LED lamp strip control circuit with touch and PWM dimming

Abstract

The utility model relates to a light adjusting circuit technical field discloses a kind of LED lamp strip control circuit with touch and PWM light adjustment with simple structure, touch sensitivity is high and stable light adjustment effect, including touch area circuit (100), touch detection circuit (110), MCU main control circuit (120), LED drive circuit (130) and MOS tube power supply on-off circuit (140), wherein, when the control signal of MCU main control circuit (120) input is high level, MOS tube power supply on-off circuit (140) is controlled to be conducted, to control MOS tube power supply on-off circuit (140) to LED drive circuit (130) output a voltage signal, the duty cycle of LED drive circuit (130) regulation output PWM signal, to control the voltage of LED drive circuit (130) loading in LED lamp strip.

Description

Technical Field

[0001] This utility model relates to the field of dimming circuit technology, and more specifically, to an LED light strip control circuit with touch control and PWM dimming. Background Technology

[0002] With the development of LED lighting technology, LED light strips, due to their low energy consumption, long lifespan, and rich colors, are widely used in home decoration, commercial lighting, and landscape lighting. To enhance user experience, the control methods for LED light strips are gradually developing towards intelligence and convenience, with touch control and brightness adjustment functions becoming important technical requirements.

[0003] Currently, LED strip light control circuits on the market have the following shortcomings: Limited control methods: Most use mechanical buttons or infrared remote control. Mechanical buttons are prone to wear and tear, have poor waterproof performance, and the operation feedback is not intuitive. Infrared remote control requires additional equipment, is easily affected by obstruction, and is not convenient to use. Poor dimming performance: Traditional dimming mostly uses analog dimming, which has problems such as low efficiency and poor linearity of brightness adjustment; some PWM dimming circuits have unstable dimming frequency due to controller performance limitations, which are prone to flickering and affect the visual experience. The circuit is relatively complex: In existing integrated touch and dimming solutions, the touch module and dimming module are often designed separately, requiring additional signal conversion circuits, resulting in a large overall circuit size, high cost, and weak anti-interference capability. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide an LED strip control circuit with touch control and PWM dimming that is simple in structure, has high touch sensitivity and stable dimming effect, in view of the defects of the above-mentioned LED strip control circuit in the prior art, such as limited control method, poor dimming performance and relatively complex circuit.

[0005] The technical solution adopted by this utility model to solve its technical problem is: to construct an LED light strip control circuit with touch control and PWM dimming, which has the following features: Touch area circuitry; A touch detection circuit, the input of which is connected to the output of the touch area circuit, is used to acquire at least one touch signal output when the user touches the touch area circuit; The MCU main control circuit has its signal input terminal connected to the output terminal of the touch detection circuit, and is used to receive the touch signal and output at least one PWM signal according to the touch signal; The LED driver circuit has one signal input terminal coupled to one signal output terminal of the MCU main control circuit, which is used to receive the PWM signal. The MOSFET power supply on / off circuit has one signal input terminal coupled to another signal output terminal of the MCU main control circuit, used to receive a control signal. The output terminal of the MOS transistor power on / off circuit is connected to another signal input terminal of the LED driver circuit. When the control signal input to the MCU main control circuit is high, the MOSFET power supply switching circuit is turned on, thereby controlling the MOSFET power supply switching circuit to output a voltage signal to the LED driver circuit. The MCU main control circuit adjusts the duty cycle of the output PWM signal to control the voltage applied to the LED strip by the LED driving circuit.

[0006] In some embodiments, the touch detection circuit includes at least a first controller, the input of which is used to acquire the touch signal output when the finger touches the area. The signal output terminal of the first controller is connected to the signal input terminal of the MCU main control circuit.

[0007] In some implementations, the MCU main control circuit includes at least one main controller. The signal input terminals of the main controller are respectively connected to the signal output terminals of the first controller, for receiving the touch signals and corresponding to at least one PWM signal based on the touch signals. One signal output terminal of the main controller is coupled to the signal input terminal of the LED driver circuit. The other signal output terminal of the main controller is coupled to a signal input terminal of the MOS transistor power on / off circuit.

[0008] In some embodiments, the LED driving circuit includes at least a second controller. A signal input terminal of the second controller is connected to a signal output terminal of the main controller for receiving the PWM signal. Another signal input terminal of the second controller is connected to the output terminal of the MOS transistor power on / off circuit, and is used to receive the voltage signal. The output of the second controller is connected to the positive / negative terminal of the LED strip. The second controller adjusts the voltage input to the LED strip according to the duty cycle of the input PWM signal.

[0009] In some embodiments, the MOS transistor power on / off circuit includes at least a third controller and a first transistor. One input terminal of the third controller is connected to the output terminal of the AC rectifier circuit. The other input terminal of the third controller is connected to the collector of the first transistor. The base of the first transistor is coupled to another signal output terminal of the main controller. The output terminal of the third controller is connected to another signal input terminal of the second controller.

[0010] In some embodiments, a 3.3V regulated output circuit is also included, the input of which is connected to the output of the AC rectifier circuit. The output terminal of the 3.3V regulated output circuit is connected to the voltage input terminal of the main controller.

[0011] In some embodiments, the 3.3V regulated output circuit includes at least a three-terminal regulator and an LDO regulator. The input terminal of the three-terminal voltage regulator is connected to the output terminal of the AC rectifier circuit to regulate the input voltage of the AC rectifier circuit. The output of the three-terminal regulator is coupled to the input of the LDO regulator. The output terminal of the LDO regulator is connected to the voltage input terminal of the main controller.

[0012] In some embodiments, the AC rectifier circuit includes at least one rectifier bridge, the input of which is connected to the AC side for rectifying the input AC signal. The output terminal of the AC rectifier circuit is connected to the power on / off circuit of the MOS transistor and the input terminal of the 3.3V regulated output circuit, respectively.

[0013] The LED strip control circuit with touch control and PWM dimming described in this invention includes a touch area circuit, a touch detection circuit, an MCU main control circuit, an LED driver circuit, and a MOSFET power on / off circuit. When the control signal input to the MCU main control circuit is high, the MOSFET power on / off circuit is turned on, controlling the MOSFET power on / off circuit to output a voltage signal to the LED driver circuit. The LED driver circuit adjusts the duty cycle of the output PWM signal to control the voltage applied to the LED strip. Compared with existing technologies, the MCU main control circuit uniformly manages touch detection, power on / off, and PWM dimming, eliminating the need for signal conversion circuits between discrete modules (such as the interface circuit between the touch chip and dimming chip in traditional solutions), thus simplifying circuit design. The power supply and dimming are controlled separately. The MOSFET is responsible for the overall power supply switching (high voltage control), and the PWM is responsible for brightness adjustment (low voltage signal). The two are independent yet coordinated, which avoids the interference of power fluctuations on the touch signal during dimming and improves stability. Enhanced touch reliability: The filtering and amplification design of the touch detection circuit, combined with the software algorithm of the MCU main control circuit, can effectively suppress environmental interference (such as humidity and electromagnetic noise), solving the problem of accidental touch in traditional touch control. The dimming performance is optimized, the frequency of the PWM signal output by the MCU main control circuit is stable, which can avoid low-frequency flicker, and linear dimming is achieved through subdivision, which improves the visual experience. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a circuit diagram of an embodiment of the touch area circuit and touch detection circuit provided by this utility model; Figure 2 This is a circuit schematic diagram of an embodiment of the MCU main control circuit provided by this utility model; Figure 3 This is a circuit schematic diagram of an embodiment of the LED driver circuit provided by this utility model; Figure 4 This is a circuit diagram of an embodiment of the MOS transistor power on / off circuit provided by this utility model; Figure 5 This is a circuit schematic diagram of an embodiment of the 3.3V regulated output circuit provided by this utility model; Figure 6 This is a circuit diagram of an embodiment of the AC rectifier circuit provided by this utility model. Detailed Implementation

[0015] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0016] like Figures 1-6 As shown, in the first embodiment of the LED strip control circuit with touch control and PWM dimming of this utility model, the LED strip control circuit with touch control and PWM dimming includes a touch area circuit 100, a touch detection circuit 110, an MCU main control circuit 120, an LED driver circuit 130, a MOS tube power supply switching circuit 140, a 3.3V regulated output circuit 150, and an AC rectifier circuit 160. Among them, the touch area circuit 100 is equivalent to a copper foil, which is used to acquire the touch signal formed by the user's fingertip touching the touch area or the sensing area; The touch detection circuit 110 is used to receive touch signals generated when the touch area circuit 100 is touched. The MCU main control circuit 120 has the functions of logic operation, signal reception / processing, outputting PWM signal / control signal, and adjusting the duty cycle of the output PWM signal according to the state of the touch signal; The MOSFET power supply switching circuit 140 functions as a switch. It receives the voltage signal input from the AC rectifier circuit 160 and outputs the voltage signal to the LED driver circuit 130 to provide the working voltage for the LED light strip. The 3.3V regulated output circuit 150 has the functions of voltage regulation and filtering. It is used to receive the voltage signal input from the AC rectifier circuit 160 and perform voltage regulation / filtering on the voltage signal to provide a +3.3V voltage for the touch detection circuit 110 and the MCU main control circuit 120. The AC rectifier circuit 160 has the function of rectification and filtering. It is used to receive the AC voltage input from the mains side and to rectify and filter the input voltage signal. Specifically, the touch area circuit 100 is used to detect the touch signal formed by the user's fingertip touching the sensing area, and output the touch signal to the touch detection circuit 110; The input terminal of the touch detection circuit 110 is connected to the output terminal of the touch area circuit 100, and is used to receive / acquire at least one touch signal output by the user when touching the touch area circuit 100, and after the touch signal is converted from analog to digital, it is output to the MCU main control circuit 120. Furthermore, the signal input terminal of the MCU main control circuit 120 is connected to the signal output terminal of the touch detection circuit 110, for receiving the touch signal input from the touch detection circuit 110, and outputting at least one PWM signal according to the touch signal, or The duty cycle of the PWM signal output is based on the touch signal; Furthermore, a signal input terminal of the LED driver circuit 130 is coupled to a signal output terminal of the MCU main control circuit 120, and is used to receive the PWM signal or the PWM signal after adjusting the duty cycle. One signal input terminal of the MOSFET power on / off circuit 140 is coupled to another signal output terminal of the MCU main control circuit 120, and is used to receive a control signal. The input control signal is used to control the on / off state of the MOSFET power on / off circuit 140. When the input control signal is low, the MOSFET power supply switching circuit 140 is turned off. When the input control signal is high, the MOSFET power supply switching circuit 140 is turned on and outputs a voltage signal. The output terminal of the MOSFET power on / off circuit 140 is connected to another signal input terminal of the LED driver circuit 130. When the control signal input to the MCU main control circuit 120 is high, the MOSFET power on / off circuit 140 is turned on to control the MOSFET power on / off circuit 140 to output a voltage signal to the LED driver circuit 130, providing a voltage signal for the LED light strip. The MCU main control circuit 120 adjusts the duty cycle of the output PWM signal according to the state of the input touch signal, so as to control the voltage applied to the LED strip by the LED driver circuit 130.

[0017] For example, the MCU main control circuit 120 reads the touch signal input from the touch detection circuit 110 through corresponding pins. If it is an analog signal, it needs to be converted into a digital signal using an internal ADC (analog-to-digital converter). For instance, the touch position or touch intensity of a capacitive touch sensor may correspond to different voltage values, and the ADC of the MCU main control circuit 120 converts this voltage value into a digital quantity. The read touch signal is then filtered to remove noise and interference signals to ensure the accuracy of the touch signal. Software filtering methods, such as mean filtering and median filtering, can be used. The MCU main control circuit 120 then determines the duty cycle of the corresponding PWM signal based on the processing result of the touch signal. For example, a mapping relationship can be established to map the numerical range of the touch signal to the duty cycle range of the PWM signal (0%-100%). For example, the digital output range of the touch area circuit 100 is 0-1023, which is linearly mapped to the duty cycle of the PWM signal 0%-100%, that is, the digital value 0 corresponds to 0% duty cycle, and the digital value 1023 corresponds to 100% duty cycle.

[0018] Using this solution, touch detection, power on / off and PWM dimming are uniformly managed by the MCU main control circuit 120, eliminating the signal conversion circuit between discrete modules (such as the interface circuit between the touch chip and the dimming chip in traditional solutions), thus simplifying circuit design. The power supply and dimming are controlled separately. The MOSFET is responsible for the overall power supply switching (high voltage control), and the PWM is responsible for brightness adjustment (low voltage signal). The two are independent yet coordinated, which avoids the interference of power fluctuations on the touch signal during dimming and improves stability. Enhanced touch reliability: The filtering and amplification design of the touch detection circuit, combined with the software algorithm of the MCU main control circuit, can effectively suppress environmental interference (such as humidity and electromagnetic noise), solving the problem of accidental touch in traditional touch control. The dimming performance is optimized, the frequency of the PWM signal output by the MCU main control circuit is stable, which can avoid low-frequency flicker, and linear dimming is achieved through subdivision, which improves the visual experience.

[0019] In some implementations, such as Figure 1 As shown, to ensure the reliability of the acquired touch signal, a first controller U101 can be set in the touch detection circuit 110, which has the function of signal reception and conversion. The input terminal (pin 3) of the first controller U101 is connected to the output terminal (pin 3) of the touch area circuit 100 through the second resistor R102, and is used to acquire the touch signal output when the finger touch area (COP) is touched. The signal output terminal (corresponding to pins 17-20) of the first controller U101 is connected to the signal input terminal (corresponding to pins 1-4) of the MCU main control circuit 120 through the eighth resistor R108-the eleventh resistor R111. The acquired touch signal is input to the MCU main control circuit 120, and the MCU main control circuit 120 can adjust the duty cycle of the output PWM signal according to the input touch signal.

[0020] In some implementations, such as Figure 2 As shown, to ensure the stability of LED strip adjustment, a main controller U201 can be set in the MCU main control circuit 120, which has the functions of logic operation, PWM signal and control signal output; Specifically, the signal input terminals (pins 1-4) of the main controller U201 are connected to the signal output terminals (pins 17-20) of the first controller U101 to receive touch signals and generate at least one PWM signal based on the touch signals. One signal output terminal (corresponding to pin 18) of the main controller U201 is coupled to the signal input terminal of the LED driver circuit 130, inputting the PWM signal into the LED driver circuit 130. Another signal output terminal (corresponding to pin 6) of the main controller U201 is coupled to a signal input terminal of the MOSFET power on / off circuit 140, and outputs the control signal to the MOSFET power on / off circuit 140 to control its on / off state.

[0021] In some implementations, such as Figure 3 As shown, to ensure the reliability of LED strip adjustment, a second controller U301 can be set in the LED driver circuit 130. It is a DC / DC regulator with a wide input voltage range of 10V-60V and has the functions of PWM and analog dimming. Specifically, a signal input terminal (pin 7) of the second controller U301 is connected to a signal output terminal (pin 6) of the main controller U201 to receive PWM signals. Another signal input terminal (corresponding to pin 5) of the second controller U301 is connected to the output terminal (corresponding to +DC2) of the MOSFET power on / off circuit 140 through the fourth inductor L302, and is used to receive voltage signals. The output terminal (corresponding to pin 3) of the second controller U301 is connected to the positive / negative terminal of the LED strip. The second controller U301 can adjust the voltage of the input LED strip according to the duty cycle of the input PWM signal.

[0022] Specifically, when the second controller U301 receives different PWM signals with different duty cycles from the main controller U201 at pin 7, different voltages are output to the LED+ and LED- terminals to the LED strip. The LED strip with a 12V withstand voltage is selected, and the resistance value of the seventeenth resistor R301 is changed to change the current at the LED+ and LED- terminals.

[0023] That is, when there is a touch action in the sensing area or control touch area of ​​the touch area circuit 100, the capacitance value of the eighth capacitor C108 will change. The first controller U101 can determine whether the finger is close or touching. Upon receiving the closeness or touch, the first controller U101 will convert it into an I2C signal and establish communication with the main controller U201. The main controller U201 outputs PWM signals with different duty cycles according to the I2C signal and sends them to the second controller U301. The second controller U301 then outputs different levels and loads them on both ends of the LED light strip to adjust its brightness.

[0024] In some implementations, such as Figure 3 As shown, the MOSFET power on / off circuit 140 includes at least a third controller Q401 and a first transistor Q402. The third controller Q401 supports high-speed switching (such as hard switching) and is suitable for DC / DC converters, communication equipment and industrial control scenarios, and can realize fast signal transmission and power control. The first transistor Q402 functions as a switch, and it is selected as an NPN transistor. Specifically, one input terminal (corresponding to pins 1-3) of the third controller Q401 is connected to the output terminal of the AC rectifier circuit 160 to receive the input voltage signal. The other input terminal (corresponding to pin 4) of the third controller Q401 is connected to the collector of the first transistor Q402 through the twentieth resistor R402. The base of the first transistor Q402 is connected to another signal output terminal (corresponding to pin 6) of the main controller U201 through the twenty-first resistor R403, and is used to receive input control signals. The output terminals (pins 5-8) of the third controller Q401 are connected in parallel with the twenty-fourth capacitor C403 and the twenty-fifth capacitor C404, which are connected to another signal input terminal (pin 5) of the second controller U301, so as to input the voltage signal into the second controller U301.

[0025] Specifically, when pin 6 (DC2_RST) of the main controller U201 is high, the emitter-collector of the first transistor Q402 is turned on, and the third controller Q401 is low. At this time, pins 8 and 1 of the third controller Q401 are connected, forming a current path.

[0026] In some implementations, such as Figure 3 As shown, in order to ensure the stability of the operation of the first controller U101 and the main controller U201, a 3.3V regulated output circuit 150 can be set in the control circuit, which has the functions of voltage reduction and filtering; The input terminal of the 3.3V regulated output circuit 150 is connected to the output terminal of the AC rectifier circuit 160 to receive voltage signals and perform voltage step-down processing on the input voltage signals. The output terminal of the 3.3V regulated output circuit 150 is connected to the voltage input terminal of the main controller U201 and the first controller U101, providing a +3.3V voltage signal to the first controller U101 and the main controller U201.

[0027] In some implementations, such as Figure 3 As shown, the 3.3V regulated output circuit 150 includes at least a three-terminal regulator U501 and an LDO regulator U502. The input terminal (pin 3) of the three-terminal regulator U501 is connected to the output terminal (+DC terminal) of the AC rectifier circuit 160 through the fifth inductor L501, thereby regulating the input voltage of the AC rectifier circuit 160. The output terminal (pin 4) of the three-terminal regulator U501 is connected to the input terminal (pin 3) of the LDO regulator U502 through the twenty-fourth resistor R503, thus inputting a +8.5V voltage to the LDO regulator U502. The output terminal (pin 2) of the LDO regulator U502 is connected to the voltage input terminal (pin 7) of the main controller U201 and the voltage input terminal (pin 16) of the first controller U101, respectively, so that the +3.3V voltage is input to the main controller U201 and the first controller U101.

[0028] Specifically, when there is a voltage input at pin 3 of the three-terminal regulator U501, the output terminal (corresponding to pin 4) is fixed at +8.5V by adjusting the 23rd resistor R501 and the 24th resistor R502. When there is a voltage input at pin 3 of the LDO regulator U502, it can be fixed at +3.3V to be used by the main controller U201 and the first controller U101.

[0029] In some implementations, such as Figure 6 As shown, the AC rectifier circuit 160 includes at least one rectifier bridge D601. The input terminal of the rectifier bridge D601 is connected to the AC side (corresponding to J3) and is used to rectify the input AC signal. The output terminal (corresponding to the +DC terminal) of the AC rectifier circuit 160 is connected to the input terminal of the MOSFET power on / off circuit 140 and the 3.3V regulated output circuit 150, respectively, to provide them with DC voltage.

[0030] Specifically, AC power is input to socket J3, and after passing through rectifier bridge D601, socket J1 will output DC power of approximately 1.414 times the AC power. After being regulated and having its power ripple filtered by the thirty-sixth capacitor C605, the application design uses transformer power supply. Therefore, this circuit is also suitable for DC power supply and can be directly connected to socket J1.

[0031] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A control circuit for an LED strip light with touch control and PWM dimming, characterized in that, have: Touch area circuitry; A touch detection circuit, the input of which is connected to the output of the touch area circuit, is used to acquire at least one touch signal output when the user touches the touch area circuit; The MCU main control circuit has its signal input terminal connected to the output terminal of the touch detection circuit, and is used to receive the touch signal and output at least one PWM signal according to the touch signal; The LED driver circuit has one signal input terminal coupled to one signal output terminal of the MCU main control circuit, which is used to receive the PWM signal. The MOSFET power supply on / off circuit has one signal input terminal coupled to another signal output terminal of the MCU main control circuit, used to receive a control signal. The output terminal of the MOS transistor power on / off circuit is connected to another signal input terminal of the LED driver circuit. When the control signal input to the MCU main control circuit is high, the MOSFET power supply switching circuit is turned on, thereby controlling the MOSFET power supply switching circuit to output a voltage signal to the LED driver circuit. The MCU main control circuit adjusts the duty cycle of the output PWM signal to control the voltage applied to the LED strip by the LED driving circuit.

2. The LED strip control circuit with touch control and PWM dimming according to claim 1, characterized in that, The touch detection circuit includes at least a first controller, the input of which is used to acquire the touch signal output when the finger touches the area. The signal output terminal of the first controller is connected to the signal input terminal of the MCU main control circuit.

3. The LED strip control circuit with touch control and PWM dimming according to claim 2, characterized in that, The MCU main control circuit includes at least one main controller. The signal input terminals of the main controller are respectively connected to the signal output terminals of the first controller, for receiving the touch signals and corresponding to at least one PWM signal based on the touch signals. One signal output terminal of the main controller is coupled to the signal input terminal of the LED driver circuit. The other signal output terminal of the main controller is coupled to a signal input terminal of the MOS transistor power on / off circuit.

4. The LED strip control circuit with touch control and PWM dimming according to claim 3, characterized in that, The LED driving circuit includes at least a second controller. A signal input terminal of the second controller is connected to a signal output terminal of the main controller for receiving the PWM signal. Another signal input terminal of the second controller is connected to the output terminal of the MOS transistor power on / off circuit, and is used to receive the voltage signal. The output of the second controller is connected to the positive / negative terminal of the LED strip. The second controller adjusts the voltage input to the LED strip according to the duty cycle of the input PWM signal.

5. The LED strip control circuit with touch control and PWM dimming according to claim 4, characterized in that, The MOS transistor power on / off circuit includes at least a third controller and a first transistor. One input terminal of the third controller is connected to the output terminal of the AC rectifier circuit. The other input terminal of the third controller is connected to the collector of the first transistor. The base of the first transistor is coupled to another signal output terminal of the main controller. The output terminal of the third controller is connected to another signal input terminal of the second controller.

6. The LED strip control circuit with touch control and PWM dimming according to claim 5, characterized in that, It also includes a 3.3V regulated output circuit, the input of which is connected to the output of the AC rectifier circuit. The output terminal of the 3.3V regulated output circuit is connected to the voltage input terminal of the main controller.

7. The LED strip control circuit with touch control and PWM dimming according to claim 6, characterized in that, The 3.3V regulated output circuit includes at least a three-terminal regulator and an LDO regulator. The input terminal of the three-terminal voltage regulator is connected to the output terminal of the AC rectifier circuit to regulate the input voltage of the AC rectifier circuit. The output of the three-terminal regulator is coupled to the input of the LDO regulator. The output terminal of the LDO regulator is connected to the voltage input terminal of the main controller.

8. The LED strip control circuit with touch control and PWM dimming according to claim 7, characterized in that, The AC rectifier circuit includes at least one rectifier bridge, the input terminal of which is connected to the AC side for rectifying the input AC signal. The output terminal of the AC rectifier circuit is connected to the power on / off circuit of the MOS transistor and the input terminal of the 3.3V regulated output circuit, respectively.

Images