Infrared emission controller with variable power

Abstract

The invention relates to the technical field of signal devices, and provides a variable-power infrared emission controller in order to solve the problem that an existing infrared emission controller cannot have good applicability in all power ranges, and the variable-power infrared emission controller comprises an alternative switch, a voltage modulation loop and a constant-current infrared control loop. The voltage modulation loop is used for generating a reference voltage and an infrared modulation signal; a high-level signal input end of the either-or switch receives a reference voltage, a low-level signal input end of the either-or switch is grounded, and a control signal input end of the either-or switch receives an infrared modulation signal and generates a modulation voltage; the constant-current infrared control loop comprises a constant-current source and an infrared transmitting tube which are connected in series, and the input end of the constant-current source receives the modulation voltage; the amplitude of the modulation voltage is the same as that of the reference voltage, and the frequency of the modulation voltage is the same as that of the infrared modulation signal. And the load current is adjusted by changing the modulation voltage, so that the adjustability and adaptability of the power of the infrared emission controller are realized.

Description

Technical Field

[0001] The invention relates to the technical field of signal devices, and in particular to an infrared emission controller with variable power. Background Art

[0002] Infrared transmitter controllers in smart homes can convert network commands into infrared remote control commands, thereby achieving control of various home appliances. However, existing infrared transmitter controllers generally have the problem of fixed and low transmitter power, which results in limited control distance and unnecessary excessive power consumption in high-power and low-power application scenarios, respectively. In view of the above situation, how to achieve adjustable power of infrared transmitter controllers to ensure that infrared transmitter controllers have good applicability in different application scenarios such as higher power and low power has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] The invention mainly solves the problem that the power of the existing infrared emission controller is fixed and small, so that it cannot have good applicability within various power ranges.

[0004] In view of the above technical problems, the present invention provides a variable-power infrared emission controller, comprising: a two-choice switch, a voltage modulation circuit and a constant-current infrared control circuit; the voltage modulation circuit is used to generate a reference voltage and an infrared modulation signal; the high-level signal input end of the two-choice switch receives the reference voltage, the low-level signal input end of the two-choice switch is grounded, the control signal input end of the two-choice switch receives the infrared modulation signal, and generates a modulation voltage according to the reference voltage and the infrared modulation signal; the constant-current infrared control circuit comprises a constant current source and an infrared emitting tube connected in series, and the input end of the constant current source receives the modulation voltage; the amplitude of the modulation voltage is the same as the value of the reference voltage, and its frequency is the same as the frequency of the infrared modulation signal; wherein the constant current source is used to adjust the load current passing through the infrared emitting tube according to the modulation voltage, wherein the modulation voltage is proportional to the load current.

[0005] Preferably, the voltage modulation circuit includes an MCU, a voltage modulation module and a voltage source; the voltage source provides power for the voltage modulation module and the MCU; the voltage modulation module receives the PWM signal of the MCU and generates the reference voltage; and the MCU generates the infrared modulation signal.

[0006] Preferably, the voltage modulation module includes a reference voltage generating unit and a reference voltage slicing unit; the reference voltage generating unit is electrically connected to the voltage source and generates a reference source voltage; the reference voltage slicing unit receives the reference source voltage and the duty cycle of the PWM signal to generate the reference voltage.

[0007] Preferably, the MCU is provided with a wireless communication module, which receives a control signal from a terminal device; the control signal includes a PWM signal duty cycle distance adjustment instruction, which is used to adjust the PWM signal duty cycle to increase or decrease; and / or the control signal includes an infrared modulation signal duty cycle adjustment instruction, which is used to adjust the infrared modulation signal duty cycle to increase or decrease.

[0008] Preferably, the MCU is also electrically connected to the first button and the second button respectively, and receives the first trigger signal and the second trigger signal respectively; the first trigger signal controls the duty cycle of the PWM signal to increase, and the second trigger signal controls the duty cycle of the PWM signal to decrease.

[0009] Preferably, the infrared modulation signal and the PWM signal output by the MCU are set as follows: the frequency of the infrared modulation signal is set to 38KHz, the duty cycle adjustment range is 20% ~ 50%, and the duty cycle of the infrared modulation signal is inversely proportional to the reference voltage; and / or the duty cycle adjustment range of the PWM signal is 10% ~ 100%.

[0010] Preferably, the constant current source comprises an operational amplifier, a MOS tube and a sampling resistor; the in-phase input terminal of the operational amplifier receives the modulation voltage; the inverting input terminal of the operational amplifier is electrically connected to the first terminal of the sampling resistor and receives the feedback voltage of the sampling resistor; the output terminal of the operational amplifier is connected to the gate of the MOS tube, and the operational amplifier is used to compare the modulation voltage with the feedback voltage and then output the gate voltage to the MOS tube; the source of the MOS tube is electrically connected to the first terminal of the sampling resistor, and the drain of the MOS tube is electrically connected to the infrared emitting tube, and the gate voltage of the MOS tube is inversely proportional to the load current; the second terminal of the sampling resistor is grounded.

[0011] Preferably, the constant current source further includes a gate driving resistor; the gate driving resistor is connected between the output end of the operational amplifier and the gate of the MOS tube to reduce the gate noise of the MOS tube.

[0012] Preferably, the constant current infrared control circuit also includes a power supply, which provides voltage for the infrared emitting tube; the voltage of the power supply is set to 5V, and the infrared emitting tube is set to a single infrared light string; or the voltage of the power supply is set to 12V, and the infrared emitting tube is set to 2-3 infrared light strings.

[0013] Preferably, the infrared light string comprises a plurality of infrared light emitting diodes connected in series.

[0014] The beneficial effects of the present invention are as follows: Firstly, by setting a two-choice switch, a modulation voltage having the same amplitude as the reference voltage and the same frequency as the infrared modulation signal is modulated according to the received infrared modulation signal and the reference voltage value, thereby achieving the ability to change the value of the modulation voltage when modulating either the reference voltage or the infrared modulation signal. According to the correlation between the modulation voltage value and the load current passing through the infrared transmitting tube, the size of the load current can be further changed, thereby achieving adjustable power of the infrared transmitting tube.

[0015] Secondly, by setting up a voltage modulation loop, the adjustability of the reference voltage is improved, so that the low-power mode is started in the short-distance mode, that is, the reference voltage is lowered, and the high-power mode is started in the long-distance mode, that is, the reference voltage is increased, so that the infrared emitting tube can meet the needs of flexible application in higher power scenarios and lower power scenarios. In addition, by setting up a constant current infrared control loop, the load current of the infrared emitting tube can be stabilized to ensure the safety of its operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The invention is a circuit diagram of a variable-power infrared emission controller according to an embodiment of the invention. DETAILED DESCRIPTION

[0017] The present invention will be described in more detail below in conjunction with the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is only illustrative and not restrictive.

[0018] Where possible, the various embodiments described below may be recombined with each other to form other embodiments not shown in the following description; the various technical features described below may also be recombined with each other to form other embodiments not shown in the following description.

[0019] Embodiment 1: Please refer to the attached Figure 1 In order to solve the problem that the power of existing infrared emission controllers is fixed and small, thus failing to have good applicability within various power ranges, this embodiment provides a variable power infrared emission controller, whose main circuit structure includes an electrically connected voltage modulation circuit, a two-selection switch and a constant current infrared control circuit.

[0020] The voltage output end of the voltage modulation loop outputs a reference voltage to the high-level signal input end 1 of the two-choice switch, and the infrared signal output end of the voltage modulation loop outputs an infrared modulation signal to the control signal input end S of the two-choice switch, while the low-level signal input end 0 of the two-choice switch is grounded, so that the duty cycle and frequency of the modulation voltage VIN waveform output by the two-choice switch are the same as those of the infrared modulation signal, and the high-level value is the same as the reference voltage V0, and the low-level value is 0. A constant current source and an infrared transmitting tube connected in series are provided in the constant current infrared control loop, wherein the input end of the constant current source receives the modulation voltage VIN output by the two-choice switch.

[0021] Among them, the voltage modulation circuit is mainly used to generate and adjust the reference voltage V0 and output the infrared modulation signal to the two-choice switch, and the two-choice switch is used to use the reference voltage V0 and 0 as the output at high level and low level respectively, and modulate the high and low level output combination according to the frequency of the infrared modulation signal to generate a modulation voltage VIN with the same frequency as the infrared modulation signal and an amplitude change to the reference voltage V0. The modulation voltage is input to the constant current source in the constant current infrared control circuit, and the constant current source performs negative feedback regulation on the constant current infrared control circuit through the modulation voltage, thereby adjusting the load current passing through the infrared transmitting tube, thereby realizing the frequency regulation of the infrared transmitting tube.

[0022] The beneficial effect of the voltage modulation loop setting is that it generates an adjustable reference voltage V0 and outputs an adjustable infrared modulation signal, which ensures the adjustability of the infrared emission controller and can create conditions for the subsequent realization of different power outputs from the root. For example, in close-range control, the reference voltage can be appropriately lowered to avoid unnecessary power consumption caused by excessive emission power. In long-range control, the reference voltage is correspondingly increased to enhance the emission power of the infrared emission tube to ensure the effective control distance, which can effectively solve the problem that the emission power of the existing infrared emission controller is fixed and small and cannot adapt to different control distances.

[0023] The working principle of the two-choice switch is described in detail as follows: the infrared modulation signal input to the control signal input terminal S of the two-choice switch is a 38KHz signal. When the 38KHz signal is at a high level, the two-choice switch outputs the voltage V0 obtained from the high-level input terminal 1, and when the 38KHz signal is at a low level, the two-choice switch outputs the voltage 0V obtained from the low-level input terminal. Therefore, the signal frequency output by the two-choice switch is equal to the frequency of the 38KHz signal, and the duty cycle D1 is the same as the duty cycle of the 38KHz signal, and only the amplitude is changed to V0. Therefore, the modulation voltage VIN finally output by the two-choice switch: high level = V0×D1, low level = 0V.

[0024] The beneficial effect of the combination of the two-choice switch and the above-mentioned circuit structure is that the reference voltage value is cleverly output at a high level according to the frequency of the infrared modulation signal, so that the modulation voltage VIN has a flexible and adjustable waveform, thereby accurately controlling the generation of the modulation voltage from the amplitude and frequency respectively, providing flexible input conditions for further adjusting the power of the infrared transmitting tube, thereby improving the applicability of the entire infrared transmitting controller in different application scenarios.

[0025] The role of the constant current infrared control loop in the above circuit structure is that the setting of the constant current source realizes the effective regulation of the load current of the infrared transmitting tube. The constant current source performs negative feedback regulation on the constant current infrared control loop by receiving the modulation voltage from the two-choice switch, and can dynamically adjust the load current through the infrared transmitting tube in real time and accurately according to the input voltage. Through the above negative feedback regulation mechanism, the power of the infrared transmitting tube is no longer fixed, and it can be adjusted on demand within a larger range, better adapting to a variety of usage environments, overcoming the limitations of the existing infrared transmitting controller in terms of power applicability, and the constant current source can ensure the stability of the current applied to the infrared transmitting tube, thereby enhancing its practical effect.

[0026] In a preferred embodiment, the specific circuit structure of the voltage modulation loop includes an MCU, a voltage modulation module and a voltage source. The voltage source supplies power to the voltage modulation module and the MCU respectively, and the PWM signal output terminal of the MCU outputs a PWM signal with a duty cycle of D to the signal input terminal of the voltage modulation module; the infrared modulation signal output terminal of the MCU transmits an infrared modulation signal to the control signal input terminal of the two-choice switch.

[0027] The power supply provides the initial voltage value for the MCU and the voltage modulation module. The voltage modulation module analyzes the duty cycle D of the PWM signal transmitted by the MCU, and calculates the reference voltage V0 according to the duty cycle, thereby accurately obtaining the high-level input value of the two-choice switch. The MCU is used to transmit the PWM signal and the infrared modulation signal to the voltage modulation module and the two-choice switch respectively, thereby further ensuring that the two-choice switch generates the modulation voltage VIN according to the frequency of the infrared modulation signal.

[0028] In a further preferred embodiment, the voltage modulation module includes a reference voltage generation unit and a reference voltage slicing unit connected in sequence; and the reference voltage generation unit is used to generate a reference source voltage, and the reference voltage slicing unit is used to modulate the reference source voltage into a reference voltage according to the duty cycle of the PWM signal, and the signal input end of the reference slicing unit receives the PWM signal transmitted by the PWM signal output end of the MCU, and its output end outputs the reference voltage to the high-level signal input end of the two-selection switch.

[0029] The reference voltage V0 is generated by the voltage modulation module, and its generation principle is that the reference voltage generation unit converts the 5V voltage delivered by the power supply into a reference source voltage of 1.25V, and the reference voltage slicing unit generates a reference voltage V0=1.25×D according to the duty cycle D of the PWM signal. By adjusting the duty cycle D of the generated PWM signal through the MCU, the value of the reference voltage V0 can be changed, thereby modulating the size of the load current, thereby affecting the power of the infrared emitting lamp.

[0030] In another preferred embodiment, the constant current source includes an operational amplifier, a MOS tube and a sampling resistor Rs, wherein the non-inverting input terminal of the operational amplifier receives a modulated voltage signal transmitted by a two-select-one switch, the reverse input terminal of the operational amplifier is electrically connected to the first end of the sampling resistor to receive a feedback voltage signal, and the output terminal of the operational amplifier is electrically connected to the gate of the MOS tube.

[0031] By comparing the modulation voltage signal and the feedback voltage signal, a larger or smaller voltage is selectively input to the MOS tube, thereby changing the internal resistance of the MOS tube. The source of the MOS tube is electrically connected to the first end of the sampling resistor Rs, and the drain is electrically connected to the infrared emitting tube. After the MOS tube adjusts its internal resistance according to the gate voltage, it is connected in series with the infrared emitting tube, which affects the load current passing through the infrared emitting tube. When its internal resistance increases, the load current decreases, and when the internal resistance decreases, the load current increases, that is, the gate voltage is inversely proportional to the load current change.

[0032] The main principle is based on the constant current source to generate constant current and shut-off current. When the load current of the load infrared emitting tube increases, the feedback voltage on the sampling resistor Rs increases, and this feedback voltage is input into the reverse input terminal of the operational amplifier. At this time, the voltage of the reverse input terminal is greater than the voltage of the non-inverting input terminal. The operational amplifier reduces the output voltage according to the operating rules, resulting in a decrease in the gate voltage applied to the MOS tube and an increase in the internal resistance of the MOS tube, thereby reducing the load current passing through the source and drain. The load current is reduced, which reduces the power of the infrared emitting tube and shortens the emission distance.

[0033] Similarly, when the load current decreases, the resistance value of Rs remains unchanged, and the feedback voltage applied to it decreases, then the voltage input to the reverse input terminal of the operational amplifier is less than the voltage at the same input terminal. The operational amplifier increases the output voltage according to the operating rules, causing the gate voltage applied to the MOS tube to increase, making the MOS tube conduction internal resistance decrease, the conduction degree increase, and thus making the load current passing through larger. Such a negative feedback mechanism makes the load current consistent with the desired current, that is, it can control the load current to be stable at VIN / Rs by inputting a given VIN at the same-phase input terminal of the operator.

[0034] According to the working principle of the above constant current source, VIN with an amplitude equal to the reference voltage and a frequency the same as the 38KHz signal is used as the voltage of the non-inverting input terminal of the operational amplifier, so that during the high-level input period, the load current I=V0 / Rs is obtained, and during the low-level input device, the load current I=V0 / Rs=0, thereby realizing that the load current changes according to the frequency of the 38KHz signal, that is, the infrared transmitting tube emits infrared modulated light for remote control of the object.

[0035] In the above process, the load current can be changed by changing the size of V0, which ultimately affects the luminous intensity of the infrared emitting tube, and the remote control distance is proportional to the luminous intensity of the infrared emitting tube, thereby achieving controllable distance and power of the infrared emitting tube.

[0036] In a further preferred embodiment, the constant current source also includes a gate drive resistor, which is connected between the output end of the operational amplifier and the gate of the MOS tube to reduce the gate noise of the MOS and further ensure the stability of the load current.

[0037] In a further preferred embodiment, an integrated constant current source driver chip may be used to replace the constant current source with separation function. It is necessary to clarify the current and voltage requirements driven by the original separation function constant current source, for example, the constant current source driver chip is selected according to the power of the infrared emitting tube to be driven, the normal load current, and the voltage drop, and the test can be completed after replacing the original constant current source.

[0038] Embodiment 2: Please refer to the attached Figure 1 The present embodiment provides a variable power infrared emission controller, and its main circuit structure refers to that of the embodiment 1, except that the present embodiment further describes the specific setting of the MCU: The MCU is provided with a wireless communication module for receiving control signals from terminal devices. It can be set as a PWM signal duty cycle distance adjustment instruction for adjusting the PWM signal duty cycle to increase or decrease, or set as an infrared modulation signal duty cycle instruction for modulating the infrared modulation signal duty cycle to increase or decrease. By using wireless communication adjustment, the infrared emission controller can be remotely controlled through a mobile terminal, that is, the signal type and signal duty cycle to be adjusted are input or selected in the terminal interface, and after input, they are transmitted to the MCU through the wireless communication module, and then transmitted by the MCU to the two-choice switch and voltage modulation module, thereby outputting the same modulation voltage as expected.

[0039] According to the above circuit structure combined with the circuit structure of Example 1, it can be known that the working process of the infrared emission controller is as follows: First, after the system is powered on, the MCU does not output a 38KHz signal, and the two-choice switch outputs a modulation voltage VIN=0V. At this time, the infrared transmitting tube does not emit an infrared signal.

[0040] Secondly, the MCU outputs a PWM signal with a duty cycle of D according to the set gear, and the voltage modulation module derives V0=1.25V×D based on the duty cycle.

[0041] Next, the MCU receives the remote control command from the network, converts it into a 38K modulated signal of an infrared code command and inputs it into the two-choice switch, that is, the two-choice switch outputs V0 during the 38K high level period and 0V during the low level period. Therefore, the infrared emitting tube obtains a load current I with the same frequency as the 38KHz signal under the action of the 38KHz signal, and emits infrared light with the same frequency as the 38KHz signal.

[0042] Next, the duty cycle of the PWM signal is adjusted by changing the first button or the second button, and the load current is changed while Rs remains unchanged.

[0043] Finally, the load current is regulated under the control of the constant current source, making the power of the infrared emitting tube adjustable, and can be flexibly applied in high-power long-distance, low-power short-distance and other application scenarios. At the same time, the farthest control distance is achieved under the maximum peak current.

[0044] According to the above process, there are the following specific examples: It is known that the maximum current allowed for the infrared emitting tube is 5A. Based on the relationship between voltage, current and resistance in the constant current source circuit, the sampling resistor Rs=1.25V / 5A=2 ohms is selected.

[0045] When the user wants to set the control distance by pressing a button, the PWM signal duty cycle corresponding to the distance set by the user is 60%. According to the principle that the voltage modulation module calculates the reference voltage according to the duty cycle, it can be concluded that the reference voltage V0=1.25×60%=0.75V at this time.

[0046] According to the current calculation method in the constant current source circuit and the relationship between various parameters, when the sampling resistor Rs remains unchanged, the load current of the infrared emitting tube is calculated to be I=0.75 / 0.25=3A. This current value is exactly 60% of the maximum current (5A). In actual remote control operation, the remote control distance is closely related to the load current. In this case, the remote control distance is 60% of the maximum distance.

[0047] At the same time, for the 38KHz signal, its duty cycle is 20%. When the MCU receives the remote control command from the network, the entire infrared transmitter controller will transmit the infrared remote control command according to the established working process based on the above-mentioned parameters, that is, the reference voltage V0=0.75, the load current I=3A, the 38KHz signal duty cycle of 20%, etc., so that the infrared transmitter can work under the corresponding power, frequency and other conditions, thereby realizing the remote control operation of the target device, and this adjustable parameter setting allows the infrared transmitter controller to be flexibly used in different application scenarios such as high-power long-distance control or low-power short-distance control, to meet diverse usage needs.

[0048] In another preferred embodiment, the wireless communication module of the MUC can be replaced by a wireless network that supports WIFI / Bluetooth / BLE, etc. The use of the above wireless network can broaden the way the infrared transmitter controller interacts with the outside world, making it more convenient to integrate into various smart device networks, enhancing the versatility and applicability of the device, and facilitating users to remotely control the infrared transmitter controller from different terminal devices.

[0049] For flexible networking, the hardware can choose an MCU chip with built-in WIFI or an external WIFI module and correctly connect the pins and power supply; the software development driver and integrated TCP / IP protocol stack to realize network communication functions. For Bluetooth compatibility, in terms of hardware, you can choose an MCU chip with integrated Bluetooth, or an external Bluetooth module and make good interface connections; at the software level, embed the Bluetooth protocol stack and develop corresponding communication services to receive control commands. For BLE compatibility, the hardware is to select an MCU chip or external module with BLE function and configure the relevant pins; the software needs to implement specific protocol layer functions and optimize broadcasting and other mechanisms to achieve low-power communication and command reception.

[0050] In a further preferred embodiment, the MCU is also electrically connected to the first button and the second button respectively, and sends a first trigger signal and a second trigger signal respectively, wherein the first trigger signal controls the duty cycle of the PWM signal to increase, and the second trigger signal controls the duty cycle of the PWM signal to decrease.

[0051] The first trigger signal causes the duty cycle of the PWM signal to increase continuously, and the second trigger signal causes the duty cycle to decrease continuously. The principle is that the MCU fine-tunes the relevant parameters through the internal algorithm according to the key duration and real-time status, so that the duty cycle can be continuously and uninterruptedly changed within the adjustable range to flexibly adapt to the power requirements of different remote control distances. Therefore, by adjusting the key, a continuous and stepless adjustment distance can be achieved, and a continuously changing duty cycle D can be obtained.

[0052] In a further preferred embodiment, the frequency of the infrared modulation signal is set to 38KHz, the duty cycle adjustment range is 20% - 50%, and the duty cycle of the infrared modulation signal is inversely proportional to the reference voltage value. The duty cycle adjustment range of the PWM signal is 10% - 100%.

[0053] The infrared modulation signal is a 38KHz signal output by the MCU according to network instructions. The MCU outputs 38KHz signals with different duty cycles according to the currently set voltage value, which can prevent the infrared emitting tube from being damaged by large current I. Therefore, when setting the 38KHz signal, if the reference voltage V0 is larger, the duty cycle of the 38KHz signal should be smaller. To ensure the compatibility of the infrared emission controller, the duty cycle of the 38KHz signal should vary between 20% and 50%.

[0054] The relationship between the magnitude of V0 and the duty cycle of the 8KHz signal can be segmented and mapped. Since the magnitude of V0 is proportional to the magnitude of the load current, the following regulations can be made: when I < 1A, the duty cycle of the 38K signal = 50%; when 1A < I < 1.5A, the duty cycle of the 38K signal = 45%; when 1.5A < I < 2A, the duty cycle of the 38K signal = 40%; when 2A < I < 2.5A, the duty cycle of the 38K signal = 35%; when 2.5A < I < 3A, the duty cycle of the 38K signal = 30%; when 3A < I < 3.5A, the duty cycle of the 38K signal = 25%; when greater than 3.5A, the duty cycle of the 38K signal = 20%.

[0055] Embodiment 3: Please refer to the appendix Figure 1 A variable - power infrared emission controller provided in this embodiment has its main circuit structure referring to Embodiment 1 or Embodiment 2. The difference lies in the specific setting of the constant - current infrared control loop.

[0056] The constant - current infrared control loop of this embodiment further includes a power supply, which is electrically connected to one end of the infrared emitting tube. When the voltage of the power supply is set to 5V, the infrared emitting tube is set as a single infrared lamp string. When the voltage of the power supply is set to 12V, the infrared emitting tube is set as 2 - 3 infrared lamp strings.

[0057] The power supply of the infrared emitting tube can be selected according to the number of infrared tubes. Usually, in the case of a 5V power supply, a single high - power infrared lamp string is used as the load, while in the case of 12V, multiple infrared lamp strings are used as the load. Among them, when multiple lamp strings are used as the load, the emission angle of 360 degrees can be formed by adjusting the number of lamp strings, so as to achieve omnidirectional infrared emission. By changing the sampling resistor or the power supply, the long - distance emission mode of the infrared emission tube can exceed 8 meters and can reach more than 50 meters in actual measurement.

[0058] When the PWM duty cycle is between 20% and 50%, pulse modulation is used. A higher duty cycle can achieve a larger load current, thereby controlling the power increase of the infrared transmitting tube to achieve a control range of 8 meters. Similarly, when the PWM duty cycle is between 80% and 50%, a control range of 50 meters can be achieved.

[0059] In a further preferred embodiment, the infrared light string includes a plurality of infrared light emitting diodes connected in series, and the infrared light emitting diodes can be 940nm and / or 850nm infrared light emitting diodes.

[0060] The 940nm light-emitting diode has good concealment, and its light is invisible to the human eye. In actual use, in scenarios such as smart home control, there will be no visible light flickering during remote control operation, keeping the environment visually clean and tidy, and avoiding light interference to people. It has strong anti-interference ability, and can filter out irrelevant interference signals with its own wavelength characteristics, ensuring stable transmission of infrared signals, reducing remote control misoperation, and improving control accuracy. It is suitable for short distances and has relatively low power consumption. In short-distance use scenarios such as home appliance remote controls, it can take into account both energy saving and equipment life, so it is an ideal choice in many short-distance applications.

[0061] The 850nm light-emitting diode has high transmission power and long transmission distance, which can allow infrared signals to reach the target device accurately over a long distance, meet the remote control distance requirements of more than 8 meters or even farther, and make long-distance control reliable. It is adapted to high-sensitivity reception. Many infrared receiving devices are highly sensitive to infrared light with a wavelength of 850nm. Even if the signal is attenuated to a certain extent, the receiving end can easily capture and complete subsequent processing, which greatly improves the success rate of long-distance control. It has good compatibility, mature supporting equipment and technical systems, and can cooperate with related existing equipment.

[0062] It should be understood that the embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A variable power infrared emission controller, comprising a two-choice switch, a voltage modulation circuit and a constant current infrared control circuit; The voltage modulation circuit is used to generate a reference voltage and an infrared modulation signal; The high level signal input terminal of the two-select-one switch receives the reference voltage, the low level signal input terminal of the two-select-one switch is grounded, and the control signal input terminal of the two-select-one switch receives the infrared modulation signal and generates a modulation voltage; The constant current infrared control loop comprises a constant current source and an infrared transmitting tube connected in series, and the input end of the constant current source receives the modulation voltage; the amplitude of the modulation voltage is the same as the value of the reference voltage, and its frequency is the same as the frequency of the infrared modulation signal; in, The constant current source is used to adjust the load current passing through the infrared emitting tube according to the modulation voltage, wherein the modulation voltage is proportional to the load current.

2. The infrared emission controller according to claim 1, characterized in that: The voltage modulation circuit includes an MCU, a voltage modulation module and a voltage source; The voltage source provides power for the voltage modulation module and the MCU; the voltage modulation module receives the PWM signal of the MCU and generates the reference voltage; and the MCU generates the infrared modulation signal.

3. The infrared emission controller according to claim 2, characterized in that: The voltage modulation module includes a reference voltage generating unit and a reference voltage slicing unit; The reference voltage generating unit is electrically connected to the voltage source and generates a reference source voltage; The reference voltage slicing unit receives the reference source voltage and the duty cycle of the PWM signal to generate the reference voltage.

4. The infrared emission controller according to claim 2, characterized in that: The MCU is provided with a wireless communication module, and the wireless communication module receives a control signal of a terminal device; The control signal includes a PWM signal duty cycle distance adjustment instruction for adjusting the PWM signal duty cycle to increase or decrease; and / or The control signal includes an infrared modulation signal duty cycle adjustment instruction, which is used to adjust the infrared modulation signal duty cycle to increase or decrease.

5. The infrared emission controller according to claim 4, characterized in that: The MCU is also electrically connected to the first button and the second button respectively, and receives the first trigger signal and the second trigger signal respectively; The first trigger signal controls the duty cycle of the PWM signal to increase, and the second trigger signal controls the duty cycle of the PWM signal to decrease.

6. The infrared emission controller according to claim 5, characterized in that: The infrared modulation signal and the PWM signal output by the MCU are set as follows: The frequency of the infrared modulation signal is set to 38KHz, the duty cycle adjustment range is 20% to 50%, and the duty cycle of the infrared modulation signal is inversely proportional to the reference voltage; and / or The duty cycle adjustment range of the PWM signal is 10%~100%.

7. The infrared emission controller according to any one of claims 1 to 6, characterized in that: The constant current source includes an operational amplifier, a MOS tube and a sampling resistor; The in-phase input terminal of the operational amplifier receives the modulation voltage; the inverting input terminal of the operational amplifier is electrically connected to the first terminal of the sampling resistor and receives the feedback voltage of the sampling resistor; the output terminal of the operational amplifier is connected to the gate of the MOS tube, and the operational amplifier is used to compare the modulation voltage with the feedback voltage and then output the gate voltage to the MOS tube; The source of the MOS tube is electrically connected to the first end of the sampling resistor, and the drain of the MOS tube is electrically connected to the infrared emitting tube. The gate voltage of the MOS tube is inversely proportional to the load current. The second end of the sampling resistor is grounded.

8. The infrared emission controller according to claim 7, characterized in that: The constant current source also includes a gate drive resistor; The gate driving resistor is connected between the output terminal of the operational amplifier and the gate of the MOS tube, and is used to reduce the gate noise of the MOS tube.

9. The infrared emission controller according to claim 8, characterized in that: The constant current infrared control loop also includes a power supply, which provides voltage for the infrared emitting tube; The voltage of the power supply is set to 5V, and the infrared emitting tube is set to a single infrared light string; or the voltage of the power supply is set to 12V, and the infrared emitting tube is set to 2-3 infrared light strings.

10. The infrared emission controller according to claim 9, characterized in that: The infrared light string includes a plurality of infrared light emitting diodes connected in series.

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