Infrared sensing circuit and infrared sensing system

Abstract

An infrared sensing circuit includes a detection circuit and a signal processing circuit, wherein the detection circuit includes: an infrared receiving tube, a transformer, a first transistor Q1 and a first resistor, wherein the infrared receiving tube receives an infrared signal and is connected to the base of the transistor Q1 through the first resistor, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the fourth end of the transformer T, the third end of the transformer T is connected to the power supply end, the second end of the transformer T is connected to the infrared receiving tube, and the first end of the transformer is connected to the signal processing circuit through the fourth resistor; the signal processing circuit processes the signal detected by the detection circuit and uses it as the output of the infrared sensing circuit. An infrared sensing system is also provided. The scheme of the present invention can ensure that the infrared sensing is sensitive and the distance sensing effect is significant.

Description

Technical Field

[0001] The invention relates to the field of infrared sensing, and more specifically to an infrared sensing circuit and an infrared sensing system. Background Art

[0002] Traditional infrared sensors cannot fully discharge infrared signals, so that the sensed infrared signals cannot be subsequently processed and used.

[0003] The above information disclosed in this background section is only for further understanding of the background of the invention and therefore it may contain information that does not constitute the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0004] The present invention provides an infrared sensing circuit and an infrared sensing system. The new infrared detection method provided by the present invention can accurately amplify infrared signals through a transformer.

[0005] The first aspect of the present invention provides an infrared sensing circuit, the detection circuit comprising: the detection circuit comprising: an infrared receiving tube, a transformer, a first transistor Q1 and a first resistor, wherein the infrared receiving tube receives an infrared signal and is connected to the base of the transistor Q1 through the first resistor, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the fourth end of the transformer T, the third end of the transformer T is connected to the power supply end, the second end of the transformer T is connected to the infrared receiving tube, the first end of the transformer is connected to the signal processing circuit through the fourth resistor; the signal processing circuit processes the signal detected by the detection circuit and uses it as the output of the infrared sensing circuit.

[0006] According to an embodiment of the present invention, the signal processing circuit includes: capacitors C2 and C3, transistor Q2, a second resistor, a third resistor and a fourth resistor, wherein the first end of the transformer is connected to the collector of the transistor Q2 through the fourth resistor; the collector of the transistor Q1 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is connected to the base of the transistor Q2 through the second resistor, the first end of the third resistor is connected to the second end of the capacitor C3, the second end of the third resistor is grounded, the first end of the capacitor C2 is connected to the base of the transistor Q2, the second end of the capacitor C2 is grounded, the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 serves as the output of the infrared sensing circuit. The third and fourth ends of the transformer are the two ends of the primary coil, and the first and second ends of the transformer are the two ends of the secondary coil.

[0007] According to an embodiment of the present invention, the C2 is a transistor filter capacitor, and the C3 is an AC coupling capacitor.

[0008] According to one embodiment of the present invention, when the infrared receiving tube does not receive an infrared signal, the transistor Q1 is cut off, the transformer T has no voltage change, the C3 has no change that can be transmitted, the transistor Q2 is cut off by grounding through the third resistor, and the output of the infrared sensing circuit is high level.

[0009] According to one embodiment of the present invention, when the infrared receiving tube receives an infrared signal, Q1 is turned on and outputs a current signal. The output signal is fed back to the second resistor through the secondary coil of the transformer to change the current, so that Q1 adjusts the output. The signal processing circuit transmits the changed current signal through C3. The changed current signal enters Q2 through a filter circuit composed of a third resistor and C2, so that Q2 is turned on, and the power supply is connected to the fourth resistor and connected to ground with Q2. Before Q2 is saturated, the output value of the infrared sensing circuit is: power supply voltage-resistance value of the fourth resistor*base current of Q2*amplification factor of Q2. After Q2 is saturated, the output value of the infrared sensing circuit is the saturation voltage drop value of Q2.

[0010] According to an embodiment of the present invention, the transistors Q1 and Q2 are NPN transistors or PNP transistors.

[0011] According to an embodiment of the present invention, in the circuit of claim 1, the parameter selection of the first resistor is related to the parameters of the transistor Q1, the transformer T and the infrared receiving tube.

[0012] According to an embodiment of the present invention, the selection of the first resistor parameter satisfies the following conditions: the signal received by the infrared receiving tube can pass through the first resistor to turn on Q1, and when Q1 is turned on, the change of the infrared signal strength can be detected.

[0013] The second aspect of the present invention provides an infrared sensing system, comprising the above-mentioned infrared sensing circuit and a controller, wherein the controller comprises a memory and a processor, and the memory stores instructions, and when the processor executes the instructions, the controller performs the following operations: reading the output signal of the infrared sensing circuit, determining that the infrared signal is sensed if there is an infrared pulse in the output signal, reading the AD value in the infrared signal, calculating the infrared distance according to the AD value, and executing related instructions according to the sensed infrared signal and infrared distance; if there is no infrared pulse in the output signal, determining that the infrared signal is not sensed, and continuing to read the output signal of the infrared sensing circuit. The controller may be an MCU.

[0014] According to the solution of the present invention, the infrared sensor is sensitive and the distance sensing effect is significant; the switching process keeps the circuit running normally without power outage. The infrared signal is accurately amplified by a transformer; the infrared signal is converted into a signal that can be read and recognized by the MCU. A strong driving force is provided to the infrared signal, and it will not cause attenuation and failure to detect during the transmission process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is an exemplary infrared sensing circuit schematic diagram according to the prior art of the present invention.

[0017] Figure 2 1 is a working principle diagram of an infrared sensing circuit when there is no infrared signal according to an exemplary embodiment of the present invention.

[0018] Figure 3 It is a working principle diagram of an infrared sensing circuit when there is an infrared signal according to an exemplary embodiment of the present invention.

[0019] Figure 4 is a block diagram of an MCU portion of an infrared sensing system according to an exemplary embodiment of the present invention.

[0020] Figure 5 4 is a simulation diagram of an infrared sensing circuit when there is no infrared signal according to an exemplary embodiment of the present invention.

[0021] Figure 6 4 is a simulation diagram of an infrared sensing circuit when the infrared signal is small according to an exemplary embodiment of the present invention.

[0022] Figure 7 4 is a simulation diagram of an infrared sensing circuit when the infrared signal is large according to an exemplary embodiment of the present invention. Specific embodiments

[0023] As used herein, the words "first", "second", etc. may be used to describe elements in exemplary embodiments of the present invention. These words are only used to distinguish one element from another, and the inherent characteristics or order of the corresponding elements, etc. are not limited by the words. Unless otherwise defined, all terms (including technical or scientific terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the technical field to which the present invention belongs. Those terms defined in common dictionaries are interpreted as having the same meaning as the contextual meaning in the relevant technical field, and are not interpreted as having ideal or overly formal meanings, unless they are clearly defined as having such meanings in the present invention.

[0024] It will be understood by those skilled in the art that the apparatus and methods of the present invention described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments, and the scope of the present invention is limited only by the claims. Features illustrated or described in conjunction with one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are included within the scope of the present invention.

[0025] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, detailed descriptions of related known functions or configurations are omitted to avoid unnecessary obscuration of the technical points of the present invention. In addition, throughout the description, the same reference numerals always refer to the same circuits, modules or units, and for the sake of brevity, repeated descriptions of the same circuits, modules or units are omitted.

[0026] In addition, it should be understood that one or more of the following methods or aspects thereof can be performed by at least one control unit or controller. The term "control unit", "controller", "control module" or "main control module" can refer to a hardware device including a memory and a processor, and the term "air conditioner" can refer to a device similar to an air conditioner. The memory or computer readable storage medium is configured to store program instructions, and the processor is specifically configured to execute program instructions to perform one or more processes that will be further described below. Moreover, it should be understood that, as will be appreciated by a person of ordinary skill in the art, the following methods can be performed by including a processor in combination with one or more other components.

[0027] The present invention provides an infrared sensing circuit, an important component of which is an infrared detection circuit of module two, which uses a transformer and Q1 to accurately sense and amplify infrared signals; wherein the degree of signal amplification is determined by the turns ratio of the transformer; a strong driving force is provided to the infrared signal, and no attenuation will cause the signal to be undetectable during the transmission process; the signal processing circuit of module one of the present invention preliminarily processes the signal, and the present invention only applies capacitors, resistors and triodes to filter and read the signal, and other methods can apply comparators and other schemes to accurately read the signal.

[0028] Figure 1 It is an exemplary infrared sensing circuit schematic diagram according to the prior art of the present invention.

[0029] like Figure 1 As shown, the infrared sensing circuit includes a detection circuit of module one and a signal processing circuit of module two, wherein the detection circuit includes: an infrared receiving tube LED, a transformer T, a first transistor Q1 and a first resistor R2, wherein the infrared receiving tube receives an infrared signal and is connected to the base of the transistor Q1 through the first resistor R2, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the T4 end of the primary coil of the transformer T, the T3 end of the primary coil is connected to the power supply VCC, and the T2 end of the secondary coil of the transformer T is connected to the infrared receiving tube; the signal processing circuit includes capacitors C2 and C3, transistors Q2, a second resistor R1, a third resistor R5 and a fourth resistor R1, wherein the collector of the transistor Q1 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is connected to the collector of the transistor Q2 through the second resistor R6, the first end of the third resistor is connected to the second end of the capacitor C3, the second end of the third resistor R5 is grounded, the first end of the capacitor C2 is connected to the collector of the transistor Q2, the second end of the capacitor C2 is grounded, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the T1 end of the secondary coil of the transformer through the fourth resistor, and serves as the output OUT of the infrared sensing circuit.

[0030] According to one or more embodiments of the present invention, Figure 1 In the figure, 1. VCC is the power supply; 2. T is the transformer; 3. LED is the infrared receiving tube; 4. R1, R2, R5 are resistors; 5. C2, C3 are capacitors; 6. Q1, Q2 are NPN transistors; 7. OUT is the signal output; 8. Module 1 is the signal processing part; 9. Module 2 is the signal detection and amplification part; 10. GND is the reference ground of VCC.

[0031] According to one or more embodiments of the present invention, the filter capacitors C2 and C3 are selected as follows: C2 is a filter capacitor for the transistor, and a conventional capacitor such as 102, 104, etc. may be used according to actual tests; C3 is an AC coupling capacitor, and the energy after coupling of the capacitor needs to be able to turn on the transistor, so its selection is related to the transistor; using 104 during circuit testing can achieve the purpose of testing; when selecting different transistors, it is necessary to follow the test.

[0032] According to one or more embodiments of the present invention, R1 is an NPN or PNP transistor collector resistor (connected to the collector of Q2), which is related to the output. If it is a common single-chip microcomputer, 4.7k-10k can be used, which is specifically considered in relation to the signal reading method;

[0033] According to one or more embodiments of the present invention, R6 (next to C2, connected to the collector of Q2) is the base input resistor of the transistor, which plays the role of filtering and controlling the base current, controls the state of the transistor, and is related to the selection of the transistor, which is a conventional transistor selection judgment.

[0034] According to one or more embodiments of the present invention, the resistor R5 plays a filtering role and also serves as a discharge resistor of the capacitor C3. The resistor R5 can be selected from tens of k to hundreds of k, and there is no fixed requirement.

[0035] According to one or more embodiments of the present invention, resistor R2 is selected as a key component of the infrared sensing circuit, and its selection is related to the transistor, transformer and infrared receiving tube, and the requirement is that the signal received by the infrared can make Q1 turn on through R2; after Q1 is turned on and the infrared intensity change can be detected, the various limit parameters of Q1 are tested to meet the requirements of the Q1 specification book; R2 is tested, and the temperature rise of Q1 meets the requirements of the device.

[0036] Figure 2 1 is a working principle diagram of an infrared sensing circuit when there is no infrared signal according to an exemplary embodiment of the present invention.

[0037] like Figure 2 As shown, when the LED does not receive the infrared signal, Q1 is cut off, T has no voltage change, C3 has no change and can be transmitted, Q2 is connected to GND through R5 and is cut off. At this time, OUT is high and equal to VCC.

[0038] Figure 3 It is a working principle diagram of an infrared sensing circuit when there is an infrared signal according to an exemplary embodiment of the present invention.

[0039] like Figure 3 As shown, when the LED receives an infrared signal, the current through R2 increases, Q1 starts to conduct, and outputs a signal. The output signal is fed back to the R2 line through the transformer turns ratio, the current changes, and Q1 adjusts the output; C3 starts to transmit the change, which enters Q2 through the filtering of R5 and C2, making Q2 conduct. At this time, VCC is connected to R1, and Q2 is connected to GND. The value of OUT before Q2 saturates is VCC-R1*Ib2*Q2 magnification, and after saturation, it is Q2's saturation voltage drop Vce. Ib2 is the base current of Q2 transistor, and Vceo2 represents the Vce value when Q2 transistor is saturated, which is determined by the component specification.

[0040] like Figure 3As shown, the processing process of the induction circuit when there is an infrared signal is as follows: the signal s provided by VCC passes through T(1-2) to the infrared receiving tube LED. The receiving strength of the infrared receiving tube determines the degree of opening of the infrared tube. The current flowing through the LED is amplified by s. After passing through the LED, it reaches Q1 through the current limit of R2, making Q1 turned on; after Q1 is turned on, its working state determines the charging speed of T(3-4). Due to the characteristics of the transformer, the change of the T(3-4) coil makes T-2 decrease, and finally Q1 is turned off. At this time, T(3-4) has been charged. Due to the cut-off of Q1, a higher pulse will appear in T-4 under the inductance characteristics to release the energy when Q1 is turned on. The size of this pulse is related to the current of the base of Q1. When R2 is fixed, only the change of the infrared receiving strength can affect the size of the pulse; then under the transformer characteristics, T-2 begins to increase, making Q1 start to turn on, forming a cycle; at this time, the AC signal is taken from T-4, filtered by resistors and capacitors, and reaches Q2, and its signal can be calculated by the basic formula of the triode.

[0041] Figure 4 is a block diagram of an MCU portion of an infrared sensing system according to an exemplary embodiment of the present invention.

[0042] like Figure 4 As shown, the control is a part of the infrared sensing system, the infrared sensing system includes the above-mentioned infrared sensing circuit, and the controller. The controller includes a memory and a processor, and the memory stores instructions. When the processor executes the instructions, the control performs the following operations: read the output signal of the infrared sensing circuit, if there is an infrared pulse in the output signal, it is determined that the infrared signal is sensed, read the AD value in the infrared signal, (the voltage is an analog quantity, which is converted into a digital quantity for MCU to identify as an AD value), calculate the infrared distance according to the AD value, and execute related instructions according to the sensed infrared signal and infrared distance; if there is no infrared pulse in the output signal, it is determined that the infrared signal is not sensed, and continue to read the output signal of the infrared sensing circuit. The controller can be an MCU.

[0043] According to one or more embodiments of the present invention, the MOS tube can be replaced with a suitable transistor to achieve this function; the transistor can also use PNP to achieve the function; the detection circuit of module one can use common signal reading means such as a comparator to read the signal.

[0044] Figure 5 4 is a simulation diagram of an infrared sensing circuit when there is no infrared signal according to an exemplary embodiment of the present invention. Figure 6 4 is a simulation diagram of an infrared sensing circuit when the infrared signal is small according to an exemplary embodiment of the present invention. Figure 74 is a simulation diagram of an infrared sensing circuit when the infrared signal is large according to an exemplary embodiment of the present invention.

[0045] like Figure 5 As shown in Figures 6 and 7, the infrared sensing circuit according to the present invention can discharge and process infrared signals well.

[0046] According to one or more embodiments of the present invention, the control logic of the present invention can use coded instructions (e.g., computer and / or machine readable instructions) stored on a non-transitory computer and / or machine readable medium (e.g., a hard drive, flash memory, read-only memory, optical disk, digital versatile disk, cache, random access memory and / or any other storage device or storage disk) to implement the processing of the above-described scheme of the present invention, storing information for any time period (e.g., an extended period of time, permanent, transient instance, temporary cache and / or information cache) in the non-transitory computer and / or machine readable medium. As used herein, the term "non-transitory computer readable medium" is expressly defined to include any type of computer readable storage device and / or storage disk, and excludes propagation signals and excludes transmission media.

[0047] According to one or more embodiments of the present invention, the controller (control logic, main control system or control module) of the method or device of the present invention may include one or more processors, and may also include a non-transitory computer-readable medium inside. Specifically, the device or apparatus (main control system or control module) may include a microcontroller MCU, which is arranged in the air conditioner to automatically implement the operation of the present invention and implement various functions. The processor used to implement the scheme of the present invention may be such as but not limited to one or more single-core or multi-core processors. (One or more) processors may include any combination of general-purpose processors and special-purpose processors (for example, graphics processors, application processors, etc.). The processor may be coupled thereto and / or may include a memory / storage device, and may be configured to execute instructions stored in the memory / storage device to implement various applications and / or operating systems running on the controller in the present invention.

[0048] The accompanying drawings and detailed description of the present invention referred to above as examples of the present invention are used to explain the present invention, but do not limit the meaning or scope of the present invention described in the claims. Therefore, those skilled in the art can easily realize modifications from the above description. In addition, those skilled in the art can delete some components described herein without degrading performance, or can add other components to improve performance. In addition, those skilled in the art can change the order of the steps of the method described herein according to the environment of the process or equipment. Therefore, the scope of the present invention should not be determined by the embodiments described above, but by the claims and their equivalents.

[0049] While the invention has been described in connection with what are presently considered to be capable of implementation, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An infrared sensing circuit, comprising a detection circuit and a signal processing circuit, wherein The detection circuit comprises: Infrared receiving tube, transformer, transistor Q1 and the first resistor, The infrared receiving tube receives the infrared signal and is connected to the base of the transistor Q1 through the first resistor, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the fourth end of the transformer T, the third end of the transformer T is connected to the power supply end, the second end of the transformer T is connected to the infrared receiving tube, and the first end of the transformer is connected to the signal processing circuit; The signal processing circuit processes the signal detected by the detection circuit and uses it as the output of the infrared sensing circuit.

2. The infrared sensing circuit according to claim 1, wherein the signal processing circuit comprises: Capacitors C2 and C3, transistor Q2, second resistor, third resistor and fourth resistor, Among them, the first end of the transformer is connected to the collector of the transistor Q2 through the fourth resistor; the collector of the transistor Q1 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is connected to the base of the transistor Q2 through the second resistor, the first end of the third resistor is connected to the second end of the capacitor C3, the second end of the third resistor is grounded, the first end of the capacitor C2 is connected to the base of the transistor Q2, the second end of the capacitor C2 is grounded, the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 serves as the output of the infrared sensing circuit.

3. The infrared sensing circuit according to claim 2, wherein: The C2 is a transistor filter capacitor, and the C3 is an AC coupling capacitor.

4. The infrared sensing circuit according to claim 2, wherein: When the infrared receiving tube does not receive an infrared signal, the transistor Q1 is turned off, the transformer T has no voltage change, the C3 has no change that can be transmitted, the transistor Q2 is turned off by grounding through the third resistor, and the output of the infrared sensing circuit is high level.

5. The infrared sensing circuit according to claim 2, wherein: When the infrared receiving tube receives an infrared signal, Q1 is turned on and outputs a current signal. The output signal is fed back to the base of the transistor Q1 through the secondary coil of the transformer, and the current changes, so that Q1 adjusts the output. The signal processing circuit transmits the changed current signal through C3. The changed current signal enters Q2 through the filter circuit composed of the third resistor and C2, so that Q2 is turned on, and the power supply is connected to the fourth resistor and connected to the ground with Q2. Before Q2 is saturated, the output value of the infrared sensing circuit is: power supply voltage-resistance value of the fourth resistor*base current of Q2*amplification factor of Q2. After Q2 is saturated, the output value of the infrared sensing circuit is the saturation voltage drop value of Q2. 6 . The infrared sensing circuit according to claim 2 , wherein the transistors Q1 and Q2 are NPN transistors or PNP transistors. 7 . The infrared sensing circuit according to claim 1 , wherein the parameter selection of the first resistor is related to the parameters of the transistor Q1 , the transformer T and the infrared receiving tube.

8. The infrared sensing circuit according to claim 7, wherein the selection of the first resistor parameter satisfies the following conditions: the signal received by the infrared receiving tube can pass through the first resistor to turn on Q1, and when Q1 is turned on, the change in the infrared signal strength can be detected.

9. An infrared sensing system, comprising the infrared sensing circuit according to any one of claims 1 to 8, and a controller, wherein the controller comprises a memory and a processor, wherein the memory stores instructions, and when the processor executes the instructions, the controller performs the following operations: Read the output signal of the infrared sensing circuit, if there is an infrared pulse in the output signal, determine that the infrared signal is sensed, read the AD value in the infrared signal, calculate the infrared distance according to the AD value, and execute related instructions according to the sensed infrared signal and infrared distance; If there is no infrared pulse in the output signal, it is determined that no infrared signal is sensed, and the output signal of the infrared sensing circuit continues to be read.

10. The infrared sensing system according to claim 9, wherein the controller is an MCU.

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