Laser acquisition and feedback circuit and particle counter

Abstract

The utility model discloses a laser acquisition and feedback circuit and a particle counter. The circuit comprises a photodiode, an isolation amplification module, a signal pulse output module, an amplification integration module and a laser tube driving module. The isolation amplification module comprises a first amplification unit and a blocking capacitor; the signal pulse output module comprises a voltage stabilizing unit and a signal output unit; the amplification integral module comprises a second amplification unit and a comparison integral unit; the first amplification unit comprises a first operational amplifier; according to the utility model, by arranging the blocking capacitor, a DC signal can be isolated, a pulse signal is output through the signal output unit, and reference line drift of a photoelectric signal does not need to be concerned. By arranging the second amplification unit, the comparison integration unit and the laser tube driving module, laser current can be increased through feedback adjustment when optical signals are insufficient, and the laser current can be reduced when the signals are high, so that the output acquisition signals can reflect the number of particles more accurately, and the particles are counted accurately.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser collection and feedback technical field especially relates to a kind of laser collection and feedback circuit and particle counter. BACKGROUND

[0002] Online particle counter receives photoelectric signal by photodiode, and carries out counting according to received photoelectric signal.

[0003] Since the baseline of photoelectric signal will drift with time, and the size of particle is determined by the peak height of photoelectric signal by counter, it will affect the judgment of particle number, and further affect the determination of oil contamination degree.In addition, the emission of laser tube is not controlled, which will also affect the size of photoelectric signal received by photodiode, thereby affecting the judgment of particle number.How to output accurate feedback signal to accurately count particles is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0004] The utility model provides a kind of laser collection and feedback circuit and particle counter, the collection signal output by the utility model embodiment can more accurately reflect particle number, to accurately count particles.

[0005] In the first aspect, the utility model embodiment provides a kind of laser collection and feedback circuit, comprising: photodiode, isolation amplification module, signal pulse output module, amplification integration module and laser tube drive module;

[0006] The isolation amplification module includes first amplification unit and direct current isolation capacitor;The signal pulse output module includes voltage stabilizing unit and signal output unit;The amplification integration module includes second amplification unit and contrast integration unit;The first amplification unit includes first operational amplifier;

[0007] The noninverting input terminal of the first operational amplifier is grounded, the anode of the photodiode is electrically connected with the noninverting input terminal of the first operational amplifier, and the cathode of the photodiode is electrically connected with the inverting input terminal of the first operational amplifier;The output terminal of the first operational amplifier is electrically connected with the first end of the direct current isolation capacitor, and the second end of the direct current isolation capacitor is electrically connected with the first end of the signal output unit;The second end of the signal output unit and the first end of the second amplification unit are both electrically connected with the output terminal of the voltage stabilizing unit, and the output terminal of the first operational amplifier is also electrically connected with the second end of the second amplification unit;

[0008] The output terminal of the second amplification unit is electrically connected with the input terminal of the contrast integration unit, the output terminal of the contrast integration unit is electrically connected with the input terminal of the laser tube drive module, the output terminal of the laser tube drive module is electrically connected with the anode of first laser tube, and the cathode of the first laser tube is grounded.

[0009] Optionally, the voltage stabilizing unit comprises a voltage stabilizing diode, and the signal output unit comprises a second operational amplifier;

[0010] The second end of the direct-current blocking capacitor is electrically connected to the inverting input terminal of the second operational amplifier, the non-inverting input terminal of the second operational amplifier is electrically connected to the negative electrode of the voltage stabilizing diode, and the positive electrode of the voltage stabilizing diode is grounded.

[0011] Optionally, the second amplifying unit comprises a third operational amplifier, and the contrast integrating unit comprises a fourth operational amplifier;

[0012] The non-inverting input terminal of the third operational amplifier is electrically connected to the output terminal of the voltage stabilizing unit, the output terminal of the first operational amplifier is also electrically connected to the inverting input terminal of the third operational amplifier, and the output terminal of the third operational amplifier is electrically connected to the non-inverting input terminal of the fourth operational amplifier.

[0013] Optionally, the laser tube driving module comprises a triode;

[0014] The base of the triode is electrically connected to the output terminal of the contrast integrating unit, the collector of the triode is electrically connected to a power supply, and the emitter of the triode is electrically connected to the positive electrode of the first laser tube.

[0015] Optionally, the first amplifying unit further comprises a first resistor and a second capacitor;

[0016] The first end of the first resistor is electrically connected to the inverting input terminal of the first operational amplifier, the second end of the first resistor is electrically connected to the output terminal of the first operational amplifier, and the second capacitor is connected in parallel with the first resistor.

[0017] Optionally, the voltage stabilizing unit further comprises a second resistor and a third capacitor, and the signal output unit further comprises a third resistor, a fourth resistor and a fourth capacitor;

[0018] The first end of the second resistor is electrically connected to a power supply, the second end of the second resistor is electrically connected to the negative electrode of the voltage stabilizing diode, and the third capacitor is connected in parallel with the voltage stabilizing diode;

[0019] The first end of the third resistor is electrically connected to the second end of the direct-current blocking capacitor, and the second end of the third resistor is electrically connected to the inverting input terminal of the second operational amplifier;

[0020] The first end of the fourth resistor is electrically connected to the inverting input terminal of the second operational amplifier, the second end of the fourth resistor is electrically connected to the output terminal of the second operational amplifier, and the fourth capacitor is connected in parallel with the fourth resistor.

[0021] Optionally, the signal output unit further comprises a fifth resistor, a sixth resistor and a fifth capacitor;

[0022] The first end of the fifth resistor is electrically connected with the negative electrode of the voltage stabilizing diode, and the second end of the fifth resistor is electrically connected with the non-inverting input terminal of the second operational amplifier;

[0023] The first end of the sixth resistor is electrically connected with the non-inverting input terminal of the second operational amplifier, and the second end of the sixth resistor is grounded, and the fifth capacitor is connected in parallel with the sixth resistor.

[0024] Optionally, the second amplifying unit further comprises a seventh resistor, an eighth resistor, a ninth resistor and a sixth capacitor, and the contrast integrating unit further comprises a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor and an eighth capacitor;

[0025] The first end of the seventh resistor is electrically connected with the output terminal of the first operational amplifier, and the second end of the seventh resistor is electrically connected with the inverting input terminal of the third operational amplifier; the first end of the eighth resistor is electrically connected with the output terminal of the voltage stabilizing unit, and the second end of the eighth resistor is electrically connected with the non-inverting input terminal of the third operational amplifier;

[0026] The first end of the ninth resistor is electrically connected with the inverting input terminal of the third operational amplifier, and the second end of the ninth resistor is electrically connected with the output terminal of the third operational amplifier, and the sixth capacitor is connected in parallel with the ninth resistor;

[0027] The first end of the tenth resistor is electrically connected with the output terminal of the third operational amplifier, and the second end of the tenth resistor and the first end of the seventh capacitor are both electrically connected with the first end of the eleventh resistor, the second end of the seventh capacitor is grounded, and the second end of the eleventh resistor is electrically connected with the non-inverting input terminal of the fourth operational amplifier;

[0028] The first end of the twelfth resistor and the first end of the eighth capacitor are both electrically connected with the inverting input terminal of the fourth operational amplifier, the second end of the twelfth resistor is grounded, and the second end of the eighth capacitor is electrically connected with the input terminal of the laser tube driving module.

[0029] Optionally, the laser tube driving module further comprises a thirteenth resistor, a fourteenth resistor and a ninth capacitor;

[0030] The first end of the thirteenth resistor is electrically connected with the output end of the contrast integration unit, and the second end of the thirteenth resistor is electrically connected with the base of the triode; the first end of the fourteenth resistor is electrically connected with the collector of the triode, and the second end of the fourteenth resistor is electrically connected with a power supply; the first end of the ninth capacitor is electrically connected with the base of the triode, and the second end of the ninth capacitor is grounded.

[0031] In a second aspect, the utility model embodiment further provides a particle counter, including laser collection and feedback circuit and first laser tube as any one of the first aspect embodiment.

[0032] The utility model embodiment provides a kind of laser collection and feedback circuit and particle counter, circuit includes: photodiode, isolation amplification module, signal pulse output module, amplification integration module and laser tube drive module;Isolation amplification module includes first amplification unit and isolation capacitor;Signal pulse output module includes voltage stabilizing unit and signal output unit;Amplification integration module includes second amplification unit and contrast integration unit;First amplification unit includes first operational amplifier;The same phase input end of first operational amplifier is grounded, and the anode of photodiode is electrically connected with the same phase input end of first operational amplifier, and the cathode of photodiode is electrically connected with the opposite phase input end of first operational amplifier;The output end of first operational amplifier is electrically connected with the first end of isolation capacitor, and the second end of isolation capacitor is electrically connected with the first end of signal output unit;The second end of signal output unit and the first end of second amplification unit are all electrically connected with the output end of voltage stabilizing unit, and the output end of first operational amplifier is also electrically connected with the second end of second amplification unit;The output end of second amplification unit is electrically connected with the input end of contrast integration unit, and the output end of contrast integration unit is electrically connected with the input end of laser tube drive module;The output end of laser tube drive module is electrically connected with the anode of first laser tube, and the cathode of first laser tube is grounded.By setting isolation capacitor, direct current signal can be isolated, and pulse signal is output by signal output unit, without caring the reference line drift of photoelectric signal.Through the setting of second amplification unit, contrast integration unit and laser tube drive module, when light signal is not enough, laser current can be increased by feedback adjustment, and when signal is high, laser current is reduced, so that the collection signal output can more accurately reflect the number of particles, to accurately count particles.

[0033] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, and is not used to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to make the technical scheme in the embodiments of the present application clearer, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 A structure schematic diagram of a laser acquisition and feedback circuit provided by the embodiment of the present application is shown in the figure.

[0036] Figure 2 A partial circuit diagram of the laser acquisition and feedback circuit provided by the embodiment of the present application is shown in the figure.

[0037] Figure 3 A partial circuit diagram of another laser acquisition and feedback circuit provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0038] In order to make the technical scheme in the embodiments of the present application clearer, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0039] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] Figure 1 A structure schematic diagram of a laser acquisition and feedback circuit provided by the embodiment of the present application is shown in the figure. Figure 1The circuit comprises a photodiode MD1, an isolation amplification module 110, a signal pulse output module 120, an amplification integration module 130 and a laser tube driving module 140. The isolation amplification module 110 comprises a first amplification unit 111 and a direct current isolation capacitor C1; the signal pulse output module 120 comprises a voltage stabilizing unit 121 and a signal output unit 122; the amplification integration module 130 comprises a second amplification unit 131 and a comparison integration unit 132; the first amplification unit 111 comprises a first operational amplifier U1.

[0041] With reference to the accompanying drawings Figure 1 , the non-inverting input terminal of the first operational amplifier U1 is grounded, the anode of the photodiode MD1 is electrically connected to the non-inverting input terminal of the first operational amplifier U1, and the cathode of the photodiode MD1 is electrically connected to the inverting input terminal of the first operational amplifier U1; the output terminal of the first operational amplifier U1 is electrically connected to the first terminal of the direct current isolation capacitor C1, and the second terminal of the direct current isolation capacitor C1 is electrically connected to the first terminal of the signal output unit 122; the second terminal of the signal output unit 122 and the first terminal of the second amplification unit 131 are both electrically connected to the output terminal of the voltage stabilizing unit 121, and the output terminal of the first operational amplifier U1 is also electrically connected to the second terminal of the second amplification unit 131. The output terminal of the second amplification unit 131 is electrically connected to the input terminal of the comparison integration unit 132, the output terminal of the comparison integration unit 132 is electrically connected to the input terminal of the laser tube driving module 140, and the output terminal of the laser tube driving module 140 is electrically connected to the anode of the first laser tube D1, and the cathode of the first laser tube D1 is grounded.

[0042] It should be noted that, with reference to the accompanying drawings Figure 1 , the laser emitted by the first laser tube D1 irradiates the photodiode MD1 to generate an optical signal, the signal is amplified by the first operational amplifier U1 and outputs a first signal TP1, the first signal TP1 is divided into two paths, the first path isolates the direct current signal in the first signal TP1 through the direct current isolation capacitor C1, the alternating current signal in the first signal TP1 is transmitted to the first terminal of the signal output unit 122, the output terminal of the voltage stabilizing unit 121 outputs a reference voltage signal S-1 to the second terminal of the signal output unit 122 and the first terminal of the second amplification unit 131, and the acquisition signal S-OUT output by the signal output unit 122 is transmitted to the signal acquisition module (not shown in the figure). The second path is compared and delayed by the second amplification unit 131, and then the current flowing through the first laser tube D1 is controlled by the comparison integration unit 132, so as to adjust the brightness of the laser.

[0043] The embodiment of the utility model discloses through setting up the direct current isolation capacitor C1, can isolate direct current signal, and the pulse signal S-OUT is exported through the signal output unit, need not care the reference line drift of photoelectric signal.Through setting up the second amplification unit 131, contrast integration unit 132 and laser tube drive module 140 can when the light signal is not enough, through feedback regulation increases laser current, signal is high and reduces laser current, thereby making the collection signal of output can more accurately reflect the particle number, thereby accurately to particle count.

[0044] The embodiment of the utility model can adjust laser intensity according to the photoelectric signal received by the photodiode MD1, filter out direct current signal, eliminate the drift of baseline over time, and the output pulse signal is more accurate.

[0045] Figure 2 Part of the circuit diagram of the laser acquisition and feedback circuit provided by the embodiment of the utility model is Figure 1 The part of the circuit diagram of the laser acquisition and feedback circuit in the above embodiment, optionally, on the basis of the above embodiment, reference Figure 2 The voltage stabilizing unit 121 includes a voltage stabilizing diode D2, and the signal output unit 122 includes a second operational amplifier U2; the second end of the direct current isolation capacitor C1 is electrically connected with the inverting input end of the second operational amplifier U2; the noninverting input end of the second operational amplifier U2 is electrically connected with the negative electrode of the voltage stabilizing diode D2, and the positive electrode of the voltage stabilizing diode D2 is grounded.

[0046] The voltage stabilizing diode D2 is used for outputting a reference voltage signal S-1, and the second operational amplifier U2 is used for outputting a collection signal S-OUT to a signal acquisition module (not shown in the figure).

[0047] Figure 3 Part of the circuit diagram of the laser acquisition and feedback circuit provided by the embodiment of the utility model is Figure 1 The part of the circuit diagram of the laser acquisition and feedback circuit in the above embodiment, optionally, on the basis of the above embodiment, reference Figures 1-3 The second amplification unit 131 includes a third operational amplifier U3, and the contrast integration unit 132 includes a fourth operational amplifier U4; the noninverting input end of the third operational amplifier U3 is electrically connected with the output end of the voltage stabilizing unit 121, the output end of the first operational amplifier U1 is also electrically connected with the inverting input end of the third operational amplifier U3, and the output end of the third operational amplifier U3 is electrically connected with the noninverting input end of the fourth operational amplifier U4.

[0048] It can be understood that the laser emitted by the first laser tube D1 irradiates on the photodiode MD1 to generate an optical signal, the signal is amplified by the first operational amplifier U1 and then a first signal TP1 is output, the first signal TP1 is divided into two paths, one of which is input to the inverting input terminal of the third operational amplifier U3, the output terminal of the voltage stabilizing unit 121 outputs a reference voltage signal S-1 to the non-inverting input terminal of the third operational amplifier U3, the third operational amplifier U3 can amplify and output after comparison and delay, and then the fourth operational amplifier U4 is used for comparison and integration, and then a laser tube driving module 140 is output, so that the current flowing through the first laser tube D1 can be controlled, and the laser brightness can be adjusted.

[0049] Optionally, based on the above embodiment, continuing to refer to Figure 3 The laser tube driving module 140 comprises a triode Q1; the base of the triode Q1 is electrically connected with the output terminal of the comparison and integration unit 132, the collector of the triode Q1 is electrically connected with the power supply VCC, and the emitter of the triode Q1 is electrically connected with the positive electrode of the first laser tube D1.

[0050] It can be understood that the triode Q1 can be a power triode, which can amplify the signal.

[0051] Optionally, based on the above embodiment, continuing to refer to Figure 2 The first amplifying unit 111 further comprises a first resistor R1 and a second capacitor C2; the first end of the first resistor R1 is electrically connected with the inverting input terminal of the first operational amplifier U1, the second end of the first resistor R1 is electrically connected with the output terminal of the first operational amplifier U1; and the second capacitor C2 is connected with the first resistor R1 in parallel.

[0052] The second capacitor C2 can provide a filtering effect to eliminate power supply high-frequency interference.

[0053] Optionally, based on the above embodiment, continuing to refer to Figure 2 The voltage stabilizing unit 121 further comprises a second resistor R2 and a third capacitor C3, and the signal output unit 122 further comprises a third resistor R3, a fourth resistor R4 and a fourth capacitor C4; the first end of the second resistor R2 is electrically connected with the power supply VCC, the second end of the second resistor R2 is electrically connected with the negative electrode of the voltage stabilizing diode D2, and the third capacitor C3 is connected with the voltage stabilizing diode D2 in parallel; the first end of the third resistor R3 is electrically connected with the second end of the direct-current blocking capacitor C1, and the second end of the third resistor R3 is electrically connected with the inverting input terminal of the second operational amplifier U2; the first end of the fourth resistor R4 is electrically connected with the inverting input terminal of the second operational amplifier U2, the second end of the fourth resistor R4 is electrically connected with the output terminal of the second operational amplifier U2, and the fourth capacitor C4 is connected with the fourth resistor R4 in parallel.

[0054] The fourth capacitor C4 can provide a filtering effect to eliminate power supply high-frequency interference.

[0055] Optionally, based on the above embodiment, continuing to refer to Figure 2 , the signal output unit 122 further comprises a fifth resistor R5, a sixth resistor R6 and a fifth capacitor C5; a first end of the fifth resistor R5 is electrically connected with the negative electrode of the voltage stabilizing diode D2, and a second end of the fifth resistor R5 is electrically connected with the non-inverting input terminal of the second operational amplifier U2; a first end of the sixth resistor R6 is electrically connected with the non-inverting input terminal of the second operational amplifier U2, and a second end of the sixth resistor R6 is grounded, and the fifth capacitor C5 is connected with the sixth resistor R6 in parallel.

[0056] The reference voltage signal S-1 output by the voltage stabilizing diode D2 is input into the non-inverting input terminal of the second operational amplifier U2 after being divided by the fifth resistor R5 and the sixth resistor R6.

[0057] Optionally, based on the above embodiment, continuing to refer to Figure 3 , the second amplifying unit 131 further comprises a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a sixth capacitor C6, and the contrast integrating unit 132 further comprises a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a seventh capacitor C7 and an eighth capacitor C8; a first end of the seventh resistor R7 is electrically connected with the output terminal of the first operational amplifier U1, and a second end of the seventh resistor R7 is electrically connected with the inverting input terminal of the third operational amplifier U3; a first end of the eighth resistor R8 is electrically connected with the output terminal of the voltage stabilizing unit 121, and a second end of the eighth resistor R8 is electrically connected with the non-inverting input terminal of the third operational amplifier U3; a first end of the ninth resistor R9 is electrically connected with the inverting input terminal of the third operational amplifier U3, a second end of the ninth resistor R9 is electrically connected with the output terminal of the third operational amplifier U3, and the sixth capacitor C6 is connected with the ninth resistor R9 in parallel; a first end of the tenth resistor R10 is electrically connected with the output terminal of the third operational amplifier U3, and a second end of the tenth resistor R10 and a first end of the seventh capacitor C7 are both electrically connected with a first end of the eleventh resistor R11, a second end of the seventh capacitor C7 is grounded, and a second end of the eleventh resistor R11 is electrically connected with the non-inverting input terminal of the fourth operational amplifier U4; a first end of the twelfth resistor R12 and a first end of the eighth capacitor C8 are both electrically connected with the inverting input terminal of the fourth operational amplifier U4, a second end of the twelfth resistor R12 is grounded, and a second end of the eighth capacitor C8 is electrically connected with the input terminal of the laser tube driving module 140.

[0058] Optionally, based on the above embodiment, continuing to refer to Figure 3The laser tube driving module 140 further comprises a thirteenth resistor R13, a fourteenth resistor R14 and a ninth capacitor C9; a first end of the thirteenth resistor R13 is electrically connected with an output end of the contrast integration unit 132, and a second end of the thirteenth resistor R13 is electrically connected with a base of the triode Q1; a first end of the fourteenth resistor R14 is electrically connected with a collector of the triode Q1, and a second end of the fourteenth resistor R14 is electrically connected with the power supply VCC; a first end of the ninth capacitor C9 is electrically connected with the base of the triode Q1, and a second end of the ninth capacitor C9 is grounded.

[0059] Optionally, on the basis of the above embodiment, continuing to refer to Figure 3 The laser tube driving module 140 further comprises a fifteenth resistor R15, a sixteenth resistor R16, a tenth capacitor C10 and an eleventh capacitor C11; a first end of the fifteenth resistor R15 is electrically connected with a non-inverting input end of the fourth operational amplifier U4, a first end of the fifteenth resistor R15 is electrically connected with a first end of the sixteenth resistor R16, and a second end of the sixteenth resistor R16 is electrically connected with the power supply VCC; a first end of the tenth capacitor C10 and a first end of the eleventh capacitor C11 are both electrically connected with the first end of the sixteenth resistor R16, and a second end of the tenth capacitor C10 and a second end of the eleventh capacitor C11 are both grounded.

[0060] The utility model embodiment through setting up the direct current capacity C1, can isolate direct current signal, the pulse signal S-OUT is outputted through the signal output unit, need not care the reference line of photoelectric signal drift. Through setting up the second amplification unit 131, contrast integration unit 132 and laser tube driving module 140 can be when the light signal is not enough, through the feedback regulation and increase laser current, signal high reduces laser current, thereby making the output collection signal can more accurately reflect the particle number, thereby accurately to the particle count. In addition, setting up the voltage stabilizing diode D2 for output reference voltage signal S-1, setting up the second operational amplifier U2 for output collection signal S-OUT transmission to signal acquisition module. Setting up the third operational amplifier U3 for signal comparison delay, amplifies a times output, again contrast integration is outputted to laser tube driving module 140 through the fourth operational amplifier U4, thereby can control the current flowing through the first laser tube D1, thereby can adjust the laser brightness. Setting up the triode Q1 for amplifying signal. Setting up the second capacitor C2 and the fourth capacitor C4 can provide the filtering effect, eliminates the power supply high frequency interference. Setting up the fifth resistor R5 and the sixth resistor R6 for dividing voltage signal S-1 that the voltage stabilizing diode D2 outputs and inputing the non-inverting input end of the second operational amplifier U2.

[0061] The utility model embodiment further provides a particle counter, including laser collection and feedback circuit and first laser tube D1 that any one embodiment provided by the above.

[0062] The laser emitted by the first laser tube D1 is irradiated onto the photodiode MD1 to generate an optical signal after passing through the oil and the slit

[0063] The granule counter provided in the embodiment of the utility model comprises the laser collection and feedback circuit and the first laser tube D1 provided in any one of the above embodiments, and therefore has the same beneficial effects.

[0064] The above specific embodiment does not constitute a limitation on the protection scope of the utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A laser acquisition and feedback circuit, characterized in that, include: Photodiode, isolation amplifier module, signal pulse output module, amplification and integration module, and laser tube driver module; The isolation amplification module includes a first amplification unit and a DC blocking capacitor; the signal pulse output module includes a voltage regulation unit and a signal output unit; the amplification integration module includes a second amplification unit and a comparison integration unit; the first amplification unit includes a first operational amplifier; The non-inverting input terminal of the first operational amplifier is grounded; the positive terminal of the photodiode is electrically connected to the non-inverting input terminal of the first operational amplifier, and the negative terminal of the photodiode is electrically connected to the inverting input terminal of the first operational amplifier; the output terminal of the first operational amplifier is electrically connected to the first terminal of the DC blocking capacitor, and the second terminal of the DC blocking capacitor is electrically connected to the first terminal of the signal output unit; the second terminal of the signal output unit and the first terminal of the second amplification unit are both electrically connected to the output terminal of the voltage regulator unit, and the output terminal of the first operational amplifier is also electrically connected to the second terminal of the second amplification unit. The output terminal of the second amplification unit is electrically connected to the input terminal of the comparison integration unit, the output terminal of the comparison integration unit is electrically connected to the input terminal of the laser tube driving module, the output terminal of the laser tube driving module is electrically connected to the positive terminal of the first laser tube, and the negative terminal of the first laser tube is grounded.

2. The laser acquisition and feedback circuit according to claim 1, characterized in that, The voltage regulation unit includes a Zener diode, and the signal output unit includes a second operational amplifier; The second terminal of the DC blocking capacitor is electrically connected to the inverting input terminal of the second operational amplifier; the non-inverting input terminal of the second operational amplifier is electrically connected to the negative terminal of the Zener diode, and the positive terminal of the Zener diode is grounded.

3. The laser acquisition and feedback circuit according to claim 1, characterized in that, The second amplification unit includes a third operational amplifier, and the comparison integration unit includes a fourth operational amplifier; The non-inverting input of the third operational amplifier is electrically connected to the output of the voltage regulator unit. The output of the first operational amplifier is also electrically connected to the inverting input of the third operational amplifier. The output of the third operational amplifier is electrically connected to the non-inverting input of the fourth operational amplifier.

4. The laser acquisition and feedback circuit according to claim 1, characterized in that, The laser tube driving module includes a transistor; The base of the transistor is electrically connected to the output terminal of the comparison and integration unit, the collector of the transistor is electrically connected to the power supply, and the emitter of the transistor is electrically connected to the positive terminal of the first laser tube.

5. The laser acquisition and feedback circuit according to claim 1, characterized in that, The first amplification unit also includes a first resistor and a second capacitor; The first end of the first resistor is electrically connected to the inverting input terminal of the first operational amplifier, and the second end of the first resistor is electrically connected to the output terminal of the first operational amplifier; the second capacitor is connected in parallel with the first resistor.

6. The laser acquisition and feedback circuit according to claim 2, characterized in that, The voltage regulation unit further includes a second resistor and a third capacitor, and the signal output unit further includes a third resistor, a fourth resistor, and a fourth capacitor; The first end of the second resistor is electrically connected to the power supply, the second end of the second resistor is electrically connected to the negative terminal of the Zener diode, and the third capacitor is connected in parallel with the Zener diode; The first end of the third resistor is electrically connected to the second end of the DC blocking capacitor, and the second end of the third resistor is electrically connected to the inverting input terminal of the second operational amplifier. The first end of the fourth resistor is electrically connected to the inverting input terminal of the second operational amplifier, the second end of the fourth resistor is electrically connected to the output terminal of the second operational amplifier, and the fourth capacitor is connected in parallel with the fourth resistor.

7. The laser acquisition and feedback circuit according to claim 2, characterized in that, The signal output unit also includes a fifth resistor, a sixth resistor, and a fifth capacitor; The first end of the fifth resistor is electrically connected to the negative terminal of the Zener diode, and the second end of the fifth resistor is electrically connected to the non-inverting input terminal of the second operational amplifier. The first end of the sixth resistor is electrically connected to the non-inverting input of the second operational amplifier, the second end of the sixth resistor is grounded, and the fifth capacitor is connected in parallel with the sixth resistor.

8. The laser acquisition and feedback circuit according to claim 3, characterized in that, The second amplification unit further includes a seventh resistor, an eighth resistor, a ninth resistor, and a sixth capacitor; the comparison integration unit further includes a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor, and an eighth capacitor. The first end of the seventh resistor is electrically connected to the output terminal of the first operational amplifier, and the second end of the seventh resistor is electrically connected to the inverting input terminal of the third operational amplifier; the first end of the eighth resistor is electrically connected to the output terminal of the voltage regulator unit, and the second end of the eighth resistor is electrically connected to the non-inverting input terminal of the third operational amplifier. The first end of the ninth resistor is electrically connected to the inverting input terminal of the third operational amplifier, the second end of the ninth resistor is electrically connected to the output terminal of the third operational amplifier, and the sixth capacitor is connected in parallel with the ninth resistor; The first end of the tenth resistor is electrically connected to the output terminal of the third operational amplifier. The second end of the tenth resistor and the first end of the seventh capacitor are both electrically connected to the first end of the eleventh resistor. The second end of the seventh capacitor is grounded. The second end of the eleventh resistor is electrically connected to the non-inverting input terminal of the fourth operational amplifier. The first end of the twelfth resistor and the first end of the eighth capacitor are both electrically connected to the inverting input of the fourth operational amplifier. The second end of the twelfth resistor is grounded, and the second end of the eighth capacitor is electrically connected to the input of the laser tube driving module.

9. The laser acquisition and feedback circuit according to claim 4, characterized in that, The laser tube driving module also includes a thirteenth resistor, a fourteenth resistor, and a ninth capacitor; The first end of the thirteenth resistor is electrically connected to the output terminal of the comparison integration unit, and the second end of the thirteenth resistor is electrically connected to the base of the transistor; the first end of the fourteenth resistor is electrically connected to the collector of the transistor, and the second end of the fourteenth resistor is electrically connected to the power supply; the first end of the ninth capacitor is electrically connected to the base of the transistor, and the second end of the ninth capacitor is grounded.

10. A particle counter, characterized in that, It includes the laser acquisition and feedback circuit and the first laser tube as described in any one of claims 1-9.

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