CN102393384B - Photosensitive diode-based turbidity measuring circuit - Google Patents
Photosensitive diode-based turbidity measuring circuit Download PDFInfo
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- CN102393384B CN102393384B CN 201110265535 CN201110265535A CN102393384B CN 102393384 B CN102393384 B CN 102393384B CN 201110265535 CN201110265535 CN 201110265535 CN 201110265535 A CN201110265535 A CN 201110265535A CN 102393384 B CN102393384 B CN 102393384B
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Abstract
The invention discloses a photosensitive diode-based turbidity measuring circuit. Square signals are generated by a 555 timer, and are used for controlling the working state of a light-emitting diode, the light-emitting diode and a photosensitive diode convert the turbidity of liquid into a photoelectric signal to be measured, an operational amplifier converts a weak current signal into a voltage signal and amplifies the voltage signal, and a voltage signal capable of undergoing analog/digital (A/D) conversion is generated through phase compensation and filtration in the converting process. A square signal generating circuit with the duty cycle of 1:2 generated by the 555 timer controls the on/off of a triode so as to modulate a light source; therefore, the interference of natural light can be avoided.
Description
Technical field
The invention belongs to the Detection of Weak Signals field, especially a kind of turbidity measuring circuit based on photodiode.
Background technology
Now the turbidity transducer overwhelming majority of usefulness is photonephelometer, and the light-receiving that light source is sent with the device of photoelectric cell and so on also is converted to electric signal and processes.The turbidity concept all will be applied in many industries.Just need strict control water quality in the waterworks, to guarantee the healthy of people, suspension can increase the incidence probability of infectious disease too much in the potable water.The hydrometric station also needs water quality is monitored.And the atmospheric researcher needs the pollution level of many air to study, the toxic emission of various factories, and the use of hydraulic valve all will be studied the pollution level of using medium.Also have Beer Brewage, medicament production, manufacturing film, production glass, manufacturing paper all will in production procedure, monitor the medium turbidity.Turbidity also is the concept of often using in medical research, for example all will use the concept of turbidity to the mensuration of various cells, number of bacteria and various content of material in the blood.The turbidity monitoring is carried out in the inland river, can be understood the silt loss situation, the content of microorganism in water pollution condition and the water.The turbidity monitoring is carried out in offshore waters, can understand the content of suspended biological.Deep-marine-environment is carried out the turbidity monitoring, can survey suspended biological content and seabed abnormal conditions, seek mineral deposit or interested environment.
Summary of the invention
The present invention is directed to the deficiencies in the prior art, proposed a kind of turbidity measuring circuit based on photodiode.The technical scheme that technical solution problem of the present invention adopts is:
A kind of turbidity measuring circuit based on photodiode comprises radiating circuit and receiving circuit two parts.
Radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R 10, the 11 resistance R 11, the 12 resistance R 12, the 13 resistance R 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3, NE555P timer U4.
7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4,4 pin of the 9th resistance R 9 one termination NE555P timer U4,7 pin of another ground termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4, the base stage of another termination the first triode Q1,2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection, 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4, other end ground connection, the 1 pin ground connection of NE555P timer U4,2 pin with are connected pin and connect, 4 pin and 8 pin connect voltage and are the power supply of+3.3V, the collector of the 11 resistance R 11 1 terminations the first triode Q1, the in-phase input end of another termination the 3rd operational amplifier U3, the in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection, the homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3, other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection, the base stage of the first triode Q1 connects the tenth resistance R 10, collector connects the 11 resistance R 11, emitter connects voltage and is the power supply of+3.3V, the base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3, diode D1 is penetrated in the collector sending and receiving, emitter connects the inverting input of the 3rd operational amplifier U3, the inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3, other end ground connection, emitting diode D1 one termination voltage is+power supply of 5V, the collector of another termination the second triode Q2, the homophase power input of the 3rd operational amplifier U3 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
Receiving circuit partly comprises the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the first phase place building-out capacitor C1, the second filter capacitor C2, the 3rd filter capacitor C3, the 4th filter capacitor C4, the 5th filter capacitor C5, the 6th filter capacitor C6, the 7th filter capacitor C7, the 8th filter capacitor C8, the 9th filter capacitor C9, the tenth filter capacitor C10, reception diode D2, the first operational amplifier U1, the second operational amplifier U2.
The first resistance R 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the first capacitor C 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the inverting input of the second resistance R 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the inverting input of the second capacitor C 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the output terminal of the 3rd resistance R 3 one terminations the first operational amplifier U1, the inverting input of another termination the second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations the first operational amplifier U1, other end ground connection, the inverting input of the 4th capacitor C 4 one terminations the second operational amplifier U2, other end ground connection, the homophase power input of the 6th capacitor C 6 one terminations the first operational amplifier U1, other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations the first operational amplifier U1, other end ground connection, the 5th resistance R 5 one end ground connection, the in-phase input end of another termination the second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the 4th resistance R 4 one end ground connection, the inverting input of another termination the second operational amplifier U2, the inverting input of the 6th resistance R 6 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the output terminal of the 7th resistance R 7 one terminations the second operational amplifier U2, the 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations the second operational amplifier U2, other end ground connection, the inverting power supplies input end of the 9th capacitor C 9 one terminations the second operational amplifier U2, other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip, the termination voltage of reception diode D2 is+power supply of 5V, the inverting input of another termination the first operational amplifier U1, the homophase power input of the first operational amplifier U1 connects voltage and is the power supply of+3.3V, inverting power supplies input termination voltage is-power supply of 3.3V, the homophase power input of the second operational amplifier U2 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
The present invention can avoid the impact of natural light and receiving device dark current, by each parameter in the circuit is set, carries out repeatedly filtering and phase compensation, so that this circuit has preferably noise robustness.
Description of drawings
Fig. 1 is the radiating circuit of circuit diagram of the present invention;
Fig. 2 is the receiving circuit of circuit diagram of the present invention.
Embodiment
The invention will be further described below in conjunction with accompanying drawing.
A kind of turbidity measuring circuit based on photodiode comprises radiating circuit and receiving circuit two parts.
As shown in Figure 1, radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R 10, the 11 resistance R 11, the 12 resistance R 12, the 13 resistance R 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3, NE555P timer U4.
7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4,4 pin of the 9th resistance R 9 one termination NE555P timer U4,7 pin of another ground termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4, the base stage of another termination the first triode Q1,2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection, 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4, other end ground connection, the 1 pin ground connection of NE555P timer U4,2 pin with are connected pin and connect, 4 pin and 8 pin connect voltage and are the power supply of+3.3V, the collector of the 11 resistance R 11 1 terminations the first triode Q1, the in-phase input end of another termination the 3rd operational amplifier U3, the in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection, the homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3, other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection, the base stage of the first triode Q1 connects the tenth resistance R 10, collector connects the 11 resistance R 11, emitter connects voltage and is the power supply of+3.3V, the base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3, diode D1 is penetrated in the collector sending and receiving, emitter connects the inverting input of the 3rd operational amplifier U3, the inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3, other end ground connection, emitting diode D1 one termination voltage is+power supply of 5V, the collector of another termination the second triode Q2, the homophase power input of the 3rd operational amplifier U3 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
As shown in Figure 2, receiving circuit partly comprises the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the first phase place building-out capacitor C1, the second filter capacitor C2, the 3rd filter capacitor C3, the 4th filter capacitor C4, the 5th filter capacitor C5, the 6th filter capacitor C6, the 7th filter capacitor C7, the 8th filter capacitor C8, the 9th filter capacitor C9, the tenth filter capacitor C10, reception diode D2, the first operational amplifier U1, the second operational amplifier U2.
The first resistance R 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the first capacitor C 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the inverting input of the second resistance R 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the inverting input of the second capacitor C 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the output terminal of the 3rd resistance R 3 one terminations the first operational amplifier U1, the inverting input of another termination the second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations the first operational amplifier U1, other end ground connection, the inverting input of the 4th capacitor C 4 one terminations the second operational amplifier U2, other end ground connection, the homophase power input of the 6th capacitor C 6 one terminations the first operational amplifier U1, other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations the first operational amplifier U1, other end ground connection, the 5th resistance R 5 one end ground connection, the in-phase input end of another termination the second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the 4th resistance R 4 one end ground connection, the inverting input of another termination the second operational amplifier U2, the inverting input of the 6th resistance R 6 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the output terminal of the 7th resistance R 7 one terminations the second operational amplifier U2, the 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations the second operational amplifier U2, other end ground connection, the inverting power supplies input end of the 9th capacitor C 9 one terminations the second operational amplifier U2, other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip, the termination voltage of reception diode D2 is+power supply of 5V, the inverting input of another termination the first operational amplifier U1, the homophase power input of the first operational amplifier U1 connects voltage and is the power supply of+3.3V, inverting power supplies input termination voltage is-power supply of 3.3V, the homophase power input of the second operational amplifier U2 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
Groundwork principle and the process of this circuit:
The infrared light that emitting diode D1 sends produces scattering in liquid environment, the power that how much has determined the scattered light that reception diode D2 receives of suspension number in the liquid environment, thereby further determined the power of the photocurrent that reception diode D2 produces, and how much the suspension content in the liquid be the important indicator of weighing the liquid turbidity size, therefore can measure by scattered light method the turbidity of liquid.This circuit is measured the turbidity that ratio juris is measured liquid by scattered light just.
At first, the dutycycle that produces by the NE555P timer is the square wave circuit for generating of 1:2.The resistance of the 8th resistance R 8 is 100K Ω, and the resistance of the 9th resistance R 9 is 1K Ω, and the capability value of the 11 capacitor C 11 and the 12 capacitor C 12 all is 10nF.Have according to the some more oscillators that formed by the NE555P timer:
Oscillation period
The dutycycle of output waveform
Control emitting diode D1 work by the on-off action of the first triode Q1 again.The resistance of the tenth resistance R 10 is 1K Ω, the resistance of the 11 resistance R 11 and the 12 resistance R 12 all is 1K Ω, the resistance of the 13 resistance R 13 is 60 Ω, one termination of emitting diode D1+5V power supply the first triode Q1 plays the effect of switch, when the low level of the square wave of NE555P timer U4 output, the first triode Q1 conducting, the supply voltage of+3.3V is through the dividing potential drop effect of the 11 resistance R 11 and the 12 resistance R 12, produce the voltage of pact+1.6V at the positive input of the 3rd operational amplifier U3, the output terminal of the 3rd operational amplifier U3 of this moment is also exported a forward voltage, control the second triode Q2 conducting, emitting diode D1 begins luminous, when the high level of the square wave of NE555P timer U4 output, the first triode Q1 cut-off owing to there is each device dark the influence of peak current, is exported a low level at its output terminal after through the amplification of the 3rd operational amplifier U3, control the second triode Q2 cut-off, emitting diode D1 begins to extinguish.
In receiving circuit, reception diode D2 reversal connection+5V power supply, when receiving the signal of emitting diode D1 emission, produce low current signal, signal is by the negative input input of the first operational amplifier U1, low current signal is converted to voltage signal output, the resistance of the second resistance R 2 is 100K Ω, play degenerative effect, the first resistance R 1 is a biasing resistor, resistance is 100K Ω, the first capacitor C 1 is phase compensation electric capacity, capability value is 0.1uF, the second capacitor C 2 is filter capacitor, capability value is 15pF, the voltage signal of the first operational amplifier U1 output is through current-limiting resistance R3, and after the filtering of the 3rd capacitor C 3 and the 4th capacitor C 4, be input to the negative input of the second operational amplifier U2, the resistance of the 3rd resistance R 3 is 1K Ω, the capability value of the 3rd electric capacity and the 4th electric capacity all is 100pF, the 5th resistance R 5 is a biasing resistor, resistance is 1K Ω, and the resistance of the 4th resistance R 4 is 1K Ω, and the 6th resistance R 6 is an adjustable resistance, resistance is 10K Ω, voltage signal just can carry out the AD conversion after through the further amplification of the second operational amplifier U2, and the 5th capacitor C 5 is filter capacitor, and capability value is 100pF, the 7th resistance R 7 is current-limiting resistance, resistance is 100 Ω, and the 8th capacitor C 8 and the 9th capacitor C 9 are power filtering capacitors, and capability value is 0.1uF, the tenth capacitor C 10 is filter capacitors, capability value is 0.1uF, and current signal amplifies through the two-stage of receiving circuit, has finally realized the voltage transitions of low current signal.
Claims (1)
1. the turbidity measuring circuit based on photodiode comprises radiating circuit and receiving circuit two parts, it is characterized in that:
Radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R 10, the 11 resistance R 11, the 12 resistance R 12, the 13 resistance R 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3 and NE555P timer U4,7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4,4 pin of the 9th resistance R 9 one termination NE555P timer U4,7 pin of another termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4, the base stage of another termination the first triode Q1,2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection, 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4, other end ground connection, the 1 pin ground connection of NE555P timer U4,2 pin with are connected pin and connect, 4 pin and 8 pin connect voltage and are the power supply of+3.3V, the collector of the 11 resistance R 11 1 terminations the first triode Q1, the in-phase input end of another termination the 3rd operational amplifier U3, the in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection, the homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3, other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection, the base stage of the first triode Q1 connects the tenth resistance R 10, collector connects the 11 resistance R 11, emitter connects voltage and is the power supply of+3.3V, the base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3, diode D1 is penetrated in the collector sending and receiving, emitter connects the inverting input of the 3rd operational amplifier U3, the inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3, other end ground connection, emitting diode D1 one termination voltage is+power supply of 5V, the collector of another termination the second triode Q2, the homophase power input of the 3rd operational amplifier U3 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V;
Receiving circuit partly comprises the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the first phase place building-out capacitor C1, the second filter capacitor C2, the 3rd filter capacitor C3, the 4th filter capacitor C4, the 5th filter capacitor C5, the 6th filter capacitor C6, the 7th filter capacitor C7, the 8th filter capacitor C8, the 9th filter capacitor C9, the tenth filter capacitor C10, reception diode D2, the first operational amplifier U1 and the second operational amplifier U2, the first resistance R 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the first capacitor C 1 one end ground connection, the in-phase input end of another termination the first operational amplifier U1, the inverting input of the second resistance R 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the inverting input of the second capacitor C 2 one terminations the first operational amplifier U1, the output terminal of another termination the first operational amplifier U1, the output terminal of the 3rd resistance R 3 one terminations the first operational amplifier U1, the inverting input of another termination the second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations the first operational amplifier U1, other end ground connection, the inverting input of the 4th capacitor C 4 one terminations the second operational amplifier U2, other end ground connection, the homophase power input of the 6th capacitor C 6 one terminations the first operational amplifier U1, other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations the first operational amplifier U1, other end ground connection, the 5th resistance R 5 one end ground connection, the in-phase input end of another termination the second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the 4th resistance R 4 one end ground connection, the inverting input of another termination the second operational amplifier U2, the inverting input of the 6th resistance R 6 one terminations the second operational amplifier U2, the output terminal of another termination the second operational amplifier U2, the output terminal of the 7th resistance R 7 one terminations the second operational amplifier U2, the 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations the second operational amplifier U2, other end ground connection, the inverting power supplies input end of the 9th capacitor C 9 one terminations the second operational amplifier U2, other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip, the termination voltage of reception diode D2 is+power supply of 5V, the inverting input of another termination the first operational amplifier U1, the homophase power input of the first operational amplifier U1 connects voltage and is the power supply of+3.3V, inverting power supplies input termination voltage is-power supply of 3.3V, the homophase power input of the second operational amplifier U2 connects voltage and is the power supply of+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
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| CN 201110265535 CN102393384B (en) | 2011-09-08 | 2011-09-08 | Photosensitive diode-based turbidity measuring circuit |
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| CN 201110265535 CN102393384B (en) | 2011-09-08 | 2011-09-08 | Photosensitive diode-based turbidity measuring circuit |
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| CN102393384A CN102393384A (en) | 2012-03-28 |
| CN102393384B true CN102393384B (en) | 2013-03-13 |
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| CN104849238B (en) * | 2015-06-10 | 2017-10-03 | 浙江诸暨奇创电子科技有限公司 | A kind of infrared turbidity detection device |
| CN105630056A (en) * | 2016-02-29 | 2016-06-01 | 成都乐维斯科技有限公司 | Circuit with current-voltage conversion, amplification and filter functions |
| CN105785387B (en) * | 2016-04-20 | 2018-01-30 | 浙江大学 | The underwater laser rangefinder and its distance-finding method that can be calibrated automatically in different water bodys |
| CN111836425A (en) * | 2020-06-24 | 2020-10-27 | 马瑞利汽车零部件(芜湖)有限公司 | Hardware design circuit for realizing LED breathing animation effect |
| CN113008837B (en) * | 2021-02-18 | 2022-08-23 | 交通运输部天津水运工程科学研究所 | High-precision turbidity sensor |
| CN113655011B (en) * | 2021-10-20 | 2022-02-08 | 武汉新烽光电股份有限公司 | Microfluidic detection system and detection method thereof |
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| DE2219830B2 (en) * | 1972-04-22 | 1977-03-10 | Rowenta-Werke Gmbh, 6050 Offenbach | HV pulse tester esp. for piezo ignition - has adjustable high-input impedance amplifier sensing positive peaks |
| US5828458A (en) * | 1995-01-26 | 1998-10-27 | Nartron Corporation | Turbidity sensor |
| CN201629666U (en) * | 2010-01-20 | 2010-11-10 | 徐剑雄 | IGBT driving circuit based on EXB841 chip |
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