A color temperature adjustment system

Abstract

The application relates to a color temperature adjusting system which comprises a voltage boosting module, a color temperature adjusting control module and an LED load; wherein the voltage boosting module is connected with the LED load and is used for boosting the input working voltage to supply power for the LED load; the color temperature adjusting control module is connected with the LED load and is used for switching the warm light branch and the cold light branch of the LED load based on the received PWM control signal; compared with the prior art, the technical scheme of the application can reduce the occupied number of MCU interfaces of the circuit.

Description

Technical Field

[0001] This application relates to the technical field of LED lighting control, and more particularly to a color temperature adjustment system. Background Technology

[0002] In existing technologies, BOOST constant current circuits for LED dimming and color temperature adjustment typically employ a multi-interface control scheme. This circuit receives the dimming signal through a separate DIM pin and relies on two complementary PWM signals, PWM1 and PWM2, to adjust the color temperature. Specifically, PWM1 and PWM2 control the on / off ratio of the warm-light LED branch and the cool-light LED branch, respectively, thereby adjusting the output color temperature. From a hardware control perspective, this existing circuit requires three interfaces of the microcontroller unit (MCU), corresponding to the DIM pin, PWM1 pin, and PWM2 pin, to achieve coordinated control of dimming and color temperature adjustment.

[0003] However, the aforementioned existing technologies have obvious drawbacks: in some application scenarios where interface resources are scarce, such as the power control unit of an electric clothes dryer, the MCU often needs to handle multiple functions such as motor drive and status detection at the same time, and the number of interfaces that can be allocated to LED dimming and color temperature adjustment is limited, making it difficult to meet the requirement of occupying 3 interfaces.

[0004] Therefore, how to reduce the number of MCU interfaces occupied by the circuit while ensuring the normal implementation of dimming and color temperature adjustment functions has become a technical problem that needs to be solved in the current technology. Utility Model Content

[0005] This application provides a color temperature adjustment system that can reduce the number of circuits required to access the MCU interface.

[0006] In a first aspect, this application provides a color temperature adjustment system, including: a boost module, a color temperature control module, and an LED load; wherein, the boost module is connected to the LED load and is used to boost the input operating voltage to supply power to the LED load; the color temperature control module is connected to the LED load and is used to switch the warm light branch and the cold light branch of the LED load based on the received PWM control signal.

[0007] In one possible implementation, the color temperature control module includes a warm light branch switch unit and a cool light branch switch unit; wherein the warm light branch switch unit is used to control the on / off state of the warm light branch, and the cool light branch switch unit is used to control the on / off state of the cool light branch.

[0008] In one possible implementation, the cold light branch switching unit includes a first switching transistor and a second switching transistor, and the warm light branch switching unit includes a third switching transistor; or, the warm light branch switching unit includes a first switching transistor and a second switching transistor, and the cold light branch switching unit includes a third switching transistor; wherein, the first terminal of the first switching transistor is connected to the first terminal of the second switching transistor, the second terminal of the first switching transistor is connected to the second terminal of the third switching transistor, and the third terminal of the second switching transistor is connected to the first terminal of the third switching transistor; the first terminals of the first switching transistor, the second switching transistor, and the third switching transistor are all used to receive the PWM control signal.

[0009] In one possible implementation, when the first switch is a first MOS transistor, the second switch is a second MOS transistor, and the third switch is a third MOS transistor, the first terminal is the gate, the second terminal is the source, and the third terminal is the drain; or, when the first switch is a first transistor, the second switch is a second transistor, and the third switch is a third transistor, the first terminal is the base, the second terminal is the emitter, and the third terminal is the collector.

[0010] In one possible implementation, the LED load includes a branch inductor unit; the branch inductor unit is used to filter the current of the warm light branch or the cold light branch, the first end of the branch inductor unit is connected to the drain of the first MOS transistor, the second end of the branch inductor unit is connected to the drain of the third MOS transistor, and the third end of the branch inductor unit is connected to the output terminal of the boost module.

[0011] In one possible implementation, the boost module includes a boost control unit, a switching unit, an energy storage unit, and a freewheeling unit; wherein the boost control unit is connected to the switching unit and is used to output a drive signal to the switching unit, and the switching unit is controlled by the drive signal to turn on or off; the switching unit is connected to both the energy storage unit and the freewheeling unit; the energy storage unit is used to store energy when the switching unit is turned on and to release the stored energy when the switching unit is turned off; the freewheeling unit is used to allow the energy released by the energy storage unit to flow when the switching unit is turned off.

[0012] In one possible implementation, the boost control unit includes a boost control chip, the switching unit includes a fourth switching transistor, the energy storage unit includes an energy storage inductor, and the freewheeling unit includes a freewheeling diode; the drive output terminal of the boost control chip is connected to the first terminal of the fourth switching transistor, the third terminal of the fourth switching transistor is connected to one end of the energy storage inductor, the other end of the energy storage inductor is connected to the operating voltage input terminal, the anode of the freewheeling diode is connected to the connection node between the fourth switching transistor and the energy storage inductor, and the cathode of the freewheeling diode is connected to the power supply terminal of the LED load.

[0013] In one possible implementation, the boost control module further includes a filter unit and a first sampling resistor unit; wherein the filter unit is connected to the cathode of the freewheeling diode and is used to filter the boosted voltage; the second terminal of the fourth switching transistor is connected to the first terminal of the first sampling resistor unit, and the second terminal of the first sampling resistor unit is grounded.

[0014] In one possible implementation, the color temperature adjustment system provided in this application further includes a current detection module; the current detection module is connected to the boost module and the LED load respectively, and is used to detect the operating current of the LED load and feed it back to the boost module to achieve constant current control.

[0015] In one possible implementation, the current detection module includes a second sampling resistor unit and an LC filter unit; wherein the second sampling resistor unit is connected to the LC filter unit, and the LC filter unit is connected to the voltage control chip; the second sampling resistor unit is connected in series between the LED load and ground to collect the operating current of the LED load and form a voltage drop; the LC filter unit includes a filter inductor and a filter capacitor, wherein the first end of the filter inductor and the first end of the filter capacitor are connected to the target pin of the current detection unit, the second end of the filter inductor is connected to the first end of the second sampling resistor unit, and the second end of the filter capacitor is grounded.

[0016] The technical solutions provided in this application have the following advantages compared with the prior art:

[0017] This application provides a color temperature adjustment system, including: a boost module, a color temperature control module, and an LED load; wherein, the boost module is connected to the LED load and is used to boost the input operating voltage to power the LED load; the color temperature control module is connected to the LED load and is used to switch the warm light branch and the cold light branch of the LED load based on the received PWM control signal; compared with the prior art, the color temperature control module in this application can complete the switching between the warm light branch and the cold light branch by receiving a single PWM control signal, which only requires one interface of the MCU, avoiding the need to occupy two interfaces of the MCU in the prior art. It relies on two complementary PWM signals, PWM1 and PWM2, to achieve color temperature adjustment, which can reduce the occupation of the MCU interface and alleviate the problem of interface resource shortage. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a schematic diagram of the structure of a color temperature adjustment system provided in this application;

[0022] Figure 2 This is a schematic diagram of the structure of a boost module according to an embodiment of this application;

[0023] Figure 3 This is another structural schematic diagram of a boost module according to an embodiment of the present application;

[0024] Figure 4 This is a schematic diagram of the circuit structure of a boost module according to one embodiment of the present application;

[0025] Figure 5 This is a schematic diagram of the circuit structure of a color temperature control module according to one embodiment of the present application;

[0026] Figure 6This is a schematic diagram of the circuit structure of an LED load according to an embodiment of this application;

[0027] Figure 7 This is another structural schematic diagram of a color temperature adjustment system provided in this application;

[0028] Figure 8 This is another structural schematic diagram of a current detection module provided in this application;

[0029] Figure 9 This is a schematic diagram of the circuit structure of a current detection module provided in this application;

[0030] Figure 10 This is another structural schematic diagram of a color temperature adjustment system provided in this application;

[0031] Figure 11 This is a schematic diagram of the circuit structure of a color temperature adjustment system provided in this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] Boost module 10, color temperature control module 11, LED load 12, current detection module 13, power conversion module 14, boost control unit 101, switching unit 102, energy storage unit 103, freewheeling unit 104, filtering unit 105, first sampling resistor unit 106, second sampling resistor unit 131, LC filtering unit 132. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0036] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0037] Figure 1 This application provides a schematic diagram of the structure of a color temperature adjustment system; as shown below. Figure 1 As shown, the color temperature adjustment system includes a boost module 10, a color temperature control module 11, and an LED load 12, as detailed below:

[0038] In one embodiment, the boost module 10 is connected to the LED load 12 and is used to boost the input operating voltage to power the LED load 12; the color temperature control module 11 is connected to the LED load 12 and is used to switch the warm light branch and the cold light branch of the LED load 12 based on the received PWM control signal.

[0039] In one embodiment, the boost module 10 includes a boost control unit 101, a switching unit 102, an energy storage unit 103, and a freewheeling unit 104.

[0040] Specifically, the boost module 10 adopts a BOOST boost topology; the voltage boosting function is achieved through the coordinated work of the boost control unit 101, the switching unit 102, the energy storage unit 103, and the freewheeling unit 104, providing a stable and demand-compliant power supply voltage for the LED load 12; these four units form a closed-loop cooperative mechanism, with the boost control unit 101 taking the lead in issuing control commands, the switching unit 102 acting as the execution component to control the on / off state of the circuit, the energy storage unit 103 responsible for energy storage and release, and the freewheeling unit ensuring the smooth flow of energy release path, together completing the boost conversion from input working voltage to output voltage.

[0041] In one embodiment, the boost control unit 101 is connected to the switching unit 102, and the switching unit 102 is connected to the energy storage unit 103 and the freewheeling unit 104 respectively. The boost control unit 101 is used to output a drive signal to the switching unit 102, and the switching unit 102 is turned on or off under the control of the drive signal. The energy storage unit 103 is used to store energy when the switching unit 102 is turned on and to release the stored energy when the switching unit 102 is turned off. The freewheeling unit 104 is used to allow the energy released by the energy storage unit 103 to flow when the switching unit 102 is turned off. Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a boost module according to an embodiment of this application.

[0042] Specifically, the boost control unit 101 is directly connected to the switching unit 102. The output drive signal can change the on and off duration of the switching unit 102, thereby regulating the energy conversion efficiency of the energy storage unit 103 and ultimately achieving stable control of the output voltage.

[0043] Specifically, the switching unit 102 is connected to the energy storage unit 103 and the freewheeling unit 104 respectively. Its on or off working state is completely determined by the drive signal output by the boost control unit 101. When the drive signal meets the on condition, the switching unit 102 closes to form an energy storage circuit. When the drive signal is interrupted, the switching unit 102 opens, triggering the energy release process of the energy storage unit 103.

[0044] Specifically, during the conduction of the switching unit 102, the input operating voltage charges the energy storage unit 103 through the closed switching circuit, converting electrical energy into magnetic field energy for storage; and when the switching unit 102 is turned off, the energy storage unit 103 immediately releases the stored energy, which is superimposed with the input voltage to form a higher output voltage.

[0045] Specifically, the energy storage unit 103 has the characteristic that the current cannot change abruptly. When the switching unit 102 is suddenly turned off, a reverse electromotive force will be generated. If there is no freewheeling path, the excessively high reverse voltage may damage the circuit components. The freewheeling unit 104 provides a low-impedance flow path for the energy released by the energy storage unit 103, which not only ensures that the energy can be continuously delivered to the load, but also avoids the impact of reverse voltage on components such as the switching unit 102.

[0046] In one embodiment, the boost control unit 101 includes a boost control chip U2, the switching unit 102 includes a fourth switching transistor Q4, the energy storage unit 103 includes an energy storage inductor L1, and the freewheeling unit 104 includes a freewheeling diode D1. The drive output terminal of the boost control chip U2 is connected to the first terminal of the fourth switching transistor Q4, the third terminal of the fourth switching transistor Q4 is connected to one end of the energy storage inductor L1, the other end of the energy storage inductor L1 is connected to the working voltage input terminal, the anode of the freewheeling diode D1 is connected to the connection node between the fourth switching transistor Q4 and the energy storage inductor L1, and the cathode of the freewheeling diode D1 is connected to the power supply terminal of the LED load 12.

[0047] Specifically, the working principle of the boost module 10 is as follows: When the boost control chip U2 outputs a drive signal to the first terminal of the fourth switch Q4 to turn it on, the working voltage input at the working voltage input terminal flows through the energy storage inductor L1 and the turned-on fourth switch Q4. At this time, the energy storage inductor L1 converts electrical energy into magnetic energy for energy storage. When the fourth switch Q4 is turned off by the drive signal, the energy storage inductor L1 will generate a reverse electromotive force because the current cannot change abruptly. At this time, the freewheeling diode D1 turns on, and the magnetic energy stored in the energy storage inductor L1 is converted into electrical energy and released. After being superimposed with the input working voltage, it is delivered to the power supply terminal of the LED load 12 through the freewheeling diode D1, thereby realizing the voltage increase.

[0048] Specifically, the fourth switching transistor can be a fourth MOSFET or a fourth transistor.

[0049] Specifically, when the fourth switch is a fourth MOS transistor and the MOSI transistor is a PMOS transistor, the first terminal of the fourth switch is the gate, the second terminal is the source, and the third terminal is the drain. In this embodiment, the fourth switch is a fourth MOS transistor and the MOSI transistor is a PMOS transistor, which will be used as an example for specific explanation.

[0050] Specifically, when the fourth switch is a fourth MOS transistor and the MOSI transistor is an NMOS transistor, the first terminal of the fourth switch is the gate, the second terminal is the drain, and the third terminal is the source; when the fourth switch is the fourth transistor, the first terminal is the base, the second terminal is the emitter, and the third terminal is the collector.

[0051] Specifically, through the coordinated operation of each unit in the boost module 10, the input voltage can be stably boosted to supply power to the LED load 12, meeting the LED load 12's operating voltage requirements; at the same time, the presence of the freewheeling diode D1 avoids damage to the circuit components by the reverse electromotive force when the switching unit 102 is turned off, improving the reliability and service life of the circuit.

[0052] In one embodiment, the boost control module 10 includes a filter unit 105 and a first sampling resistor unit 106; as Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of a boost module according to an embodiment of this application.

[0053] In one embodiment, the filter unit 105 is connected to the cathode of the freewheeling diode D1 to filter the boosted voltage; the second terminal of the fourth switch Q4 is connected to the first terminal of the first sampling resistor unit 106, and the second terminal of the first sampling resistor unit 106 is grounded.

[0054] Specifically, the first sampling resistor unit 106 includes a first sampling resistor R15 and a second sampling resistor R13; the filtering unit 105 is an output filter inductor EC2; as Figure 4 As shown, Figure 4 This is a schematic diagram of the circuit structure of a boost module according to an embodiment of this application.

[0055] Specifically, during the operation of the boost module 10, after the energy is released by the energy storage inductor and the current is freed by the freewheeling diode, the output voltage will have a certain ripple. If this ripple directly affects the LED load 12, it may affect the stability of LED light emission and even cause problems such as flickering. The output filter inductor EC2 uses the impedance of the inductor to AC signal to effectively filter out the ripple component in the voltage, making the voltage output to the power supply terminal of the LED load 12 smoother and more stable, thereby providing a stable operating voltage for the LED and ensuring the stability and consistency of LED light emission.

[0056] Specifically, the second terminal of the fourth switch Q4 is connected to the first terminal of the first sampling resistor unit 106, which is composed of the first sampling resistor R15 and the second sampling resistor R13. The second terminal of the first sampling resistor unit 106 is grounded. The main function of the first sampling resistor R15 and the second sampling resistor R13 is to sample the operating current of the fourth switch Q4. When the current flows through these two sampling resistors, a corresponding voltage drop will be generated across them. The boost control chip U2 can detect this voltage drop and thus obtain the operating current information of the fourth switch Q4. Based on this current information, the boost control chip U2 can precisely adjust the output drive signal to control the on and off time of the fourth switch Q4, thereby achieving precise control of the output current of the boost module 10. Ultimately, this ensures that the boost module 10 can stably and reliably provide the required current to the LED load 12, ensuring the stable operation of the entire dimming and color temperature adjustment circuit.

[0057] In one embodiment, the color temperature control module 11 includes a warm light branch switch unit and a cold light branch switch unit; wherein, the warm light branch switch unit is used to control the on / off state of the warm light branch, and the cold light branch switch unit is used to control the on / off state of the cold light branch.

[0058] Specifically, the color temperature control module 11 achieves the switching and mixing of warm and cool light on the LED load 12 through the independent control of the warm light branch switch unit and the cool light branch switch unit, thereby adjusting the output color temperature. The warm light branch switch unit is responsible for controlling the on / off state of the warm light LED branch. When the warm light branch switch unit is on, current flows through the warm light LED branch, and the circuit outputs warm light. When the warm light branch switch unit is off, there is no current in the warm light branch, and the warm light output stops. Similarly, the cool light branch switch unit only controls the on / off state of the cool light LED branch. Its on / off state directly determines the current on / off state of the cool light branch. The two work together to achieve three color temperature modes: warm light only, cool light only, and a mixture of warm and cool light.

[0059] like Figure 5 As shown, Figure 5 This is a schematic diagram of the circuit structure of a color temperature control module according to one embodiment of this application.

[0060] In one embodiment, the cold light branch switching unit includes a first switching transistor Q1 and a second switching transistor Q2, and the warm light branch switching unit includes a third switching transistor Q3.

[0061] Preferably, the cold light branch switch unit may include a first switch tube Q1 and a second switch tube Q2, and the warm light branch switch unit may include a third switch tube Q3.

[0062] Taking the cold light branch switch unit including a first switch transistor Q1 and a second switch transistor Q2, and the warm light branch switch unit including a third switch transistor Q3 as an example, the connection relationship between the cold light branch switch unit and the warm light branch switch unit is as follows: the first terminal of the first switch transistor Q1 is connected to the first terminal of the second switch transistor Q2, the second terminal of the first switch transistor Q1 is connected to the second terminal of the third switch transistor Q3, and the third terminal of the second switch transistor Q2 is connected to the first terminal of the third switch transistor Q3; the first terminals of the first switch transistor Q1, the second switch transistor Q2, and the third switch transistor Q3 are all used to receive the PWM control signal.

[0063] Specifically, when the first switch Q1 is a first MOS transistor, the second switch Q2 is a second MOS transistor, and the third switch Q3 is a third MOS transistor, the first terminal is the gate, the second terminal is the source, and the third terminal is the drain.

[0064] Preferably, since the MOS transistor can be either a PMOS transistor or an NMOS transistor, when the MOS transistor is a PMOS transistor, the first terminal is set as the gate, the second terminal as the source, and the third terminal as the drain; when the MOS transistor is an NMOS transistor, the first terminal is set as the gate, the second terminal as the drain, and the third terminal as the source.

[0065] Specifically, when the first switch Q1 is a first transistor, the second switch Q2 is a second transistor, and the third switch Q3 is a third transistor, the first electrode is the base, the second electrode is the emitter, and the third electrode is the collector.

[0066] In this embodiment, taking the first switch Q1 as a first MOS transistor, the second switch Q2 as a second MOS transistor, and the third switch Q3 as a third MOS transistor, and the MOS transistors as PMOS transistors, the cold light branch switching unit includes the first MOS transistor Q1 and the second MOS transistor Q2, and the warm light branch switching unit includes the third MOS transistor Q3; wherein, the gate of the first MOS transistor Q1 is connected to the gate of the second MOS transistor Q2, the source of the first MOS transistor Q1 is connected to the source of the third MOS transistor Q3, and the drain of the second MOS transistor Q2 is connected to the gate of the third MOS transistor Q3; the gates of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are all used to receive the PWM control signal.

[0067] Specifically, the cold light branch switching unit adopts a combination structure of a first switch Q1 and a second switch Q2. The first terminal of the first switch Q1 is directly connected to the first terminal of the second switch Q2. This design ensures that both can receive the same PWM control signal synchronously. When the PWM signal is high, the first terminals of both the first switch Q1 and the second switch Q2 simultaneously obtain the turn-on voltage, and both are turned on synchronously. When the PWM signal is low, the voltage at the first terminals of both disappears, and they are turned off synchronously, avoiding the cold light branch from being delayed due to the turn-on of a single switch. The current is unstable. In addition, the second terminal of the first switch Q1 is connected to the second terminal of the third switch Q3 in the subsequent warm light branch switch unit, forming a common potential terminal of the circuit, ensuring that the reference potential of the current loop of the cold and warm light branches is consistent. The third terminal of the second switch Q2 is connected to the first terminal of the third switch Q3. When the second switch Q2 is turned on, its third terminal potential will pull down the first terminal potential of the third switch Q3, forcing the third switch Q3 to turn off, and vice versa, thereby avoiding current conflict or color temperature disorder caused by the simultaneous conduction of the cold and warm light branches.

[0068] Specifically, the warm light branch switching unit only requires the third switch Q3 to control the on / off state of the warm light branch. Its operating state is entirely determined by the PWM control signal and the output state of the second switch Q2. The first terminal of the third switch Q3 receives the PWM control signal on one hand and is affected by the potential of the third terminal of the second switch Q2 on the other hand: when the PWM signal is low, the first switch Q1 and the second switch Q2 are turned off synchronously, the third terminal of the second switch Q2 loses its pull-down effect, and the first terminal of the third switch Q3 obtains the conduction voltage under the action of the circuit auxiliary voltage VDD, the warm light branch is turned on, and the circuit outputs warm light; when the PWM signal is high, the first switch Q1 and the second switch Q2 are turned on synchronously, the third terminal of the second switch Q2 pulls the potential of the first terminal of the third switch Q3 down to the cutoff voltage, the third switch Q3 is turned off, the warm light branch is disconnected, the cold light branch is turned on, and the circuit outputs cold light.

[0069] Specifically, this complementary logic—where the first switch Q1 and the second switch Q2 are on while the third switch Q3 is off, and vice versa—allows for switching between warm and cool light branches to be achieved using only one PWM control signal. When the PWM signal outputs a specific duty cycle, the first switch Q1, the second switch Q2, and the third switch Q3 will alternately turn on according to the duty cycle, resulting in alternating output of warm and cool light. This utilizes the persistence of vision in the human eye to create a mixed color temperature, ultimately achieving color temperature adjustment controlled by a single PWM signal, which reduces the occupancy of the MCU interface.

[0070] In one embodiment, the LED load 12 includes a branch inductor unit; the branch inductor unit is used to filter the current of the warm light branch or the cold light branch; wherein, the branch inductor unit is an inductor LF1.

[0071] like Figure 6 As shown, Figure 6 This is a schematic diagram of the circuit structure of an LED load according to an embodiment of this application.

[0072] Specifically, the branch inductor unit LF1.

[0073] The first end of the branch inductor unit LF1 is connected to the third terminal of the first switching transistor Q1, the second end of the branch inductor unit LF1 is connected to the third terminal of the third switching transistor Q3, and the third end of the branch inductor unit LF1 is connected to the output terminal of the boost module 10.

[0074] Specifically, the current output from the boost module 10 first flows through the branch inductor unit LF1, and then into the LED load 12. After the current flows out of the LED load 12, it flows to different branches according to the on / off state of the switching transistors determined by the PWM control signal. For example, when the cold light branch is working, i.e., the first switch Q1 and the second switch Q2 are turned on and the third switch Q3 is turned off, the current flowing out of the LED load 12 will flow through LF1 to the first switch Q1 and the second switch Q2. When the warm light branch is working, i.e., the third switch Q3 is turned on and the first switch Q1 and the second switch Q2 are turned off, the current flowing out of the LED load 12 will flow through LF1 to the third switch Q3. In this process, the branch inductor unit LF1 can filter the current before it enters the LED load 12, and at the same time, after the current flows out of the LED load 12, it guides the current to the corresponding switching transistor according to the working state of different branches, thus achieving both filtering of the current in the two branches and ensuring the normal operation logic of the circuit.

[0075] In one embodiment, the color temperature adjustment system provided in this application further includes a current detection module 13, such as... Figure 7 As shown, Figure 7 This is another structural schematic diagram of a color temperature adjustment system provided in this application.

[0076] In one embodiment, the current detection module 13 is connected to the boost module 10 and the LED load 12 respectively, and is used to detect the operating current of the LED load 12 and feed it back to the boost module 10 to achieve constant current control.

[0077] Specifically, the current detection module 13 is connected between the boost module 10 and the LED load 12. It can detect the operating current of the LED load 12 in real time and feed back the detected current information to the boost module 10. The boost module 10 adjusts its own operating state according to the feedback current information, thereby achieving constant control of the operating current of the LED load 12, ensuring that the LED can emit light stably in different color temperature modes, and avoiding problems such as brightness changes or color temperature shifts caused by current fluctuations.

[0078] like Figure 8 As shown, Figure 8 This is another structural schematic diagram of a current detection module provided in this application.

[0079] In one embodiment, the current detection module 13 includes a second sampling resistor unit 131 and an LC filter unit 132; wherein, the second sampling resistor unit 131 is connected to the LC filter unit, and the LC filter unit is connected to the boost control chip U2; the second sampling resistor unit 131 is connected in series between the LED load 12 and ground, and is used to collect the operating current of the LED load 12 and form a voltage drop.

[0080] like Figure 9 As shown, Figure 9 This is a schematic diagram of the circuit structure of a current detection module provided in this application.

[0081] Specifically, the LC filter unit includes a filter inductor L3 and a filter capacitor C4. The first end of the filter inductor L3 and the first end of the filter capacitor C4 are connected to the target pin of the current detection unit. The second end of the filter inductor L3 is connected to the first end of the second sampling resistor unit 131. The second end of the filter capacitor C4 is grounded. The target pin of the boost control chip U2 is the FB pin.

[0082] Specifically, the second sampling resistor unit 131 includes a third sampling resistor R17 and a fourth sampling resistor R16, wherein the first terminals of the third sampling resistor R17 and the fourth sampling resistor R16 are respectively connected to the third terminals of the first switch Q1 and the third switch Q3, and the sources of the first switch Q1 and the third switch Q3 are grounded.

[0083] Specifically, the second sampling resistor unit 131 is connected in series between the LED load 12 and ground. When current flows through the LED load 12, the current will flow through the sampling resistor. According to Ohm's law, a voltage drop proportional to the current will be generated across the resistor. By detecting the magnitude of this voltage drop, the operating current of the LED load 12 can be indirectly known. This can provide basic current information for subsequent feedback control.

[0084] Specifically, during operation, the voltage signal generated by the second sampling resistor unit 131 first passes through the LC filter unit. Since the operating current of the LED load 12 may contain ripple and other interference components, these interferences will make the sampled voltage signal impure. The LC filter unit utilizes the impedance of the inductor to the AC signal and the conduction of the capacitor to the AC signal to effectively filter out the ripple and noise in the voltage signal. The filtered pure voltage signal is then transmitted to the boost control chip U2. The boost control chip U2 adjusts the output of the boost module 10 based on this accurate voltage signal, thereby achieving constant current control of the operating current of the LED load 12, ensuring stable circuit operation and accurate color temperature adjustment.

[0085] In one embodiment, the color temperature adjustment system provided in this application further includes a power conversion module 14, such as... Figure 10 As shown, Figure 10 This is another structural schematic diagram of a color temperature adjustment system provided in this application; as shown Figure 11 As shown, Figure 11 This is a schematic diagram of the circuit structure of a color temperature adjustment system provided in this application.

[0086] Specifically, the power conversion module 14 includes a power conversion chip U1, which converts the input 24V+ voltage and outputs a stable VDD voltage to provide a suitable operating voltage for the color temperature control module 11.

[0087] In one embodiment, the input terminal of the power conversion module 14 is connected to the first terminal of the energy storage inductor in the boost module 10, the output terminal of the power conversion module 14 is connected to the VDD power input pin of the color temperature control module 11, and the ground terminal of the power conversion module 14 is grounded. In this connection relationship, the input terminal IN of the power conversion chip U1 is connected to the 24V+ power supply to obtain externally input electrical energy as the energy source for conversion. The output terminal of the power conversion chip U1 is connected to the color temperature control module 11 to provide a stable voltage after conversion. At the same time, the ground terminal GND of the power conversion chip U1 is connected to the common ground of the circuit to establish a stable potential reference point and ensure the stability of voltage conversion and circuit operation.

[0088] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0089] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0090] 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 this application, "multiple" means two or more, unless otherwise explicitly specified.

[0091] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a 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 application according to the specific circumstances.

[0092] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0094] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0095] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A color temperature adjustment system, characterized in that, include: Boost module, color temperature control module, and LED load; The boost module is connected to the LED load and is used to boost the input operating voltage to power the LED load. The color temperature control module is connected to the LED load and is used to switch the warm light branch and the cold light branch of the LED load based on the received PWM control signal.

2. The color temperature adjustment system as described in claim 1, characterized in that, The color temperature control module includes a warm light branch switch unit and a cold light branch switch unit; The warm light branch switch unit is used to control the on / off state of the warm light branch, and the cold light branch switch unit is used to control the on / off state of the cold light branch.

3. The color temperature adjustment system as described in claim 2, characterized in that, The cold light branch switch unit includes a first switch and a second switch, and the warm light branch switch unit includes a third switch. Alternatively, the warm light branch switch unit includes a first switch and a second switch, and the cold light branch switch unit includes a third switch; Wherein, the first terminal of the first switch is connected to the first terminal of the second switch, the second terminal of the first switch is connected to the second terminal of the third switch, and the third terminal of the second switch is connected to the first terminal of the third switch. The first terminal of the first switch, the second switch, and the third switch are all used to receive the PWM control signal.

4. The color temperature adjustment system as described in claim 3, characterized in that, When the first switch is a first MOS transistor, the second switch is a second MOS transistor, and the third switch is a third MOS transistor, the first terminal is the gate, the second terminal is the source, and the third terminal is the drain. or, When the first switching transistor is a first transistor, the second switching transistor is a second transistor, and the third switching transistor is a third transistor, the first transistor is the base, the second transistor is the emitter, and the third transistor is the collector.

5. The color temperature adjustment system as described in claim 3, characterized in that, The LED load includes a branch inductor unit; The branch inductor unit is used to filter the current of the warm light branch or the cold light branch; The first end of the branch inductor unit is connected to the third terminal of the first switching transistor, the second end of the branch inductor unit is connected to the third terminal of the third switching transistor, and the third end of the branch inductor unit is connected to the output terminal of the boost module.

6. The color temperature adjustment system as described in claim 1, characterized in that, The boost module includes a boost control unit, a switching unit, an energy storage unit, and a freewheeling unit; The boost control unit is connected to the switching unit and is used to output a drive signal to the switching unit. The switching unit is turned on or off under the control of the drive signal. The switching unit is connected to the energy storage unit and the freewheeling unit respectively; The energy storage unit is used to store energy when the switching unit is turned on and to release the stored energy when the switching unit is turned off. The freewheeling unit is used to allow the stored energy released by the energy storage unit to flow when the switching unit is turned off.

7. The color temperature adjustment system as described in claim 6, characterized in that, The boost control unit includes a boost control chip, the switching unit includes a fourth switching transistor, the energy storage unit includes an energy storage inductor, and the freewheeling unit includes a freewheeling diode. The drive output terminal of the boost control chip is connected to the first terminal of the fourth switching transistor. The third terminal of the fourth switching transistor is connected to one end of the energy storage inductor. The other end of the energy storage inductor is connected to the working voltage input terminal. The anode of the freewheeling diode is connected to the connection node between the fourth switching transistor and the energy storage inductor. The cathode of the freewheeling diode is connected to the power supply terminal of the LED load.

8. The color temperature adjustment system as described in claim 7, characterized in that, The boost control module also includes a filtering unit and a first sampling resistor unit; The filtering unit is connected to the cathode of the freewheeling diode and is used to filter the boosted voltage. The second terminal of the fourth switching transistor is connected to the first terminal of the first sampling resistor unit, and the second terminal of the first sampling resistor unit is grounded.

9. The color temperature adjustment system as described in claim 7, characterized in that, It also includes a current detection module; The current detection module is connected to both the boost module and the LED load, and is used to detect the operating current of the LED load and feed it back to the boost module to achieve constant current control.

10. The color temperature adjustment system as described in claim 9, characterized in that, The current detection module includes a second sampling resistor unit and an LC filter unit; The second sampling resistor unit is connected to the LC filter unit, and the LC filter unit is connected to the voltage control chip. The second sampling resistor unit is connected in series between the LED load and ground to collect the operating current of the LED load and generate a voltage drop. The LC filter unit includes a filter inductor and a filter capacitor. The first end of the filter inductor and the first end of the filter capacitor are connected to the target pin of the current detection unit. The second end of the filter inductor is connected to the first end of the second sampling resistor unit. The second end of the filter capacitor is grounded.

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