A sensitivity adjustment circuit for a PIR sensor lamp

Abstract

This utility model provides a sensitivity adjustment circuit for a PIR sensor lamp, characterized by including: a digital-to-analog converter chip U4 and a microcontroller, wherein the OUT pin of the microcontroller outputs to a switching transistor Q1 to output a control signal to control the switching transistor Q1 to conduct, thereby closing the relay to conduct the live wire; it also includes a photodiode CDS, a potentiometer R14, and a potentiometer R21, wherein the photodiode CDS, potentiometer R14, and potentiometer R21 are effective when the digital-to-analog converter chip U4 is working in different modes, and are input to the corresponding pin of the microcontroller through a voltage divider of the photodiode CDS, potentiometer R14, or potentiometer R21, so that the microcontroller outputs a control signal to the switching transistor Q1 or changes the sensing distance of the probe or changes the output time of the control signal.

Description

Technical Field

[0001] This utility model relates to a sensitivity adjustment circuit for a PIR sensor lamp. Background Technology

[0002] Most PIR sensor lights currently on the market use common control solutions such as direct sensing or DIP switches to control the sensing distance. Furthermore, existing technologies typically offer three adjustable sensing distance settings: LOW, NORMAL, and HIGH. This means that the range of adjustable sensing sensitivity is relatively limited and cannot be precisely adjusted. Utility Model Content

[0003] The main technical problem to be solved by this utility model is to provide a sensitivity adjustment circuit for a PIR sensor lamp, which can achieve precise sensitivity adjustment.

[0004] To solve the above-mentioned technical problems, this utility model provides a sensitivity adjustment circuit for a PIR sensor lamp, including: a digital-to-analog converter chip U4 and a microcontroller. The OUT pin of the microcontroller outputs to the switching transistor Q1 to output a control signal to control the switching transistor Q1 to conduct, thereby driving the relay to close and conduct the live wire.

[0005] It also includes a photodiode CDS, potentiometer R14, and potentiometer R21. The photodiode CDS, potentiometer R14, and potentiometer R21 take effect when the digital-to-analog converter chip U4 is working in different modes. They are input to the corresponding pins of the microcontroller through the voltage divider of the photodiode CDS, potentiometer R14, or potentiometer R21, so that the microcontroller outputs a control signal to the switching transistor Q1 or changes the sensing distance of the probe or changes the output time of the control signal.

[0006] In a preferred embodiment: the OUT pin of the microcontroller is output to the base of the switching transistor Q1, the emitter of the switching transistor Q1 is connected to GND, and the collector is connected to the relay.

[0007] In a preferred embodiment: the output terminal of the photodiode CDS is connected to the CDS pin of the digital-to-analog converter chip U4, so as to obtain the voltage divider Vcds of the photodiode CDS through the digital-to-analog converter chip U4; the microcontroller stores a first reference voltage Vref1 and a second reference voltage Vref2.

[0008] The microcontroller compares Vcds with the first reference voltage Vref1 and the second reference voltage Vref2:

[0009] If Vcds is greater than Vref1, the microcontroller will not output a control signal to the switching transistor Q1.

[0010] If Vcds is less than Vref2, the microcontroller outputs a control signal to the switching transistor Q1.

[0011] If Vref1 > Vcds > Vref2, the microcontroller will maintain the state of the previous stage.

[0012] In a preferred embodiment: the first reference voltage Vref1 and the second reference voltage Vref2 are affected by potentiometer R14, which is connected between the power supply voltage and GND, and a resistor R12 is connected between potentiometer R14 and the power supply voltage. One end of potentiometer R14 connected to resistor R12 is connected to the LUX pin of the microcontroller to change the first reference voltage Vref1 and the second reference voltage Vref2.

[0013] In a preferred embodiment: the potentiometer R21 is connected to the SENSE pin of the digital-to-analog converter chip U4.

[0014] In a preferred embodiment: the potentiometer R13 is connected to the TIME pin of the digital-to-analog converter chip U4.

[0015] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0016] This invention provides a sensitivity adjustment circuit for a PIR sensor lamp. Utilizing the voltage divider principle of potentiometers, different voltage levels are adjusted and compared with a microcontroller reference voltage to determine whether the lamp is working. Three potentiometers correspond to the sensing distance, delay time, and photosensitive level, respectively. Because of the high precision of the potentiometers, the desired parameters can be accurately controlled electronically. Furthermore, since it directly uses a relay to control the continuity of the live wire, it can be widely applied to various lighting power supplies. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of a preferred embodiment of the present invention. Detailed Implementation

[0018] To make the technical solution and features of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only for illustrating this utility model and are not intended to limit the scope of this utility model. After reading this utility model, any modifications of this utility model by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0019] refer to Figure 1 This embodiment provides a sensitivity adjustment circuit for a PIR sensor lamp, including: a digital-to-analog converter chip U4 and a microcontroller. The OUT pin of the microcontroller outputs to the switching transistor Q1 to output a control signal to control the switching transistor Q1 to conduct, thereby closing the relay to conduct the live wire.

[0020] It also includes a photodiode CDS, potentiometer R14, and potentiometer R21. The photodiode CDS, potentiometer R14, and potentiometer R21 take effect when the digital-to-analog converter chip U4 is working in different modes. They are input to the corresponding pins of the microcontroller through the voltage divider of the photodiode CDS, potentiometer R14, or potentiometer R21, so that the microcontroller outputs a control signal to the switching transistor Q1 or changes the sensing distance of the probe or changes the output time of the control signal.

[0021] Specifically, the OUT pin of the microcontroller outputs to the base of the switching transistor Q1, the emitter of the switching transistor Q1 is connected to GND, and the collector is connected to the relay.

[0022] The digital-to-analog converter chip U4 can operate in three modes: AUTO, D2D, and ON-TIME. In ON-TIME mode, the microcontroller does not need to detect the voltage of the potentiometer. It directly outputs a control signal to the switching transistor Q1 through the OUT pin, which turns on the switching transistor Q1, closes the relay, connects the live wire, and powers on the lamp.

[0023] In D2D mode, the photosensitive sensitivity can be adjusted. For this purpose, the output terminal of the photodiode CDS is connected to the CDS pin of the digital-to-analog converter chip U4, so that the voltage Vcds of the photodiode CDS can be obtained through the digital-to-analog converter chip U4; the microcontroller stores a first reference voltage Vref1 and a second reference voltage Vref2.

[0024] The microcontroller compares Vcds with the first reference voltage Vref1 and the second reference voltage Vref2:

[0025] If Vcds is greater than Vref1, the microcontroller will not output a control signal to the switching transistor Q1.

[0026] If Vcds is less than Vref2, the microcontroller outputs a control signal to the switching transistor Q1.

[0027] If Vref1 > Vcds > Vref2, the microcontroller will maintain the state of the previous stage.

[0028] Therefore, the photosensitive sensitivity can be adjusted by simply changing the values ​​of the first reference voltage Vref1 and the second reference voltage Vref2. Thus, in this embodiment, the first reference voltage Vref1 and the second reference voltage Vref2 are affected by potentiometer R14, which is connected between the power supply voltage and GND. A resistor R12 is connected between the potentiometer R14 and the power supply voltage. One end of the potentiometer R14 connected to the resistor R12 is connected to the LUX pin of the microcontroller to change the first reference voltage Vref1 and the second reference voltage Vref2.

[0029] In AUTO mode, the sensing distance and delay time of the probe can be adjusted. Specifically, potentiometer R21 is connected to the SENSE pin of the digital-to-analog converter chip U4, and potentiometer R13 is connected to the TIME pin of the digital-to-analog converter chip U4. By changing potentiometer R21, the voltage at pin SENSE7 of U4 changes, thereby causing U4 to process the probe signal and change the probe sensing distance. Potentiometer R13 changes the TIME voltage; the microcontroller U4 detects the voltage change and controls the output voltage at pin OUT for a specific duration, thus changing the delay time.

[0030] The above is only one specific embodiment of the present utility model, but the design concept of the present utility model is not limited thereto. Any non-substantial modifications made to the present utility model using this concept shall be deemed as an infringement of the protection scope of the present utility model.

Claims

1. A sensitivity adjustment circuit for a PIR sensor lamp, characterized in that... include: The digital-to-analog converter chip U4 and the microcontroller are provided. The OUT pin of the microcontroller outputs to the switching transistor Q1 to output a control signal to control the switching transistor Q1 to conduct, thereby closing the relay to connect the live wire. It also includes a photodiode CDS, potentiometer R14, and potentiometer R21. The photodiode CDS, potentiometer R14, and potentiometer R21 take effect when the digital-to-analog converter chip U4 is working in different modes. They are input to the corresponding pins of the microcontroller through the voltage divider of the photodiode CDS, potentiometer R14, or potentiometer R21, so that the microcontroller outputs a control signal to the switching transistor Q1 or changes the sensing distance of the probe or changes the output time of the control signal.

2. The sensitivity adjustment circuit for a PIR sensor lamp according to claim 1, characterized in that: The OUT pin of the microcontroller outputs to the base of the switching transistor Q1, the emitter of the switching transistor Q1 is connected to GND, and the collector is connected to the relay.

3. The sensitivity adjustment circuit for a PIR sensor lamp according to claim 1, characterized in that: The output terminal of the photodiode CDS is connected to the CDS pin of the digital-to-analog converter chip U4 so as to obtain the voltage Vcds of the photodiode CDS through the digital-to-analog converter chip U4; the microcontroller stores the first reference voltage Vref1 and the second reference voltage Vref2. The microcontroller compares Vcds with the first reference voltage Vref1 and the second reference voltage Vref2: If Vcds is greater than Vref1, the microcontroller will not output a control signal to the switching transistor Q1. If Vcds is less than Vref2, the microcontroller outputs a control signal to the switching transistor Q1. If Vref1 > Vcds > Vref2, the microcontroller will maintain the state of the previous stage.

4. The sensitivity adjustment circuit for a PIR sensor lamp according to claim 3, characterized in that: The first reference voltage Vref1 and the second reference voltage Vref2 are affected by the potentiometer R14, which is connected between the power supply voltage and GND. A resistor R12 is connected between the potentiometer R14 and the power supply voltage. One end of the potentiometer R14 connected to the resistor R12 is connected to the LUX pin of the microcontroller to change the first reference voltage Vref1 and the second reference voltage Vref2.

5. The sensitivity adjustment circuit for a PIR sensor lamp according to claim 1, characterized in that: The potentiometer R21 is connected to the SENSE pin of the digital-to-analog converter chip U4.

6. The sensitivity adjustment circuit for a PIR sensor lamp according to claim 1, characterized in that: The potentiometer R13 is connected to the TIME pin of the digital-to-analog converter chip U4.

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