Photoresistor detection circuit

Abstract

The utility model relates to the technical field of electronic component detection, and discloses a photosensitive resistor detection circuit which is high in product detection qualified rate and reliable, and comprises a photosensitive sensing module (110) used for receiving different external brightness signals and converting the brightness signals into first voltage signals, a voltage dividing module (120), a comparison module (130), a switch module (140) and a master controller (MCU), when the input control signal is at a high level, the switch module (140) is controlled to be closed, and the detection end of the main controller (MCU) is in a high level state, the product to be detected is indicated to be a defective product, and when the input control signal is at a low level, the switch module (140) is controlled to be conducted, the + 5V voltage is grounded through the switch module (140), and the detection end of the main controller (MCU) is in a low level state, the product to be detected is indicated to be a qualified product.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic component detection, and more specifically to a photoresistor detection circuit. Background Art

[0002] Photoresistors can be used to adjust the current. At present, many companies will observe the input power of the finished products and the working status of the LED to determine whether the products are qualified when they are packed. However, when manual testing is used, long-term work and visual fatigue or eye fatigue occur, it is easy to cause mismeasurement and misjudgment, which requires rework, resulting in low product qualification rate and production efficiency.

[0003] Therefore, how to avoid visual fatigue or eye fatigue caused by manual inspection, which may lead to misdetection and misjudgment, so as to improve product qualification rate and production efficiency has become a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a photoresistor detection circuit with a high product detection pass rate and reliability, in view of the defect that the above-mentioned manual test in the prior art may cause misdetection and misjudgment when visual fatigue or eye fatigue occurs.

[0005] The technical solution adopted by the utility model to solve the technical problem is to construct a photoresistor detection circuit having:

[0006] A light-sensitive sensor module is configured in the detection circuit, and is used to receive different external brightness signals and convert the brightness signals into a first voltage signal;

[0007] A voltage divider module, one end of which is connected to the +5V power supply terminal;

[0008] A comparison module, one input end of which is connected to the output end of the light-sensitive sensor module and is used to receive the first voltage signal.

[0009] The other input end of the comparison module is connected to the output end of the voltage divider module, and is used to receive the divided second voltage signal, compare the first voltage signal with the second voltage signal, and output a control signal according to the comparison result;

[0010] A switch module, whose input terminal is coupled to the output terminal of the comparison module and is used to receive the input control signal;

[0011] A main controller, whose detection end is respectively connected to the output end of the switch module and the +5V power supply end;

[0012] When the input control signal is at a high level, the switch module is controlled to be closed, and the detection end of the main controller is at a high level, indicating that the product to be inspected is a defective product.

[0013] When the input control signal is at a low level, the switch module is controlled to be turned on, the +5V voltage is connected to the ground through the switch module, and the detection end of the main controller is at a low level, indicating that the product to be inspected is qualified.

[0014] In some embodiments, the light-sensitive sensing module includes a photoresistor sensor.

[0015] One end of the photoresistor sensor is connected to the +5V power supply end.

[0016] The other end of the photoresistor sensor is connected to an input end of the comparison module.

[0017] In some embodiments, the voltage dividing module includes a third resistor and a sixth resistor connected in series.

[0018] One end of the third resistor is connected to the +5V power supply terminal,

[0019] The connection end of the third resistor and the sixth resistor is connected to another input end of the comparison module,

[0020] One end of the sixth resistor is connected to the common end.

[0021] In some implementations, the sixth resistor is selected to be an adjustable resistor.

[0022] In some embodiments, the comparison module includes a voltage comparator.

[0023] The non-inverting terminal of the voltage comparator is coupled to the connection terminal of the third resistor and the sixth resistor.

[0024] The inverting terminal of the voltage comparator is connected to the output terminal of the photoresistor sensor.

[0025] The output end of the voltage comparator is connected to the input end of the switch module.

[0026] In some embodiments, the switch module includes a field effect transistor.

[0027] The gate of the field effect tube is connected to the output end of the voltage comparator.

[0028] The source of the field effect tube is coupled to the detection terminal of the main controller.

[0029] The drain of the field effect tube is connected to the common terminal.

[0030] In some implementations, the field effect transistor is selected to be a P-channel MOS transistor.

[0031] In some implementations, the detection terminal of the main controller is connected to the +5V power supply terminal through a fifth resistor.

[0032] In the photoresistor detection circuit described in the utility model, it includes a photosensitive sensor module, a voltage divider module, a comparison module, a switch module and a main controller for receiving different external brightness signals and converting them into a first voltage signal according to the brightness signal, wherein when the input control signal is a high level, the switch module is controlled to be closed, and the detection end of the main controller is in a high level state, indicating that the product to be inspected is a defective product, and when the input control signal is a low level, the switch module is controlled to be turned on, and the +5V voltage is connected to the ground through the switch module, and the detection end of the main controller is in a low level state, indicating that the product to be inspected is a qualified product. Compared with the prior art, the photosensitive sensor module receives different external brightness signals, and then converts them into a first voltage signal, the voltage divider module outputs a second voltage signal, the comparison module compares the two, and controls the level state of the detection end of the main controller according to the comparison result to determine whether the product to be inspected is qualified, which can effectively solve the problem that when manual testing is used, when visual fatigue or naked eye fatigue occurs, it is easy to have misdetection and misjudgment, so that rework is required, resulting in low product qualification rate and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0034] Figure 1 The utility model provides a circuit principle diagram of a photoresistor detection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0036] like Figure 1 As shown, in the first embodiment of the photoresistor detection circuit 100 of the present utility model, the photoresistor detection circuit 100 includes a photosensitive sensor module 110, a voltage divider module 120, a comparison module 130, a switch module 140 and a main controller MCU.

[0037] The light-sensitive sensor module 110 is used to receive external brightness signals of different intensities and convert the brightness signals into first voltage signals;

[0038] The voltage dividing module 120 is used to divide the voltage signal input from the +5V power supply terminal to output a second voltage signal;

[0039] The comparison module 130 has the function of comparing signals and outputting a control signal (such as high level / low level) according to the comparison result;

[0040] The switch module 140 has a switch function;

[0041] The main controller MCU is the core of the detection circuit, which has the functions of signal reception, comparison, calculation and output of warning signals;

[0042] Specifically, the light-sensitive sensor module 110 is configured in the detection circuit, and is used to receive different external brightness signals, and convert the brightness signals into first voltage signals, and then output the first voltage signals to the comparison module 130;

[0043] One end of the voltage dividing module 120 is connected to the +5V power supply end, and is used to receive a +5V voltage signal and perform voltage dividing processing on the +5V voltage signal to output a second voltage signal;

[0044] Furthermore, an input terminal of the comparison module 130 is connected to the output terminal of the light-sensitive sensor module 110 for receiving the first voltage signal.

[0045] Another input terminal of the comparison module 130 is connected to the output terminal of the voltage division module 120, and is used to receive the divided second voltage signal.

[0046] The comparison module 130 compares the input first voltage signal with the second voltage signal, and outputs a control signal (such as a high level / low level) according to the comparison result;

[0047] Furthermore, the input end of the switch module 140 is coupled to the output end of the comparison module 130 for receiving an input control signal (such as a high level / low level);

[0048] The detection end of the main controller MCU is connected to the output end of the switch module 140 and the +5V power supply end respectively. The on / off state of the switch module 140 can control the level state of the detection end of the main controller MCU.

[0049] When the input control signal is at a high level, the switch module 140 is controlled to be closed, and the detection end of the main controller MCU is at a high level, indicating that the product to be inspected is a defective product, and a warning signal is output accordingly.

[0050] When the input control signal is at a low level, the switch module 140 is controlled to be turned on, and the +5V voltage reaches the ground through the switch module 140. At this time, the detection end of the main controller MCU is at a low level state, indicating that the product to be inspected is qualified.

[0051] By using the present technical solution, different external brightness signals are received by the photosensitive sensor module 110 and then converted into a first voltage signal. The voltage divider module 120 outputs a second voltage signal. The comparison module 130 compares the two and controls the level state of the detection end of the main controller MCU according to the comparison result to determine whether the product to be inspected is qualified. This can effectively solve the problem of false detection and misjudgment that may occur when visual fatigue or eye fatigue occurs during manual testing, which requires rework and leads to low product qualification rate and production efficiency.

[0052] In some embodiments, Figure 1 As shown, the light-sensitive sensor module 110 includes a photoresistor sensor LDR, wherein one end of the photoresistor sensor LDR is connected to the +5V power supply terminal, and the other end of the photoresistor sensor LDR is connected to the common terminal through a second resistor R102, so that the photoresistor sensor LDR is in a working state, can receive external brightness signals of different intensities, and convert the brightness signal into a first voltage signal.

[0053] The other end of the photoresistor sensor LDR is connected to an input end of the comparison module 130 , and the first voltage signal is input into the comparison module 130 .

[0054] In some embodiments, Figure 1 As shown, the voltage dividing module 120 includes a third resistor R103 and a sixth resistor R106 connected in series, wherein the sixth resistor R106 is selected as an adjustable resistor.

[0055] Specifically, one end of the third resistor R103 is connected to the +5V power supply terminal for receiving a +5V voltage signal.

[0056] The connection end of the third resistor R103 and the sixth resistor R106 is connected to the other input end of the comparison module 130 , and one end of the sixth resistor R106 is connected to the common end.

[0057] The input +5V voltage signal is divided by the third resistor R103 and the sixth resistor R106 to form a second voltage signal, and the second voltage signal is output to the comparison module 130 .

[0058] In some embodiments, the comparison module 130 includes a voltage comparator U1A, which has a signal comparison function.

[0059] The in-phase terminal (corresponding to pin 3) of the voltage comparator U1A is coupled to the connection terminal of the third resistor R103 and the sixth resistor R106 for receiving the second voltage signal.

[0060] The inverting terminal (corresponding to pin 4) of the voltage comparator U1A is connected to the output terminal of the photoresistor sensor LDR to receive the first voltage signal.

[0061] The output terminal (corresponding to pin 1) of the voltage comparator U1A is connected to the input terminal of the switch module 140.

[0062] The voltage comparator U1A compares the first voltage signal with the second voltage signal.

[0063] When the first voltage signal is greater than the second voltage signal, the output of the voltage comparator U1A is low level.

[0064] When the second voltage signal is greater than the first voltage signal, the output of the voltage comparator U1A is a high level.

[0065] In some embodiments, the switch module 140 includes a field effect transistor Q101, which is selected as a P-channel MOS transistor and has a switch function;

[0066] Specifically, the gate of the field effect transistor Q101 is connected to the output end (corresponding to pin 1) of the voltage comparator U1A, and is used to receive the control signal output by the voltage comparator U1A.

[0067] The source of the field effect transistor Q101 is coupled to the detection terminal of the main controller MCU.

[0068] The drain of the field effect transistor Q101 is connected to the common terminal.

[0069] When the input control signal is at a high level, the field effect tube Q101 is controlled to be turned off, and the detection end of the main controller MCU is at a high level, indicating that the product to be inspected is a defective product, and a warning signal is output accordingly.

[0070] When the input control signal is at a low level, the field effect transistor Q101 is controlled to be turned on, and the +5V voltage reaches the ground through the source-drain of the field effect transistor Q101. At this time, the detection end of the main controller MCU is in a low level state, indicating that the product to be inspected is qualified.

[0071] In some implementations, in order to ensure the reliability of the input level signal, the detection terminal of the main controller MCU may be connected to the +5V power supply terminal through the fifth resistor R105.

[0072] The resistance value of the fifth resistor R105 is selected to be 10K, and the +5V voltage signal outputted from the +5V power supply terminal is inputted into the detection terminal of the main controller MCU after being current limited by the fifth resistor R105.

[0073] Its working principle is: when the photoresistor sensor LDR receives different brightness, its resistance value changes. When the light is strong, the bright resistance is 5-10KΩ, and when the light is dark, the dark resistance is 500KΩ. The SOT23-5 package, the photoresistor detection circuit and the sealed cover can be well used in production.

[0074] Among them, "+5V" is divided by the third resistor R103 and the sixth resistor R106 to provide a 2.4V reference voltage (corresponding to the second voltage signal) for the voltage comparator U1A. At this time, the resistance of the sixth resistor R106 can be adjusted to 9.24KΩ;

[0075] The calculation formula of the reference voltage is: 5*sixth resistor R106 / (third resistor R103+sixth resistor R106)=5*9.24 / 19.24≈2.4V,

[0076] When the product is placed in a photoresistor detection circuit with a sealed cover, the photoresistor sensor LDR is illuminated by an LED light. At this time, the resistance value of the photoresistor sensor LDR will change. When the resistance value is about 500K (equal to the dark resistance value of the photoresistor),

[0077] At this time, the voltage at pin 4 of the voltage comparator U1A is approximately: 5V*LDR / (LDR+second resistor R102)=5V*10 / 510≈0.1V. At this time, the voltage at pin 4 of the voltage comparator U1A is lower than the voltage at pin 3 of the voltage comparator U1A. Pin 1 of the voltage comparator U1A outputs a high level. Since the field effect tube Q101 is a P-MOS,

[0078] At this time, the G pole of the field effect tube Q101 is at a high level, which is the same as the S pole voltage of the field effect tube Q101, so the field effect tube Q101 is not turned on, and the "+5V" voltage is sent to the network "to MCU" through the fifth resistor R105. The level is high and sent to the main controller MCU for detection. When the main controller MCU detects that it is at a high level at this time, it means that the LED light of the product is not on, indicating that the product is defective. At this time, the main controller MCU sends an alarm signal;

[0079] It should be noted that this circuit mainly explains the change process of the photoresistor in the detection circuit, that is, the induction of the photoresistor, and only sends the result to the MCU, so the main controller MCU part is omitted;

[0080] When the resistance of the photoresistor sensor LDR is detected to be 5-10KΩ (equal to the light resistance of the photoresistor), the "+5V" voltage is divided by the photoresistor sensor LDR and the second resistor R102, and the voltage obtained is approximately: 5V*second resistor R102 / (LDR+second resistor R102)=2.5~3.3V,

[0081] At this time, the voltage at pin 4 of the voltage comparator U1A is greater than the voltage at pin 3 of the voltage comparator U1A, so the output of pin 1 of the voltage comparator U1A is low level, and the voltage signal of "+5V" is sent to the G pole of the field effect tube Q101 through the fourth resistor R104, and the voltage of the G pole of the field effect tube Q101 is pulled down. The voltage of the G pole of the field effect tube Q101 is lower than the voltage of the S pole, so the field effect tube Q101 is controlled to be turned on, and "+5V" passes through the fifth resistor R105, and the DS pole of the field effect tube Q101 is grounded, so the level sent to "to MCU" is low level;

[0082] When the main controller MCU detects that "to MCU" is at a low level, it indicates that the LED light of this product is lit normally. The main controller MCU sends a corresponding qualified signal and records the number of qualified products in turn, thereby improving the product production speed and ensuring the product quality, ensuring the product quality pass rate.

[0083] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A photoresistor detection circuit, characterized in that: have: A light-sensitive sensor module is configured in the detection circuit, and is used to receive different external brightness signals and convert the brightness signals into a first voltage signal; A voltage divider module, one end of which is connected to the +5V power supply terminal; A comparison module, one input end of which is connected to the output end of the light-sensitive sensor module, and is used to receive the first voltage signal. The other input end of the comparison module is connected to the output end of the voltage divider module, and is used to receive the divided second voltage signal, compare the first voltage signal with the second voltage signal, and output a control signal according to the comparison result; A switch module, whose input terminal is coupled to the output terminal of the comparison module and is used to receive the input control signal; A main controller, whose detection end is respectively connected to the output end of the switch module and the +5V power supply end; When the input control signal is at a high level, the switch module is controlled to be closed, and the detection end of the main controller is at a high level, indicating that the product to be inspected is a defective product. When the input control signal is at a low level, the switch module is controlled to be turned on, the +5V voltage is connected to the ground through the switch module, and the detection end of the main controller is at a low level, indicating that the product to be inspected is qualified.

2. The photoresistor detection circuit according to claim 1, characterized in that: The photosensitive sensing module includes a photoresistor sensor, One end of the photoresistor sensor is connected to the +5V power supply end. The other end of the photoresistor sensor is connected to an input end of the comparison module.

3. The photoresistor detection circuit according to claim 2, characterized in that: The voltage dividing module includes a third resistor and a sixth resistor connected in series, One end of the third resistor is connected to the +5V power supply terminal, The connection end of the third resistor and the sixth resistor is connected to another input end of the comparison module, One end of the sixth resistor is connected to the common end.

4. The photoresistor detection circuit according to claim 3, characterized in that: The sixth resistor is selected as an adjustable resistor.

5. The photoresistor detection circuit according to claim 3, characterized in that: The comparison module includes a voltage comparator, The non-inverting terminal of the voltage comparator is coupled to the connection terminal of the third resistor and the sixth resistor. The inverting terminal of the voltage comparator is connected to the output terminal of the photoresistor sensor. The output end of the voltage comparator is connected to the input end of the switch module.

6. The photoresistor detection circuit according to claim 5, characterized in that: The switch module includes a field effect transistor, The gate of the field effect tube is connected to the output end of the voltage comparator. The source of the field effect tube is coupled to the detection terminal of the main controller. The drain of the field effect tube is connected to the common terminal.

7. The photoresistor detection circuit according to claim 6, characterized in that: The field effect tube is selected as a P-channel MOS tube.

8. The photoresistor detection circuit according to any one of claims 1 to 6, characterized in that: The detection terminal of the main controller is connected to the +5V power supply terminal through a fifth resistor.

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