CN109374576B - Near infrared receiving and transmitting control device with adjustable transmitting power - Google Patents
Near infrared receiving and transmitting control device with adjustable transmitting power Download PDFInfo
- Publication number
- CN109374576B CN109374576B CN201811579721.7A CN201811579721A CN109374576B CN 109374576 B CN109374576 B CN 109374576B CN 201811579721 A CN201811579721 A CN 201811579721A CN 109374576 B CN109374576 B CN 109374576B
- Authority
- CN
- China
- Prior art keywords
- amplifier
- voltage
- power supply
- potentiometer
- output end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 23
- 230000035945 sensitivity Effects 0.000 claims abstract description 12
- 239000003990 capacitor Substances 0.000 claims description 64
- 230000002441 reversible effect Effects 0.000 claims description 12
- 238000002955 isolation Methods 0.000 claims description 5
- 230000000087 stabilizing effect Effects 0.000 claims description 4
- 230000001052 transient effect Effects 0.000 claims description 4
- 230000003321 amplification Effects 0.000 abstract description 6
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 6
- 230000005514 two-phase flow Effects 0.000 description 16
- 239000000523 sample Substances 0.000 description 15
- 238000010586 diagram Methods 0.000 description 10
- 229910052715 tantalum Inorganic materials 0.000 description 8
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 8
- 238000001914 filtration Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 230000003750 conditioning effect Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 238000013178 mathematical model Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000012800 visualization Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/359—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Amplifiers (AREA)
Abstract
The invention provides a near infrared receiving and transmitting control device with adjustable transmitting power. The device comprises a power supply module, a transmitting module, a receiving module, an A/D conversion circuit, a display module and a voltage amplifying circuit. The power supply module adopts DC9-36V input, isolates output + -12V, and is converted from 12V to 5V and 3.3V, and the next stage is not affected by interference of a city network and the like at the input end. The transmitting module adopts constant current driving and the transmitting power is adjustable, so that the amplifier is combined with the N-channel MOS tube, and the voltage is adjusted by connecting the high-precision potentiometer with the constant resistor in series. The receiving module adopts a current-to-voltage mode to convert photocurrent generated by the photodiode into voltage through an amplifier. The sensitivity of the amplifier to the received light intensity can be controlled by controlling the feedback resistance of the amplifier. The next stage adds an inverting amplifier to amplify the voltage. The two-stage linkage adjustment is convenient for adjusting the sensitivity and the amplification factor, is more convenient in practical application, and the obtained signal is more stable.
Description
Technical Field
The invention relates to the technical field of gas-liquid two-phase flow detection and analog electronics, in particular to a near infrared receiving and transmitting control device with adjustable transmitting power.
Background
Infrared technology is mostly used for wireless data transmission of infrared carrier codes, and the most common is an infrared remote controller. Numerous prior patent applications have disclosed the relevant structure of infrared emission and infrared receiving circuits. For example: the infrared transmitting circuit, the infrared receiving circuit and the infrared receiving and transmitting system (patent application number: 201310699015.7) are applied to infrared wireless data communication, electric energy can be directly converted into near infrared light (invisible light) to radiate through an infrared transmitter of the system through data of a serial port, then an infrared receiver receives infrared signals and independently completes receiving and outputting signals compatible with TTL level signals from the infrared, and the infrared transmitting circuit is suitable for various infrared remote control and infrared data transmission; an amplifying circuit (patent application number 201711475379.1) for an infrared detection system is designed for receiving and amplifying a mid-infrared alarm; an infrared circuit board (patent application number: 201410710503.8) integrating receiving and transmitting is characterized in that an upper computer sends a control signal to control the on-off of an infrared lamp tube, infrared receiving and transmitting are integrated, and a lamp holder is used for connecting a transmitting tube and a receiving tube; a485-to-infrared circuit and a data transmission method (patent application number: 201610581236.8) convert 485 data into infrared data by using pure hardware, and also convert the infrared data into 485 data.
The circuits in the patent application all use infrared for data transmission, and the principle is that pulse waves are converted into optical signals to be transmitted through an infrared transmitting tube with the common wavelength of 940nm, and carrier frequencies are mainly 38kHz and 40 kHz. In terms of power, the transmitting power is changed by using a power amplifying tube or changing the selection of parallel resistors in a circuit through the on-off of an external switch. After the internal of the infrared receiving IC is amplified, gained, filtered, demodulated, shaped and restored, the original codes given by the remote controller are restored and input to a code recognition circuit at the back through the signal output pin of the receiving head. The coding rule is for a binary signal "0", one pulse taking 1.2ms; for a binary signal "1", one pulse takes 2.4ms, while the low level in each pulse is 0.6ms on average.
In the detection process of gas-liquid two-phase flow, the phase content is often measured based on the absorption characteristics of near infrared spectrum. When in measurement, the near infrared transmitting probe transmits near infrared light, the near infrared light passes through the fluid in the pipeline and is received by the near infrared receiving probe, the near infrared light can be absorbed by the fluid in the pipeline, and the phase content of the two-phase flow can be calculated according to the light intensity change before and after the near infrared light is absorbed and by combining with the lambert law.
The two-phase flow phase content is measured by utilizing the absorption characteristic of near infrared, and further research on the driving of a near infrared transmitting probe and the conditioning of a near infrared receiving probe after receiving signals is needed.
Disclosure of Invention
The invention aims to realize the driving of a near infrared transmitting probe and the conditioning of a receiving signal in the process of measuring the phase content of a two-phase flow by utilizing near infrared through a near infrared receiving and transmitting control device with adjustable transmitting power on the existing device for measuring the gas-liquid two-phase flow of a vertical pipeline, and solve the problems of weak penetrating capacity and weak receiving signal of a receiving end caused by insufficient driving power of the infrared probe due to different infrared light absorption capacities of mediums.
The invention is realized in the following way: the near infrared receiving and transmitting control device with adjustable transmitting power comprises a power supply module, a transmitting module, a receiving module, an A/D conversion circuit, a display module and a voltage amplifying circuit;
the power supply module is externally connected with a direct-current 9V-36V power supply; the power supply module comprises an isolated high-voltage power supply, a first LDO power supply chip and a second LDO power supply chip, and a direct-current 9V-36V power supply outputs +12V, 0V and-12V direct-current voltages after passing through the isolated high-voltage power supply; the input ends of the first LDO power supply chip and the second LDO power supply chip are both connected with a +12V direct current output end for isolating a high-voltage power supply, and the output end of the first LDO power supply chip outputs +5V direct current voltage which is used for providing voltage for driving the light emitting diode and simultaneously providing voltage required by the work for the display module; the output end of the second LDO power chip outputs +3.3V direct current voltage, which is used for providing voltage required by work for the A/D conversion circuit;
the emitting module comprises a light emitting diode interface, an N-channel MOS tube and a first two-way amplifier; the LED interface is used for connecting an LED, one pin of the LED interface is connected with the source electrode of the N-channel MOS tube, and the other pin of the LED interface is connected with the digital ground after being connected in series with the first potentiometer through the first constant value resistor; the drain electrode of the N channel MOS tube is connected with a +12V direct current output end of the isolation high-voltage power supply, and the grid electrode of the N channel MOS tube is connected with the output end of a post-stage amplifier of the first two-way amplifier; the front-stage amplifier of the first two-way amplifier is used as a follower, the non-inverting input end of the front-stage amplifier is connected with the output end of the first LDO power chip, and the inverting input end of the front-stage amplifier is connected with the output end of the first LDO power chip; the output end of the front-stage amplifier of the first two-way amplifier is connected with the non-inverting input end of the rear-stage amplifier, and the inverting input end of the rear-stage amplifier is connected with a connection node of the first constant value resistor and the light-emitting diode interface;
the A/D conversion circuit is used for collecting voltages at two ends of a first potentiometer in the transmitting module, performing analog-to-digital conversion on the collected voltages, and then converting voltage values into current values;
the display module is connected with the A/D conversion circuit, and can display the current flowing through the first potentiometer;
the receiving module comprises a photodiode interface, an amplifier, a second potentiometer and a second constant value resistor; the photodiode interface is used for connecting a photodiode, two pins of the photodiode interface are respectively connected with two input ends of the amplifier, and one pin of the photodiode interface is connected with digital ground; the second potentiometer and the second constant value resistor are arranged in parallel between a non-grounding pin of the photodiode interface and the output end of the amplifier; the amplifier is used for converting the current into voltage; the photodiode receives the light to generate reverse current, and the reverse current flows through the photodiode interface and then generates voltage output after passing through the amplifier, the second potentiometer and the second constant value resistor; the second potentiometer is used for adjusting the sensitivity of the light intensity received by the photodiode;
the voltage amplifying circuit comprises a second double-path amplifier, a band-pass filter, a third potentiometer and an external interface; the front-stage amplifier of the second dual-path amplifier is used as a follower, the non-inverting input end of the front-stage amplifier is connected with the movable contact of the second potentiometer in the receiving module, and the inverting input end of the front-stage amplifier is connected with the output end of the front-stage amplifier after passing through a third constant value resistor; the output end of the front-stage amplifier of the second dual-circuit amplifier is connected with the inverting input end of the rear-stage amplifier after passing through a fourth constant value resistor, the inverting input end of the rear-stage amplifier is connected with the output end after passing through the third potentiometer at the same time, and the non-inverting input end of the rear-stage amplifier is connected with digital ground after passing through a fifth constant value resistor; the output end of the post-stage amplifier is connected with an external interface through the band-pass filter.
The band-pass filter comprises a sixth constant value resistor, a seventh constant value resistor, a first capacitor and a second capacitor; the output end of the rear-stage amplifier of the second dual-path amplifier is connected with a non-grounding pin of an external interface after passing through a first capacitor and a sixth constant value resistor in sequence, and two ends of the second capacitor are respectively connected with two pins of the external interface; one end of the seventh constant value resistor is connected with a grounding pin of the external interface, and the other end of the seventh constant value resistor is connected with a connecting node of the first capacitor and the sixth constant value resistor.
The first potentiometer is a high-precision (high-precision refers to high resolution and high precision) potentiometer, and may be, for example, a 3950S precision multi-turn potentiometer. The second potentiometer and the third potentiometer may be 0932 long handle potentiometers.
In the power module, an external direct current 9V-36V power supply is connected with one end of a filter capacitor after passing through a power switch, and the other end of the filter capacitor is grounded; EMC gas discharge tubes are connected in parallel at two ends of the filter capacitor. The non-grounding end of the filter capacitor is connected with the anode of the diode after passing through a fuse, and the cathode of the diode is connected with the input end of the isolated high-voltage power supply after passing through a power inductor; and a bypass capacitor and a decoupling capacitor which are connected in parallel are arranged at the input end and the ground end of the isolated high-voltage power supply. And transient voltage stabilizing diodes are connected in parallel at two ends of the decoupling capacitor.
According to the invention, 970nm can be selected as an infrared light-emitting diode, the current voltage value is read by the A/D conversion circuit through adjusting the high-precision potentiometer connected in series with the constant value resistor, the current value is calculated and transmitted to the display module for display, the adjustment of the driving power of the infrared light-emitting diode is realized, the visualization of the current value is realized, and the driving circuit is driven by the constant current source. Aiming at near infrared shortwave with the wavelength of 780-1100 nm in infrared rays, the wavelength of light which can be received by the used photodiode is 320-1100 nm, weak photocurrent is generated according to the received light intensity, the weak photocurrent is amplified in an integer mode, the amplification is three stages, the first stage of amplification can adjust the sensitivity of the received light intensity, the second stage of amplification can enhance the carrying capacity of output voltage, the external equipment is not limited to an A/D converter and can also be used as a control signal, and the third stage of amplification can improve the voltage value after conditioning.
The invention can convert optical signals into electric signals through the near infrared receiving probe, and the driving power of the near infrared transmitting probe can be changed according to the difference of the infrared light absorption capacity of the measured medium. Meanwhile, the invention has a certain shielding effect on power supply interference and external electromagnetic interference by reasonable circuit principle design and the completion of the functions.
The device is applied to the detection of the phase content of the two-phase flow, the two-phase flow is tested according to the principle that near infrared light is absorbed differently by the same medium with different thickness, valuable electric signals are extracted, signal characteristic extraction is carried out, the gas phase volume content is calculated, and a mathematical model is established. Based on different gas phase volume contents, an electric signal obtained by the device is combined to establish a two-phase flow phase content measurement formula, and the rationality and feasibility of the device are verified.
Drawings
Fig. 1 is a block diagram of the circuit configuration of the present invention.
Fig. 2 is a circuit configuration diagram of a power module in the present invention.
Fig. 3 is a circuit configuration diagram of a transmitting module in the present invention.
Fig. 4 is a circuit configuration diagram of a receiving module in the present invention.
Fig. 5 is a voltage amplifying circuit diagram in the present invention.
Detailed Description
Based on theoretical analysis and early working experience, the invention designs the relation between the light intensity of the optical signal received by the photodiode and the output electric signal after the near infrared light emitted by the near infrared light emitting diode passes through the two-phase flow according to the photoelectric effect mechanism.
The invention provides an integral structure of a near infrared receiving and transmitting control device with adjustable transmitting power, which is a circuit board, wherein 8 channels can be arranged on the circuit board, a power supply module, a transmitting module, a receiving module, a voltage amplifying circuit, an A/D converting circuit and a display module are arranged on the circuit board, and a power supply interface, a power supply switch, a power supply indicator lamp, a photosensitive sensitivity adjusting knob, an electric signal amplifying knob, a near infrared transmitting probe interface, a photodiode receiving probe interface and an electric signal output interface are also arranged on the circuit board.
The invention realizes the measurable quantity of the light intensity by driving the infrared light emitting diode (corresponding to the near infrared emission probe) and carrying out voltage conversion on the reverse photocurrent generated by the light intensity received by the photodiode (corresponding to the near infrared receiving probe). The power module, the transmitting module, the receiving module, the voltage amplifying circuit, the a/D converting circuit, the display module, and the like in the present invention will be described in detail with reference to fig. 1 to 5.
Fig. 1 is a general block diagram of the circuit configuration of the present invention. The power module is used for providing required voltages for the transmitting module, the receiving module, the voltage amplifying circuit, the A/D conversion circuit and the display module; the emitting module is used for driving the infrared light emitting diode, the emitting module drives the infrared light emitting diode by adopting constant current source driving, the emitting power is adjustable, and the adjustment of the emitting power can be realized by adjusting a high-precision potentiometer connected with a fixed value resistor in series; the A/D conversion circuit can collect terminal voltage values of the high-precision potentiometer on the transmitting module in real time, then convert the terminal voltage values into current values, and display the current values flowing through the high-precision potentiometer by the display module, so that people can observe specific working conditions of the transmitting module in real time. The infrared light-emitting diode emits near infrared light to irradiate the two-phase flow in the pipeline, the near infrared light is received by the photodiode after being absorbed by partial energy of the two-phase flow, and the receiving module can convert photocurrent generated after the photodiode receives light signals into voltage to be output; the voltage amplifying circuit is used for amplifying the voltage value output by the receiving module.
Fig. 2 is a circuit configuration diagram of a power module in the present invention. The external power supply SVCC provides DC9-36V voltage for the power supply module, the external power supply SVCC is connected with one end of the filter capacitor C2 after passing through the power switch S1, the other end of the filter capacitor C2 is connected with the power supply ground OGND, and the stability of the external power supply SVCC can be ensured through the filter capacitor C2. The two ends of the filter capacitor C2 are connected with EMC gas discharge tubes D3 in parallel, and the EMC gas discharge tubes D3 are used for protecting the whole power supply module. The pin 1 of the EMC gas discharge tube D3 is connected with the non-grounding end of the filter capacitor C2, the pin 3 of the EMC gas discharge tube D3 is connected with the power supply ground OGND, and the pin 2 of the EMC gas discharge tube D3 is connected with the ground PG; meanwhile, a high-voltage (1 KV) large-capacity capacitor C8 is arranged between the pin 2 of the EMC gas discharge tube D3 and the power supply ground OGND, and the high-voltage large-capacity capacitor C8 can filter external interference signals. The non-grounding end of the filter capacitor C2 is connected with the anode of the diode D1 through the self-recovery fuse F1, the fuse F1 can timely disconnect a power supply when a large current is generated due to short circuit and the like of a later-stage circuit, and the fuse F1 automatically recovers after the circuit is normal, so that the circuit can be ensured to work normally. The diode D1 can prevent the circuit element from burning out caused by reverse connection of the power supply. The negative electrode of the diode D1 is connected with the bypass capacitor C6 and the decoupling capacitor C7 through the power inductor L1, the bypass capacitor C6 and the decoupling capacitor C7 are arranged in parallel, and the bypass capacitor C6, the decoupling capacitor C7 and the power inductor L1 form a filter. The two ends of the decoupling capacitor C7 are also connected with a transient voltage stabilizing diode D4 in parallel, and the transient voltage stabilizing diode D4 can clamp the instantaneously input large voltage in a certain voltage range. The two ends of the bypass capacitor C6 and the decoupling capacitor C7 are respectively connected with the input end Vin and the ground end GND of the isolation high-voltage power supply U2, and the ground end GND of the isolation high-voltage power supply U2 is connected with the power supply ground OGND. The isolated high voltage source U2 is a wide voltage input DC+ -12V output, and the output DC+ -12V is an isolated output, which can ensure that the pre-stage interference is not coupled to the lower stage by transmission. The isolated high-voltage power supply U2 is provided with three output ends, namely +Vo, 0V and-Vo; the output end +vo is connected with the power supply VCC and outputs +12V direct current voltage; the output end-Vo is connected with the power supply VEE and outputs-12V direct-current voltage; the output terminal 0V is connected with the digital ground DGND and outputs 0V voltage. A tantalum capacitor C3 is arranged between the power source VCC and the output terminal 0V, and the tantalum capacitor C3 plays a role in filtering. The input end Vin of the LDO power supply chip U1 is connected with a power supply VCC through a pin 2, the ground end G of the LDO power supply chip U1 is connected with a digital ground DGND through a pin 1, the output end Vo of the LDO power supply chip U1 is connected with a power supply W-VCC through a pin 3, and the output end Vo of the LDO power supply chip U1 outputs DC5V to provide voltage for driving of a light emitting diode. A tantalum capacitor C4 with a filtering function is arranged between an input end Vin and a ground end G of the LDO power supply chip U1; a tantalum capacitor C5 with a filtering function is arranged between an output end Vo and a ground end G of the LDO power chip U1. Two parallel branches are arranged between the power supply W-VCC and the digital ground DGND, a capacitor C1 with a filtering function is arranged on one branch, a resistor R1 and a power supply indicator lamp D2 are arranged on the other branch in series, the resistor R1 has a current limiting function, the negative electrode of the power supply indicator lamp D2 is connected with the digital ground DGND, and whether the power supply W-VCC works normally can be displayed through the on-off of the power supply indicator lamp D2. The input end Vin of the LDO power supply chip U4 is connected with a power supply VCC through a pin 2, the ground end G of the LDO power supply chip U4 is connected with a digital ground DGND through a pin 1, the output end Vo of the LDO power supply chip U4 is connected with a power supply MCU-VCC through a pin 3, and the output end Vo of the LDO power supply chip U4 outputs DC+3.3V to supply power for the A/D conversion circuit. A tantalum capacitor C10 with a filtering function is arranged between an input end Vin and a ground end G of the LDO power supply chip U4; a tantalum capacitor C11 with a filtering function is arranged between an output end Vo and a ground end G of the LDO power chip U4. Two parallel branches are arranged between the power MCU-VCC and the digital DGND, a capacitor C9 with a filtering function is arranged on one branch, a resistor R3 and a power indicator lamp D5 are arranged on the other branch in series, the resistor R3 has a current limiting function, the negative electrode of the power indicator lamp D5 is connected with the digital DGND, and whether the power MCU-VCC works normally can be displayed through the on-off of the power indicator lamp D5.
The power supply module adopts DC9-36V input, isolates DC + -12V output, and converts DC +12V into DC +5V and DC +3.3V, so that the next-stage voltage cannot be influenced by interference of a mains supply and the like at the input DC9-36V end, and EMC protection, reverse connection protection, short circuit protection and the like are considered in the circuit.
Fig. 3 is a circuit configuration diagram of a transmitting module in the present invention. The invention designs a constant current driving transmitting circuit, and the transmitting power is adjustable. Fig. 3 shows a two-way amplifier (i.e., a first two-way amplifier), which is a first amplifier U3A (also called a pre-amplifier) and a second amplifier U3B (also called a post-amplifier), respectively, and the first amplifier U3A is used as a follower for enhancing the driving capability. The non-inverting input end +INA of the first path amplifier U3A is connected with a power supply W-VCC through a pin 1, the power supply W-VCC can provide DC +5V voltage, the inverting input end-INA of the first path amplifier U3A is connected with an output end OUTA of the first path amplifier U3A through a pin 8, and the output end OUTA is connected with a pin 7; the power supply negative electrode V-of the first path amplifier U3A is connected with digital DGND through a pin 2. The positive power supply V+ of the second path amplifier U3B is connected with a power supply VCC through a pin 6, the power supply VCC can provide +12V direct current voltage, the non-inverting input end +INB of the second path amplifier U3B is connected with the output end OUTA of the first path amplifier U3A through a pin 3, the inverting input end-INB of the second path amplifier U3B is connected with one end of a fixed value resistor R19 through a pin 4, the other end of the fixed value resistor R19 is connected with a movable contact of a high-precision potentiometer R14, one fixed contact of the high-precision potentiometer R14 is suspended, and the other fixed contact is connected with digital DGND. The high-precision potentiometer R14 is a 3950S precision multi-turn potentiometer. The high-precision potentiometer R14 and the fixed resistor R19 are in series connection, and tantalum capacitors C91 are connected in parallel to two ends of the high-precision potentiometer R14. Therefore, for the second amplifier U3B, the non-inverting input terminal +inb is the output dc+5v of the first amplifier U3A, and the inverting input terminal-INB is the voltage value obtained by connecting the fixed resistor R19 and the high-precision potentiometer R14 in series, thus forming a comparator. The output end OUTB of the second amplifier U3B is connected with the grid electrode of an N-channel MOSFET Q2 (MOSFET for short MOS tube) through a pin 5, the drain electrode of the N-channel MOSFET Q2 is connected with a power supply VCC, the source electrode of the N-channel MOSFET Q2 is connected with a pin 1 of a light emitting diode interface P4, and a pin 2 of the light emitting diode interface P4 is connected with the inverting input end-INB of the second amplifier U3B and one end of a constant value resistor R19. The led interface P4 is used to connect leds. When the voltage value of the fixed resistor R19 and the high-precision potentiometer R14 which are connected in series is smaller than DC5V, the N-channel MOSFET Q2 is turned on, and the light-emitting diode has current flowing through; when the load changes, the voltage value of the fixed resistor R19 and the high-precision potentiometer R14 which are connected in series is more than or equal to DC5V, the N-channel MOSFET Q2 is turned off, and no current flows through the light-emitting diode. When the load changes within a certain range, the PWM wave drives the N-channel MOSFET Q2 to control the constant current, and the constant current for driving the light emitting diode is formed.
The A/D conversion circuit is connected with the power module, the emission module and the display module, and the power module is used for providing 3.3V voltage for the A/D conversion circuit. In the invention, the core device of the A/D conversion circuit is MCU, and the model of MCU can be MSP430F1611. The MCU is connected with a connection node A0 of a fixed value resistor R19 and a high-precision potentiometer R14 in the transmitting module of FIG. 3, and is used for collecting the voltage at the node A0, carrying out analog-digital conversion on the collected voltage, and converting the voltage into a current value flowing through the high-precision potentiometer R14. The MCU sends the processed current value to the display module, and the nixie tube in the display module displays the current flowing through the high-precision potentiometer R14, so that people can grasp the transmitting power condition of the transmitting module in real time. The display module comprises a latch and a nixie tube, the latch can drive the nixie tube to work under the control of the MCU, the latch is connected with the power module, and the power module can provide +5V working voltage for the latch.
The transmitting module adopts a constant current driving mode, the voltage is regulated by connecting the high-precision potentiometer R14 and the fixed resistor R19 in series by utilizing a mode of combining an amplifier and an N-channel MOS tube, the voltage at two ends of the high-precision potentiometer R14 is acquired through an A/D (analog to digital) conversion circuit, a current value is obtained, and the current value is displayed through a nixie tube in the display module. The output current is kept constant within a certain load range by comparing the input voltage with the voltage value at both ends of the resistor.
Fig. 4 is a circuit configuration diagram of a receiving module in the present invention. P2 in fig. 4 is a photodiode interface for connecting a photodiode. The photodiode receives light and generates a reverse photocurrent. U5 is an amplifier, and is applied to current-to-voltage conversion, the reverse current generated by the photodiode is very small, and the bias current and bias voltage of the amplifier U5 are very small, so that the conversion accuracy is satisfied. Pin 1 of photodiode interface P2 is connected to pin 3 of amplifier U5, and pin 2 of photodiode interface P2 is connected to pin 2 of amplifier U5. Pin 3 and pin 2 of amplifier U5 are two inputs, and amplifier U5's pin 1 and 4 are unsettled, and amplifier U5's pin 3, pin 5, pin 8 all connect digital ground DGND, and amplifier U5's pin 6 is the output, and power VCC is connected to amplifier U5's pin 7, still is provided with tantalum capacitor C11 between amplifier U5's pin 7 and the digital ground DGND. Pin 2 of photodiode interface P2 is connected to one end of capacitor C10, and the other end of capacitor C10 is connected to pin 6 of amplifier U5. Pin 2 of photodiode interface P2 is also connected to one fixed contact of potentiometer R2, the other fixed contact of potentiometer R2 being suspended. The capacitor C9 is connected with the resistor R3 in parallel, one end of the capacitor C9 is connected with the pin 2 of the photodiode interface P2, and the other end of the capacitor C9 is connected with the movable contact of the potentiometer R2. The movable contact of the potentiometer R2 is connected with one end of a resistor R8, and the other end of the resistor R8 is connected with a pin 6 of the amplifier U5. The photodiode receives light to generate reverse current, and the reverse current generates voltage output through a feedback resistor connected with the resistor R3 in parallel through the potentiometer R2. The sensitivity of the light intensity of the photodiode can be adjusted by the potentiometer R2, i.e. when the potentiometer R2 is very large, a dead zone phenomenon occurs when the near infrared transmitting probe irradiates the near infrared receiving probe. Therefore, the sensitivity of the received light intensity can be improved by properly adjusting the resistance value of the potentiometer R2, and if the distance to be transmitted by the near infrared light is long, the resistance value of the potentiometer R2 can be properly increased. The potentiometer R2 can be a 0932 long handle potentiometer.
Fig. 5 is a voltage amplifying circuit diagram in the present invention. After the sensitivity of the received light intensity is adjusted according to fig. 4, an amplifying circuit composed of a rail-to-rail amplifier at the next stage is entered. The rail-to-rail amplifier also includes two-way amplifiers (i.e., a second dual-way amplifier), a first-way amplifier U4A (also referred to as a pre-stage amplifier) and a second-way amplifier U4B (also referred to as a post-stage amplifier), respectively. The non-inverting input end of the first path amplifier U4A is connected with the movable contact of the potentiometer R2 in FIG. 4 through a pin 3, the inverting input end of the first path amplifier U4A is connected with one end of a resistor R4 through a pin 2, the other end of the resistor R4 is connected with the output end of the first path amplifier U4A, and the output end of the first path amplifier U4A is connected with a pin 1. The pin 4 of the first path amplifier U4A is connected with a power supply VEE, the power supply VEE can provide-12V direct current voltage, and a capacitor C14 is arranged between the pin 4 of the first path amplifier U4A and the digital ground DGND. The pin 8 of the first path amplifier U4A is connected to the power supply VCC, and a capacitor C12 is provided between the pin 8 of the first path amplifier U4A and the digital ground DGND. The output end of the first path of amplifier U4A is connected with the inverting input end of the second path of amplifier U4B after passing through the resistor R7, the non-inverting input end of the second path of amplifier U4B is connected with one end of the resistor R11 through the pin 5, and the other end of the resistor R11 is connected with the digital ground DGND. Pin 4 of the second path amplifier U4B is connected to the power supply VEE, and pin 8 of the second path amplifier U4B is connected to the power supply VCC. The inverting input end of the second path amplifier U4B is connected with one fixed contact of the potentiometer R5 through the pin 6, the other fixed contact of the potentiometer R5 is suspended, the potentiometer R5 can be a 0932 long handle potentiometer, and the movable contact of the potentiometer R5 is connected with the output end of the second path amplifier U4B through the pin 7. The output end of the second path amplifier U4B is also connected with one end of a capacitor C13 through a pin 7, the other end of the capacitor C13 is connected with a pin 1 of an external interface P3 through a resistor R9, and a pin 2 of the external interface P3 is connected with a digital DGND. Both ends of the capacitor C15 are respectively connected to the pin 1 and the pin 2 of the external interface P3. One end of the resistor R10 is connected to the digital ground DGND, and the other end is connected to a connection node between the capacitor C13 and the resistor R9. The capacitor C13, the resistor R10, the resistor R9 and the capacitor C15 constitute a band-pass filter. In order to ensure that the voltage signal output by the external interface P3 has certain driving capability and ensure that the signal output by the external interface P3 can be connected with A/D acquisition and can also be used as a driving signal source, and the like, the invention designs the first path amplifier U4A as a follower and the second path amplifier U4B as an inverting amplifier, and can regulate the output voltage value by regulating the resistance value of the potentiometer R5.
In the invention, the receiving module converts photocurrent generated by the photodiode into a voltage value through an amplifier in a mode of converting current into voltage. The sensitivity of the received light intensity can be controlled by controlling the feedback resistor of the partial amplifier, the larger the resistance value of the feedback resistor is, the higher the sensitivity is, but a part of dead zone can appear when the resistance value is too large, and the received photodiode is saturated with reverse current. After the photocurrent generated by the photodiode is converted into a voltage value by an amplifier, the next stage is added into an inverting amplifier to amplify the voltage value. The sensitivity and the amplification factor can be conveniently adjusted by two-stage linkage adjustment, so that the method is more convenient in the practical application process, and the obtained signal is more stable.
The invention provides support for an experimental device for measuring the phase content of the two-phase flow in the device for measuring the flow of the gas-liquid two-phase flow of the vertical pipeline. The method is characterized in that the phase content of the two-phase flow is tested by changing the thickness d of water in a pipeline, valuable electric signals are extracted through signal conditioning, signal characteristic extraction is performed, signal characteristic parameters are obtained through a nonlinear data processing method, the gas phase volume content is calculated, and a mathematical model is established. The change of the thickness d of water in the pipeline is stable and the attenuation trend is very obvious, and because the power supply part of the device adopts an isolation technology, EMC protection is fully considered, and the interference of noise can be effectively reduced, the two-phase flow phase content obtained by collecting the electric signal has good credibility and the measurement result is more accurate; meanwhile, the function of driving the light emitting diode to change the emitting power is added, the problem that the penetration capacity is weak due to the fact that the infrared emission probe is insufficient in driving power due to the fact that the infrared absorption capacity of a medium is different is solved, and the measuring mode is more reasonable and effective.
Claims (4)
1. The near infrared receiving and transmitting control device with adjustable transmitting power is characterized by comprising a power supply module, a transmitting module, a receiving module, an A/D conversion circuit and a display module;
the power supply module is externally connected with a direct-current 9V-36V power supply; the power supply module comprises an isolated high-voltage power supply, a first LDO power supply chip and a second LDO power supply chip, and a direct-current 9V-36V power supply outputs +12V, 0V and-12V direct-current voltages after passing through the isolated high-voltage power supply; the input ends of the first LDO power supply chip and the second LDO power supply chip are both connected with a +12V direct current output end for isolating a high-voltage power supply, and the output end of the first LDO power supply chip outputs +5V direct current voltage which is used for providing voltage for driving the light emitting diode and simultaneously providing voltage required by the work for the display module; the output end of the second LDO power chip outputs +3.3V direct current voltage, which is used for providing voltage required by work for the A/D conversion circuit;
the emitting module comprises a light emitting diode interface, an N-channel MOS tube and a first two-way amplifier; the LED interface is used for connecting an LED, one pin of the LED interface is connected with the source electrode of the N-channel MOS tube, and the other pin of the LED interface is connected with the digital ground after being connected in series with the first potentiometer through the first constant value resistor; the drain electrode of the N channel MOS tube is connected with a +12V direct current output end of the isolation high-voltage power supply, and the grid electrode of the N channel MOS tube is connected with the output end of a post-stage amplifier of the first two-way amplifier; the front-stage amplifier of the first two-way amplifier is used as a follower, the non-inverting input end of the front-stage amplifier is connected with the output end of the first LDO power chip, and the inverting input end of the front-stage amplifier is connected with the output end of the first LDO power chip; the output end of the front-stage amplifier of the first two-way amplifier is connected with the non-inverting input end of the rear-stage amplifier, and the inverting input end of the rear-stage amplifier is connected with a connection node of the first constant value resistor and the light-emitting diode interface;
the A/D conversion circuit is used for collecting voltages at two ends of a first potentiometer in the transmitting module, performing analog-to-digital conversion on the collected voltages, and then converting voltage values into current values;
the display module is connected with the A/D conversion circuit, and can display the current flowing through the first potentiometer;
the receiving module comprises a photodiode interface, an amplifier, a second potentiometer and a second constant value resistor; the photodiode interface is used for connecting a photodiode, two pins of the photodiode interface are respectively connected with two input ends of the amplifier, and one pin of the photodiode interface is connected with digital ground; the second potentiometer and the second constant value resistor are arranged in parallel between a non-grounding pin of the photodiode interface and the output end of the amplifier; the amplifier is used for converting the current into voltage; the photodiode receives the light to generate reverse current, and the reverse current flows through the photodiode interface and then generates voltage output after passing through the amplifier, the second potentiometer and the second constant value resistor; the second potentiometer is used for adjusting the sensitivity of the light intensity received by the photodiode;
the near infrared receiving and transmitting control device with adjustable transmitting power further comprises a voltage amplifying circuit; the voltage amplifying circuit comprises a second double-path amplifier, a band-pass filter, a third potentiometer and an external interface; the front-stage amplifier of the second dual-path amplifier is used as a follower, the non-inverting input end of the front-stage amplifier is connected with the movable contact of the second potentiometer in the receiving module, and the inverting input end of the front-stage amplifier is connected with the output end of the front-stage amplifier after passing through a third constant value resistor; the output end of the front-stage amplifier of the second dual-circuit amplifier is connected with the inverting input end of the rear-stage amplifier after passing through a fourth constant value resistor, the inverting input end of the rear-stage amplifier is connected with the output end after passing through the third potentiometer at the same time, and the non-inverting input end of the rear-stage amplifier is connected with digital ground after passing through a fifth constant value resistor; the output end of the rear-stage amplifier is connected with an external interface through the band-pass filter;
the band-pass filter comprises a sixth constant value resistor, a seventh constant value resistor, a first capacitor and a second capacitor; the output end of the rear-stage amplifier of the second dual-path amplifier is connected with a non-grounding pin of an external interface after passing through a first capacitor and a sixth constant value resistor in sequence, and two ends of the second capacitor are respectively connected with two pins of the external interface; one end of the seventh constant value resistor is connected with a grounding pin of an external interface, and the other end of the seventh constant value resistor is connected with a connecting node of the first capacitor and the sixth constant value resistor;
the third potentiometer is a 0932 long-handle potentiometer;
the first potentiometer is a 3950S precise multi-turn potentiometer, and the second potentiometer is a 0932 long-handle potentiometer.
2. The near infrared receiving and transmitting control device with adjustable transmitting power according to claim 1, wherein an external direct current 9V-36V power supply is connected with one end of a filter capacitor after passing through a power switch, and the other end of the filter capacitor is connected with a power ground; EMC gas discharge tubes are connected in parallel at two ends of the filter capacitor.
3. The near infrared receiving and transmitting control device with adjustable transmitting power according to claim 2, wherein the non-grounding end of the filter capacitor is connected with the anode of the diode after passing through a fuse, and the cathode of the diode is connected with the input end of the isolated high-voltage source after passing through a power inductor; and a bypass capacitor and a decoupling capacitor which are connected in parallel are arranged at the input end and the ground end of the isolated high-voltage power supply.
4. The near infrared receiving and transmitting control device with adjustable transmitting power according to claim 3, wherein transient voltage stabilizing diodes are connected in parallel at two ends of the decoupling capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811579721.7A CN109374576B (en) | 2018-12-24 | 2018-12-24 | Near infrared receiving and transmitting control device with adjustable transmitting power |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811579721.7A CN109374576B (en) | 2018-12-24 | 2018-12-24 | Near infrared receiving and transmitting control device with adjustable transmitting power |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109374576A CN109374576A (en) | 2019-02-22 |
| CN109374576B true CN109374576B (en) | 2023-10-03 |
Family
ID=65371669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811579721.7A Active CN109374576B (en) | 2018-12-24 | 2018-12-24 | Near infrared receiving and transmitting control device with adjustable transmitting power |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109374576B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110470388B (en) * | 2019-08-22 | 2024-07-23 | 合肥利弗莫尔仪器科技有限公司 | High-speed acquisition circuit for pulse laser average power quasi-real-time monitoring |
| CN111044089A (en) * | 2020-01-03 | 2020-04-21 | 上海兰宝传感科技股份有限公司 | Photoelectric sensor capable of automatically adjusting gain |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5733042A (en) * | 1994-12-26 | 1998-03-31 | Commissariat A L'energie Atomique | Device and method for testing an optical element subjected to radiation |
| JP2005217468A (en) * | 2004-01-27 | 2005-08-11 | Nec Kansai Ltd | Photocurrent/voltage conversion circuit |
| CN1715865A (en) * | 2005-07-22 | 2006-01-04 | 公安部沈阳消防研究所 | Smoke concentration detector |
| CN102262057A (en) * | 2011-04-28 | 2011-11-30 | 北京农业信息技术研究中心 | Automatic targeting/spraying target spectral detector based on sine-wave modulation |
| CN103149172A (en) * | 2013-02-28 | 2013-06-12 | 山东大学 | Method for improving stability of infrared gas detection system based on digital potentiometer |
| CN104849238A (en) * | 2015-06-10 | 2015-08-19 | 浙江诸暨奇创电子科技有限公司 | Infrared turbidity detection device |
| CN105547951A (en) * | 2016-01-29 | 2016-05-04 | 中绿环保科技股份有限公司 | Particulate matter concentration measuring system in low-concentration particulate matter on-line tester |
| CN106918390A (en) * | 2017-04-18 | 2017-07-04 | 昆山金鸣光电科技有限公司 | A kind of receiving terminal optical power control system for optical fiber vibration sensing |
| CN209231210U (en) * | 2018-12-24 | 2019-08-09 | 河北大学 | A kind of adjustable near-infrared of transmission power receives and launch control unit |
-
2018
- 2018-12-24 CN CN201811579721.7A patent/CN109374576B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5733042A (en) * | 1994-12-26 | 1998-03-31 | Commissariat A L'energie Atomique | Device and method for testing an optical element subjected to radiation |
| JP2005217468A (en) * | 2004-01-27 | 2005-08-11 | Nec Kansai Ltd | Photocurrent/voltage conversion circuit |
| CN1715865A (en) * | 2005-07-22 | 2006-01-04 | 公安部沈阳消防研究所 | Smoke concentration detector |
| CN102262057A (en) * | 2011-04-28 | 2011-11-30 | 北京农业信息技术研究中心 | Automatic targeting/spraying target spectral detector based on sine-wave modulation |
| CN103149172A (en) * | 2013-02-28 | 2013-06-12 | 山东大学 | Method for improving stability of infrared gas detection system based on digital potentiometer |
| CN104849238A (en) * | 2015-06-10 | 2015-08-19 | 浙江诸暨奇创电子科技有限公司 | Infrared turbidity detection device |
| CN105547951A (en) * | 2016-01-29 | 2016-05-04 | 中绿环保科技股份有限公司 | Particulate matter concentration measuring system in low-concentration particulate matter on-line tester |
| CN106918390A (en) * | 2017-04-18 | 2017-07-04 | 昆山金鸣光电科技有限公司 | A kind of receiving terminal optical power control system for optical fiber vibration sensing |
| CN209231210U (en) * | 2018-12-24 | 2019-08-09 | 河北大学 | A kind of adjustable near-infrared of transmission power receives and launch control unit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109374576A (en) | 2019-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN209231210U (en) | A kind of adjustable near-infrared of transmission power receives and launch control unit | |
| CN109374576B (en) | Near infrared receiving and transmitting control device with adjustable transmitting power | |
| CN104020346A (en) | Micro-current signal extraction system | |
| CN113447750B (en) | Optical device test circuit | |
| CN102323466A (en) | Weak signal acquisition and processing circuit | |
| CN202693474U (en) | Turbidity sensor for water quality on producing line detection | |
| CN109270026B (en) | Near infrared receiving and transmitting control device | |
| CN105182061A (en) | Ceramic machinery equipment AC current acquisition circuit | |
| CN101162198A (en) | Mod/demod method suitable for large caliber laser scintilloscope | |
| CN104165862A (en) | Laser driving signal generator of laser gas analyzer | |
| CN204631100U (en) | Be applicable to the high-speed light isolation voltage sensor of lightning surge environment | |
| CN209198313U (en) | A kind of near-infrared receives and launch control unit | |
| CN204166094U (en) | A kind of LED photovoltaic parameter measurement system | |
| CN208208052U (en) | A kind of smoke sensor device and its control circuit | |
| CN102778434A (en) | Turbidity transducer for online detection of water quality and detection method thereof | |
| CN102854114A (en) | Optoelectronic signal acquisition and conversion device for sensor used for detecting dust concentration | |
| CN205120534U (en) | Dust detection device | |
| CN110601724B (en) | Weak photoelectric signal anti-interference long-distance transmission system | |
| CN210953809U (en) | Variable light form gas sensor | |
| CN208283224U (en) | A kind of preceding scattering dust measurement instrument sample gas pond photoelectric detective circuit | |
| CN103472012A (en) | Signal conditioning circuit used for monitoring crop growth information | |
| CN103487631B (en) | Modulation-demodulation type current sensor | |
| CN206411008U (en) | A kind of dust amount detecting device of the screen pack of VMC | |
| CN202748309U (en) | Photoelectric signal acquiring and converting device for optical dust concentration sensor | |
| CN102866089A (en) | Photoelectric signal collection conversion device for dust concentration sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |