A multi-channel LED dimming and color temperature adjustment current control circuit and its dimming and color temperature adjustment control method

Abstract

The present invention relates to the technical field of LED lamp dimming and color temperature control technology, and more specifically, to a multi-channel LED dimming and color temperature control current control circuit and a dimming and color temperature control method thereof. The multi-channel LED dimming and color temperature control current control circuit comprises a power management circuit connected to a dimming decoding control circuit and providing a 5V drive voltage thereto. The dimming decoding control circuit comprises a UCS512D DMX decoder driver, which is provided with signal ports RPWM, GPWM, BPWM, and WPWM corresponding to a red light adjustment circuit, a green light adjustment circuit, a blue light adjustment circuit, and a white light adjustment circuit, respectively. The red light adjustment circuit, the green light adjustment circuit, the blue light adjustment circuit, and the white light adjustment circuit form feedback circuits to maintain a stable total output current of each circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of LED lamp dimming and color temperature adjustment control, and in particular to a multi-channel LED dimming and color temperature adjustment current control circuit and a dimming and color temperature adjustment control method thereof. Background Art

[0002] With the gradual elimination of incandescent lamps and the implementation of energy conservation and emission reduction policies around the world, LED lighting has been rapidly popularized and penetrated. At the same time, LED driver power supply, as a key component of LED lighting, also has a broad market prospect. Today, the LED market and technology are gradually maturing, and its application has also fully penetrated into various fields.

[0003] When multiple LED drivers are dimming and adjusting the color temperature of LED lamps, the total current of the LEDs is very large and the total brightness is very high when multiple color temperature LEDs are adjusted to the brightest at the same time; but when a single color temperature LED is dimmed to the brightest, the total current is very small and the LED brightness is very low. As a result, the brightness of the lamps varies greatly under different color temperatures. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings, the present invention aims to provide a technical solution that can solve the above-mentioned problems.

[0005] A multi-channel LED dimming and color temperature adjustment current control circuit includes a power management circuit, a dimming decoding control circuit, and a red light adjustment circuit, a green light adjustment circuit, a blue light adjustment circuit, and a white light adjustment circuit respectively connected to the dimming decoding control circuit, as well as red lights, green lights, blue lights, and white lights whose dimming is controlled by the corresponding adjustment circuits. The power management circuit is connected to the dimming decoding control circuit and provides it with a 5V driving voltage. The dimming decoding control circuit is composed of a DMX decoding driver. The DMX decoding driver is provided with signal ports RPWM, GPWM, BPWM, and WPWM respectively connected to the red light adjustment circuit, the green light adjustment circuit, the blue light adjustment circuit, and the white light adjustment circuit. The red light adjustment circuit, the green light adjustment circuit, the blue light adjustment circuit, and the white light adjustment circuit form a feedback circuit to keep the total output current of each circuit stable.

[0006] Furthermore, the model of the DMX decoding driver is UCS512D, and each of the red light adjustment circuit, green light adjustment circuit, blue light adjustment circuit, and white light adjustment circuit is equipped with a dimming controller of model LM3414. The third pins of each dimming controller are connected to each other to form a feedback circuit, and one of the red light, green light, blue light, and white light is respectively connected between the seventh and eighth pins of the corresponding dimming controller, and the sixth pin of each dimming controller is respectively connected to the corresponding signal port.

[0007] Furthermore, the third pin of each dimming controller is respectively provided with voltage sampling ports RADJ, GADJ, BADJ, and WADJ, and the feedback circuit on each dimming controller is composed of three voltage followers, wherein the input ends of the three voltage followers are connected in parallel to a corresponding dimming controller to obtain a voltage reference value, and the output ends of the three voltage followers are respectively connected to the voltage sampling ports on the remaining three dimming controllers.

[0008] Optionally, the input ends of the three voltage followers corresponding to each dimming controller are connected in parallel to the third pin of the dimming controller.

[0009] Optionally, the input ends of the three voltage followers corresponding to each dimming controller are connected in parallel to the sixth pin of the dimming controller.

[0010] Optionally, the third pin of each dimming controller is connected in series with a resistor and then connected in parallel to a resistor R19 and grounded to form a feedback circuit.

[0011] A dimming and color temperature adjustment control method applied to the above-mentioned multi-channel LED dimming and color temperature adjustment current control circuit specifically includes the following steps:

[0012] S1: Set the input ports PI and PO for inputting code to the DMX decoding driver;

[0013] S2: Input the dimming and color temperature adjustment signal to the DMX decoding driver through the input ports PI and PO;

[0014] S3: The DMX decoding driver decodes the dimming and color temperature adjustment signal to generate 4-way R, G, B, and W dimming and color temperature adjustment PWM signals, which are respectively output to the corresponding dimming controller through the signal ports RPWM, GPWM, BPWM, and WPWM;

[0015] S4: The dimming controller receives the dimming and color temperature adjustment PWM signal from the corresponding signal port and adjusts the current of one of the red, green, blue and white lights on its 7th and 8th pins according to the signal. At the same time, the dimming controller outputs a feedback signal to the feedback circuit through its 3rd pin.

[0016] S5: The dimming controller on each adjustment circuit receives the feedback signal of other adjustment circuits through its third pin and performs current compensation adjustment on one of the red light, green light, blue light and white light on the 7th and 8th pins of the dimming controller to keep the total input current to the red light, green light, blue light and white light stable.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a feedback circuit to realize current compensation between the dimming circuits, which can ensure that the total input current of the LED remains unchanged when the single-channel and multi-channel LEDs in the LED lamps are dimmed to the maximum at different color temperatures, so the brightness remains basically unchanged.

[0018] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 FIG. 4 is a circuit structure diagram of the power management circuit in the present invention.

[0021] Figure 2 This is a circuit structure diagram of the dimming decoding control circuit in the present invention.

[0022] Figure 3 This is a circuit structure diagram of the red light adjustment circuit in Example 1 of the present invention.

[0023] Figure 4 This is a circuit structure diagram of the red light adjustment circuit in the second embodiment of the present invention.

[0024] Figure 5 2 is a circuit structure diagram of three feedback circuits according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0026] See also Figures 1-2A multi-channel LED dimming and color temperature adjustment current control circuit includes a power management circuit, a dimming decoding control circuit, and a red light adjustment circuit, a green light adjustment circuit, a blue light adjustment circuit, and a white light adjustment circuit respectively connected to the dimming decoding control circuit, and a red light R-LED, a green light G-LED, a blue light B-LED, and a white light W-LED whose dimming is controlled by the corresponding adjustment circuits; the power management circuit is connected to the dimming decoding control circuit and provides it with a 5V driving voltage. The dimming decoding control circuit is composed of a DMX decoding driver U2, and the DMX decoding driver U2 is provided with signal ports RPWM, GPWM, BPWM, and WPWM respectively connected to the red light adjustment circuit, the green light adjustment circuit, the blue light adjustment circuit, and the white light adjustment circuit, wherein the red light adjustment circuit, the green light adjustment circuit, the blue light adjustment circuit, and the white light adjustment circuit form a feedback circuit with each other to keep the total output current of each circuit stable. The present invention adopts a feedback circuit to realize current compensation between each dimming circuit, so that the current output size of each adjustment circuit can realize a synchronous adjustment mode of "one increases while the other decreases". It can ensure that the total input current of the LED remains unchanged when the single-channel and multi-channel LEDs of the LED lamp are dimmed to the maximum at different color temperatures in the dimming and color adjustment, so the brightness remains basically unchanged.

[0027] Furthermore, the model of the DMX decoding driver U2 is UCS512D, and the red light adjustment circuit, green light adjustment circuit, blue light adjustment circuit, and white light adjustment circuit are each equipped with a dimming controller (U3~U5) with the model LM3414. The third pins of each dimming controller (U3~U5) are connected to each other to form a feedback circuit, and one of the red light, green light, blue light, and white light is respectively connected between the seventh and eighth pins of the corresponding dimming controller (U3~U5), and the sixth pin of each dimming controller (U3~U5) is respectively connected to the corresponding signal port.

[0028] A dimming and color temperature adjustment control method applied to the above-mentioned multi-channel LED dimming and color temperature adjustment current control circuit specifically includes the following steps:

[0029] S1: Set the input ports PI and PO for inputting code to the DMX decoding driver U2;

[0030] S2: Input the dimming and color temperature adjustment signal to the DMX decoding driver U2 through the input ports PI and PO;

[0031] S3: The DMX decoding driver U2 decodes the dimming and color temperature adjustment signal to generate 4-way R, G, B, and W dimming and color temperature adjustment PWM signals, which are respectively output to the corresponding dimming controllers (U3 to U5) through the signal ports RPWM, GPWM, BPWM, and WPWM.

[0032] S4: The dimming controller (U3-U5) receives the dimming and color temperature adjustment PWM signal from the corresponding signal port and adjusts the current of one of the red light R-LED, green light G-LED, blue light B-LED, and white light W-LED on its 7th and 8th pins according to the signal. At the same time, the dimming controller (U3-U5) outputs a feedback signal to the feedback circuit through its 3rd pin;

[0033] S5: The dimming controller (U3~U5) on each adjustment circuit receives the feedback signal of other adjustment circuits through its third pin and performs current compensation adjustment on one of the red light R-LED, green light G-LED, blue light B-LED, and white light W-LED on the 7th and 8th pins of the dimming controller (U3~U5) to keep the total input current to the red light R-LED, green light G-LED, blue light B-LED, and white light W-LED stable.

[0034] Based on the inventive concept of the above-mentioned multi-channel LED dimming and color temperature adjustment current control circuit, the adjustment circuit in the present invention has the following three embodiments:

[0035] [Example 1]

[0036] The third pin of each dimming controller (U3~U5) is respectively provided with a voltage sampling port RADJ, GADJ, BADJ, and WADJ. The feedback circuit on each dimming controller (U3~U5) is composed of three voltage followers (U7~U9), wherein the input ends of the three voltage followers (U7~U9) are connected in parallel to a corresponding dimming controller (U3~U5) to obtain a voltage reference value, and the output ends of the three voltage followers are respectively connected to the voltage sampling ports on the other three dimming controllers (U3~U5).

[0037] Optionally, the input terminals of the three voltage followers (U7-U9) corresponding to each dimming controller (U3-U5) are connected in parallel to the third pin of the dimming controller (U3-U5). Taking the red light adjustment circuit as an example, the circuit structure is as follows: Figure 3 shown.

[0038] When the dimming controller (U3~U5) is used as a constant current driver for LEDs, the voltage follower (U7~U9) is used to perform voltage follow detection on the ADJ pin of the dimming controller (U3~U5). The output end of the voltage follower (U7~U9) is simultaneously connected to the ADJ pins of other dimming controllers (U3~U5) to adjust the voltage impedance so that when one or more constant currents become smaller, the impedance of the ADJ pins of the other one or more dimming controllers (U3~U5) is pulled down, and the constant current output current becomes larger, thereby achieving the effect of keeping the total current of the multiple constant current output LEDs unchanged.

[0039] [Example 2]

[0040] The third pin of each dimming controller (U3-U5) is respectively provided with voltage sampling ports RADJ, GADJ, BADJ, and WADJ. The feedback circuit on each dimming controller (U3-U5) is composed of three voltage followers (U7-U9), wherein the input ends of the three voltage followers (U7-U9) are connected in parallel to a corresponding dimming controller (U3-U5) to obtain a voltage reference value, and the output ends of the three voltage followers (U7-U9) are respectively connected to the voltage sampling ports on the other three dimming controllers (U3-U5).

[0041] Optionally, the input terminals of the three voltage followers (U7-U9) corresponding to each dimming controller (U3-U5) are connected in parallel to the 6th pin of the dimming controller (U3-U5). Taking the red light adjustment circuit as an example, the circuit structure is as follows: Figure 4 shown.

[0042] When the dimming controller (U3~U5) is used as a constant current driver for LEDs, the PWM dimming signal is integrated into a DC signal and input into the voltage follower (U7~U9). The voltage follower (U7~U9) outputs the voltage impedance adjustment for the ADJ pin of the dimming controller (U3~U5). At the same time, multiple voltage followers (U7~U9) are used to adjust the voltage impedance of the ADJ pins connected to other dimming controllers (U3~U5) so that when one or more constant currents become smaller, the other one or more constant currents are adjusted to increase, so as to achieve the effect of keeping the total LED current unchanged.

[0043] [Example 3]

[0044] Optionally, the third pin of each dimming controller (U3~U5) is connected in series with a resistor (R8~R11) and then connected in parallel with a resistor R12 to ground to form a feedback circuit. The circuit structure diagram is as follows Figure 5 shown.

[0045] When using the dimming controller (U3~U5) as a constant current driver for LEDs, a current setting method is adopted in which resistors are connected in series to the ADJ pins of the multiple constant current drivers of the dimming controller (U3~U5) and then connected together in series with a resistor to ground. The total output current remains unchanged when the constant current dimming and color adjustment of multiple LEDs is achieved by using resistor-current proportional control.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A multi-channel LED dimming and color temperature adjustment current control circuit, comprising a power management circuit, a dimming decoding control circuit, and red, green, blue, and white light adjustment circuits connected to the dimming decoding control circuit, respectively, and the red, green, blue, and white lights dimmed by the corresponding adjustment circuits; Its characteristics are: The power management circuit is connected to the dimming decoding control circuit and provides it with a 5V driving voltage. The dimming decoding control circuit is composed of a DMX decoding driver. The DMX decoding driver has signal ports RPWM, GPWM, BPWM, and WPWM corresponding to the red light adjustment circuit, green light adjustment circuit, blue light adjustment circuit, and white light adjustment circuit, respectively. Among them, the red light adjustment circuit, green light adjustment circuit, blue light adjustment circuit, and white light adjustment circuit form a feedback circuit to keep the total output current of each circuit stable; The model of the DMX decoding driver is UCS512D. The red light adjustment circuit, green light adjustment circuit, blue light adjustment circuit, and white light adjustment circuit are each equipped with a corresponding dimming controller model LM3414. The third pins of each dimming controller are connected to each other to form a feedback circuit. One of the red light, green light, blue light, and white light is respectively connected between the seventh and eighth pins of the corresponding dimming controller. The sixth pin of each dimming controller is respectively connected to the corresponding signal port. The third pin of each dimming controller is respectively provided with a voltage sampling port RADJ, GADJ, BADJ, and WADJ. The feedback circuit on each dimming controller is composed of three voltage followers, wherein the input ends of the three voltage followers are connected in parallel to the corresponding dimming controller to obtain the voltage reference value, and the output ends of the three voltage followers are respectively connected to the voltage sampling ports on the other three dimming controllers.

2. A multi-channel LED dimming and color temperature adjustment current control circuit according to claim 1, characterized in that: The input ends of the three voltage followers corresponding to each dimming controller are connected in parallel to the third pin of the dimming controller.

3. A dimming and color temperature control method applied to a multi-channel LED dimming and color temperature control current control circuit as claimed in any one of claims 1 to 2, characterized in that: The specific steps include: S1: Set the input ports PI and PO for inputting code to the DMX decoding driver; S2: Input the dimming and color temperature adjustment signal to the DMX decoding driver through the input ports PI and PO; S3: The DMX decoding driver decodes the dimming and color temperature adjustment signal to generate 4-way R, G, B, and W dimming and color temperature adjustment PWM signals, which are respectively output to the corresponding dimming controller through the signal ports RPWM, GPWM, BPWM, and WPWM; S4: The dimming controller receives the dimming and color temperature adjustment PWM signal from the corresponding signal port and adjusts the current of one of the red, green, blue and white lights on its 7th and 8th pins according to the signal. At the same time, the dimming controller outputs a feedback signal to the feedback circuit through its 3rd pin. S5: The dimming controller on each adjustment circuit receives the feedback signal of other adjustment circuits through its third pin and performs current compensation adjustment on one of the red light, green light, blue light and white light on the 7th and 8th pins of the dimming controller to keep the total input current to the red light, green light, blue light and white light stable.

Images