Human body pyroelectric infrared sensor signal amplification circuit

By setting up a charging circuit in the human body's pyroelectric infrared sensor signal amplification circuit and assisting charging, the problem of long preheating time in the prior art is solved, and faster startup time and higher efficiency are achieved.

CN222547450UActive Publication Date: 2025-02-28OPTEX (DONGGUAN) CO LTD +1
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Patent Information

Application Number
CN202421115477.X
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-05-22
Publication Date
2025-02-28
Estimated Expiration
2034-05-22

AI Technical Summary

Technical Problem

The existing human pyroelectric infrared sensor signal amplification circuit has a long preheating time and low efficiency, which affects the start time and efficiency of the infrared detector.

Method used

A human body pyroelectric infrared sensor signal amplifier circuit is designed. By setting up a charging circuit at the output end of the signal amplifier circuit, it is connected to the central control chip port. After the circuit is powered on, the high-level signal is output inversely to the output end of the signal amplifier circuit through the charging circuit, assisting in charging the working capacitor, thereby reducing preheating time.

Benefits of technology

Through auxiliary charging technology, the preheating time of the signal amplification circuit is significantly shortened, the preheating time between 50% and 70% can be shortened, and the starting efficiency of the infrared detector is improved.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a signal amplification circuit of a human body pyroelectric infrared sensor, which comprises a sensor circuit, a first-stage amplification circuit with a signal input end electrically connected with the sensor circuit, and a second-stage amplification circuit with a signal input end electrically connected with a signal output end of the first-stage amplification circuit, the central control chip and the charging circuit are electrically connected with the signal output end of the second-stage amplifying circuit, and the signal amplifying circuit power input circuit is electrically connected with the sensor circuit and the second-stage amplifying circuit. A signal amplification circuit working capacitor is arranged between the first-stage amplification circuit and the second-stage amplification circuit, when the signal amplification circuit of the human body pyroelectric infrared sensor is in cold start, the charging circuit outputs a high level, and the second-stage amplification circuit assists in charging the signal amplification circuit working capacitor. Therefore, the charging time of the working capacitor of the signal amplification circuit is reduced, and the preheating time of the signal amplification circuit is reduced. And the preheating time can be shortened by 50-70%.
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Description

Technical Field

[0001] The utility model relates to the field of infrared signal detection, in particular to a human body pyroelectric infrared sensor signal amplification circuit. Background Art

[0002] Before the human body pyroelectric infrared sensor starts working, it is necessary to preheat the human body pyroelectric infrared sensor signal amplifier circuit, that is, when the circuit is powered on, the capacitor of the human body pyroelectric infrared sensor amplifier circuit must be charged. After the capacitor is charged to the working voltage, the human body pyroelectric infrared sensor amplifier circuit enters a normal working state. This preheating time often takes tens of seconds, which makes the infrared detector using the human body pyroelectric infrared sensor have a longer startup time, affecting the efficiency of the infrared detector. Utility Model Content

[0003] The utility model aims to provide a human body pyroelectric infrared sensor signal amplification circuit to solve the problems of long preheating time and low efficiency of the existing human body pyroelectric infrared sensor signal amplification circuit in view of the deficiencies of the existing technology.

[0004] The technical solution adopted by the utility model to achieve the above-mentioned purpose is:

[0005] A human body pyroelectric infrared sensor signal amplification circuit comprises a sensor circuit, a first-stage amplification circuit whose signal input end is electrically connected to the sensor circuit, a second-stage amplification circuit whose signal input end is electrically connected to the signal output end of the first-stage amplification circuit, a central control chip and a charging circuit electrically connected to the signal output end of the second-stage amplification circuit, and a signal amplification circuit power input circuit electrically connected to the sensor circuit and the second-stage amplification circuit; a signal amplification circuit working capacitor is provided between the first-stage amplification circuit and the second-stage amplification circuit, and when the human body pyroelectric infrared sensor signal amplification circuit is cold-started, the charging circuit outputs a high level, and the signal amplification circuit working capacitor is auxiliary charged through the second-stage amplification circuit, thereby reducing the charging time of the signal amplification circuit working capacitor, and further reducing the preheating time of the signal amplification circuit.

[0006] The working capacitor of the signal amplifying circuit is C20.

[0007] The charging circuit includes an IC chip U6, wherein the second pin of the IC chip U6 is connected to one end of a resistor R47, the sixth pin of the IC chip U6, one end of a capacitor C46 and the emitter of a transistor Q2, the base of the transistor Q2 is connected to one end of a resistor R45 and one end of a resistor R46, the third pin of the IC chip U6 is connected to the gate of a MOS transistor Q3, the drain of the MOS transistor Q3 is connected to one end of a resistor R48, the other end of the resistor R48, the other end of the resistor R45, the other end of the resistor R47, the fourth pin and the eighth pin of the IC chip U6 are connected to a 5V power supply, the source of the MOS transistor Q3 is connected to the output end of the second-stage operational signal amplification circuit, the first pin of the IC chip U6, the other end of the capacitor C46, ​​the collector of the transistor Q2 and the other end of the resistor R46 are grounded.

[0008] The first-stage amplifier circuit includes an operational amplifier U4A, wherein the first pin of the operational amplifier U4A is connected to one end of a resistor R8, one end of a capacitor C26, one end of a resistor R11 and one end of a diode D2, the second pin of the operational amplifier U4A is connected to one end of a capacitor C22, the other end of a flashlight C26, the other end of a resistor R11, the other end of a diode D2 and one end of a resistor R14, the third pin of the operational amplifier U4A is connected to the other end of a capacitor C22, one end of a capacitor C21 and one end of a resistor R6, the other end of a resistor R6 is connected to the sensor circuit, the other end of a resistor R14 is connected to one end of a capacitor C28, the other end of a capacitor C28 and the other end of a capacitor C21 are both grounded, and the other end of a resistor R8 is connected to one end of a capacitor C20.

[0009] The second-stage amplifier circuit includes an operational amplifier U4B, one end of a resistor R7, one end of a capacitor C27 and one end of a resistor R12 connected to the seventh pin of the operational amplifier U4B, the sixth pin of the operational amplifier U4B is connected to the other end of the capacitor C27, the other end of the resistor R12, one end of the capacitor C18 and the other end of the capacitor C20, the fifth pin of the operational amplifier U4B is connected to the other end of the capacitor C18, one end of the resistor R3, one end of the capacitor C15 and one end of the resistor R5, the other end of the resistor R3 is connected to the signal amplifier circuit power input circuit, the eighth pin of the operational amplifier U4B is connected to the signal amplifier circuit power input circuit and one end of the capacitor C14, the other end of the resistor R7 is connected to one end of the capacitor C23 and the central control chip, the fourth pin of the operational amplifier U4B, the other end of the capacitor C15, the other end of the resistor R5, the other end of the capacitor C14 and the other end of the capacitor C23 are grounded.

[0010] The signal amplifying circuit power input circuit includes an inductor L4 connected to a 5V power supply at one end, the other end of the inductor L4 is connected to the second-stage operational amplifier circuit and one end of the resistor R1, the other end of the resistor R1 is connected to one end of the three-terminal filter F1, the other end of the three-terminal filter F1 is connected to one end of the capacitor C3, one end of the capacitor C4 and one end of the resistor R4, the other end of the capacitor C4, the other end of the capacitor C3 and the third end of the three-terminal filter F1 are all grounded.

[0011] The sensor circuit includes a human body pyroelectric infrared sensor PD1, the second pin of the human body pyroelectric infrared sensor PD1 is connected to one end of a capacitor C16, one end of a capacitor C17 and a power input circuit of a signal amplifying circuit, the third pin of the human body pyroelectric infrared sensor PD1 is connected to the other end of the capacitor C17, one end of a resistor R6, one end of a capacitor C19 and one end of a resistor R9, the other end of the capacitor C16, the other end of the capacitor C19, the other end of the resistor R9 and the first pin of the human body pyroelectric infrared sensor PD1 are all grounded.

[0012] The beneficial effects of the utility model are as follows: the human body pyroelectric infrared sensor signal amplifying circuit of the utility model provides a charging circuit at the output end of the signal amplifying circuit. After the circuit is powered on, a high-level signal is reversely output to the output end of the signal amplifying circuit for a period of time to charge the working capacitor through the charging circuit, thereby accelerating the charging process of the working capacitor of the human body pyroelectric infrared sensor signal amplifying circuit, thereby shortening the preheating time.

[0013] The utility model can shorten the preheating time of the existing human body pyroelectric infrared sensor signal amplifying circuit by 50% to 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the circuit diagram of the utility model;

[0015] Figure 2 It is the central control chip of the utility model. DETAILED DESCRIPTION

[0016] Example: See Figure 1 to Figure 2The present embodiment provides a human body pyroelectric infrared sensor signal amplifying circuit, which includes a sensor circuit, a first-stage amplifying circuit whose signal input end is electrically connected to the sensor circuit, a second-stage amplifying circuit whose signal input end is electrically connected to the signal output end of the first-stage amplifying circuit, a central control chip and a charging circuit electrically connected to the signal output end of the second-stage amplifying circuit, and a signal amplifying circuit power input circuit electrically connected to the sensor circuit and the second-stage amplifying circuit; a signal amplifying circuit working capacitor is provided between the first-stage amplifying circuit and the second-stage amplifying circuit, and when the human body pyroelectric infrared sensor signal amplifying circuit is cold-started, the charging circuit outputs a high level, and the signal amplifying circuit working capacitor is assisted in charging through the second-stage amplifying circuit, thereby reducing the charging time of the signal amplifying circuit working capacitor, and further reducing the preheating time of the signal amplifying circuit.

[0017] The central control chip used in this embodiment is of the model R5F100GCAFB#V0.

[0018] The output end of the human body pyroelectric infrared sensor signal amplifier circuit is connected to the 19th pin (ADC) of the R5F100GCAFB#V0 central control chip.

[0019] The working capacitor of the signal amplifying circuit is C20.

[0020] The charging circuit includes an IC chip U6, wherein the second pin of the IC chip U6 is connected to one end of a resistor R47, the sixth pin of the IC chip U6, one end of a capacitor C46 and the emitter of a transistor Q2, the base of the transistor Q2 is connected to one end of a resistor R45 and one end of a resistor R46, the third pin of the IC chip U6 is connected to the gate of a MOS transistor Q3, the drain of the MOS transistor Q3 is connected to one end of a resistor R48, the other end of the resistor R48, the other end of the resistor R45, the other end of the resistor R47, the fourth pin and the eighth pin of the IC chip U6 are connected to a 5V power supply, the source of the MOS transistor Q3 is connected to the output end of the second-stage operational signal amplification circuit, the first pin of the IC chip U6, the other end of the capacitor C46, ​​the collector of the transistor Q2 and the other end of the resistor R46 are grounded.

[0021] The first-stage amplifier circuit includes an operational amplifier U4A, wherein the first pin of the operational amplifier U4A is connected to one end of a resistor R8, one end of a capacitor C26, one end of a resistor R11 and one end of a diode D2, the second pin of the operational amplifier U4A is connected to one end of a capacitor C22, the other end of a flashlight C26, the other end of a resistor R11, the other end of a diode D2 and one end of a resistor R14, the third pin of the operational amplifier U4A is connected to the other end of a capacitor C22, one end of a capacitor C21 and one end of a resistor R6, the other end of a resistor R6 is connected to the sensor circuit, the other end of a resistor R14 is connected to one end of a capacitor C28, the other end of a capacitor C28 and the other end of a capacitor C21 are both grounded, and the other end of a resistor R8 is connected to one end of a capacitor C20.

[0022] The second-stage amplifier circuit includes an operational amplifier U4B, one end of a resistor R7, one end of a capacitor C27 and one end of a resistor R12 connected to the seventh pin of the operational amplifier U4B, the sixth pin of the operational amplifier U4B is connected to the other end of the capacitor C27, the other end of the resistor R12, one end of the capacitor C18 and the other end of the capacitor C20, the fifth pin of the operational amplifier U4B is connected to the other end of the capacitor C18, one end of the resistor R3, one end of the capacitor C15 and one end of the resistor R5, the other end of the resistor R3 is connected to the signal amplifier circuit power input circuit, the eighth pin of the operational amplifier U4B is connected to the signal amplifier circuit power input circuit and one end of the capacitor C14, the other end of the resistor R7 is connected to one end of the capacitor C23 and the central control chip, the fourth pin of the operational amplifier U4B, the other end of the capacitor C15, the other end of the resistor R5, the other end of the capacitor C14 and the other end of the capacitor C23 are grounded.

[0023] The signal amplifying circuit power input circuit includes an inductor L4 connected to a 5V power supply at one end, the other end of the inductor L4 is connected to the second-stage operational amplifier circuit and one end of the resistor R1, the other end of the resistor R1 is connected to one end of the three-terminal filter F1, the other end of the three-terminal filter F1 is connected to one end of the capacitor C3, one end of the capacitor C4 and one end of the resistor R4, the other end of the capacitor C4, the other end of the capacitor C3 and the third end of the three-terminal filter F1 are all grounded.

[0024] The sensor circuit includes a human body pyroelectric infrared sensor PD1, the second pin of the human body pyroelectric infrared sensor PD1 is connected to one end of a capacitor C16, one end of a capacitor C17 and a power input circuit of a signal amplifying circuit, the third pin of the human body pyroelectric infrared sensor PD1 is connected to the other end of the capacitor C17, one end of a resistor R6, one end of a capacitor C19 and one end of a resistor R9, the other end of the capacitor C16, the other end of the capacitor C19, the other end of the resistor R9 and the first pin of the human body pyroelectric infrared sensor PD1 are all grounded.

[0025] In the human body pyroelectric infrared sensor signal amplifier circuit of this embodiment, under normal charging conditions, one route is the signal amplifier circuit power input circuit, which charges the working capacitor C20 through the operational amplifier U4A and the resistor R8, another route is the signal amplifier circuit power input circuit, which charges the working capacitor C20 through the 6th pin of the operational amplifier U4B, and another route is the charging circuit that emits a high level to the output end of the human body pyroelectric infrared sensor signal amplifier circuit, which charges the working capacitor C20 through the resistor R7 and the resistor R12, thereby realizing the rapid charging of the working capacitor C20. When the working capacitor C20 reaches the working voltage, the charging circuit stops outputting the high level, and the human body pyroelectric infrared sensor signal amplifier circuit enters the normal working state.

[0026] In this embodiment, the central control chip can also transmit a high level to the output end of the human body pyroelectric infrared sensor signal amplifier circuit, and then charge the working capacitor C20 through the resistor R7 and the resistor R12, thereby realizing the rapid charging of the working capacitor C20. When the working capacitor C20 reaches the working voltage, the central control chip stops outputting the high level, and the human body pyroelectric infrared sensor signal amplifier circuit enters the normal working state.

[0027] However, the above description is only a preferred feasible embodiment of the present utility model and is not intended to limit the patent scope of the present utility model. Therefore, all other embodiments recorded in the present utility model and equivalent changes made thereto are included in the protection scope of the present utility model.

Claims

1. A human body pyroelectric infrared sensor signal amplification circuit, characterized in that: It includes a sensor circuit, a first-stage amplifier circuit whose signal input end is electrically connected to the sensor circuit, a second-stage amplifier circuit whose signal input end is electrically connected to the signal output end of the first-stage amplifier circuit, a central control chip and a charging circuit electrically connected to the signal output end of the second-stage amplifier circuit, and a signal amplifier circuit power input circuit electrically connected to the sensor circuit and the second-stage amplifier circuit; a signal amplifier circuit working capacitor is provided between the first-stage amplifier circuit and the second-stage amplifier circuit, and when the human body pyroelectric infrared sensor signal amplifier circuit is cold-started, the charging circuit outputs a high level, and the signal amplifier circuit working capacitor is auxiliary charged through the second-stage amplifier circuit, thereby reducing the charging time of the signal amplifier circuit working capacitor, and further reducing the preheating time of the signal amplifier circuit.

2. The human body pyroelectric infrared sensor signal amplification circuit according to claim 1, characterized in that: The working capacitor of the signal amplifying circuit is C20.

3. The human body pyroelectric infrared sensor signal amplification circuit according to claim 1, characterized in that: The charging circuit includes an IC chip U6, wherein the second pin of the IC chip U6 is connected to one end of a resistor R47, the sixth pin of the IC chip U6, one end of a capacitor C46 and the emitter of a transistor Q2, the base of the transistor Q2 is connected to one end of a resistor R45 and one end of a resistor R46, the third pin of the IC chip U6 is connected to the gate of a MOS transistor Q3, the drain of the MOS transistor Q3 is connected to one end of a resistor R48, the other end of the resistor R48, the other end of the resistor R45, the other end of the resistor R47, the fourth pin and the eighth pin of the IC chip U6 are connected to a 5V power supply, the source of the MOS transistor Q3 is connected to the output end of the second-stage operational signal amplification circuit, the first pin of the IC chip U6, the other end of the capacitor C46, ​​the collector of the transistor Q2 and the other end of the resistor R46 are grounded.

4. The human body pyroelectric infrared sensor signal amplification circuit according to claim 1, characterized in that: The first-stage amplifier circuit includes an operational amplifier U4A, wherein the first pin of the operational amplifier U4A is connected to one end of a resistor R8, one end of a capacitor C26, one end of a resistor R11 and one end of a diode D2, the second pin of the operational amplifier U4A is connected to one end of a capacitor C22, the other end of a flashlight C26, the other end of a resistor R11, the other end of a diode D2 and one end of a resistor R14, the third pin of the operational amplifier U4A is connected to the other end of a capacitor C22, one end of a capacitor C21 and one end of a resistor R6, the other end of a resistor R6 is connected to the sensor circuit, the other end of a resistor R14 is connected to one end of a capacitor C28, the other end of a capacitor C28 and the other end of a capacitor C21 are both grounded, and the other end of a resistor R8 is connected to one end of a capacitor C20.

5. The human body pyroelectric infrared sensor signal amplification circuit according to claim 1, characterized in that: The second-stage amplifier circuit includes an operational amplifier U4B, one end of a resistor R7, one end of a capacitor C27 and one end of a resistor R12 connected to the seventh pin of the operational amplifier U4B, the sixth pin of the operational amplifier U4B is connected to the other end of the capacitor C27, the other end of the resistor R12, one end of the capacitor C18 and the other end of the capacitor C20, the fifth pin of the operational amplifier U4B is connected to the other end of the capacitor C18, one end of the resistor R3, one end of the capacitor C15 and one end of the resistor R5, the other end of the resistor R3 is connected to the signal amplifier circuit power input circuit, the eighth pin of the operational amplifier U4B is connected to the signal amplifier circuit power input circuit and one end of the capacitor C14, the other end of the resistor R7 is connected to one end of the capacitor C23 and the central control chip, the fourth pin of the operational amplifier U4B, the other end of the capacitor C15, the other end of the resistor R5, the other end of the capacitor C14 and the other end of the capacitor C23 are grounded.

6. The human body pyroelectric infrared sensor signal amplification circuit according to claim 1, characterized in that: The signal amplifying circuit power input circuit includes an inductor L4 connected to a 5V power supply at one end, the other end of the inductor L4 is connected to the second-stage operational amplifier circuit and one end of the resistor R1, the other end of the resistor R1 is connected to one end of the three-terminal filter F1, the other end of the three-terminal filter F1 is connected to one end of the capacitor C3, one end of the capacitor C4 and one end of the resistor R4, the other end of the capacitor C4, the other end of the capacitor C3 and the third end of the three-terminal filter F1 are all grounded.

7. The human body pyroelectric infrared sensor signal amplifier circuit according to claim 1, characterized in that: The sensor circuit includes a human body pyroelectric infrared sensor PD1, the second pin of the human body pyroelectric infrared sensor PD1 is connected to one end of a capacitor C16, one end of a capacitor C17 and a power input circuit of a signal amplifying circuit, the third pin of the human body pyroelectric infrared sensor PD1 is connected to the other end of the capacitor C17, one end of a resistor R6, one end of a capacitor C19 and one end of a resistor R9, the other end of the capacitor C16, the other end of the capacitor C19, the other end of the resistor R9 and the first pin of the human body pyroelectric infrared sensor PD1 are all grounded.