Color temperature adjusting circuit and electronic device

Abstract

The utility model provides a kind of color temperature adjusting circuit and electronic equipment, including a power supply VCC and a signal output circuit for output single-channel PWM signal and the LED circuit group being connected with power supply VCC and signal output circuit respectively;Signal output circuit includes single-channel PWM signal source, isolation optocoupler (U1) and the optocoupler current-limiting resistor (R1) being connected with single-channel PWM signal source and isolation optocoupler (U1), LED circuit group includes first circuit group and second circuit group, single-channel PWM signal source, isolation optocoupler (U1) and optocoupler current-limiting resistor (R1) control the current size of first circuit group and the second circuit group and mix ratio, to realize multi-section color temperature adjustment, the utility model utilizes single-channel PWM circuit to realize the accurate proportion control of multiple LED circuit groups, to realize more accurate color temperature adjustment.

Description

Technical Field

[0001] This utility model belongs to the technical field of circuit control, specifically relating to a color temperature adjustment circuit and electronic device. Background Technology

[0002] With the rapid development of LED technology and the gradual increase in market maturity, the demand for LED equipment is also increasing. Therefore, in the design of LED equipment, it is necessary to continuously optimize the color temperature change scenarios so that LED equipment can be suitable for certain occasions.

[0003] like Figure 1 As shown, current color temperature adjustment circuits typically require two or more PWM signal outputs to perform multi-segment color temperature adjustment. This necessitates a larger storage capacity for the MCU and more complex programming, resulting in high program complexity, increased storage resource consumption, and increased costs. Secondly, to achieve signal isolation, additional external components are required, leading to a larger circuit size and increased product price. Furthermore, synchronization errors between multiple PWM signals can cause uneven color temperature mixing, resulting in visible color spots or flickering. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a color temperature adjustment circuit and electronic device to solve the problems in the background art.

[0005] The present invention provides the following technical solution: a color temperature adjustment circuit, comprising a power supply VCC, a signal output circuit for outputting a single-channel PWM signal, and an LED circuit group respectively connected to the power supply VCC and the signal output circuit;

[0006] The signal output circuit includes a single-channel PWM signal source, an isolation optocoupler U1, and an optocoupler current-limiting resistor R1 connecting the single-channel PWM signal source and the isolation optocoupler U1. The LED circuit group includes a first circuit group and a second circuit group. The single-channel PWM signal source, the isolation optocoupler U1, and the optocoupler current-limiting resistor R1 control the current magnitude of the first circuit group and the second circuit group to mix and match, thereby realizing multi-segment color temperature adjustment.

[0007] Compared with the prior art, the beneficial effects of this application are as follows: it uses a single PWM line to realize precise proportional control of multiple LED circuit groups, thereby achieving more accurate color temperature adjustment, simplifying the control of the number of peripheral components in the circuit, thereby reducing costs, improving performance, and making color temperature adjustment more convenient and smoother.

[0008] Furthermore, the output terminal of the isolation optocoupler U1 is connected to the driving unit Q1 of the first circuit group and the driving unit Q2 of the second circuit group.

[0009] Furthermore, a first resistor R2, a power supply capacitor C1, and a Zener diode ZD1 are provided between the isolation optocoupler U1 and the power supply VCC, and the Zener diode ZD1 and the power supply capacitor C1 are connected in parallel.

[0010] Furthermore, a first voltage-regulating resistor R3 and a first filter capacitor C2 are provided between the isolation optocoupler U1 and the driving unit Q1 of the first circuit group.

[0011] Furthermore, a second voltage-regulating resistor R4 and a second filter capacitor C3 are provided between the isolation optocoupler U1 and the driving unit Q2 of the second circuit group, and a base driving diode D2 is provided between the driving unit Q2 of the second circuit group and the first circuit group.

[0012] Furthermore, a first clamping resistor VS1 is connected between the driving unit Q1 of the first circuit group and the power supply VCC, and a second clamping resistor VS2 is connected between the driving unit Q2 of the second circuit group and the power supply VCC.

[0013] Furthermore, the driving unit Q1 of the first circuit group and the driving unit Q2 of the second circuit group are N-channel MOSFETs or transistors.

[0014] Furthermore, the first circuit group and the second circuit group have different color temperatures.

[0015] The present invention also provides the following technical solution: an electronic device, the electronic device including the above-mentioned color temperature adjustment circuit. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a circuit diagram of a color temperature adjustment circuit in the prior art;

[0018] Figure 2 A circuit diagram of the color temperature adjustment circuit provided for an embodiment of this utility model;

[0019] Figure 3 A block diagram illustrating the working principle of the color temperature adjustment circuit provided in this embodiment of the utility model;

[0020] Figure 4The PWM signal provided for this embodiment of the utility model is a 50% conduction amplitude diagram.

[0021] The present invention will be further described below with reference to the accompanying drawings. Detailed Implementation

[0022] The embodiments of the present invention are described in detail below, examples of which are shown 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 the embodiments of the present invention, and should not be construed as limiting the present invention.

[0023] In the description of the embodiments of this utility model, 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 drawings. They are only for the convenience of describing the embodiments of this utility model 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 this utility model.

[0024] 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 indicated technical features. 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 this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "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 this embodiment of the invention according to the specific circumstances.

[0026] like Figures 2 to 3 As shown, this embodiment specifically discloses a color temperature adjustment circuit, including a power supply VCC, a signal output circuit for outputting a single-channel PWM signal, and an LED circuit group connected to the power supply VCC and the signal output circuit respectively.

[0027] Specifically, in this embodiment, the signal output circuit includes a single-channel PWM signal source, an isolation optocoupler U1, and an optocoupler current-limiting resistor R1. The input terminal of the isolation optocoupler U1 is connected to the single-channel PWM signal source through the optocoupler current-limiting resistor R1. The LED circuit group includes a first circuit group W1-W. n Second circuit group L1-L n The output terminal of the isolation optocoupler U1 is connected to the first circuit group W1-W n The drive unit Q1 and the second circuit group L1-L n In this embodiment, the first circuit group and the second circuit group have different color temperatures, and their series and parallel connections depend on the power of the line being used. In this embodiment, the first circuit group W1-W is determined by controlling the conduction amplitude of the driving units Q1 and Q2. n Second circuit group L1-L n The current magnitude is mixed to achieve multi-segment color temperature adjustment.

[0028] Specifically, a first resistor R2, a power supply capacitor C1, and a Zener diode ZD1 are provided between the isolation optocoupler U1 and the power supply VCC. The Zener diode ZD1 and the power supply capacitor C1 are connected in parallel. The first resistor R2 is used to provide the collector voltage (VCC) to the output terminal of the isolation optocoupler U1, and the Zener diode ZD1 is the base point of the stable driving unit Q1, used to provide a stable voltage for the driving unit Q1 to conduct.

[0029] In this embodiment, a first voltage regulator R3 and a first filter capacitor C2 are provided between the isolation optocoupler U1 and the driving unit Q1 of the first circuit group, a second voltage regulator R4 and a second filter capacitor C3 are provided between the isolation optocoupler U1 and the driving unit Q2 of the second circuit group, and a base driving diode D2 is provided between the driving unit Q2 of the second circuit group and the first circuit group.

[0030] Understandably, the first voltage regulator R3 and the second voltage regulator R4 are pull-down resistors for the drive circuit to ensure that the light does not flash when the drive voltage is too low. The first filter capacitor C2 and the second filter capacitor C3 are base filter anti-interference capacitors for drive units Q1 and Q2 to suppress high-frequency interference.

[0031] Specifically, the first circuit group's drive unit Q1 is connected to the power supply VCC via a first clamping resistor VS1, and the second circuit group's drive unit Q2 is connected to the power supply VCC via a second clamping resistor VS2.

[0032] Understandably, the first clamping resistor VS1 and the second clamping resistor VS2 are used to prevent the collector voltage of drive unit Q1 and drive unit Q2 from being too high and burning out the tubes.

[0033] In this embodiment, the driving unit Q1 of the first circuit group and the driving unit Q2 of the second circuit group are N-channel MOS transistors or bipolar transistors.

[0034] Furthermore, the working principle of the above embodiment is described in detail as follows:

[0035] When V+ / V- are respectively connected to the power supply, when there is no PWM signal input and the input signal is 0V, there is no signal input to the emitting side of the isolation optocoupler U1, and there is no signal at the receiving pole. The 3rd and 4th pins of the isolation optocoupler U1 are not opened, and there is no driving potential at the base of the driving unit Q1 of the first circuit group. The driving unit Q1 is in the cut-off state. At this time, the voltage and current pass through the first circuit group W1-W n , and the base driving diode D2 provides base voltage and current for the driving unit Q2 of the first circuit group. At this time, the driving unit Q2 is 100% conductive, and the lamp beads of the second circuit group L1-L n are fully lit. At this time, it is the highest color temperature. Because the clamping voltage of the first clamping resistor VS1 is always lower than the voltage of the first circuit group W1-W n lamp string and cannot reach the LED series turn-on voltage, therefore, the lamp beads of the first circuit group W1-W n do not light up.

[0036] When the PWM signal input is maximum and the input signal is 5V, the receiving pole receives a straight 5V high-level voltage with a conduction amplitude of 100%. The 3rd and 4th pins of the isolation optocoupler U1 are conductive, and a 100% amplitude straight voltage is obtained. The base of the driving unit Q1 of the first circuit group obtains a maximum conduction potential, and the driving unit Q1 of the first circuit group is fully conductive. At this time, the lamp beads of the first circuit group W1-W n are 100% fully lit. At this time, it is the lowest color temperature, and the driving unit Q2 of the second circuit group has no conduction potential. Therefore, the lamp beads of the second circuit group L1-L n do not light up.

[0037] When the input signal 0 < y < 100%, the receiving end of the isolation optocoupler U1 receives a conduction amplitude voltage signal to provide a conduction amplitude voltage for the base of the driving unit Q1 of the first circuit group. The driving unit Q1 opens the relevant amplitude of the driving unit Q1 according to the size of the provided conduction amplitude signal. The lamp beads of the first circuit group W1-W n light up. When the driving unit Q1 is turned off, the base of the driving unit Q2 of the second circuit group receives a conduction amplitude voltage, and the lamp beads of the second circuit group L1-L n light up. Since the driving unit Q1 and the driving unit Q2 are amplitude inverse control, therefore, the conduction amplitude of the driving unit Q1 plus the driving unit Q2 is always equal to 100% within a cycle. By controlling the conduction amplitude of the driving unit Q1 and the driving unit Q2, the first circuit group W1-W nSecond circuit group L1-L n The magnitude of the current is mixed to achieve multi-segment color temperature adjustment. Figure 4 The diagram shows the amplitude of the PWM signal at 50% conduction, where y is the input 50% PWM signal, a is the base drive signal of drive unit Q1, and b is the base drive signal of drive unit Q1.

[0038] Meanwhile, in another embodiment of this utility model, an electronic device is also provided, which includes the color temperature adjustment circuit provided in the above embodiment.

[0039] In summary, compared with the prior art, the color temperature adjustment circuit in the above embodiments of this utility model has the following advantages: it uses a single PWM circuit to achieve precise proportional control of multiple LED circuit groups, thereby achieving more precise color temperature adjustment, simplifying the control of the number of peripheral components in the circuit, thereby reducing costs, improving performance, and making color temperature adjustment more convenient and smoother.

[0040] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A color temperature adjustment circuit, characterized in that, It includes a power supply VCC, a signal output circuit for outputting a single-channel PWM signal, and an LED circuit group connected to the power supply VCC and the signal output circuit respectively. The signal output circuit includes a single-channel PWM signal source, an isolation optocoupler (U1), and an optocoupler current-limiting resistor (R1) connecting the single-channel PWM signal source and the isolation optocoupler (U1). The LED circuit group includes a first circuit group and a second circuit group. The single-channel PWM signal source, the isolation optocoupler (U1), and the optocoupler current-limiting resistor (R1) control the current magnitude of the first circuit group and the second circuit group to mix and match, thereby realizing multi-segment color temperature adjustment.

2. The color temperature adjustment circuit according to claim 1, characterized in that, The output terminal of the isolation optocoupler (U1) is connected to the driving unit (Q1) of the first circuit group and the driving unit (Q2) of the second circuit group.

3. The color temperature adjustment circuit according to claim 1, characterized in that, A first resistor (R2), a power supply capacitor (C1), and a Zener diode (ZD1) are provided between the isolation optocoupler (U1) and the power supply VCC. The Zener diode (ZD1) and the power supply capacitor (C1) are connected in parallel.

4. The color temperature adjustment circuit according to claim 1, characterized in that, A first voltage regulator (R3) and a first filter capacitor (C2) are provided between the isolation optocoupler (U1) and the driving unit (Q1) of the first circuit group.

5. The color temperature adjustment circuit according to claim 1, characterized in that, A second voltage regulator (R4) and a second filter capacitor (C3) are provided between the isolation optocoupler (U1) and the driving unit (Q2) of the second circuit group, and a base driving diode (D2) is provided between the driving unit (Q2) of the second circuit group and the first circuit group.

6. The color temperature adjustment circuit according to claim 1, characterized in that, A first clamping resistor (VS1) is connected between the drive unit (Q1) of the first circuit group and the power supply VCC, and a second clamping resistor (VS2) is connected between the drive unit (Q2) of the second circuit group and the power supply VCC.

7. The color temperature adjustment circuit according to claim 1, characterized in that, The driving unit (Q1) of the first circuit group and the driving unit (Q2) of the second circuit group are N-channel MOSFETs or transistors.

8. The color temperature adjustment circuit according to claim 1, characterized in that, The first circuit group and the second circuit group have different color temperatures.

9. An electronic device, characterized in that, The electronic device includes a color temperature adjustment circuit as described in any one of claims 1-7.

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