility model content

The embodiment of the utility model provides an LED lighting control device, including: a pulse width modulation generator, a power tube and an LED lighting device; the pulse width modulation generator is connected to the power tube; the power tube is connected to the The LED lighting device; the pulse width modulation generator generates a pulse width modulation signal, and modulates the duty ratio of the LED lighting device through the power tube, thereby controlling the luminous brightness of the LED lighting device and realizing R, G, B mixed colors. The LED lighting device also includes a current limiting resistor connected in series with the LED for stabilizing the current.

The embodiment of the utility model generates pulse width modulation signals of different periods according to the adjustment of the pulse width modulation generator, so that the on-duty ratio of each corresponding power tube is different at the same time, resulting in LED lamp groups of different colors At the same moment, its brightness is also different. Moreover, the lighting control device of the utility model can randomly realize infinitely many changes of lighting colors without software programming control, making it easy for non-professionals to grasp, and the circuit is concise, with few components and parts, saving costs.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the utility model, constitute a part of the application, and do not constitute a limitation to the utility model. In the attached picture:

Fig. 1 is a structural block diagram of an LED lighting control device according to an embodiment of the present invention;

Fig. 2 is a schematic structural view of an embodiment of the LED lighting control device of the present invention;

Fig. 3 is a schematic diagram of a color mixing structure of an embodiment of the LED lighting control device of the present invention;

Fig. 4 is the change curve of the turn-on duty ratio of the R, G, and B three lamp groups of the embodiment shown in Fig. 3;

Fig. 5 is the logical structural diagram of the Schmitt trigger CD4093 of the utility model embodiment;

Fig. 6 is the logical structural diagram of four op-amp integrated circuits LM324 of the utility model embodiment;

FIG. 7 is a schematic circuit diagram of an LED lighting control circuit formed by using the logic elements shown in FIG. 5 and FIG. 6 according to the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the embodiments of the present utility model will be further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiment of the utility model and its description are used to explain the utility model, but not as a limitation to the utility model.

Fig. 1 is a structural block diagram of the LED lighting control device of the present invention. The LED lighting control device includes a pulse width modulation (Pulse Width Modulation, PWM) generator 10 , a power tube 20 and an LED lighting device 30 . Wherein, the PWM generator 10 is used to generate a pulse width modulation signal, and the on-duty ratio of the LED lighting device 30 is controlled through the power tube 20, thereby adjusting the luminance of the LED lighting device. Because the brightness of the LED lamp is related to the average voltage applied to it, as long as the average operating voltage of the LED is changed, the brightness of the LED can be changed.

Assuming that the rated operating voltage of the LED lamp is Uo, and the average operating voltage of the LED is Uavg, there are:

Uavg＝D×Uo (1)

Wherein, D is the on-duty ratio of the LED lamp group. However, the rated operating voltage Uo is a constant voltage of ~220V commercial power after rectification and stabilization, and cannot be changed arbitrarily, so the value of Uavg can only be changed by changing the duty cycle D.

Wherein, the LED lighting device 30 can be one LED tube or a group of LED tubes or several lamp groups of different colors, for example, three groups of red, green and blue lamp groups of different colors.

FIG. 2 is a schematic structural view of an embodiment of the LED lighting control device of the present invention. In this embodiment, the power transistor 20 is a field effect transistor. As shown in the figure, a current limiting resistor 40 is added between the power tube 20 and the LED lighting device 30 to stabilize the current in the circuit. The current limiting resistor 40 can also be included in the LED lighting device 30 .

In the embodiment shown in Figure 1 and Figure 2, because only one PWM generator is used to modulate the duty cycle, it can only control the brightness change of the LED lighting device, that is, whether it is an LED tube or a group of single-color The color of the LED tube will not change, but the brightness of the color will change.

Fig. 3 is a schematic diagram of a color mixing structure of an embodiment of the LED lighting control device of the present invention. In this embodiment, the transformation of multiple colors is realized by using the principle of three primary colors, that is, three colors of red, green and blue are used as the basic colors, and various colors can be produced by mixing them according to different ratios. For example, the The three lamp groups R, G, and B are respectively divided into 100 brightness levels, so according to the arrangement and combination principle, the lighting control device in this embodiment can randomly generate 100×100×100=10 ⁶ kinds of color mixing effects. In this embodiment, the brightness of the three different-color lamp groups changes continuously, that is, in infinite levels, so an infinite number of colors can be randomly generated.

As shown in Fig. 3, the LED lighting device is LED lamp groups 104 of three colors, which are respectively red LED lamp group R, green LED lamp group G and blue LED lamp group B, wherein each lamp group is connected to a corresponding PWM generator and power tube. As shown in the figure, the PWM generator group 101, the power tube group 102 and the three LED lamp groups 104 are connected in one-to-one correspondence. Wherein, a group of resistors 103 are connected in series between the power tube and the lamp groups of different colors to stabilize the current in the circuit and protect the LED lamp group 104 . In this embodiment, the power transistor is a field effect transistor VN0602, but the utility model is not limited thereto.

Among them, the circuit structures of the three PWM generators are exactly the same, and drive the power transistors V1, V2 and V3 respectively, so that the on-duty ratio changes periodically according to the sawtooth wave between 0 and 100%. However, the difference between the three PWM generators is that their changing periods are set differently, that is: asynchronous. Therefore, the duty cycles of the R lamp group, the G lamp group and the B lamp group are different at any time, so that the brightness of the three lamp groups is different at each moment. Wherein, FIG. 4 is a variation curve of on-duty ratios of the three lamp groups R, G, and B in the embodiment shown in FIG. 3 . At time t1, the duty ratios of the three groups of LED lamps are r1, g1, b1, and at time t2, the duty ratios of the three groups of LED lamps are r2, g2, b2. Obviously, r1, g1, b1 are obviously different from r2, g2, b2, so according to the above formula (1), the average voltages applied to the three groups of LED lights are different at the time t1 and t2, so the three groups of LED lights The brightness is different, so the colors mixed by them are also different.

Certainly, the utility model is not limited thereto. LED light groups can also be set to two, four, or even five or more. If there are two LED light groups of different colors, which correspond to two PWM generators and two power tubes, of course the mixed colors are relatively small, and the effect is not very obvious. When the LED lamp group is four or five or more LED lamp groups of different colors, it corresponds to four PWM generators and four power tubes. At this time, there are more color changes. However, according to the principle of three primary colors, almost all colors can be mixed by using the three colors of red, green, and blue. Therefore, the use of red, green, and blue LED lights can meet people's needs for different colors. If 4, 5 or even more LED light groups are set up, PWM generators and power tubes need to be increased accordingly, which undoubtedly increases the complexity of the hardware circuit and the design cost.

In the embodiment shown in Figure 3, the three PWM generators are composed of Schmitt triggers and operational amplifier integrated circuits. Wherein, the Schmitt trigger is used to generate harmonic oscillation, which can be a four-two-input NAND gate Schmitt trigger CD4093. Fig. 5 is the logical structure diagram of the Schmitt trigger CD4093 of the utility model embodiment, wherein, pin 7 is Vss, pin 14 is Vdd, is power supply input end respectively, remaining 12 pins form 4 independent A Schmitt trigger dual-input NAND gate is used as a NOT gate in this embodiment. The operational amplifier integrated circuit can be four operational amplifier integrated circuits LM324. The logical structure diagram of LM324 is shown in Figure 6. Pin 11 and pin 4 are power input terminals V- and V+ respectively, and the remaining 12 pins form 4 independent operational amplifiers.

FIG. 7 is a schematic circuit diagram of an LED lighting control circuit formed by using the logic elements shown in FIG. 5 and FIG. 6 in the embodiment shown in FIG. 3 . in,

Module 701 is an oscillating circuit composed of an operational amplifier in the four operational amplifier integrated circuit LM324 and the first RC circuit. The first RC circuit includes R16, R17, R18, R19 and C7. This oscillator circuit generates a sawtooth wave with a frequency of 250Hz. Among them, R16, R17 and R18 form a positive feedback circuit, and R19 and C7 are used to control the cycle of the sawtooth wave.

Modules 7021, 7022 and 7023 are all harmonic oscillation circuits. The working principle and circuit structure of these three circuits are the same, but the resistance value in the RC circuit of each module is different, so the working frequency is different. By adjusting the resistance value, the oscillation frequency of the generated harmonic can be controlled.

Modules 7031, 7032, and 7033 are comparator circuits, which are composed of operational amplifiers using four op-amp integrated circuits LM324. By comparing the levels of two different sawtooth waves generated by module 701 and modules 7021, 7022, and 7023, pulses are generated. wide different pulse modulation signals.

Take modules 701, 7021 and 7031 as examples to illustrate the working principle of the PWM generator. Module 701, module 7021 and module 7031 together form a PWM generator for controlling R lamp group. Its working principle is: the module 7021 is composed of a NAND gate circuit of a four-2 input NAND gate Schmitt trigger CD4093, a second RC circuit and a third RC circuit, wherein the second RC circuit includes R10, R13 and C4, the third RC circuit includes R7, C1, the output terminal of the NAND gate circuit is added to the third RC circuit, and the capacitor of the third RC circuit is charged and discharged to generate a sawtooth wave with a very low frequency. When the capacitor is being charged, its output level is constantly increasing, and when the capacitor is being discharged, the output level is constantly decreasing. The two sawtooth waves generated by module 701 and module 7021 are sent to comparator circuit 7031 for comparison, thereby generating a pulse width modulation signal.

Similarly, modules 701, 7022 and 7032 form a PWM generator for controlling lamp group G, and modules 701, 7023 and 7033 form a PWM generator for controlling lamp group B. However, since the resistance values of the RC circuits in modules 7021, 7022 and 7023 are different, the generated harmonic frequencies are different, and the greater the resistance, the lower the frequency. Therefore, the pulse width modulation signal generated at each moment The duty cycle is also different. As shown in Figure 4. In this embodiment, one NAND circuit in the 4-2 input NAND Schmitt trigger CD4093 is not used, and in this utility model, the practical frequency is about 0.03Hz-0.01Hz.

The embodiment of the utility model generates pulse width modulation signals of different periods according to the adjustment of the pulse width modulation generator, so that the on-duty ratio of each corresponding power tube is different at the same time, resulting in LED lamp groups of different colors At the same moment, the brightness is also different, and different colors are produced by mixing colors. Moreover, the lighting control device of the present utility model does not need software programming control, and can randomly realize infinite changes in lighting colors, making it easy for non-professionals to grasp. Moreover, the circuit is concise, the components are few, and the cost is saved.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present utility model in detail. Within the protection scope of the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims (10)

1. A LED light control device, characterized in that, the LED light control device comprises: a pulse width modulation generator, a power tube and an LED lighting device; The pulse width modulation generator is connected to the power tube; the power tube is connected to the LED lighting device; The pulse width modulation generator generates a pulse width modulation signal, and modulates the duty cycle of the LED lighting device through the power tube, thereby controlling the luminous brightness of the LED lighting device. 2. The LED lighting control device according to claim 1, wherein the LED lighting device further comprises a current limiting resistor connected in series with the LED for stabilizing the current. 3. The LED lighting control device according to claim 1, wherein the LED lighting device is an LED light tube. 4 . The LED lighting control device according to claim 1 , wherein the LED lighting device is a group of red LED lights, a group of green LED lights and a group of blue LED lights. 5. The LED lighting control device according to claim 1, wherein the LED lighting device is a plurality of LED lamp groups of different colors. 6. The LED lighting control device according to claim 1, wherein the pulse width modulation generator is composed of a Schmitt trigger and an operational amplifier integrated circuit. 7. The LED lighting control device according to claim 6, wherein the Schmitt trigger is used to generate harmonic oscillation. 8. The LED lighting control device according to claim 6, wherein the Schmitt trigger is a four-two-input NAND Schmitt trigger CD4093. 9. The LED lighting control device according to claim 6, wherein the operational amplifier integrated circuit is a four operational amplifier integrated circuit LM324. 10. The LED lighting control device according to claim 1, wherein the power transistor is a field effect transistor VN0602.

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