Analog light dimming and color mixing circuit

Abstract

The application belongs to the technical field of LED lighting, and particularly relates to a simulation light and color adjusting circuit, which comprises a first control module, a second control module, an amplification module and an output module. The first control module receives an external light adjusting signal and generates a first PWM signal and an adjusting signal. The second control module is connected with the first control module, receives the external light adjusting signal and the adjusting signal and generates a second PWM signal. The first PWM signal and the second PWM signal are alternately output. The amplification module is connected with the first control module and the second control module, receives the first PWM signal and the second PWM signal and amplifies. The output module is connected with the amplification module. The first control module and the second control module are arranged in the circuit. The light and color adjusting temperature function is realized by using the analog signal through the alternately output of the first PWM signal and the second PWM signal. The inflexible limitation of using the single-chip microcomputer is avoided, the debugging period is reduced, the artificial cost and the production cost are reduced, and the stability is good and is not easy to be disturbed.

Description

Technical Field

[0001] This invention belongs to the field of LED lighting technology, and particularly relates to an analog dimming and color-tuning circuit. Background Technology

[0002] Existing technologies often utilize microcontrollers or smart modules, employing the microcontroller's two AD ports to achieve LED dimming and color temperature adjustment. Using a microcontroller requires fewer external components but necessitates repeated firmware debugging, resulting in a long debugging cycle, high labor costs, and high production costs. Using smart modules in conjunction with apps, Wi-Fi, Bluetooth, or 2.4G networks is not only costly but also susceptible to external environmental interference, exhibiting significant instability. Both of these solutions have their own drawbacks and fail to meet user needs. Therefore, it is necessary to design a new solution to address these issues. Summary of the Invention

[0003] The purpose of this invention is to provide an analog dimming and color tuning circuit, which aims to solve the technical problems of long debugging cycle, high labor cost, high production cost and poor stability in the prior art.

[0004] To achieve the above objectives, embodiments of the present invention provide an analog dimming and color tuning circuit, comprising:

[0005] The first control module receives an external dimming signal and generates a first PWM signal and an adjustment signal.

[0006] A second control module is connected to the first control module. The second control module receives external dimming signals and adjustment signals and generates a second PWM signal.

[0007] An amplification module is provided, which is connected to the first control module and the second control module. The amplification module receives and amplifies the first PWM signal and the second PWM signal.

[0008] An output module, which is connected to the amplification module.

[0009] As a preferred embodiment, the first control module includes a control chip U1, which includes a dimming signal conversion unit, a main control unit, a current source unit, a dimming signal detection unit, and a power supply unit. The main control unit is connected to the dimming signal conversion unit, the current source unit is connected to the main control unit, the dimming signal detection unit is connected to both the dimming signal conversion unit and the main control unit, and the power supply unit is connected to the dimming signal conversion unit, the main control unit, the current source unit, and the dimming signal detection unit.

[0010] As a preferred embodiment, the second control module includes a control chip U2, which is the same model as the control chip U1. The sixth pin of the control chip U2 is connected to the seventh pin of the control chip U1 to receive adjustment signals.

[0011] As a preferred embodiment, a multi-stage filtering circuit is also included, which includes resistor R12, capacitor C19, resistor R6 and capacitor C8. The seventh pin of the control chip U1 is connected to the sixth pin of the control chip U2 after passing through the multi-stage filtering circuit.

[0012] As a preferred embodiment, an isolation optocoupler U4 is provided between the first control module and the amplification module. The input terminal of the isolation optocoupler U4 is connected to the first control module, and the output terminal of the isolation optocoupler U4 is connected to the amplification module.

[0013] As a preferred embodiment, the first control module further includes an amplifying transistor Q4, the base of which is connected to the seventh pin of the control chip U1 and the seventh pin of the control chip U2.

[0014] As a preferred embodiment, a linear voltage regulator circuit is also included, comprising a transistor Q1, a resistor R2, a diode D1, and a capacitor C2; the collector of the transistor Q1 is connected to an external power supply, and the emitter of the transistor Q1 is connected to the first pin of the control chip U1; the first end of the resistor R2 is connected to the collector of the transistor Q1, and the second end of the resistor R2 is connected to the base of the transistor Q1; the cathode of the diode D1 is connected to the base of the transistor Q1; the first end of the capacitor C2 is connected to the collector of the transistor Q1, and the second end of the capacitor C2 is connected to the anode of the diode D2.

[0015] As a preferred embodiment, the amplification module includes transistor Q3, resistors R9 and R10, transistor Q2, resistors R7 and R8; transistor Q3, resistors R9 and R10 form a first common-emitter amplification circuit, and the base of transistor Q3 is connected to the first control module; transistor Q2, resistors R7 and R8 form a second common-emitter amplification circuit, and the base of transistor Q2 is connected to the collector of transistor Q3.

[0016] As a preferred embodiment, the output circuit includes a DC-DC chip U5, which is connected to the collector of transistor Q3 and the collector of transistor Q2.

[0017] As a preferred embodiment, the output circuit includes MOSFET Q5 and MOSFET Q6; the gate of MOSFET Q5 is connected to the collector of transistor Q3, the gate of MOSFET Q6 is connected to the collector of transistor Q2, and the source of MOSFET Q6 is connected to the source of MOSFET Q5.

[0018] The above-described technical solutions in the analog dimming and color tuning circuit provided in this invention embodiment have at least one of the following technical effects:

[0019] By alternately outputting the first PWM signal and the second PWM signal, the dimming and color temperature adjustment functions are realized using analog signals. This avoids the inflexibility limitations of using a microcontroller, reduces the debugging cycle, lowers labor and production costs, and provides good stability that is not easily affected by interference. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A circuit diagram of the analog dimming and color tuning circuit provided in an embodiment of the present invention;

[0022] Figure 2 This is a block diagram of the internal structure of the control chip U1 provided in an embodiment of the present invention;

[0023] Figure 3 The circuit schematic diagram of the output module provided in the embodiment of the present invention;

[0024] Figure 4 A circuit schematic diagram of an output module provided in another embodiment of the present invention;

[0025] Figure 5 A schematic diagram showing the relationship between the sixth and seventh pins of the control chip U1 provided in an embodiment of the present invention;

[0026] Figure 6 A schematic diagram showing the relationship between the eighth and seventh pins of the control chip U1 provided in an embodiment of the present invention;

[0027] Figure 7 The waveform diagrams of square wave signal PWM1 and square wave signal PWM2 provided in the embodiments of the present invention are shown.

[0028] The following are the labeling elements in the figure:

[0029] 100 - First control module; 110 - Dimming signal conversion unit; 120 - Main control unit; 130 - Current source unit; 140 - Dimming signal detection unit; 150 - Power supply unit; 160 - Voltage regulation unit; 200 - Second control module; 300 - Amplification circuit; 400 - Output module; 500 - Multi-stage filter circuit; 600 - Linear voltage regulation circuit. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain embodiments of the present invention, and should not be construed as limiting the present invention.

[0031] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0034] In one embodiment of the present invention, such as Figures 1-4 As shown, an analog dimming and color-tuning circuit is provided, including a first control module 100, a second control module 200, an amplification module 300, and an output module 400.

[0035] The first control module 100 receives an external dimming signal and generates a first PWM signal and an adjustment signal. The first control module 100 includes a control chip U1, filter capacitors C9, C14, C15, C16, C17, C18, and C19, and a resistor R15. The control chip U1 includes a dimming signal conversion unit 110, a main control unit 120, a current source unit 130, a dimming signal detection unit 140, a power supply unit 150, and a regulated power supply 160. The main control unit 120 is connected to the dimming signal conversion unit 110, the current source unit 130 is connected to the main control unit 120, the dimming signal detection unit 140 is connected to the dimming signal conversion unit 110 and the main control unit 120, the power supply unit 150 is connected to the dimming signal conversion unit 110, the main control unit 120, the current source unit 130 and the dimming signal detection unit 140, and the voltage regulator unit 160 is connected to the power supply unit 150.

[0036] The fourth pin of the control chip U1 is a 5V reference voltage. Resistor R15 provides a stable voltage to the sixth pin. The eighth pin is connected to an external dimming signal. The dimming signal detection unit 140 detects the voltage of the external dimming signal. The seventh pin outputs an inverse PWM signal. The sixth pin is a DC reference voltage pin. When the sixth pin is low, the seventh pin outputs a high level; when the sixth pin is high, the seventh pin outputs a low level; when the sixth pin is 50% of the reference voltage, the seventh pin outputs a 50% duty cycle. The correspondence between the sixth and seventh pins is as follows: Figure 5 As shown, the correspondence between the seventh and eighth pins is as follows: Figure 6 As shown, the voltages of pin 6 and pin 8 are positively correlated. It should be noted that all pins referred to in this paragraph are pins of the control chip U1.

[0037] The second control module 200 is connected to the first control module 100. The second control module 200 receives external dimming signals and adjustment signals and generates a second PWM signal. The second control module 200 includes a control chip U2, filter capacitors C1, C5, C6, C7, C3, and C4. The control chip U2 is the same model as the control chip U1, and the sixth pin of the control chip U2 is connected to the seventh pin of the control chip U1 to receive the adjustment signal.

[0038] Furthermore, the analog dimming and color tuning circuit also includes a multi-stage filtering circuit 500, which includes a resistor R12, a capacitor C19, a resistor R6, and a capacitor C8. The seventh pin of the control chip U1 is converted into a DC signal after passing through the multi-stage filtering circuit 500 and connected to the sixth pin of the control chip U2 to provide a reference voltage for the control chip U2.

[0039] Furthermore, the first control module 100 also includes an amplifying transistor Q4, the base of which is connected to the seventh pin of the control chip U1 and the seventh pin of the control chip U2.

[0040] The amplification module 300 is connected to the first control module 100 and the second control module 200. The amplification module 300 receives the first PWM signal and the second PWM signal and amplifies them into square wave signals PWM1 and PWM2, respectively. Figure 7 As shown. The amplification module 300 includes transistor Q3, resistors R9 and R10, transistor Q2, resistors R7 and R8. Transistor Q3, resistors R9 and R10 form a first common-emitter amplification circuit, and the base of transistor Q3 is connected to the first control module; transistor Q2, resistors R7 and R8 form a second common-emitter amplification circuit, and the base of transistor Q2 is connected to the collector of transistor Q3.

[0041] Furthermore, an isolation optocoupler U4 is provided between the first control module 100 and the amplification module 300 to achieve dimming isolation. The input terminal of the isolation optocoupler U4 is connected to the first control module 100, and the output terminal of the isolation optocoupler U4 is connected to the amplification module 300.

[0042] The output module 400 is connected to the amplification module 300.

[0043] In one embodiment of the present invention, such as Figure 3 As shown, the output circuit 400 includes a DC-DC chip U5, which is connected to the collector of transistor Q3 and the collector of transistor Q2.

[0044] In another embodiment of the invention, such as Figure 4 As shown, the output circuit 400 includes MOSFET Q5 and MOSFET Q6; the gate of MOSFET Q5 is connected to the collector of transistor Q3, the gate of MOSFET Q6 is connected to the collector of transistor Q2, and the source of MOSFET Q6 is connected to the source of MOSFET Q5.

[0045] When there is no external dimming signal connected to the eighth pin of the control chip U2, the seventh pin outputs the duty cycle corresponding to that of the sixth pin, such as... Figure 5 As shown, the duty cycle is inversely proportional to and linearly changes with the sixth pin. When the sixth pin outputs a high level, the seventh pin outputs a 0% duty cycle; when the sixth pin outputs a low level, the seventh pin outputs a 100% duty cycle. It should be noted that all pins described in this paragraph refer to the pins of the control chip U2.

[0046] The first and second PWM signals are amplified by transistors Q3 and Q2, respectively, generating square wave signals PWM1 and PWM2 at the collectors of transistors Q3 and Q2 to drive the output module 400. Square wave signals PWM1 and PWM2 are output alternately. When LED1 and LED2 are connected to LEDs with different color temperatures, the output current is adjusted by changing the duty cycle of square wave signals PWM1 and PWM2, thereby changing the color temperature of the LED.

[0047] When an external dimming signal is received by the control chip U2, the potential of the sixth pin is detected first, and the duty cycle of the seventh pin is latched. At this time, the output duty cycle of the seventh pin = DV6 * DV8. That is, under the condition that the potential of the sixth pin is fixed, the duty cycle of the eighth pin multiplied by the fixed duty cycle of the sixth pin is the output duty cycle of the seventh pin, which is the second PWM signal. The first PWM signal and the second PWM signal are amplified by the amplification module 300 and generate square wave signals PWM1 and PWM2 at the collectors of transistors Q3 and Q2 to drive the output module 400. Since the color temperature adjustment duty cycle is latched, the square wave signals PWM1 and PWM2 are always output according to a fixed ratio. When LED1 and LED2 are connected to LEDs with different color temperature LEDs, the color temperature will be fixed due to the fixed ratio of square wave signals PWM1 and PWM2. An external signal on the eighth pin causes the output PWM duty cycle to change proportionally, thereby achieving the purpose of dimming and color temperature adjustment by adjusting the output current. It should be noted that all the pins described in this paragraph refer to the pins of the control chip U2.

[0048] In another embodiment of the present invention, the analog dimming and color-tuning circuit further includes a linear voltage regulator circuit 600, which includes a transistor Q1, a resistor R2, a diode D1, and a capacitor C2. The collector of the transistor Q1 is connected to an external power supply, and the emitter of the transistor Q1 is connected to the first pin of the control chip U1; the first end of the resistor R2 is connected to the collector of the transistor Q1, and the second end of the resistor R2 is connected to the base of the transistor Q1; the cathode of the diode D1 is connected to the base of the transistor Q1; the first end of the capacitor C2 is connected to the collector of the transistor Q1, and the second end of the capacitor C2 is connected to the anode of the diode D2.

[0049] It should be noted that this application aims to protect the circuit structure. As for the program control part, those skilled in the art should select appropriate circuits and chips according to the chip models in this application or as needed and program them appropriately to realize the corresponding program control functions in this invention. Therefore, some of them are mature and established technologies in the prior art and are not the focus of protection in this application. Therefore, this application will not elaborate on this control part.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An analog dimming and color-tuning circuit, characterized in that, include: The first control module receives an external dimming signal and generates a first PWM signal and an adjustment signal. The second control module is connected to the first control module. The second control module receives external dimming signals and adjustment signals and generates a second PWM signal. The first PWM signal and the second PWM signal are output alternately. An amplification module is provided, which is connected to the first control module and the second control module. The amplification module receives and amplifies the first PWM signal and the second PWM signal. Output module, the output module being connected to the amplification module; The first control module includes a control chip U1, which includes a dimming signal conversion unit, a main control unit, a current source unit, a dimming signal detection unit, and a power supply unit. The main control unit is connected to the dimming signal conversion unit, the current source unit is connected to the main control unit, the dimming signal detection unit is connected to both the dimming signal conversion unit and the main control unit, and the power supply unit is connected to the dimming signal conversion unit, the main control unit, the current source unit, and the dimming signal detection unit. The second control module includes a control chip U2, which is the same model as the control chip U1. The sixth pin of the control chip U2 is connected to the seventh pin of the control chip U1 to receive adjustment signals. The analog dimming and color tuning circuit also includes a multi-stage filtering circuit, which includes resistor R12, capacitor C19, resistor R6 and capacitor C8. The seventh pin of the control chip U1 is connected to the sixth pin of the control chip U2 after passing through the multi-stage filtering circuit. An isolation optocoupler U4 is provided between the first control module and the amplification module. The input terminal of the isolation optocoupler U4 is connected to the first control module, and the output terminal of the isolation optocoupler U4 is connected to the amplification module. The fourth pin of the control chip U1 is a 5V reference voltage. A resistor R15 provides a stable voltage to the sixth pin of the control chip U1. The eighth pin of the control chip U1 is connected to an external dimming signal. The dimming signal detection unit detects the voltage of the external dimming signal. The seventh pin of the control chip U1 outputs an opposite PWM signal.

2. The analog dimming and color-tuning circuit according to claim 1, characterized in that, The first control module further includes an amplifying transistor Q4, the base of which is connected to the seventh pin of the control chip U1 and the seventh pin of the control chip U2.

3. The analog dimming and color-tuning circuit according to any one of claims 1-2, characterized in that, It also includes a linear voltage regulator circuit, which comprises a transistor Q1, a resistor R2, a diode D1, and a capacitor C2. The collector of the transistor Q1 is connected to an external power supply, and the emitter of the transistor Q1 is connected to the first pin of the control chip U1. The first end of the resistor R2 is connected to the collector of the transistor Q1, and the second end of the resistor R2 is connected to the base of the transistor Q1. The cathode of the diode D1 is connected to the base of the transistor Q1. The first end of the capacitor C2 is connected to the collector of the transistor Q1, and the second end of the capacitor C2 is connected to the anode of the diode D2.

4. The analog dimming and color-tuning circuit according to any one of claims 1-2, characterized in that, The amplification module includes transistor Q3, resistors R9 and R10, transistor Q2, resistors R7 and R8; transistor Q3, resistors R9 and R10 form a first common-emitter amplification circuit, and the base of transistor Q3 is connected to the first control module; transistor Q2, resistors R7 and R8 form a second common-emitter amplification circuit, and the base of transistor Q2 is connected to the collector of transistor Q3.

5. The analog dimming and color-tuning circuit according to claim 4, characterized in that, The output module includes a DC-DC chip U5, which is connected to the collector of transistor Q3 and the collector of transistor Q2.

6. The analog dimming and color-tuning circuit according to claim 4, characterized in that, The output module includes MOSFET Q5 and MOSFET Q6; the gate of MOSFET Q5 is connected to the collector of transistor Q3, the gate of MOSFET Q6 is connected to the collector of transistor Q2, and the source of MOSFET Q6 is connected to the source of MOSFET Q5.

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