Light trigger detection circuit for filtering slowly-changing strong ambient light interference, alarm and electronic equipment

Abstract

The utility model relates to the technical field of photoelectricity, in particular to a light trigger detection circuit, an alarm and electronic equipment for filtering slowly changing strong ambient light interference, a power supply circuit is used for supplying power, and a control circuit is used for quantifying voltage output by a charge amplification module in the light trigger detection circuit and outputting a comparison threshold value required by a comparison module in the detection circuit; meanwhile, the light trigger detection circuit is used for converting light intensity into electric signals, comparing a comparison threshold value given by the control circuit, outputting trigger signals for light intensity electric signals exceeding the threshold value, obtaining comparison threshold value signals through real-time calculation according to the light intensity signals, and comparing and judging the comparison threshold value signals and the light intensity electric signals. Therefore, the influence caused by the slow change of the ambient light is eliminated, the sudden change of the light intensity is accurately detected, and the accuracy of early warning is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of optoelectronic technology, in particular to a light trigger detection circuit, an alarm and electronic equipment that can filter out the interference of slowly changing strong ambient light. Background Art

[0002] With the development of electronic technology, the application of photoelectric detection has also developed rapidly, and the intelligence and digitization of products have become a trend that people pursue. Equipment performance, price and development space have attracted much attention from consumers.

[0003] For electronic devices with excellent performance, in order to extend the service life of the equipment, the requirements for the peripheral protection circuit of the equipment will be very high, especially for some precision instruments, which have higher requirements for the light in the use environment, so that researchers have carried out a lot of research on light detection alarm circuits for the purpose of equipment protection. For example, patent No. 201420735329.8 discloses a light intensity detection circuit and a light intensity alarm, which adopts a light intensity acquisition unit, a first filtering unit, a voltage stabilizing unit, a signal processing unit and a second filtering unit to achieve the output after amplification and processing of the light intensity signal obtained by the light intensity acquisition unit, and can detect a wider range of light intensity, realize the detection from weak light to high intensity light, and can output the change of light intensity signal to the subsequent module circuit in real time, and can compare and judge whether the real-time light intensity change is within the set range. It can be seen that the existing technology directly warns whether the light intensity exceeds the preset threshold range, and the sudden change of light intensity in the use environment of the electronic equipment, such as interference from conditions such as day and night alternation and dark clouds, cannot accurately detect the sudden change of light intensity, which in turn affects the accuracy of the warning. Utility Model Content

[0004] In order to solve the above technical problems existing in the prior art, the utility model provides a light trigger detection circuit, an alarm and an electronic device for filtering out slowly changing strong ambient light interference.

[0005] This is achieved specifically through the following technical solutions:

[0006] One of the purposes of the invention is to provide a light-triggered detection circuit for filtering out slowly changing strong ambient light interference, comprising: a power supply circuit, a charge amplification module, a comparison module, an output port and a control circuit, wherein the charge amplification module is connected to the comparison module, the comparison module is connected to the output port, the charge amplification module is connected to the power supply circuit, the control circuit is connected to the charge amplification module, the comparison module and the control circuit, and the control circuit is connected to the power supply circuit.

[0007] Preferably, the charge amplification module includes a photodiode D1, an operational amplifier U1, a capacitor C1, a resistor R1, a capacitor C8, a resistor R8, a resistor R9 and a resistor R3, the photodiode D1 is directly connected to the operational amplifier U1, and the photodiode D1 is connected to the operational amplifier U1 through the capacitor C1 and the resistor R1 respectively; the operational amplifier U1 is grounded through the capacitor C8 and the resistor R8 respectively; the operational amplifier U1 is connected to the control circuit, and a resistor R9 is provided between the operational amplifier U1 and the control circuit; the operational amplifier U1 is connected to the power supply circuit, and the operational amplifier U1 is connected to the comparison module through the resistor R3.

[0008] Preferably, the comparison module includes a comparator U2, an RS422 cable driver U3, a resistor R2, a resistor R3 and a resistor R5, the comparator U2 is connected to the charge amplification module via the resistor R3, the comparator U2 is connected to the control circuit via the resistor R5, the comparator U2 is connected to the power supply circuit, and the comparator U2 is connected to the output port; the RS422 cable driver U3 is connected to the comparator U2, and the RS422 cable driver U3 is connected to the power supply circuit via the resistor R2.

[0009] More preferably, capacitors C44 and C43 are provided between the power supply circuit and the RS422 cable driver U3.

[0010] More preferably, capacitors C9 and C10 are provided between the power supply circuit and the charge amplification module.

[0011] More preferably, capacitors C2 and C3 are provided between the power supply circuit and the comparison module.

[0012] The second purpose of the present invention is to provide a light-triggered detection alarm that filters out slowly changing strong ambient light interference, including a light-triggered detection circuit and an alarm circuit as described above, wherein the alarm circuit is connected to the light-triggered detection circuit, the alarm circuit is connected to the control circuit, and the alarm circuit is connected to the power supply circuit.

[0013] The third purpose of the invention is to provide a light-triggered detection electronic device for filtering out slowly changing strong ambient light interference, including the above-mentioned light-triggered detection circuit.

[0014] The fourth purpose of the present invention is to provide a light-triggered detection electronic device for filtering out slowly changing strong ambient light interference, including the above-mentioned light-triggered detection circuit and alarm circuit, the alarm circuit is connected to the light-triggered detection circuit, the alarm circuit is connected to the control circuit, and the alarm circuit is connected to the power supply circuit.

[0015] Compared with the prior art, the technical effects created by the present invention are embodied in:

[0016] The power supply circuit is used for power supply, and the control circuit is used to quantify the voltage output by the charge amplifier module in the light trigger detection circuit, and output the comparison threshold required by the comparison module in the detection circuit; at the same time, the light trigger detection circuit is used to convert the light intensity into an electrical signal, and compare the comparison threshold given by the control circuit, and output a trigger signal for the light intensity electrical signal exceeding the threshold. The comparison threshold signal can be obtained according to the real-time calculation of the light intensity signal, and then the comparison threshold signal and the light intensity electrical signal are compared and judged, thereby eliminating the influence caused by the slow change of ambient light, and then accurately detecting the sudden change of light intensity to ensure the accuracy of the early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A structural block diagram of a light-triggered alarm and a light-triggered electronic device provided for an embodiment of the present invention.

[0018] Figure 2 A block diagram of the structure of a light-triggered detection circuit for filtering out slowly changing strong ambient light interference provided by an embodiment of the present invention.

[0019] Figure 3 An example diagram of the structure of a light-triggered detection circuit for filtering out slowly changing strong ambient light interference provided in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0020] The technical solution created by the present invention is further defined below in conjunction with the accompanying drawings and specific implementation methods, but the scope of protection required is not limited to the description.

[0021] It should be noted that, although the functional modules are divided in the structural diagram and the logical order is shown, in some cases, the steps shown or described in the module division or logical order in the structural diagram may be different. Unless otherwise defined, the technical and scientific terms used in the invention have the same meaning as those commonly understood by technicians in the technical field of the invention. The terms used in the invention are only for the purpose of describing the embodiments of the invention and are not intended to limit the invention.

[0022] The blocks shown in the accompanying drawings are only functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0023] like Figure 1 and Figure 2As shown, in some embodiments, a light-triggered detection circuit for filtering out slowly changing strong ambient light interference includes: a power supply circuit 20, a charge amplification module 31, a comparison module 32, an output port 33 and a control circuit 10, wherein the charge amplification module 31 is connected to the comparison module 32, the comparison module 32 is connected to the output port 33, the charge amplification module 31 is connected to the power supply circuit 20, the control circuit 10 is connected to the charge amplification module 31, the comparison module 32 and the control circuit 10, and the control circuit 10 is connected to the power supply circuit 20. The power supply circuit 20 is used to supply power to each circuit. The charge amplifier module 31, the comparison module 32 and the output port 33 together constitute a detection circuit 30. The control circuit is used to quantify the voltage output by the charge amplifier module 31 in the detection circuit 30, and output the comparison threshold required by the comparison module 32 in the detection circuit 30; the detection circuit 30 is used to convert the light intensity into an electrical signal, and output a trigger signal for the light signal exceeding the threshold by comparing it with the comparison threshold given by the control circuit 10; the detection circuit can be used to detect changes in ambient light intensity, and give a trigger signal for the intensity change exceeding a fixed value per unit time, which is then output through the output port 33.

[0024] like Figure 3 As shown, in some embodiments, the charge amplification module 31 includes a photodiode D1 (SFH2030F), an operational amplifier U1 (LTC6268), a capacitor C1, a resistor R1, a capacitor C8, a resistor R8, a resistor R9 and a resistor R3, the photodiode D1 (SFH2030F) is directly connected to the operational amplifier U1 (LTC6268), and the photodiode D1 (SFH2030F) is connected to the operational amplifier U1 (LTC6268) through the capacitor C1, the resistor R1 and the operational amplifier U1 (LTC6268). 268); the operational amplifier U1 (LTC6268) is connected to the ground through the capacitor C8 and the resistor R8 respectively; the operational amplifier U1 (LTC6268) is connected to the control circuit 10, and a resistor R9 is provided between the operational amplifier U1 (LTC6268) and the control circuit 10; the operational amplifier U1 (LTC6268) is connected to the power supply circuit 20, and the operational amplifier U1 (LTC6268) is connected to the comparison module 32 through the resistor R3.

[0025] like Figure 3As shown, in some embodiments, the comparison module 32 includes a comparator U2 (TLV3501), an RS422 cable driver U3 (MAX3485EESA), a resistor R2, a resistor R3 and a resistor R5, the comparator U2 (TLV3501) is connected to the charge amplification module 31 via the resistor R3, the comparator U2 (TLV3501) is connected to the control circuit 10 via the resistor R5, the comparator U2 (TLV3501) is connected to the power supply circuit 20, and the comparator U2 (TLV3501) is connected to the output port 33; the RS422 cable driver U3 (MAX3485EESA) is connected to the comparator U2 (TLV3501), and the RS422 cable driver U3 (MAX3485EESA) is connected to the power supply circuit 20 via the resistor R2.

[0026] In order to filter the power supply, Figure 3 In some more excellent embodiments, capacitors C44 and C43 are provided between the power supply circuit 20 and the RS422 cable driver U3 (MAX3485EESA). Capacitors C9 and C10 are provided between the power supply circuit 20 and the charge amplification module 31. Capacitors C2 and C3 are provided between the power supply circuit 20 and the comparison module 32.

[0027] like Figure 1 As shown, in order to detect the light trigger detection circuit and output the trigger signal alarm display, the present invention creates an embodiment, providing a light trigger detection alarm that filters out the slowly changing strong ambient light interference, including the light trigger detection circuit and the alarm circuit 40 as described above, the alarm circuit 40 is connected to the light trigger detection circuit, the alarm circuit 40 is connected to the control circuit 10, and the alarm circuit 40 is connected to the power supply circuit 20. The light trigger detection circuit detects the change of the ambient light intensity, and gives a trigger signal when the intensity change exceeds a fixed value within a unit time, and then outputs it through the output port 33 and is displayed by the alarm circuit 40, that is: the alarm circuit 40 is used for the alarm display of the trigger signal output by the light trigger detection circuit.

[0028] like Figure 1As shown, in some embodiments, a light-triggered detection electronic device for filtering out slowly changing strong ambient light interference includes a detection circuit 30 for detecting changes in ambient light intensity; a power supply circuit 20 for powering; a control circuit 10 for quantifying the voltage output in the detection circuit 30 and outputting the comparison threshold required in the detection circuit; an alarm circuit 40 for alarming and displaying a trigger signal output by the detection circuit 30; the detection circuit 30 is connected to the control circuit 10, the detection circuit 30 is connected to the power supply circuit 20, and the detection circuit 30 is connected to the alarm circuit 40; the control circuit 10 is connected to the alarm circuit 40, the control circuit 10 is connected to the power supply circuit 20; the alarm circuit 40 is connected to the power supply circuit 20.

[0029] like Figure 2 As shown, in a more excellent embodiment, the detection circuit 30 includes a charge amplification module 31, a comparison module 32 and an output port 33; the charge amplification module 31 is connected to the comparison module 32, the comparison module 32 is connected to the output port 33, the charge amplification module 31 is connected to the power supply circuit 20, and the output port 33 is connected to the alarm circuit 40; the charge amplification module 31 and the comparison module 32 are respectively connected to the control circuit 10.

[0030] In order to more fully illustrate and clarify the technical content of the present invention, the following specific Figure 3 An example of a detection circuit 30 is shown:

[0031] like Figure 3 As shown, in this example, the detection circuit 30 includes a photodiode D1 (SFH2030F), an operational amplifier U1 (LTC6268), a comparator U2 (TLV3501), an RS422 cable driver U3 (MAX3485EESA), capacitors C1, C2, C3, C8, C9, C10, C43, and C44; resistors R1, R2, R3, R4, R5, R7, R8, and R9, and a power supply MCU3V3.

[0032] like Figure 3 As shown, the operational amplifier U1 (LTC6268) includes nine pins, which are numbered 1-9 respectively; the comparator U2 (TLV3501) includes 6 pins, which are numbered 1-6 respectively; the RS422 cable driver U3 (MAX3485EESA) includes 8 pins, which are numbered 1-8 respectively.

[0033] like Figure 3As shown, the pin 1 of the photodiode D1 (SFH2030F) is connected to the pin 2 of the operational amplifier U1 (LTC6268), and the signal is used as the inverting input of the operational amplifier; the pin 1 of the photodiode D1 (SFH2030F) is connected to the pin 1 of the operational amplifier U1 (LTC6268) through the capacitor C1 and the resistor R1, and the capacitor C1 and the resistor R1 are connected in parallel; the pin 1 of the operational amplifier U1 (LTC6268) is connected to the inverting end of the pin 1 of the comparator U2 (TLV3501) through the resistor R3; the pin 1 of the operational amplifier U1 (LTC6268) is connected to the inverting end of the pin 1 of the comparator U2 (TLV3501) through the resistor R9 Connected to the control circuit 10 for AD sampling and quantization; the 3rd pin of the operational amplifier U1 (LTC6268) is grounded through a resistor R8 and a capacitor C8, and the resistor R8 is connected in parallel with the capacitor C8; the 4th and 9th pins of the operational amplifier U1 (LTC6268) are reference ground pins, connected to the reference ground; the 8th pin of the operational amplifier U1 (LTC6268) is a power pin, connected to the power supply MCU3V3; the capacitor C9 and the capacitor C10 are used for filtering the power supply MCU3V3 of the operational amplifier U1 (LTC6268), and are arranged close to the chip power pin position.

[0034] like Figure 3 As shown, the in-phase end of pin 3 of the comparator U2 (TLV3501) is connected to the output of pin 5 through a resistor R7, and pin 4 of the comparator U2 (TLV3501) is a power pin, connected to the power supply MCU3V3; pin 2 of the comparator U2 (TLV3501) is a reference ground pin, connected to the reference ground; the synchronous resistor R5 of the in-phase end of pin 3 of the comparator U2 (TLV3501) is connected to the DA output of the control circuit 10; the capacitors C2 and C3 are used to filter the power supply MCU3V3 of the comparator U2 (TLV3501), and are arranged close to the chip power pin.

[0035] like Figure 3As shown, pin 4 of the RS422 cable driver U3 (MAX3485EESA) is connected to pin 5 of the comparator U2 (TLV3501), pins 6 and 7 of the RS422 cable driver U3 (MAX3485EESA) are differential signals, connected to the alarm circuit 40; pins 2 and 3 of the RS422 cable driver U3 (MAX3485EESA) are short-circuited, connected to the power supply MCU3V3 through a resistor R2, pin 8 of the RS422 cable driver U3 (MAX3485EESA) is a power supply pin, connected to the power supply MCU3V3, and pin 5 of the RS422 cable driver U3 (MAX3485EESA) is a reference ground pin, connected to the reference ground; the capacitor C44 and the capacitor C43 are used for filtering the power supply MCU3V3 of the RS422 cable driver U3 (MAX3485EESA), and are arranged close to the chip power pin position.

[0036] According to the simple formula of the charge amplifier circuit output voltage U=-Q / C, it can be known that every 18pC of charge corresponds to a 1V voltage output. After the photodiode senses the ambient light, it is converted and output through pin 1 of the operational amplifier U1 (LTC6268). The output voltage signal enters the control circuit 10 for AD quantization, and is finally converted into a threshold voltage and output to pin 3 of the comparator U2 (TLV3501). The "real-time" light intensity voltage signal connected to pin 1 of the comparator U2 (TLV3501) is compared with the output threshold voltage of the control circuit 10 to form a trigger signal, which is converted into a level through the RS422 cable driver U3 (MAX3485EESA) to form a differential signal that is easy to transmit. The light-triggered detection circuit based on the light-triggered system can filter out the slowly changing strong ambient light interference. The detection object is the sudden change of light intensity. At the same time, it is required that there should be no false alarm for the slow light intensity change, such as the alternation of day and night, dark cloud cover, etc. For the fixed light intensity detection application, the AD quantization parameter variable can be ignored in the control circuit 10, and the threshold voltage can be set to a predetermined value.

[0037] Other matters not covered by the present invention may be achieved by conventional technical means with reference to the prior art or common knowledge known to those skilled in the art.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A light-triggered detection circuit for filtering out slowly changing strong ambient light interference, characterized in that: include: A power supply circuit (20), a charge amplification module (31), a comparison module (32), an output port (33) and a control circuit (10), wherein the charge amplification module (31) is connected to the comparison module (32), the comparison module (32) is connected to the output port (33), the charge amplification module (31) is connected to the power supply circuit (20), the control circuit (10) is connected to the charge amplification module (31), the comparison module (32) is connected to the control circuit (10), and the control circuit (10) is connected to the power supply circuit (20).

2. The light-triggered detection circuit for filtering out slowly changing strong ambient light interference as claimed in claim 1, characterized in that: The charge amplification module (31) comprises a photodiode D1, an operational amplifier U1, a capacitor C1, a resistor R1, a capacitor C8, a resistor R8, a resistor R9 and a resistor R3; the photodiode D1 is directly connected to the operational amplifier U1, and the photodiode D1 is connected to the operational amplifier U1 via the capacitor C1 and the resistor R1 respectively; the operational amplifier U1 is grounded via the capacitor C8 and the resistor R8 respectively; the operational amplifier U1 is connected to the control circuit (10), and a resistor R9 is provided between the operational amplifier U1 and the control circuit (10); the operational amplifier U1 is connected to the power supply circuit (20), and the operational amplifier U1 is connected to the comparison module (32) via the resistor R3.

3. The light-triggered detection circuit for filtering out slowly changing strong ambient light interference as claimed in claim 1, characterized in that: The comparison module (32) comprises a comparator U2, an RS422 cable driver U3, a resistor R2, a resistor R3 and a resistor R5; the comparator U2 is connected to the charge amplification module (31) via the resistor R3; the comparator U2 is connected to the control circuit (10) via the resistor R5; the comparator U2 is connected to the power supply circuit (20); and the comparator U2 is connected to the output port (33); the RS422 cable driver U3 is connected to the comparator U2; and the RS422 cable driver U3 is connected to the power supply circuit (20) via the resistor R2.

4. The light-triggered detection circuit for filtering out slowly changing strong ambient light interference as claimed in claim 3, characterized in that: Capacitors C44 and C43 are provided between the power supply circuit (20) and the RS422 cable driver U3.

5. The light-triggered detection circuit for filtering out slowly changing strong ambient light interference as claimed in claim 1, characterized in that: Capacitors C9 and C10 are provided between the power supply circuit (20) and the charge amplification module (31).

6. The light-triggered detection circuit for filtering out slowly changing strong ambient light interference as claimed in claim 1, characterized in that: Capacitors C2 and C3 are provided between the power supply circuit (20) and the comparison module (32).

7. A light-triggered detection alarm that filters out slowly changing strong ambient light interference, characterized in that: The invention comprises a light-triggered detection circuit and an alarm circuit (40) as claimed in any one of claims 1 to 6, wherein the alarm circuit (40) is connected to the light-triggered detection circuit, the alarm circuit (40) is connected to the control circuit (10), and the alarm circuit (40) is connected to the power supply circuit (20).

8. An electronic device for light-triggered detection that filters out slowly changing strong ambient light interference, characterized in that: It comprises a light-triggered detection circuit as described in any one of claims 1 to 6.

9. An electronic device for light-triggered detection that filters out slowly changing strong ambient light interference, characterized in that: The invention comprises a light-triggered detection circuit and an alarm circuit (40) as claimed in any one of claims 1 to 6, wherein the alarm circuit (40) is connected to the light-triggered detection circuit, the alarm circuit (40) is connected to the control circuit (10), and the alarm circuit (40) is connected to the power supply circuit (20).

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