A kind of high sensitivity IR detection system based on Linear Driving
Technical field
The utility model relates to electronic applications, specifically refers to a kind of high sensitivity IR detection system based on Linear Driving.
Background technology
There is the advantage of its uniqueness due to infrared detection technique thus make it obtain investigation and application widely in military and national defense and civil area, especially under the traction of military requirement and the promotion of correlation technique development, infrared detection technique as new and high technology will be more extensive in the application in future, and status is more important.
Infrared eye sightless infrared energy is transformed into the energy transfer machine that other is easy to the form of energy measured, current infra-red detection is with through being widely used in the middle of people live, the infra-red thermometer commonly used as people uses infra-red detection technology exactly, and it brings and very large makes profit.But current used IR detection system sensitivity is not high and result of detection is not accurate, easily makes people cause erroneous judgement.
Utility model content
The purpose of this utility model is to overcome the high and result of detection of current IR detection system sensitivity water not defect accurately, provides a kind of and reacts fast, that accuracy is high high sensitivity IR detection system.
The following technical scheme of the purpose of this utility model realizes: a kind of high sensitivity IR detection system based on Linear Driving, by sensor U, the linear drive circuit be connected with sensor U, the power circuit be all connected with linear drive circuit and two-stage low-pass filtering amplifying circuit, the comparator circuit be connected with two-stage low-pass filtering amplifying circuit, forms with the change-over circuit that comparator circuit is connected with power circuit simultaneously, described linear drive circuit is by driving chip U1, triode Q3, triode Q4, triode Q5, triode Q6, positive pole is connected with sensor U, the polar capacitor C9 that negative pole is connected with the IN1 pin of driving chip U1 after resistance R11, one end is connected with the collector of triode Q3, the resistance R12 that the other end is connected with the base stage of triode Q5 after resistance R13, positive pole is connected with the base stage of triode Q3, the polar capacitor C11 that negative pole is connected with the IN1 pin of driving chip U1, positive pole is connected with the IN2 pin of driving chip U1, the polar capacitor C10 of minus earth, one end is connected with the emitter of triode Q3, the resistance R15 that the other end is connected with the base stage of triode Q4, one end is connected with the base stage of triode Q4, the resistance R14 that the other end is connected with the base stage of triode Q5, N pole is connected with the collector of triode Q3, the diode D3 that P pole is connected with the collector of triode Q4, positive terminal is connected with the collector of triode Q3, the not gate K that end of oppisite phase is connected with triode Q6 collector, one end is connected with triode Q6 emitter, the resistance R17 that the other end is connected with the emitter of triode Q5 after resistance R16, the end of oppisite phase of P pole Sheffer stroke gate K is connected, the diode D4 that N pole is connected with the tie point of resistance R16 with resistance R17 forms, the VCC pin of described driving chip U1 is connected with the base stage of triode Q3, END pin ground connection, OUT pin are connected with the collector of triode Q4, the collector of triode Q4 is also connected with the base stage of triode Q6, its emitter is connected with the base stage of triode Q5, the grounded collector of triode Q5, the N pole of diode D4 is connected with two-stage low-pass filtering amplifying circuit.
Described power circuit is by triode Q1, and polar capacitor C6, polar capacitor C7, resistance R5, resistance R6 form; The emitter of triode Q1 is connected with the N pole of diode D4, its base stage ground connection, its collector after polar capacitor C6 are connected with power supply after resistance R6, and the positive pole of polar capacitor C7 is connected with the collector of triode Q1 after resistance R5, minus earth.
Described two-stage low-pass filtering amplifying circuit is by amplifier P1, amplifier P2, positive pole is connected with the N pole of diode D4 the polar capacitor C1 of minus earth, one end is connected with the positive pole of polar capacitor C1, the resistance R1 that the other end is then connected with the normal phase input end of amplifier P1, negative pole is connected with the negative pole of polar capacitor C1, the polar capacitor C2 that positive pole is connected with the inverting input of amplifier P1 after resistance R2, be serially connected in the polar capacitor C3 between amplifier P1 inverting input and output terminal, negative pole is connected with the output terminal of amplifier P1, the polar capacitor C4 that positive pole is connected with the inverting input of amplifier P2 after resistance R3, the resistance R4 be in parallel with resistance R3, and positive pole is connected with the inverting input of amplifier P2, the polar capacitor C5 that negative pole is connected with the output terminal of amplifier P2 forms, the normal phase input end of described amplifier P2 is all connected with comparator circuit with output terminal.
Described comparator circuit is by amplifier P3, amplifier P4, triode Q2, the resistance R7 that one end is connected with the normal phase input end of amplifier P2, the other end is then connected with the normal phase input end of amplifier P3, the diode D1 that P pole is connected with the emitter of triode Q2, N pole is connected with the normal phase input end of amplifier P4, be serially connected in the polar capacitor C8 between the inverting input of amplifier P4 and output terminal, one end is connected with the output terminal of amplifier P4, resistance R9 that the other end is connected with the output terminal of amplifier P3 after resistance R8 forms; The base stage of described triode Q2 is connected with the output terminal of amplifier P2, collector is connected with the inverting input of amplifier P3, and resistance R8 is connected with change-over circuit with the tie point of resistance R9.
Described change-over circuit comprises amplifier P5, amplifier P6, diode D2, resistance R10; The P pole of diode D2 is connected with the output terminal of amplifier P5, N pole is connected with the normal phase input end of amplifier P6, the normal phase input end of amplifier P5 is connected with resistance R6, inverting input is connected with the tie point of resistance R9 with resistance R8, inverting input ground connection after resistance R10 of amplifier P6.
Described sensor U is the pyroelectric infrared sensor of dual-element type.
The utility model compared with prior art, has the following advantages and beneficial effect:
(1) the utility model adopts dual-element type pyroelectric infrared sensor, makes that the receiving sensitivity of detection system is higher, reaction is faster.
(2) the utility model is provided with two-stage low-pass filtering amplifying circuit, the distortionless amplification of Weak frequency signal that it can receive sensor, thus makes the testing result of detection system more accurate.
(3) the utility model is provided with linear drive circuit, the driving detection system that it can be stable.
Accompanying drawing explanation
Fig. 1 is one-piece construction schematic diagram of the present utility model.
Fig. 2 is linear drive circuit structural representation of the present utility model.
Embodiment
Below in conjunction with specific embodiment, the utility model is described in further detail, but embodiment of the present utility model is not limited thereto.
Embodiment
As shown in Figure 1, high sensitivity IR detection system based on Linear Driving of the present utility model, by sensor U, the linear drive circuit be connected with sensor U, the power circuit be all connected with linear drive circuit and two-stage low-pass filtering amplifying circuit, the comparator circuit be connected with two-stage low-pass filtering amplifying circuit, forms with the change-over circuit that comparator circuit is connected with power circuit simultaneously.
As shown in Figure 2, described linear drive circuit is by driving chip U1, triode Q3, triode Q4, triode Q5, triode Q6, positive pole is connected with sensor U, the polar capacitor C9 that negative pole is connected with the IN1 pin of driving chip U1 after resistance R11, one end is connected with the collector of triode Q3, the resistance R12 that the other end is connected with the base stage of triode Q5 after resistance R13, positive pole is connected with the base stage of triode Q3, the polar capacitor C11 that negative pole is connected with the IN1 pin of driving chip U1, positive pole is connected with the IN2 pin of driving chip U1, the polar capacitor C10 of minus earth, one end is connected with the emitter of triode Q3, the resistance R15 that the other end is connected with the base stage of triode Q4, one end is connected with the base stage of triode Q4, the resistance R14 that the other end is connected with the base stage of triode Q5, N pole is connected with the collector of triode Q3, the diode D3 that P pole is connected with the collector of triode Q4, positive terminal is connected with the collector of triode Q3, the not gate K that end of oppisite phase is connected with triode Q6 collector, one end is connected with triode Q6 emitter, the resistance R17 that the other end is connected with the emitter of triode Q5 after resistance R16, the end of oppisite phase of P pole Sheffer stroke gate K is connected, the diode D4 that N pole is connected with the tie point of resistance R16 with resistance R17 forms, the VCC pin of described driving chip U1 is connected with the base stage of triode Q3, END pin ground connection, OUT pin are connected with the collector of triode Q4, the collector of triode Q4 is also connected with the base stage of triode Q6, its emitter is connected with the base stage of triode Q5, the grounded collector of triode Q5, the N pole of diode D4 is connected with two-stage low-pass filtering amplifying circuit.Linear drive circuit, the driving detection system that it can be stable.In order to ensure implementation result, described driving chip U is preferably LM387 integrated chip, its highly sensitive and low price.
Described power circuit is by triode Q1, and polar capacitor C6, polar capacitor C7, resistance R5, resistance R6 form; The emitter of triode Q1 is connected with the N pole of diode D4, its base stage ground connection, its collector after polar capacitor C6 are connected with power supply after resistance R6, and the positive pole of polar capacitor C7 is connected with the collector of triode Q1 after resistance R5, minus earth.
Described two-stage low-pass filtering amplifying circuit is by amplifier P1, amplifier P2, positive pole is connected with the N pole of diode D4 the polar capacitor C1 of minus earth, one end is connected with the positive pole of polar capacitor C1, the resistance R1 that the other end is then connected with the normal phase input end of amplifier P1, negative pole is connected with the negative pole of polar capacitor C1, the polar capacitor C2 that positive pole is connected with the inverting input of amplifier P1 after resistance R2, be serially connected in the polar capacitor C3 between amplifier P1 inverting input and output terminal, negative pole is connected with the output terminal of amplifier P1, the polar capacitor C4 that positive pole is connected with the inverting input of amplifier P2 after resistance R3, the resistance R4 be in parallel with resistance R3, and positive pole is connected with the inverting input of amplifier P2, the polar capacitor C5 that negative pole is connected with the output terminal of amplifier P2 forms, the normal phase input end of described amplifier P2 is all connected with comparator circuit with output terminal.
Described comparator circuit is by amplifier P3, amplifier P4, triode Q2, the resistance R7 that one end is connected with the normal phase input end of amplifier P2, the other end is then connected with the normal phase input end of amplifier P3, the diode D1 that P pole is connected with the emitter of triode Q2, N pole is connected with the normal phase input end of amplifier P4, be serially connected in the polar capacitor C8 between the inverting input of amplifier P4 and output terminal, one end is connected with the output terminal of amplifier P4, resistance R9 that the other end is connected with the output terminal of amplifier P3 after resistance R8 forms; The base stage of described triode Q2 is connected with the output terminal of amplifier P2, collector is connected with the inverting input of amplifier P3, and resistance R8 is connected with change-over circuit with the tie point of resistance R9.
Described change-over circuit comprises amplifier P5, amplifier P6, diode D2, resistance R10; The P pole of diode D2 is connected with the output terminal of amplifier P5, N pole is connected with the normal phase input end of amplifier P6, the normal phase input end of amplifier P5 is connected with resistance R6, inverting input is connected with the tie point of resistance R9 with resistance R8, inverting input ground connection after resistance R10 of amplifier P6.
Described sensor U is the pyroelectric infrared sensor of dual-element type.
As mentioned above, just well the utility model can be realized.