CN211378319U - Light-emitting diode light mixing control circuit and system - Google Patents

Abstract

The utility model belongs to the technical field of photoelectric lighting, a emitting diode mixes light control circuit and system is provided. The light-emitting diode light mixing control circuit comprises: the device comprises a rectification filtering module, a dimming module and a color modulation module; the input end of the rectification filter module is connected with the mains supply, and the output end of the rectification filter module is respectively connected with the first input end of the dimming module and the first input end of the color modulation module; the second input end of the dimming module inputs a dimming signal, the second input end of the color mixing module inputs a color mixing signal, the first output end of the dimming module is connected with the high-voltage power supply end and the two current proportion adjusting ends of the color mixing module, and the second output end of the dimming module is connected with the high-voltage side floating end of the color mixing module. The utility model discloses in only having realized promptly mixing of colors to adjusting luminance of emitting diode LED mixed light control circuit with two current proportion regulation ends, the circuit is simple, and is with low costs.

Description

Light-emitting diode light mixing control circuit and system

technical field

The utility model belongs to the technical field of photoelectric lighting, in particular to a light-emitting diode light mixing control circuit and system.

Background technique

A light-emitting diode (Light Emitting Diode, LED) is a semiconductor component, which is mostly used as an indicator light, a display light-emitting diode board, etc. With the emergence of white light LEDs, LEDs are also used for lighting. As a new generation of green light source, compared with traditional light sources such as incandescent lamps, fluorescent lamps and high-intensity discharge lamps, LEDs have many advantages such as energy saving, environmental protection, short response time, long life, small size and good shock resistance. It has become a hot spot of research in the field of semiconductor lighting in various countries.

With the continuous development of the LED industry, the color control requirements for adjustable color lamps and lanterns are getting higher and higher, and the color point of the mixed color is required to fall on the Planck blackbody locus. It can only be realized by the circuit control system of the circuit output, the circuit is complex and the cost is high.

Utility model content

In view of this, the embodiments of the present invention provide a light-emitting diode light mixing control circuit and system, so as to solve the problem of complex and high cost control circuits for color mixing moving along the blackbody trajectory.

A first aspect of the embodiments of the present utility model provides a light-emitting diode light mixing control circuit, including: a rectification filter module, a light adjustment module, and a color adjustment module;

The input end of the rectification and filtering module is connected to the commercial power, and the output end of the rectification and filtering module is respectively connected to the first input end of the dimming module and the first input end of the color matching module;

A dimming signal is input to the second input end of the dimming module, a dimming signal is input to the second input end of the dimming module, and the first output end of the dimming module is connected to the high-voltage power supply end of the color grading module and two current proportional adjustment terminals are connected, and the second output terminal of the dimming module is connected to the floating terminal of the high voltage side of the color matching module.

In one embodiment, the rectification filter module includes a fuse F1, a capacitor C1, a full-wave rectifier element BD1, an inductor L1, a resistor R1, a resistor R2, a resistor R3, and a non-inductive capacitor CD1;

One end of the fuse F1 is connected to the live wire of the commercial power, and the other end of the fuse F1 is respectively connected to one end of the capacitor C1 and the first input end of the full-wave rectifier element BD1;

The other end of the capacitor C1 is connected to the second input end of the full-wave rectifying element BD1; the second input end of the full-wave rectifying element BD1 is also connected to the neutral line of the commercial power, and the The first output terminal is connected to one end of the parallel circuit formed by the inductor L1 and the resistor R1 in parallel, and the second output terminal of the full-wave rectifier element BD1 is grounded;

The other end of the parallel circuit formed by the inductor L1 and the resistor R1 in parallel is connected to one end of the resistor R2 and one end of the non-inductive capacitor CD1 respectively;

One end of the resistor R2 is also connected to the first input end of the dimming module, and the other end of the resistor R2 is connected in series with the resistor R3 and then connected to the first input end of the color tone module;

The other end of the non-inductive capacitor CD1 is grounded.

In one embodiment, the dimming module includes a constant current drive unit and a step-down unit;

The first input end of the constant current drive unit is connected to one end of the resistor R2, the second input end of the constant current drive unit inputs a dimming signal, and the output end of the constant current drive unit is connected to the step-down the first input terminal of the unit is connected;

The second input end of the step-down unit is connected to one end of the resistor R2, and the first output end of the step-down unit is respectively connected to the high-voltage power supply end of the color matching module and the two current proportional adjustment ends , the second output end of the step-down unit is connected to the floating end of the high-voltage side of the color matching module.

In one embodiment, the constant current drive unit includes a constant current drive chip U1, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a capacitor C2;

The open-circuit protection voltage adjustment terminal of the constant current driving chip U1 is connected in series with the resistor R4 and then grounded;

The chip ground end of the constant current driving chip U1 is directly grounded;

The chip high-voltage power supply terminal of the constant current driving chip U1 is connected to one end of the resistor R2;

The drain terminal of the internal high-voltage power tube of the constant current driving chip U1 is connected to the first input terminal of the step-down unit;

The pulse width modulation PWM dimming signal input terminal of the constant current driving chip U1 inputs the dimming signal, and is connected to one end of the parallel circuit formed by the capacitor C2 and the resistor R5 in parallel. The other end of the parallel circuit formed by the resistor R5 in parallel is grounded;

The current sampling end of the constant current driving chip U1 is connected to one end of the resistor R6 and one end of the resistor R7, and the other end of the resistor R6 and the other end of the resistor R7 are grounded.

In one embodiment, the step-down unit includes a light-emitting diode D1, an inductor L2, a non-inductive capacitor CD2 and a resistor R8;

The anode of the light-emitting diode D1 is respectively connected to the drain terminal of the internal high-voltage power tube of the constant current driving chip U1 and one end of the inductor L2, and the cathode of the light-emitting diode D1 is connected to one end of the resistor R2;

The other end of the inductor L2 is respectively connected to one end of the non-inductive capacitor CD2 and one end of the resistor R8, and the other end of the inductor L2 is also connected to the floating end of the high voltage side of the color tone module;

The other end of the non-inductive capacitor CD2 and the other end of the resistor R8 are connected to the negative electrode of the light emitting diode D1, and the other end of the non-inductive capacitor CD2 and the other end of the resistor R8 are also connected to the color tone. The high-voltage power supply terminal of the module and the two current proportional adjustment terminals are connected.

In one embodiment, the color matching module includes a warm-color LED light-emitting diode unit, at least two cool-color LED light-emitting diode units, and a dual-channel PWM color matching unit;

One end of the one warm-color LED light-emitting diode unit and one end of the at least two cool-color LED light-emitting diode units are both connected to the first output end of the step-down unit, and the other end of the one warm-color LED light-emitting diode unit is connected to the first output end of the step-down unit. The other ends of the at least two cool-color LED light-emitting diode units are respectively connected to the first output end of the dual-channel PWM toning unit and the second output end of the dual-channel PWM toning unit;

The first input terminal of the dual-channel PWM toning unit is connected to the resistor R3, the second input terminal of the dual-channel PWM toning unit inputs the toning signal, and the second input terminal of the dual-channel PWM toning unit inputs the toning signal. The high-voltage power supply terminal and the high-voltage side floating terminal are respectively connected to the output terminal of the step-down unit.

In one embodiment, the one warm-color LED light-emitting diode unit includes a group of warm-color LED light-emitting diode light strings, and the group of warm-color LED light-emitting diode light-emitting diodes includes at least two warm-color LED light-emitting diodes connected in series and having the same color temperature.

In one embodiment, the at least two cool-color LED light-emitting diode units include a resistor R9 and at least two groups of cool-color LED light-emitting diode light strings with successively higher color temperatures, and each group of cool-color LED light-emitting diode light strings includes at least two series connected with the same color temperature. The cool-color LED light-emitting diode; among the at least two groups of cool-color LED light-emitting diode light strings, the cool-color LED light-emitting diode light string with the smallest color temperature is connected in series with the resistor R9 and then connected in parallel with other cool-color LED light-emitting diode light-emitting diode light strings with successively higher color temperatures.

In one embodiment, the dual-channel PWM color matching unit includes a dual-channel PWM color matching chip U2, a resistor R10, a resistor R11, a resistor R12, a capacitor C3, a capacitor C4, and a capacitor C5;

The high-voltage side power supply terminal of the dual-channel PWM toning chip U2 is respectively connected to one end of the resistor R10 and one end of the capacitor C3, and the other end of the resistor R10 is connected to the first output terminal of the step-down unit;

The high-voltage side floating terminal of the dual-channel PWM toning chip U2 is connected to the other end of the capacitor C3 and then connected to the capacitor C4 in series and then grounded. The high-voltage side floating terminal of the dual-channel PWM toning chip U2 is also connected to the ground. the second output end of the step-down unit is connected;

The drain terminal of the metal-oxide-semiconductor field-effect transistor MOSFET2 of the dual-channel PWM color matching chip U2 is connected to the other end of the one warm-color LED light-emitting diode unit;

The drain terminal of MOSFET1 of the dual-channel PWM color matching chip U2 is connected to the other end of the at least two cool-color LED light-emitting diode units;

The PWM color tone signal input end of the dual-channel PWM color tone chip U2 is connected to one end of the resistor R11 and then inputs the color tone signal, and the other end of the resistor R11 is connected in series with the resistor R12 and then grounded;

The low-voltage power supply terminal of the dual-channel PWM color matching chip U2 is connected to the capacitor C5 and then grounded, and the low-voltage power supply terminal of the dual-channel PWM color matching chip U2 is also connected to the resistor R3;

The chip ground end of the dual-channel PWM toning chip U2 is directly grounded.

A second aspect of the embodiments of the present utility model provides a light-emitting diode light mixing control system, including any one of the light-emitting diode light mixing control circuits described above.

In the embodiment of the present invention, the commercial power is rectified and filtered into the DC source required by the light-emitting diode mixing control circuit through the rectification and filter module, and the duty ratio of the output current of the dimming module is controlled by the dimming signal, thereby controlling the total amount of electricity entering the color matching module. The size of the current, and then realize the dimming function of the color matching module, by adjusting the duty cycle of the color matching signal, to adjust the current ratio of the two current ratio adjustment terminals in the color matching module, and then realize the color matching function of the color matching module In the embodiment of the present utility model, only two current proportional adjustment terminals are used to realize the dimming and color matching of the light-emitting diode LED light mixing control circuit, which solves the problem of the complex dimming and color matching circuit using a three-way output circuit and the conventional two-way output circuit. The problem that the circuit cannot meet the control requirements of the color tolerance of the intermediate colors, the circuit is simple, the cost is low, and it can be adjusted according to different color matching, which can achieve better color tolerance control.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present utility model. For some novel embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic diagram of a module of a light-emitting diode light mixing control circuit provided by an embodiment of the present invention;

2 is a circuit schematic diagram of a light-emitting diode light mixing control circuit provided by an embodiment of the present invention;

Fig. 3 is the CIE chromaticity diagram that the utility model embodiment provides;

4 is a segmented color mixing trajectory diagram of an LED light mixing control circuit provided by an embodiment of the present invention;

FIG. 5 is a current change curve diagram of one warm-color LED light-emitting diode unit and at least two cool-color LED light-emitting diode units provided by an embodiment of the present invention.

Detailed ways

In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to illustrate the technical solutions of the present utility model, the following specific embodiments are used to illustrate.

Referring to FIG. 1 , the light emitting diode (Light Emitting Diode, LED) light mixing control circuit provided by the present invention will now be described. The LED light mixing control circuit includes: a rectification filter module 1 , a light adjustment module 2 and a color adjustment module 3 ;

The input end of the rectification filter module 1 is connected to the commercial power for converting alternating current into direct current, and the output end of the rectification filter module 1 is connected to the first input end of the dimming module 2 and the first input end of the color matching module 3 respectively. , so as to feed the DC power to the dimming module 2 and the color matching module 3 .

The second input terminal of the dimming module 2 inputs the dimming signal PWM1, the second input terminal of the dimming module 3 inputs the dimming signal PWM2, the first output terminal of the dimming module 2 and the high-voltage power supply terminal of the dimming module 3 and two The two current proportional adjustment terminals are connected, and the second output terminal of the dimming module 2 is connected to the high-voltage side floating terminal of the color matching module 3 .

Among them, the dimming signal and the color tone signal are generally the dimming signal PWM1 and the color tone signal PWM2 generated by pulse width modulation (Pulse Width Modulation, PWM). The external dimming signal PWM1 is input to the dimming module 2 to change the dimming module 2 The output current duty ratio is used to adjust the RMS value of the LED drive current, thereby realizing dimming.

For the color matching module 3, the external color matching signal PWM2 can control the current of the two current proportional adjustment terminals. The current of one current proportional adjustment terminal is the current flowing through a warm-color LED light-emitting diode unit, and the current of the other current proportional adjustment terminal is The current flowing through at least two cool-color LED light-emitting diode units, the brightness ratio of one warm-color LED light-emitting diode unit and at least two cool-color LED light-emitting diode units is controlled by adjusting the size of the two current proportional adjustment terminal currents, so as to realize a warm-color LED light-emitting diode unit. The color temperature of the LED light-emitting diode module composed of the light-emitting diode unit and at least two cool-color LED light-emitting diode units is adjusted.

The LED light mixing control circuit of the embodiment of the present invention controls the brightness ratio of the warm-color LED light-emitting diode unit and the cool-color LED light-emitting diode unit through the external color-adjusting signal PWM2, that is, the color temperature of the LED light-emitting diode module can be adjusted through the two output circuits. The adjusted mixed color is moved along the black body locus, the control of the consistency of the intermediate color temperature and color tolerance is realized through a simple circuit, and the cost is reduced on the premise of improving the performance of the LED color mixing control circuit.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, the rectification filter module 1 includes a fuse F1, a capacitor C1, a full-wave rectifier element BD1, an inductor L1, a resistor R1, a resistor R2, a resistor R3 and a non-inductive capacitor CD1. .

One end of the fuse F1 is connected to the live wire L of the commercial power, and the other end of the fuse F1 is respectively connected to one end of the capacitor C1 and the first input end of the full-wave rectifying element BD1.

That is to say, the fuse F1 is connected between the full-wave rectifying element BD1 and the commercial power, wherein the full-wave rectifying element BD1 is used to convert the commercial power into direct current. In other embodiments of the present invention, the full-wave rectifying element can also be used Other suitable rectifier elements known in the art are not limited by the comparison of the embodiments of the present invention.

The other end of the capacitor C1 is connected to the second input end of the full-wave rectifier element BD1; the second input end of the full-wave rectifier element BD1 is also connected to the neutral line N of the commercial power, and the first output end of the full-wave rectifier element BD1 is connected to the inductor L1 One end of the parallel circuit formed in parallel with the resistor R1 is connected, and the second output end of the full-wave rectifier element BD1 is grounded.

The other end of the parallel circuit formed by the inductor L1 and the resistor R1 in parallel is connected to one end of the resistor R2 and one end of the non-inductive capacitor CD1, respectively. One end of the resistor R2 is also connected to the first input end of the dimming module 2 , and the other end of the resistor R2 is connected in series with the resistor R3 and then connected to the first input end of the color matching module 3 . The other end of the non-inductive capacitor CD1 is grounded.

Among them, the circuit composed of the inductor L1, the resistor R12 and the non-inductive capacitor CD1 is used to filter the converted direct current.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, the dimming module 2 includes a constant current driving unit 21 and a step-down unit 22 .

The first input end of the constant current drive unit 21 is connected to one end of the resistor R2 , the second input end of the constant current drive unit 21 inputs the dimming signal PWM1 , the output end of the constant current drive unit 21 is connected to the first input of the step-down unit 22 end connection.

The second input end of the step-down unit 22 is connected to one end of the resistor R2, the first output end of the step-down unit 22 is connected to the high-voltage power supply end of the color matching module 3 and the two current proportional adjustment ends respectively, and the first output end of the step-down unit 22 is connected to the The two output terminals are connected to the floating terminal of the high voltage side of the color matching module 3 .

Wherein, by inputting the dimming signal PWM1 to the constant current driving unit 21 to control the magnitude of the output current of the constant current driving unit 21, combined with the step-down unit 22, 1%-100% PWM dimming can be achieved.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, the constant current driving unit 21 includes a constant current driving chip U1 , a resistor R4 , a resistor R5 , a resistor R6 , a resistor R7 and a capacitor C2 .

The open-circuit protection voltage adjustment end of the constant current drive chip U1 is connected to the resistor R4 in series and then grounded, the chip ground end of U1 is directly grounded, and the chip high voltage power supply end of U1 is connected to one end of the resistor R2.

The drain terminal of the internal high-voltage power tube of the constant current driver chip U1 is connected to the first input terminal of the step-down unit 22, and the step-down unit 22 and the built-in field effect transistor (Metal Oxide Semiconductor, MOS) of the constant current driver chip U1 form a Buck step-down circuit to play a freewheeling role.

The PWM dimming signal input terminal of the constant current driver chip U1 inputs the dimming signal PWM1, and is connected to one end of the parallel circuit formed by the capacitor C2 and the resistor R5 in parallel, and the other end of the parallel circuit formed by the capacitor C2 and the resistor R5 in parallel is grounded.

Among them, the capacitor C2 is used to filter the dimming signal PWM1 to filter noise, and the resistor R4 is the pull-down resistor of the dimming signal PWM1, so that when the dimming signal PWM1 is suspended, it is a low voltage to avoid malfunction.

The current sampling end of the constant current driving chip U1 is connected to one end of the resistor R6 and one end of the resistor R7, and the other end of the resistor R6 and the other end of the resistor R7 are grounded.

Among them, R6 and R7 are current sampling resistors. After sampling, the current sampling terminal is input to the current control circuit and compared with the internal reference voltage of the constant current driver chip U1, which can realize high-precision output constant current control.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, the step-down unit 22 includes a light-emitting diode D1 , an inductor L2 , a non-inductive capacitor CD2 and a resistor R8 .

The anode of the light-emitting diode D1 is connected to the drain terminal of the internal high-voltage power tube of the constant current drive chip U1 and one end of the inductor L2 respectively, the cathode of the light-emitting diode D1 is connected to one end of the resistor R2, and the other end of the inductor L2 is respectively connected to the non-inductive capacitor CD2. One end is connected to one end of the resistor R8, the other end of the inductor L2 is also connected to the floating end of the high voltage side of the color matching module 3, the other end of the non-inductive capacitor CD2 and the other end of the resistor R8 are connected to the negative electrode of the light-emitting diode D1. The other end of the capacitor CD2 and the other end of the resistor R8 are also connected to the high-voltage power supply end of the color matching module 3 and the two current proportional adjustment ends.

Among them, the light-emitting diode D1, the inductor L2 and the built-in MOS tube of the constant current driver chip U1 form a Buck circuit, the inductor L2 is used for energy storage, the non-inductive capacitor CD2 is used for output filtering, and the resistor R8 is a dummy load, which is used for power off. Discharge current to non-inductive capacitor CD2.

Optionally, referring to FIGS. 2 to 4 , as an embodiment of the present invention, the color matching module 3 includes a warm-color LED light-emitting diode unit 31 , at least two cool-color LED light-emitting diode units 32 and a dual-channel PWM color matching unit 33 . .

One end of one warm-color LED light-emitting diode unit 31 and one end of at least two cool-color LED light-emitting diode units 32 are both connected to the first output end of the step-down unit 22, and the other end of one warm-color LED light-emitting diode unit 31 and at least two cool-color LEDs The other ends of the light emitting diode unit 32 are respectively connected to the first output end of the dual-channel PWM toning unit 33 and the second output end of the dual-channel PWM toning unit 33 .

The first input terminal of the dual-channel PWM toning unit 33 is connected to the resistor R3, the second input terminal of the dual-channel PWM toning unit 33 inputs the toning signal PWM2, and the high-voltage power supply terminal and the high-voltage side float of the dual-channel PWM toning unit 33 The ground terminals are respectively connected to the output terminals of the step-down unit 22 .

Referring to Figure 3, there is a Planck blackbody locus in the CIE chromaticity diagram, and the color temperature of white light follows the blackbody locus. According to the principle of color mixing, when any two colors are mixed, the color point of the mixed color must be in the first two color points. On the connecting line, that is, the change of color coordinates can only be moved along the connecting line of high and low color temperature.

For example, by mixing a low color temperature of 2700K (which can correspond to a warm-color LED light-emitting diode unit) and a high color temperature of 5000K (which can correspond to a cool-color LED light-emitting diode unit) in a certain proportion, intermediate color temperatures of 3000K, 3500K, 4000K, 4500K can be obtained. Uniform, the mixed color point cannot be guaranteed to fall in the black body trajectory. To make the mixed color point move along the black body trajectory, it can be adjusted by adding a color (that is, by adding a cool color LED light-emitting diode unit to adjust) , the color-changing color point trajectory can be changed, that is, the mixed color can be moved along the black body trajectory through a segmented mixing method. For example, refer to the segmented color mixing trajectory in Figure 4:

The first paragraph: 2700k→3500k, mixed by 2700k and 3500k, according to the mixing principle, the color point trajectory will move along the black body

The second segment: 3500k→5000k, by mixing 3500k and 5000k, according to the mixing principle, the color point trajectory will move along the black body.

That is to say, by means of segment mixing, the color tone signal PWM2 respectively controls the currents of the first output terminal and the second output terminal of the dual-channel PWM toning unit of the color tone module 3, so that the warm-color LED light-emitting diode unit and at least The cool-color LED unit with the smallest color temperature among the two cool-color LED units is mixed, and then the two cool-color LED units whose color temperature increases sequentially in the cool-color LED unit are mixed, so that the color temperature of the mixed color can move along the black body trajectory.

Optionally, the method for obtaining the mixed color temperature by segment mixing can be two segments, three segments or even more. The color matching module 3 includes one warm-color LED unit and three cool-color LED units, that is, the mixing is divided into three segments.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, a warm-color LED light-emitting diode unit 31 includes a group of warm-color LED light-emitting diode light strings, and a group of warm-color LED light-emitting diode light strings includes at least two series connected with the same color temperature. warm color LED light-emitting diodes.

Optionally, the color temperature of the warm-color LED light-emitting diode in the warm-color LED light-emitting diode unit may be 2700K, or may be other warm-color color temperature values, and the specific warm-color color temperature value is not limited in the embodiment of the present invention.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, at least two cool-color LED light-emitting diode units 32 include a resistor R9 and at least two groups of cool-color LED light-emitting diode light strings whose color temperature increases sequentially, each group of cool-color LED light-emitting diodes. The light string includes at least two cool-color LED light-emitting diodes that are connected in series and have the same color temperature; the cool-color LED light-emitting diode light-emitting diode with the smallest color temperature in the at least two groups of cool-color LED light-emitting diode light-emitting diodes is connected in series with the resistor R9 and other cool-color LED light-emitting diodes whose color temperature increases sequentially The lights are connected in parallel.

The at least two cool-color LED light-emitting diode units 32 include at least two groups of cool-color LED light-emitting diode light strings, and the color temperature of each group of cool-color LED light-emitting diode light strings is different from each other, wherein one cool-color LED light-emitting diode light string with the smallest color temperature is connected in series. The resistor R9 is then connected in series and in parallel with other cool LED light-emitting diode lights whose color temperature increases sequentially.

For example, at least two sets of cool LED light-emitting diode light strings can be cool 1 light string and cool 2 light string, the color temperature of cool color 1 light string can be 3500K, the color temperature of cool color 2 light string can be 5000K, cool color 1 light string series resistance R9 Then it is connected in parallel with the cold color 2 light strings. The packaging form of the resistor can be a patch or a plug-in. The resistance value of R9 can be adjusted according to the parameter calculation.

The total forward working voltage VF1 of the cool color 1 light string is smaller than the total forward working voltage VF2 of the cool color 2 light string, and VF1 can be 2-10V lower than VF2.

Optionally, referring to FIG. 2 , as an embodiment of the present invention, the dual-channel PWM toning unit 33 includes a dual-channel PWM toning chip U2, a resistor R10, a resistor R11, a resistor R12, a capacitor C3, a capacitor C4, and a capacitor C5. .

The high-voltage side power supply terminals of the dual-channel PWM toning chip U2 are respectively connected to one end of the resistor R10 and one end of the capacitor C3 , and the other end of the resistor R10 is connected to the first output terminal of the step-down unit 22 .

Among them, the resistor R10 provides the power supply resistance of the power supply loop for the high-voltage side power supply terminal of the dual-channel PWM toning chip U2, and the capacitor C3 filters the high-voltage side power supply terminal of the dual-channel PWM toning chip U2.

The high-voltage side floating terminal of the dual-channel PWM toning chip U2 is connected to the other end of the capacitor C3 and then connected to the capacitor C4 in series and then grounded. end connection.

Among them, the capacitor C4 filters the chip ground for the floating terminal of the high-voltage side of the dual-channel PWM toning chip U2.

The drain terminal of MOSFET2 of the metal-oxide-semiconductor field-effect transistor (MOSFET) of the dual-channel PWM color matching chip U2 is connected to the other end of a warm-color LED light-emitting diode unit 31, and the dual-channel PWM color matching chip U2 The drain terminal of the MOSFET1 is connected to the other terminals of the at least two cool-color LED light-emitting diode units 32 .

Among them, by adjusting the duty ratio of the color tone signal PWM2, the ratio of the current flowing through the MOS1 and MOS2 built in the dual-channel PWM toning chip U2 can be controlled, that is, the ratio of I1 and (I2+I3) in Fig. 2, and Fig. 2 The middle dimming signal PWM1 controls the current I _total =I1+(I2+I3) output by the dimming module 2, and I1=I _total *PWM2.

Assuming that the color temperature of a set of warm-color LED light-emitting diode light strings LED1 is 2700K, and at least two sets of cool-color LED light-emitting diode light-emitting diode light strings include cool-color 1 light-emitting diode light strings LED3 and cool-color 2 light-emitting diode light strings LED2, the color temperature of LED3 is 3500K, and the color temperature of LED2 is 5000K. LED3 is connected in series with resistor R9 and then connected in parallel with LED2 to form a Warm-grow circuit.

Referring to FIG. 2 and FIG. 5 , at the beginning, only LED1 is controlled by the color tone signal PWM2 to light up, and the color temperature is the initial color temperature of 2700K. With the adjustment of the current, since the junction voltage of LED3 is lower than that of LED2, the current flows through LED3 first, and LED3 is lit. The color temperature of the cool LED3 is 3500K and the color temperature of the warm LED1 is 2700K. According to the color mixing principle, the color point will follow the 2700K and 3500K connection for mobile. After reaching a certain current value, a part of the current starts to flow through LED2, which satisfies V _LED3 +I3*R9=V _LED2 . As the current continues to increase, the VF1 of LED3 exceeds LED2 by a lot, and the current becomes smaller and smaller, thus achieving 3500K and 5000K The color temperature is adjusted and moved along the black body locus to achieve the desired color.

The PWM toning signal input terminal of the dual-channel PWM toning chip U2 is connected to one end of the resistor R11 to input the toning signal PWM2, and the other end of the resistor R11 is connected to the resistor R12 in series and then grounded.

The resistor R11 is used for current limiting protection of the color tone signal PWM2, and the resistor R12 is a pull-down resistor of the color tone signal PWM2. When the color tone signal PWM2 is suspended, the voltage is low to avoid malfunction.

The low-voltage power supply terminal of the dual-channel PWM color matching chip U2 is connected to the capacitor C5 and then grounded, and the low-voltage power supply terminal of the dual-channel PWM color matching chip U2 is also connected to the resistor R3.

Among them, the capacitor C5 filters the low-voltage power supply terminal of the dual-channel PWM color matching chip U2.

As another embodiment of the present invention, the present invention further includes an LED light mixing control system, which includes the LED light mixing control circuit of any of the above-mentioned embodiments, and is mixed with the LED light-mixing control circuit of any of the above-mentioned embodiments. Light control circuits have the same beneficial effect.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions recorded in each embodiment are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the various embodiments of the present invention, and are It should be included within the protection scope of the present invention.

Claims (10)

1. A light mixing control circuit of a Light Emitting Diode (LED) is characterized by comprising: the device comprises a rectification filtering module, a dimming module and a color modulation module;

the input end of the rectifying and filtering module is connected with a mains supply, and the output end of the rectifying and filtering module is respectively connected with the first input end of the dimming module and the first input end of the color modulation module;

the second input end of the dimming module inputs a dimming signal, the second input end of the color mixing module inputs a color mixing signal, the first output end of the dimming module is connected with the high-voltage power supply end of the color mixing module and the two current proportion adjusting ends, and the second output end of the dimming module is connected with the high-voltage side floating end of the color mixing module.

2. The LED mixing control circuit of claim 1, wherein the rectifying and filtering module comprises a fuse F1, a capacitor C1, a full-wave rectifying element BD1, an inductor L1, a resistor R1, a resistor R2, a resistor R3 and a non-inductive capacitor CD 1;

one end of the fuse F1 is connected with a live wire of a commercial power, and the other end of the fuse F1 is respectively connected with one end of the capacitor C1 and a first input end of the full-wave rectifying element BD 1;

the other end of the capacitor C1 is connected with a second input end of the full-wave rectifying element BD 1; the second input end of the full-wave rectifying element BD1 is further connected with a zero line of a commercial power, the first output end of the full-wave rectifying element BD1 is connected with one end of a parallel circuit formed by the parallel connection of the inductor L1 and the resistor R1, and the second output end of the full-wave rectifying element BD1 is grounded;

the other end of a parallel circuit formed by the inductor L1 and the resistor R1 in parallel is respectively connected with one end of the resistor R2 and one end of the non-inductive capacitor CD 1;

one end of the resistor R2 is further connected with the first input end of the dimming module, and the other end of the resistor R2 is connected with the first input end of the dimming module after being connected with the resistor R3 in series;

the other end of the non-inductive capacitor CD1 is grounded.

3. The LED mixing control circuit according to claim 2, wherein the dimming module comprises a constant current driving unit and a voltage dropping unit;

a first input end of the constant current driving unit is connected with one end of the resistor R2, a second input end of the constant current driving unit inputs a dimming signal, and an output end of the constant current driving unit is connected with a first input end of the voltage reduction unit;

the second input end of the voltage reduction unit is connected with one end of the resistor R2, the first output end of the voltage reduction unit is respectively connected with the high-voltage power supply end of the color mixing module and the two current proportion adjusting ends, and the second output end of the voltage reduction unit is connected with the high-voltage side floating end of the color mixing module.

4. The LED light mixing control circuit of claim 3, wherein the constant current driving unit comprises a constant current driving chip U1, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a capacitor C2;

the open-circuit protection voltage regulating end of the constant current driving chip U1 is connected with a resistor R4 in series and then grounded;

the chip ground end of the constant current driving chip U1 is directly grounded;

the chip high-voltage power supply end of the constant current driving chip U1 is connected with one end of the resistor R2;

the drain end of an internal high-voltage power tube of the constant current driving chip U1 is connected with the first input end of the voltage reduction unit;

the dimming signal is input into a Pulse Width Modulation (PWM) dimming signal input end of the constant current driving chip U1 and is connected with one end of a parallel circuit formed by parallel connection of the capacitor C2 and the resistor R5, and the other end of the parallel circuit formed by parallel connection of the capacitor C2 and the resistor R5 is grounded;

the current sampling end of the constant current driving chip U1 is connected with one end of the resistor R6 and one end of the resistor R7, and the other end of the resistor R6 and the other end of the resistor R7 are grounded.

5. The LED light mixing control circuit of claim 4, wherein the voltage dropping unit comprises an LED D1, an inductor L2, a non-inductive capacitor CD2 and a resistor R8;

the anode of the light emitting diode D1 is connected to the drain end of the internal high-voltage power tube of the constant current driving chip U1 and one end of the inductor L2, and the cathode of the light emitting diode D1 is connected to one end of the resistor R2;

the other end of the inductor L2 is connected to one end of the non-inductive capacitor CD2 and one end of the resistor R8, respectively, and the other end of the inductor L2 is further connected to the high-voltage-side floating end of the color modulation module;

the other end of the non-inductive capacitor CD2 and the other end of the resistor R8 are connected with the cathode of the light emitting diode D1, and the other end of the non-inductive capacitor CD2 and the other end of the resistor R8 are also connected with the high-voltage power supply end and the two current proportion adjusting ends of the color adjusting module.

6. The LED mixing control circuit according to claim 3, wherein the color-adjusting module comprises a warm-color LED unit, at least two cool-color LED units and a two-way PWM color-adjusting unit;

one end of the warm-color LED unit and one ends of the at least two cold-color LED units are both connected to the first output end of the voltage reduction unit, and the other end of the warm-color LED unit and the other ends of the at least two cold-color LED units are respectively connected to the first output end of the two-way PWM color mixing unit and the second output end of the two-way PWM color mixing unit;

the first input end of the double-path PWM color matching unit is connected with the resistor R3, the second input end of the double-path PWM color matching unit inputs the color matching signal, and the high-voltage power supply end and the high-voltage side floating end of the double-path PWM color matching unit are respectively connected with the output end of the voltage reduction unit.

7. The LED light mixing control circuit of claim 6, wherein the warm-color LED unit comprises a set of warm-color LED strings, and the set of warm-color LED strings comprises at least two warm-color LEDs connected in series and having the same color temperature.

8. The LED mixing control circuit as claimed in claim 6, wherein the at least two cold color LED units comprise a resistor R9 and at least two sets of cold color LED strings with sequentially increasing color temperature, each set of cold color LED strings comprising at least two cold color LEDs connected in series and having the same color temperature; the cold color LED light-emitting diode light string with the minimum color temperature in the at least two groups of cold color LED light-emitting diode light strings is connected in series with the resistor R9 and then is connected in parallel with other cold color LED light-emitting diode light strings with sequentially increased color temperature.

9. The LED mixing control circuit according to any one of claims 6-8, wherein the two-way PWM color tuning unit comprises a two-way PWM color tuning chip U2, a resistor R10, a resistor R11, a resistor R12, a capacitor C3, a capacitor C4, and a capacitor C5;

the high-voltage side power supply end of the two-way PWM toning chip U2 is respectively connected with one end of the resistor R10 and one end of the capacitor C3, and the other end of the resistor R10 is connected with the first output end of the voltage reduction unit;

the high-voltage side floating end of the two-way PWM color matching chip U2 is connected with the other end of the capacitor C3, then is connected with the capacitor C4 in series and then is grounded, and the high-voltage side floating end of the two-way PWM color matching chip U2 is also connected with the second output end of the voltage reduction unit;

the drain end of a metal-oxide-semiconductor field effect transistor (MOSFET) 2 of the two-way PWM color modulation chip U2 is connected with the other end of the warm-color LED unit;

the drain end of a MOSFET1 of the two-way PWM color modulation chip U2 is connected with the other ends of the at least two cold-color LED units;

the PWM toning signal input end of the two-way PWM toning chip U2 is connected with one end of the resistor R11 and then inputs the toning signal, and the other end of the resistor R11 is connected with the resistor R12 in series and then grounded;

the low-voltage power supply end of the two-way PWM toning chip U2 is connected with the capacitor C5 and then grounded, and the low-voltage power supply end of the two-way PWM toning chip U2 is also connected with the resistor R3;

the chip ground terminal of the two-way PWM toning chip U2 is directly grounded.

10. A light-emitting diode light mixing control system, comprising the light-emitting diode light mixing control circuit as claimed in any one of claims 1 to 9.

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