Multiplexing circuit for key and lighting functions

Abstract

The application provides a key and lighting function multiplexing circuit, comprising: a key, an LED, a MOS tube, a key detection module, a control module, an LED driving module; the key is coupled with the LED in parallel, and one end of the parallel connection is coupled with the first pole of the MOS tube and the key detection module respectively, and the other end is used for coupling the first pole of a power supply; the key detection module is coupled with the control module; the control module is coupled with the LED driving module; the LED driving module is coupled with the gate of the MOS tube; the second pole of the MOS tube is used for coupling the second pole of the power supply; wherein, when the key is actuated, the key detection module detects a key signal, the control module outputs a fixed duty cycle signal according to the key signal, and the LED driving module controls the MOS tube to drive the LED according to the duty cycle signal, so that a technical scheme of a controllable lighting system with simple design and low cost which can output different brightness is realized.

Description

Technical Field

[0001] This invention relates to the field of LED lighting technology, and more particularly to a multiplexed circuit for button and lighting functions. Background Technology

[0002] In typical LED lighting systems, power is usually supplied by batteries. However, in some backup or emergency lighting systems, to maximize system operating time or reduce battery costs, there are application requirements for different brightness outputs such as 100%, 50%, and 25%.

[0003] To achieve the above objectives, existing solutions add an MCU control unit, which adjusts the steady-state brightness of the LED according to an internally compiled program. However, the MCU chip in the control unit is expensive, and the logic control within the lighting system becomes complex to accommodate the MCU chip, increasing both the system cost and the PCB design complexity.

[0004] Therefore, a low-cost, simpler PCB design integrated solution is needed to facilitate mass production and inventory preparation for end customers. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a multiplexed circuit for button and lighting functions. By simplifying the structure of the multiplexed circuit, a low-cost and simpler PCB design integration solution is achieved.

[0006] This invention provides a multiplexed circuit for button and lighting functions, comprising: a button, an LED, a MOSFET, a button detection module, a control module, and an LED driver module;

[0007] The button and the LED are connected in parallel, and one end of the parallel connection is coupled to the first terminal of the MOS transistor and the button detection module, respectively, while the other end is used to couple to the first terminal of the power supply.

[0008] The button detection module is coupled to the control module;

[0009] The control module is coupled to the LED driver module;

[0010] The LED driving module is coupled to the gate of the MOS transistor;

[0011] The second terminal of the MOSFET is used to couple to the second terminal of the power supply;

[0012] When the button is pressed, the button detection module detects the button signal, the control module outputs a fixed duty cycle signal based on the button signal, and the LED driving module controls the MOS transistor to drive the LED based on the duty cycle signal.

[0013] Furthermore, the control module includes:

[0014] A data conversion unit is used to convert the key signals into digital signals;

[0015] Encoding unit, used to encode the digital signal into a control signal;

[0016] The clock unit is used to output a clock signal group that includes two clock signals;

[0017] A counting unit is used to generate a count value group including two count values ​​based on the control signal and the clock signal group;

[0018] The comparison output unit is used to generate a duty cycle signal based on the group of count values;

[0019] The data conversion unit is coupled to the encoding unit, the encoding unit and the clock unit are respectively coupled to the counting unit, and the counting unit is coupled to the comparison output unit.

[0020] Furthermore, the clock unit includes a first clock generator and a second clock generator;

[0021] The counting unit includes a first counter and a second counter;

[0022] The output of the first clock generator is coupled to the clock input of the first counter;

[0023] The output of the second clock generator is coupled to the clock input of the second counter;

[0024] The output terminal of the first counter is coupled to the first input terminal of the comparison output unit;

[0025] The output terminal of the second counter is coupled to the second input terminal of the comparison output unit;

[0026] The control terminal of the second counter is coupled to the encoding unit;

[0027] The output terminal of the comparison output unit is used to output the duty cycle signal.

[0028] Furthermore, the data conversion unit employs an analog-to-digital converter.

[0029] Furthermore, the encoding unit employs an encoder.

[0030] Furthermore, the comparison output unit employs a digital comparator.

[0031] Furthermore, the MOS transistor is an NMOS transistor, the first electrode of the MOS transistor is the drain, the second electrode of the MOS transistor is the source, the first electrode of the power supply is the positive electrode, and the second electrode of the power supply is the negative electrode;

[0032] After the button is connected in parallel with the LED, the negative terminal of the LED is coupled to the drain of the NMOS transistor.

[0033] Furthermore, the LED driving module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first NPN transistor, a first PNP transistor, a second NPN transistor, a second PNP transistor, and a third NPN transistor;

[0034] One end of the first resistor is coupled to the control module, and the other end of the first resistor is coupled to the emitter of the first NPN transistor and the emitter of the first PNP transistor, respectively.

[0035] One end of the second resistor, the emitter of the second NPN transistor, the emitter of the third NPN transistor, and one end of the sixth resistor are all coupled to ground. The other end of the second resistor is coupled to the base of the first NPN transistor, the base of the first PNP transistor, the collector of the third NPN transistor, and one end of the third resistor, respectively.

[0036] The other end of the third resistor is coupled to the emitter of the second PNP transistor and connected to the positive terminal of the power supply;

[0037] One end of the fourth resistor is coupled to the collector of the second NPN transistor and the collector of the second PNP transistor, respectively, and the other end of the fourth resistor is coupled to one end of the fifth resistor and the gate of the NMOS transistor, respectively.

[0038] The other end of the fifth resistor is coupled to the base of the third NPN transistor and the other end of the sixth resistor, respectively.

[0039] The collector of the first NPN transistor is coupled to the base of the second PNP transistor;

[0040] The collector of the first PNP transistor is coupled to the base of the second NPN transistor.

[0041] Furthermore, the MOS transistor is a PMOS transistor, the first terminal of the MOS transistor is the source, the second terminal of the MOS transistor is the drain, the first terminal of the power supply is the negative terminal, and the second terminal of the power supply is the positive terminal;

[0042] After the button is connected in parallel with the LED, the positive terminal of the LED is coupled to the source of the PMOS transistor.

[0043] Furthermore, the LED driver module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a fourth NPN transistor, a third PNP transistor, a fifth NPN transistor, a fourth PNP transistor, and a fifth PNP transistor.

[0044] One end of the sixth resistor is coupled to the control module, and the other end of the sixth resistor is coupled to the emitter of the fourth NPN transistor and the emitter of the third PNP transistor, respectively.

[0045] One end of the seventh resistor is coupled to the emitter of the fifth NPN transistor and grounded, and the other end of the seventh resistor is coupled to the base of the fourth NPN transistor, the base of the third PNP transistor, the collector of the fifth PNP transistor, and one end of the eighth resistor.

[0046] The other end of the eighth resistor is coupled to the emitter of the fourth PNP transistor, the emitter of the fifth PNP transistor, and one end of the tenth resistor and connected to the positive terminal of the power supply.

[0047] One end of the ninth resistor is coupled to the collector of the fifth NPN transistor and the collector of the fourth PNP transistor, respectively, and the other end of the ninth resistor is coupled to one end of the eleventh resistor and the gate of the PMOS transistor.

[0048] The other end of the tenth resistor is coupled to the base of the fifth PNP transistor and the other end of the eleventh resistor, respectively.

[0049] The collector of the fourth NPN transistor is coupled to the base of the fourth PNP transistor.

[0050] The collector of the third PNP transistor is coupled to the base of the fifth NPN transistor.

[0051] The technical solution provided by this invention has at least the following beneficial effects:

[0052] The button detection module detects the button signal triggered by the button, and the control module processes the button signal and outputs a fixed duty cycle signal. Under the action of the duty cycle signal, the LED driver module controls the MOSFET to drive the LED. This realizes a technical solution for generating a duty cycle signal based on the button signal with a simple structure, which reduces production costs and simplifies PCB design. Attached Figure Description

[0053] Figure 1 A schematic diagram of a multiplexed circuit for button and lighting functions provided by the present invention;

[0054] Figure 2 A schematic diagram of the framework structure of the control module in a multiplexed circuit for button and lighting functions provided by the present invention;

[0055] Figure 3 A schematic diagram of the specific framework structure of the control module in a multiplexed circuit for button and lighting functions provided by the present invention;

[0056] Figure 4 A schematic diagram of a multiplexed circuit for button and lighting functions provided by the present invention, including an NMOS transistor;

[0057] Figure 5 A circuit diagram of an LED driving module for an NMOS transistor provided by the present invention;

[0058] Figure 6 A schematic diagram of a multiplexed circuit for button and lighting functions provided by the present invention, including a PMOS transistor;

[0059] Figure 7 This invention provides a circuit diagram of an LED driving module for a PMOS transistor. Detailed Implementation

[0060] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the invention and do not limit the scope of protection of the invention.

[0061] Please refer to Figure 1 The present invention provides a multiplexed circuit for button and lighting functions, comprising: a button S, an LED, a MOSFET, a button detection module, a control module, and an LED driver module;

[0062] The button S is connected in parallel with the LED, and one end of the parallel connection is coupled to the first terminal of the MOS transistor and the button detection module, respectively, while the other end is used to couple to the first terminal of the power supply.

[0063] The button detection module is coupled to the control module;

[0064] The control module is coupled to the LED driver module;

[0065] The LED driving module is coupled to the gate of the MOS transistor;

[0066] The second terminal of the MOSFET is used to couple to the second terminal of the power supply;

[0067] When the button S is activated, the button detection module detects the button signal, the control module outputs a fixed duty cycle signal based on the button signal, and the LED driving module controls the MOS transistor to drive the LED based on the duty cycle signal.

[0068] In this embodiment, button S can be a conventional button, and the specific model and specifications can be selected according to actual needs. LEDs are used to output light of corresponding brightness for illumination under the action of a MOSFET. MOSFETs can be PMOS or NMOS. The first and second terminals of the MOSFET are respectively the drain and source, for example: when the first terminal is the source, the second terminal is the drain; when the first terminal is the drain, the second terminal is the source. The first and second terminals of the power supply are respectively the positive and negative, for example: when the first terminal is positive, the second terminal is negative; when the first terminal is negative, the second terminal is positive. The LED driving module can use a conventional LED driving circuit. The LED driving circuit needs to match the type of MOSFET; that is, the LED driving circuits corresponding to PMOS and NMOS are different. The button detection module is used to detect the action signal of button S and output a corresponding analog signal. For example, if button S is pressed once, the button detection module detects a button signal. The specific circuit of the button detection module uses a conventional detection circuit. The control module is constructed using components such as an analog-to-digital converter, encoder, counter, comparator, and clock generator. It can generate different fixed duty cycle signals based on different button signals. The specific situation can be adjusted according to actual needs. For example: pressing button S once, the control module outputs a fixed duty cycle signal with a first ratio to control the LED output brightness to 25% of its maximum. Pressing button S twice, the control module outputs a fixed duty cycle signal with a second ratio to control the LED output brightness to 50% of its maximum. Pressing button S three times, the control module outputs a fixed duty cycle signal with a third ratio to control the LED output brightness to 100% of its maximum.

[0069] Further, please refer to Figure 2 The control module includes:

[0070] A data conversion unit is used to convert the key signals into digital signals;

[0071] Encoding unit, used to encode the digital signal into a control signal;

[0072] The clock unit is used to output a clock signal group that includes two clock signals;

[0073] A counting unit is used to generate a count value group including two count values ​​based on the control signal and the clock signal group;

[0074] The comparison output unit is used to generate a duty cycle signal based on the group of count values;

[0075] The data conversion unit is coupled to the encoding unit, the encoding unit and the clock unit are respectively coupled to the counting unit, and the counting unit is coupled to the comparison output unit.

[0076] In this embodiment, the control module can automatically process the input button signal and output a duty cycle signal corresponding to the button signal, thereby controlling the current of the LED. The data conversion unit can be an ADC (Analog-to-Digital Converter) or a combination of corresponding logic devices. The encoding unit can be a conventional encoder, the clock unit can be based on a crystal oscillator, the counting unit can be a counter, and the comparison output unit can be a digital comparator. The data conversion unit has analog signal input ports and digital signal output ports, the encoding unit has signal input ports and signal output ports, the clock unit has a clock signal output port, the counting unit has a clock signal input port, a counting output port, a control port, and an enable port, and the comparison output unit has a data input port and a comparison signal output port. The analog signal input port of the data conversion unit is used to receive external analog signals. The digital signal output port of the data conversion unit is coupled to the signal input port of the encoding unit. The signal output port of the encoding unit is coupled to the control port of the counting unit. The clock unit has two clock signal output ports, and the clock signal input ports of the counting unit are coupled one-to-one. The counting unit can be controlled to turn on and off via an enable signal through an enable port. Both the counting output port and the comparison output port have two data input ports, which are coupled one-to-one. The comparison signal output port of the comparison output unit is used to output the generated duty cycle signal.

[0077] In one specific implementation, the data conversion unit receives the key signal through the analog signal input port, converts it into a digital signal, and transmits it to the signal input port of the encoding unit through the digital signal output port. The encoding unit encodes the digital signal to obtain a control signal, which is then transmitted to the control port of the counting unit through the signal output port. The clock unit transmits clock signals to the two clock signal input ports of the counting unit through two clock signal output ports. During normal operation, the enable port of the counting unit receives an enable signal to activate the working mode. The counting unit processes one of the received clock signal groups according to the received control signal and counts it, while counting the other clock signal normally, ultimately obtaining two count values. The counting unit transmits the two count values ​​to the two data input ports of the comparison output unit through two counting output ports. The comparison output unit compares the two count values ​​in the received count value group, generates a corresponding duty cycle signal, and transmits it externally through the comparison signal output port. By setting a control module different from that of the MCU chip, not only is the compatibility of key function and lighting function achieved, but the chip design cost is also greatly reduced, improving product quality and competitiveness.

[0078] Further, please refer to Figure 3 The clock unit includes a first clock generator and a second clock generator;

[0079] The counting unit includes a first counter and a second counter;

[0080] The output of the first clock generator is coupled to the clock input of the first counter;

[0081] The output of the second clock generator is coupled to the clock input of the second counter;

[0082] The output terminal of the first counter is coupled to the first input terminal of the comparison output unit;

[0083] The output terminal of the second counter is coupled to the second input terminal of the comparison output unit;

[0084] The control terminal of the second counter is coupled to the encoding unit;

[0085] The output terminal of the comparison output unit is used to output the duty cycle signal.

[0086] In this embodiment, the first and second clock generators can be conventional clock generators, such as those using crystal oscillators to output clock signals, or other conventional methods. The first and second counters can also be conventional counters. The enable terminal of the second counter receives an enable signal. In specific implementation, the encoding unit transmits the control signal to the control terminal of the second counter through the signal output port. The first clock generator provides a clock signal to the first counter, which performs counting processing, and the corresponding count value is transmitted to the comparison output unit. The second clock generator provides another clock signal to the second counter, which processes the clock signal according to the control signal and counts, and the corresponding count value is transmitted to the comparison output unit. The comparison output unit compares the two received count values ​​and ultimately outputs a duty cycle signal. Furthermore, the control module can also set a timer, which is coupled to the second counter and provides it with a timing period. The second counter can process the received clock signal proportionally according to the timing period based on the control signal, generating a proportionally changing count value until the second counter outputs a stable count value that no longer changes. This controls the comparison output unit to proportionally decrease the duty cycle according to the timing period.

[0087] Furthermore, the data conversion unit employs an analog-to-digital converter.

[0088] In this embodiment, the analog-to-digital converter can convert the received analog signal into a digital signal. The analog-to-digital converter can be understood as an analog-to-digital converter, also known as an A / D converter or ADC for short. In specific applications, the appropriate specifications and models can be selected according to actual needs.

[0089] Furthermore, the encoding unit employs an encoder.

[0090] In this embodiment, the encoder can be a conventional device that can encode digital signals into control signals, and the specific specifications and models can be selected according to actual needs.

[0091] Furthermore, the comparison output unit employs a digital comparator.

[0092] In this embodiment, the digital comparator compares the magnitudes of two received count values ​​to output the duty cycle signal. By adjusting the corresponding count values, the corresponding duty cycle signal can be changed.

[0093] Further, please refer to Figure 4 The MOS transistor is an NMOS transistor, the first terminal of the MOS transistor is the drain, the second terminal of the MOS transistor is the source, the first terminal of the power supply is the positive terminal, and the second terminal of the power supply is the negative terminal;

[0094] After the button is connected in parallel with the LED, the negative terminal of the LED is coupled to the drain of the NMOS transistor.

[0095] In this embodiment, the LED current output by the LED driver module acts on the gate of the NMOS transistor. By triggering button S, the value of the LED current output by the LED driver module can be changed, thereby altering the on / off time between the drain and source of the NMOS transistor, thus controlling the LED's brightness. It should be noted that in lighting system design, by reusing the button function and the lighting function, end-users can easily select different brightness levels of the lighting system according to their actual needs. Reusing the button function and the lighting function also facilitates customer production management and inventory preparation, reducing production costs.

[0096] Further, please refer to Figure 5 The LED driving module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first NPN transistor QN1, a first PNP transistor QP1, a second NPN transistor QN2, a second PNP transistor QP2, and a third NPN transistor QN3.

[0097] One end of the first resistor R1 is coupled to the control module, and the other end of the first resistor R1 is coupled to the emitter of the first NPN transistor QN1 and the emitter of the first PNP transistor QP1, respectively.

[0098] One end of the second resistor R2, the emitter of the second NPN transistor QN2, the emitter of the third NPN transistor QN3, and one end of the sixth resistor R6 are all coupled to ground. The other end of the second resistor R2 is coupled to the base of the first NPN transistor QN1, the base of the first PNP transistor QP1, the collector of the third NPN transistor QN3, and one end of the third resistor R3, respectively.

[0099] The other end of the third resistor R3 is coupled to the emitter of the second PNP transistor QP2 and connected to the positive power supply VCC.

[0100] One end of the fourth resistor R4 is coupled to the collector of the second NPN transistor QN2 and the collector of the second PNP transistor QP2, respectively, and the other end of the fourth resistor R4 is coupled to one end of the fifth resistor R5 and the gate of the NMOS transistor.

[0101] The other end of the fifth resistor R5 is coupled to the base of the third NPN transistor QN3 and the other end of the sixth resistor R6, respectively.

[0102] The collector of the first NPN transistor QN1 is coupled to the base of the second PNP transistor QP2;

[0103] The collector of the first PNP transistor QP1 is coupled to the base of the second NPN transistor QN2.

[0104] In this embodiment, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are all conventional resistors. They can be single resistors or combinations of multiple resistors, selected according to actual needs. The first NPN transistor QN1, the second NPN transistor QN2, and the third NPN transistor QN3 are all conventional NPN transistors, and their specific models and specifications can be selected according to actual needs. The first PNP transistor QP1 and the second PNP transistor QP2 are both conventional PNP transistors, and their specific models and specifications can be selected according to actual needs.

[0105] Further, please refer to Figure 6 The MOS transistor is a PMOS transistor, the first terminal of the MOS transistor is the source, the second terminal of the MOS transistor is the drain, the first terminal of the power supply is the negative terminal, and the second terminal of the power supply is the positive terminal;

[0106] After the button is connected in parallel with the LED, the positive terminal of the LED is coupled to the source of the PMOS transistor.

[0107] In this embodiment, the LED current output by the LED driver module acts on the gate of the PMOS transistor. By triggering button S, the value of the LED current output by the LED driver module can be changed, thereby altering the on / off time between the drain and source of the PMOS transistor, thus controlling the LED's brightness. It should be noted that in lighting system design, by reusing the button function and the lighting function, end-users can conveniently select different brightness levels of the lighting system according to their actual needs. Reusing the button function and the lighting function also facilitates customer production management and inventory preparation, reducing production costs.

[0108] Further, please refer to Figure 7 The LED driving module includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a fourth NPN transistor QN4, a third PNP transistor QP3, a fifth NPN transistor QN5, a fourth PNP transistor QP4, and a fifth PNP transistor QP5.

[0109] One end of the sixth resistor R6 is coupled to the control module, and the other end of the sixth resistor R6 is coupled to the emitter of the fourth NPN transistor QN4 and the emitter of the third PNP transistor QP3, respectively.

[0110] One end of the seventh resistor R7 is coupled to the emitter of the fifth NPN transistor QN5 and grounded. The other end of the seventh resistor R7 is coupled to the base of the fourth NPN transistor QN4, the base of the third PNP transistor QP3, the collector of the fifth PNP transistor QP5, and one end of the eighth resistor R8.

[0111] The other end of the eighth resistor R8 is coupled to the emitter of the fourth PNP transistor QP4, the emitter of the fifth PNP transistor QP5, and one end of the tenth resistor R10 and connected to the positive power supply VCC.

[0112] One end of the ninth resistor R9 is coupled to the collector of the fifth NPN transistor QN5 and the collector of the fourth PNP transistor QP4, respectively, and the other end of the ninth resistor R9 is coupled to one end of the eleventh resistor R11 and the gate of the PMOS transistor.

[0113] The other end of the tenth resistor R10 is coupled to the base of the fifth PNP transistor QP5 and the other end of the eleventh resistor R11, respectively.

[0114] The collector of the fourth NPN transistor QN4 is coupled to the base of the fourth PNP transistor QP4.

[0115] The collector of the third PNP transistor QP3 is coupled to the base of the fifth NPN transistor QN5.

[0116] In this embodiment, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are all conventional resistors. They can be single resistors or combinations of multiple resistors, depending on actual needs. The fourth NPN transistor QN4 and the fifth NPN transistor QN5 are both conventional NPN transistors, and their specific models and specifications can be selected according to actual needs. The third PNP transistor QP3, the fourth PNP transistor QP4, and the fifth PNP transistor QP5 are all conventional PNP transistors, and their specific models and specifications can be selected according to actual needs.

[0117] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A multiplexed circuit for button and lighting functions, characterized in that, include: Buttons, LEDs, MOSFETs, button detection module, control module, LED driver module; The button and the LED are connected in parallel, and one end of the parallel connection is coupled to the first terminal of the MOS transistor and the button detection module, respectively, while the other end is used to couple to the first terminal of the power supply. The button detection module is coupled to the control module; The control module is coupled to the LED driver module; The LED driving module is coupled to the gate of the MOS transistor; The second terminal of the MOSFET is used to couple to the second terminal of the power supply; The control module includes: The data conversion unit is used to convert key signals into digital signals; Encoding unit, used to encode the digital signal into a control signal; The clock unit is used to output a clock signal group that includes two clock signals; A counting unit is used to generate a count value group including two count values ​​based on the control signal and the clock signal group; The comparison output unit is used to generate a duty cycle signal based on the group of count values; The data conversion unit is coupled to the encoding unit, the encoding unit and the clock unit are respectively coupled to the counting unit, and the counting unit is coupled to the comparison output unit; The clock unit includes a first clock generator and a second clock generator; The counting unit includes a first counter and a second counter; The output of the first clock generator is coupled to the clock input of the first counter; The output of the second clock generator is coupled to the clock input of the second counter; The output terminal of the first counter is coupled to the first input terminal of the comparison output unit; The output terminal of the second counter is coupled to the second input terminal of the comparison output unit; The control terminal of the second counter is coupled to the encoding unit; The output terminal of the comparison output unit is used to output the duty cycle signal; The data conversion unit employs an analog-to-digital converter. The encoding unit employs an encoder; When the button is pressed, the button detection module detects the button signal, the control module outputs a fixed duty cycle signal based on the button signal, and the LED driving module controls the MOS transistor to drive the LED based on the duty cycle signal.

2. The multiplexing circuit according to claim 1, characterized in that, The comparison output unit uses a digital comparator.

3. The multiplexing circuit according to claim 1, characterized in that, The MOS transistor is an NMOS transistor, the first terminal of the MOS transistor is the drain, the second terminal of the MOS transistor is the source, the first terminal of the power supply is the positive terminal, and the second terminal of the power supply is the negative terminal; After the button is connected in parallel with the LED, the negative terminal of the LED is coupled to the drain of the NMOS transistor.

4. The multiplexing circuit according to claim 3, characterized in that, The LED driver module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first NPN transistor, a first PNP transistor, a second NPN transistor, a second PNP transistor, and a third NPN transistor; One end of the first resistor is coupled to the control module, and the other end of the first resistor is coupled to the emitter of the first NPN transistor and the emitter of the first PNP transistor, respectively. One end of the second resistor, the emitter of the second NPN transistor, the emitter of the third NPN transistor, and one end of the sixth resistor are all coupled to ground. The other end of the second resistor is coupled to the base of the first NPN transistor, the base of the first PNP transistor, the collector of the third NPN transistor, and one end of the third resistor, respectively. The other end of the third resistor is coupled to the emitter of the second PNP transistor and connected to the positive terminal of the power supply; One end of the fourth resistor is coupled to the collector of the second NPN transistor and the collector of the second PNP transistor, respectively, and the other end of the fourth resistor is coupled to one end of the fifth resistor and the gate of the NMOS transistor, respectively. The other end of the fifth resistor is coupled to the base of the third NPN transistor and the other end of the sixth resistor, respectively. The collector of the first NPN transistor is coupled to the base of the second PNP transistor; The collector of the first PNP transistor is coupled to the base of the second NPN transistor.

5. The multiplexing circuit according to claim 1, characterized in that, The MOS transistor is a PMOS transistor, the first terminal of the MOS transistor is the source, the second terminal of the MOS transistor is the drain, the first terminal of the power supply is the negative terminal, and the second terminal of the power supply is the positive terminal; After the button is connected in parallel with the LED, the positive terminal of the LED is coupled to the source of the PMOS transistor.

6. The multiplexing circuit according to claim 5, characterized in that, The LED driver module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a fourth NPN transistor, a third PNP transistor, a fifth NPN transistor, a fourth PNP transistor, and a fifth PNP transistor. One end of the sixth resistor is coupled to the control module, and the other end of the sixth resistor is coupled to the emitter of the fourth NPN transistor and the emitter of the third PNP transistor, respectively. One end of the seventh resistor is coupled to the emitter of the fifth NPN transistor and grounded, and the other end of the seventh resistor is coupled to the base of the fourth NPN transistor, the base of the third PNP transistor, the collector of the fifth PNP transistor, and one end of the eighth resistor. The other end of the eighth resistor is coupled to the emitter of the fourth PNP transistor, the emitter of the fifth PNP transistor, and one end of the tenth resistor and connected to the positive terminal of the power supply. One end of the ninth resistor is coupled to the collector of the fifth NPN transistor and the collector of the fourth PNP transistor, respectively, and the other end of the ninth resistor is coupled to one end of the eleventh resistor and the gate of the PMOS transistor. The other end of the tenth resistor is coupled to the base of the fifth PNP transistor and the other end of the eleventh resistor, respectively. The collector of the fourth NPN transistor is coupled to the base of the fourth PNP transistor. The collector of the third PNP transistor is coupled to the base of the fifth NPN transistor.

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