CN213398944U

CN213398944U - Novel infrared detector

Info

Publication number: CN213398944U
Application number: CN202022769841.2U
Authority: CN
Inventors: 曹小华
Original assignee: Zhejiang University City College ZUCC
Current assignee: Zhejiang University City College ZUCC
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-06-08
Anticipated expiration: 2030-11-25

Abstract

The utility model relates to a novel infrared detector, include: the device comprises a power supply circuit, a voltage comparison circuit and a timing alarm output circuit. The utility model has the advantages that: the utility model relates to a receiving detector of an active infrared alarm system, which is suitable for the space areas needing precaution, such as an enclosure wall, a lawn and the like; the system can be combined with other detectors for use, is safe and reliable, has good economy, has long monitoring distance, and can reach more than one hundred meters; the detector has simple circuit and high stability. The used elements are fewer, and the light weight and the low cost are realized; the detector has the advantages of small volume, light weight, low power consumption, simple and convenient operation and installation, high quality, low price and the like.

Description

Novel infrared detector

Technical Field

The utility model relates to an infrared alarm field especially includes a domestic infrared alarm trigger device based on integrated fortune is put.

Background

With the progress of society and the improvement of living standard of people, a safety alarm system becomes an important infrastructure for cell management in China. In practical application, an alarm in the safety alarm system needs to be provided with a plurality of detector interfaces, including but not limited to alarm signals sent by infrared and microwave detectors, temperature detectors, gas leakage detectors and the like, wherein the alarm signals can be externally emitted through light or sound, and alarm information can be transmitted to a control room or communication equipment through communication equipment so as to be processed in time and reduce loss.

The detection technology is developed rapidly in recent years, mainly represented by the application of a composite detector, and two or more different detectors are applied at the same time, such as an ultrasonic infrared composite detector, a microwave infrared composite detector and the like, and the combination of multiple detection technologies can greatly reduce the false alarm rate of the system. The existing alarm system products in China are more and more abundant, and can be divided into small-scale, medium-scale and large-scale alarm systems according to the scale of the alarm system.

The alarm detector is the receiving part of the anti-theft alarm system, consists of a sensor and a signal processor, is a device for detecting the invasion behavior of an intruder, and is the core of the anti-theft alarm system. The working modes are distinguished into an active mode and a passive mode. The active alarm detector is a detection device which transmits a detection signal with certain energy by a detector and receives the signal to analyze and judge. Under normal working condition, the active alarm detector receives a stable detection signal, and the alarm circuit is not triggered under the condition. When an intrusion event occurs, the intrusion behavior destroys the stably received detection signal, the signal received by the alarm detector changes, and the alarm detector sends out an alarm signal when the change of the signal reaches a certain value.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the not enough among the prior art, provide a novel infrared detector.

This kind of novel infrared detector includes: the device comprises a power supply circuit, a voltage comparison circuit and a timing alarm output circuit; the power circuit comprises a power transformer, a bridge rectifier circuit and a capacitor C₁(ii) a The voltage comparator circuit comprises a photosensitive diode and a voltage comparator IC₁And integrated operational amplifier IC₂(ii) a The timing alarm output circuit comprises a rheostat R_p2Capacitor C₂BL and triode VT alarm device₁And triode VT₂(ii) a The power supply is stepped down by a power transformer in the power circuit, rectified by a bridge rectifier circuit, and passed through a capacitor C₁Filtering and supplying the filtered signal to a three-terminal regulator; the die of the photodiode is a PN junction with photosensitive characteristicsUnidirectional conductivity, applying reverse voltage during operation; current-voltage comparator IC₁Before flipping, the voltage comparator IC₁The output end of the operational amplifier is low level, and the operational amplifier IC is integrated₂The output end of the transistor is high level, the triode VT₂To be conducted; when the infrared ray received by the photosensitive diode is cut off due to the obstruction of an intruder, the photosensitive diode is cut off, and the voltage comparator IC₁The input voltage at the positive input terminal is increased, and the voltage comparator IC₁Flip, triode VT₂Conducting, triode VT₁And triode VT₂Meanwhile, the alarm device BL outputs an alarm signal, and the alarm information can be transmitted to a control room or communication equipment through communication equipment in practical application; current-voltage comparator IC₁After turning over, the varistor R_p2And a capacitor C₂The timer is started when the capacitor C is started₁When the charged voltage reaches the threshold potential, the integrated operational amplifier IC₂Turnover integrated operational amplifier IC₂Output low level enable triode VT₁Turning off and stopping outputting the alarm signal; when the shielding disappears, the voltage comparator IC₁Reset, capacitor C₁By means of a varistor R_p2Voltage-feedback comparator IC₁Discharging, regulating rheostat R_p2The resistance value of the alarm signal is changed; adjustable rheostat R_p1Change voltage comparator IC₁The sensitivity of the detector when triggering an alarm is adjusted.

Preferably, the capacitor C is connected in series with the bridge rectifier circuit and the power transformer₁A capacitor C connected in parallel at two ends of the power transformer and the bridge rectifier circuit₁One end of the three-terminal voltage stabilizer is connected with one leading-out terminal of the three-terminal voltage stabilizer and a capacitor C₁The other end of the three-terminal regulator is grounded with the other leading-out terminal of the three-terminal regulator; the bridge rectifier circuit is composed of four diodes VD₁～VD₄Composition is carried out; the rest leading-out terminal of the three-terminal voltage stabilizer is respectively connected with a rheostat R_p1A fixed contact of, a resistor R₁One-terminal, voltage comparator IC₁The inverting input terminal and the resistor R of₃One-terminal integrated operational amplifier IC₂And one end of the alarm device BLL; rheostat R_p1The other fixed contact of the switch is connected with the cathode of the photosensitive diode, and the anode of the photosensitive diode is grounded; rheostat R_p1The movable contact of which is connected with a voltage comparator IC₁The non-inverting input terminal of (1); resistance R₁The other end is divided into two paths and respectively connected with a voltage comparator IC₁And the resistor R₂One terminal, resistance R₂The other end is grounded; voltage comparator IC₁The non-inverting input terminal of the voltage comparator IC is grounded₁The output end of the three-way switch is respectively connected with a rheostat R_p2A fixed contact, a varistor R_p2Moving contact and resistor R₆One terminal, resistance R₆The other end is connected with a triode VT₂A base electrode of (1); rheostat R_p2The other fixed contact is respectively connected with the integrated operational amplifier IC in two paths₂Non-inverting input terminal and capacitor C₂One terminal of (1), capacitor C₂The other end of the first and second electrodes is grounded; resistance R₃The other end is divided into two paths to be respectively connected with an integrated operational amplifier IC₂And the resistor R₄One terminal, resistance R₄The other end is grounded; integrated operational amplifier IC₂The non-inverting input end of the integrated operational amplifier IC is grounded₂Is connected with the resistor R₅One terminal, resistance R₅The other end is connected with a triode VT₁A base electrode of (1); triode VT₁The collector of the triode VT is connected with the other end of the BL of the alarm device₁Emitter of the transistor VT₂Collector of (2), triode VT₂Emitter connection resistance R₇One terminal, resistance R₇The other end is grounded.

Preferably, in order to eliminate the interference of external infrared rays and conveniently receive the infrared rays emitted by the infrared laser, the infrared inlet of the photodiode in the laser circuit board is a cylindrical pipeline.

Preferably, the alarm device BL is a buzzer or a light emitting device, and the voltage comparator IC₁The output end of the light-emitting diode is connected with a buzzer or a light-emitting device.

Preferably, the three-terminal regulator is 7812, the photosensitive diode is PT204-66 infrared photosensitive diode, and the voltage comparator IC₁And integrated operational amplifier IC₂Are both dual operational amplifiers LM 358.

Preferably, the power supply is commercial power or a storage battery.

The utility model has the advantages that: the utility model relates to a receiving detector of an active infrared alarm system, which is suitable for the space areas needing precaution, such as an enclosure wall, a lawn and the like; the system can be combined with other detectors for use, is safe and reliable, has good economy, has long monitoring distance, and can reach more than one hundred meters; the detector has simple circuit and high stability. The used elements are fewer, and the light weight and the low cost are realized; the detector has the advantages of small volume, light weight, low power consumption, simple and convenient operation and installation, high quality, low price and the like.

Drawings

Fig. 1 is a schematic circuit diagram of the novel infrared detector.

Detailed Description

The present invention will be further described with reference to the following examples. The following description of the embodiments is merely provided to aid in understanding the invention. It should be noted that, for those skilled in the art, the present invention can be modified in several ways without departing from the principle of the present invention, and these modifications and modifications also fall into the protection scope of the claims of the present invention.

As an embodiment, a novel infrared detector circuit shown in fig. 1 is mounted on a universal circuit board:

capacitor C₁(220uF,25V) is connected in parallel at two ends of the power transformer and the bridge rectifier circuit, and a capacitor C₁One end of the three-terminal regulator 7812 is connected with a leading-out terminal and a capacitor C₁The other end of the three-terminal regulator is grounded with the other leading-out terminal of the three-terminal regulator; the bridge rectifier circuit is composed of four diodes VD₁～VD₄Composition is carried out; the rest leading-out terminal of the three-terminal voltage stabilizer is respectively connected with a rheostat R_p1(100K omega) a fixed contact, a resistor R₁(47K Ω) one terminal, voltage comparator IC₁(LM358) inverting input terminal, resistor R₃(68K omega) one end, integrated operational amplifier IC₂(LM358) an inverting input and one end of an alarm BLL; rheostat R_p1The other fixed contact of the switch is connected with the cathode of a photosensitive diode (PT204-66 type infrared photosensitive diode)The positive electrode of the photosensitive diode is grounded; rheostat R_p1The movable contact of which is connected with a voltage comparator IC₁The non-inverting input terminal of (1); resistance R₁The other end is divided into two paths and respectively connected with a voltage comparator IC₁And the resistor R₂(22 K.OMEGA.) one terminal, resistance R₂The other end is grounded;

voltage comparator IC₁The non-inverting input terminal of the voltage comparator IC is grounded₁The output end of the three-way switch is respectively connected with a rheostat R_p2(1M omega) one fixed contact, rheostat R_p2Moving contact and resistor R₆(1 K.OMEGA.) one terminal, resistance R₆The other end is connected with a triode VT₂(9014) A base electrode of (1); rheostat R_p2The other fixed contact is respectively connected with the integrated operational amplifier IC in two paths₂Non-inverting input terminal and capacitor C₂One terminal of (220pF,25V), capacitor C₂The other end of the first and second electrodes is grounded; resistance R₃The other end is divided into two paths to be respectively connected with an integrated operational amplifier IC₂And the resistor R₄(100 K.OMEGA.) one terminal, resistance R₄The other end is grounded; integrated operational amplifier IC₂The non-inverting input end of the integrated operational amplifier IC is grounded₂Is connected with the resistor R₅One terminal, resistance R₅The other end is connected with a triode VT₁(9018) A base electrode of (1); triode VT₁The collector of the triode VT is connected with the other end of the BL of the alarm device₁Emitter of the transistor VT₂Collector of (2), triode VT₂Emitter connection resistance R₇One terminal, resistance R₇The other end is grounded.

The power supply (220V commercial power) in the power circuit is stepped down (15V) by the power transformer, rectified by the bridge rectifier circuit and passed through the capacitor C₁The filtered (220uF,25V) is supplied to a three-terminal regulator 7812, 12V direct current power required by the whole circuit is supplied by the three-terminal regulator 7812, and in practical application, the power supply part in the circuit can be replaced by a storage battery. The core of the photosensitive diode is a PN junction with photosensitive characteristics, has unidirectional conductivity and applies reverse voltage during operation.

And (3) detecting by using punctate infrared rays emitted by a 980nm near-infrared semiconductor laser to check whether the infrared detector is normal.

1) The laser is aligned to PT204-66 type infrared photosensitive diode of the novel infrared detector of the embodiment in the forward direction, and rheostat R is adjusted_p1(100K Ω) change voltage comparator IC₁The sensitivity of the detector when triggering an alarm is adjusted;

2) when the infrared ray received by the photosensitive diode is cut off due to the obstruction of an intruder, the photosensitive diode is cut off, and the voltage comparator IC₁The input voltage at the positive input terminal is increased, and the voltage comparator IC₁Flip, triode VT₂Conducting, triode VT₁And triode VT₂Meanwhile, the alarm device is conducted and outputs an alarm signal, and the alarm information can be transmitted to a control room or communication equipment through communication equipment in practical application;

3) after 2 minutes of alarm, the rheostat R_p2And a capacitor C₂The timer is started when the capacitor C is started₁When the charged voltage reaches the threshold potential, the integrated operational amplifier IC₂Turnover integrated operational amplifier IC₂Output low level enable triode VT₁Turning off and stopping outputting the alarm signal;

4) changing the distance between the detector and the laser to align the light path; through actual detection, when the distance between the detector and the laser reaches 200 meters, the detector can still sensitively detect the infrared signal emitted by the infrared laser.

Claims

1. A novel infrared detector is characterized by comprising: the device comprises a power supply circuit, a voltage comparison circuit and a timing alarm output circuit; the power circuit comprises a power transformer, a bridge rectifier circuit and a capacitor C₁(ii) a The voltage comparator circuit comprises a photosensitive diode and a voltage comparator IC₁And integrated operational amplifier IC₂(ii) a The timing alarm output circuit comprises a rheostat R_p2Capacitor C₂BL and triode VT alarm device₁And triode VT₂；

After the power supply is stepped down by power transformer in power circuit, it is rectified by bridge rectifier circuit and passed through capacitorC₁Filtering and supplying the filtered signal to a three-terminal regulator; applying reverse voltage when the photosensitive diode works;

current-voltage comparator IC₁Before flipping, the voltage comparator IC₁The output end of the operational amplifier is low level, and the operational amplifier IC is integrated₂The output end of the transistor is high level, the triode VT₂To be conducted;

when the infrared ray received by the photosensitive diode is cut off due to the obstruction of an intruder, the photosensitive diode is cut off, and the voltage comparator IC₁The input voltage at the positive input terminal is increased, and the voltage comparator IC₁Flip, triode VT₂Conducting, triode VT₁And triode VT₂Meanwhile, the alarm device BL outputs an alarm signal;

current-voltage comparator IC₁After turning over, the varistor R_p2And a capacitor C₂The timer is started when the capacitor C is started₁When the charged voltage reaches the threshold potential, the integrated operational amplifier IC₂Turnover integrated operational amplifier IC₂Output low level enable triode VT₁Turning off and stopping outputting the alarm signal;

when the shielding disappears, the voltage comparator IC₁Reset, capacitor C₁By means of a varistor R_p2Voltage-feedback comparator IC₁Discharging, regulating rheostat R_p2The resistance value of the alarm signal is changed; adjustable rheostat R_p1Change voltage comparator IC₁The sensitivity of the detector when triggering an alarm is adjusted.

2. The new infrared detector as set forth in claim 1, characterized in that:

after the power transformer is connected with the bridge rectifier circuit in series, the capacitor C₁A capacitor C connected in parallel at two ends of the power transformer and the bridge rectifier circuit₁One end of the three-terminal voltage stabilizer is connected with one leading-out terminal of the three-terminal voltage stabilizer and a capacitor C₁The other end of the three-terminal regulator is grounded with the other leading-out terminal of the three-terminal regulator; the bridge rectifier circuit is composed of four diodes VD₁～VD₄Composition is carried out; the rest leading-out terminal of the three-terminal voltage stabilizer is respectively connected with a rheostat R_p1A fixed contact of, a resistor R₁One-terminal, voltage comparator IC₁The inverting input terminal and the resistor R of₃One-terminal integrated operational amplifier IC₂And one end of the alarm device BLL; rheostat R_p1The other fixed contact of the switch is connected with the cathode of the photosensitive diode, and the anode of the photosensitive diode is grounded; rheostat R_p1The movable contact of which is connected with a voltage comparator IC₁The non-inverting input terminal of (1); resistance R₁The other end is divided into two paths and respectively connected with a voltage comparator IC₁And the resistor R₂One terminal, resistance R₂The other end is grounded;

voltage comparator IC₁The non-inverting input terminal of the voltage comparator IC is grounded₁The output end of the three-way switch is respectively connected with a rheostat R_p2A fixed contact, a varistor R_p2Moving contact and resistor R₆One terminal, resistance R₆The other end is connected with a triode VT₂A base electrode of (1); rheostat R_p2The other fixed contact is respectively connected with the integrated operational amplifier IC in two paths₂Non-inverting input terminal and capacitor C₂One terminal of (1), capacitor C₂The other end of the first and second electrodes is grounded; resistance R₃The other end is divided into two paths to be respectively connected with an integrated operational amplifier IC₂And the resistor R₄One terminal, resistance R₄The other end is grounded; integrated operational amplifier IC₂The non-inverting input end of the integrated operational amplifier IC is grounded₂Is connected with the resistor R₅One terminal, resistance R₅The other end is connected with a triode VT₁A base electrode of (1); triode VT₁The collector of the triode VT is connected with the other end of the BL of the alarm device₁Emitter of the transistor VT₂Collector of (2), triode VT₂Emitter connection resistance R₇One terminal, resistance R₇The other end is grounded.

3. The new infrared detector as set forth in claim 1, characterized in that: the infrared inlet of the photosensitive diode in the circuit is a cylindrical pipeline.

4. The novel infrared detector of claim 1The method is characterized in that: the alarm device BL is a buzzer or a light-emitting device, and a voltage comparator IC₁The output end of the light-emitting diode is connected with a buzzer or a light-emitting device.

5. The new infrared detector as set forth in claim 2, characterized in that: the three-terminal regulator has model number of 7812, the photosensitive diode is PT204-66 type infrared photosensitive diode, and the voltage comparator IC₁And integrated operational amplifier IC₂Are both dual operational amplifiers LM 358.

6. The new infrared detector as set forth in claim 1, characterized in that: the power supply is commercial power or a storage battery.