CN114390748A - Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe - Google Patents
Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe Download PDFInfo
- Publication number
- CN114390748A CN114390748A CN202011113997.3A CN202011113997A CN114390748A CN 114390748 A CN114390748 A CN 114390748A CN 202011113997 A CN202011113997 A CN 202011113997A CN 114390748 A CN114390748 A CN 114390748A
- Authority
- CN
- China
- Prior art keywords
- circuit
- resistor
- output end
- led
- led lamp
- 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.)
- Pending
Links
- 239000000523 sample Substances 0.000 title claims abstract description 42
- 238000005070 sampling Methods 0.000 claims abstract description 35
- 230000003321 amplification Effects 0.000 claims abstract description 11
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 11
- 239000013078 crystal Substances 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/20—Controlling the colour of the light
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses a circuit for realizing threshold LED indication by a 4-20mA ultraviolet probe, and relates to the technical field of ultraviolet probe circuits. The input end of a circuit for outputting a 4-20mA current signal by the 4-20mA ultraviolet probe is connected with 24V direct current, the output end of the circuit is connected with a differential operational amplification circuit, the output end of the circuit for outputting the 4-20mA current signal by the 4-20mA ultraviolet probe is also connected with a first sampling resistor in series to an output end of a 4-20mA Out, the output end of the differential operational amplification circuit is connected with a comparator circuit, the differential operational amplification circuit and the comparator circuit form a current sampling comparison circuit, and the output end of the comparator circuit is connected with a first path of indicator lamp and a second path of indicator lamp through an LED driving circuit. The invention realizes the functions of transmitting and supplying 4-20mA current signals and indicating the function of being more than or less than a specific threshold value, judges the ultraviolet intensity by the LED threshold value indicating lamp and has wide application prospect.
Description
Technical Field
The invention relates to the technical field of ultraviolet probe circuits, in particular to a circuit for realizing threshold LED indication by a 4-20mA ultraviolet probe.
Background
At present, all ultraviolet probes on the market do not judge the ultraviolet intensity through the color of an LED, and the most widely adopted in industry is to transmit temperature, pressure, speed, irradiation value and the like by using analog quantity 4-20mA current signals, so that the ultraviolet probe has the advantages of long transmission distance, strong anti-interference capability and the like. The technical difficulty of the circuit for realizing the threshold LED indication by the 4-20mA ultraviolet probe is as follows:
the current sampling circuit and the LED drive circuit share the power supply problem: with the change of the detected ultraviolet value reflecting the change of the output current in the range of 4-20mA, the current sampling circuit and the LED driving circuit can not obtain stable working voltage and work abnormally, and the caused voltage drop can possibly influence the signal acquisition of the equipment end.
Connecting the current sampling circuit and the LED drive circuit in parallel between two signal lines for power supply: the current of the power supply ground wire generated by the current sampling circuit and the LED driving circuit during working is converged into the current signal output line, so that the output current signal is obviously larger, and the measurement precision is seriously influenced.
In order to solve the problems, a novel circuit for realizing threshold LED indication by using a 4-20mA ultraviolet probe is particularly necessary.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide the circuit for realizing the threshold LED indication by the 4-20mA ultraviolet probe, the circuit principle is simple, the design is reasonable, the functions of transmitting and supplying 4-20mA current signals and the function of LED indication larger or smaller than a specific threshold are realized, the size of the ultraviolet intensity is judged by the LED threshold indicator lamp, the practicability is high, and the popularization and the use are easy.
In order to achieve the purpose, the invention is realized by the following technical scheme: the circuit for realizing threshold LED indication by the 4-20mA ultraviolet probe comprises a 4-20mA current signal circuit output by the 4-20mA ultraviolet probe, a differential operational amplification circuit, a comparator circuit and an LED drive circuit, wherein the input end of the 4-20mA current signal circuit output by the 4-20mA ultraviolet probe is connected with 24V direct current, the output end of the 4-20mA current signal circuit output by the 4-20mA ultraviolet probe is connected with the differential operational amplification circuit, the output end of the 4-20mA current signal circuit output by the 4-20mA ultraviolet probe is also connected with a first sampling resistor to a 4-20mA Out output end in series, the output end of the differential operational amplification circuit is connected with the comparator circuit, the differential operational amplification circuit and the comparator circuit form a current sampling comparison circuit, and the output end of the comparator circuit is connected with a first path of indicator lamp through the LED drive circuit, The second path of indicator light is connected.
Preferably, the differential operational amplifier circuit comprises an operational amplifier, a second resistor and a fifth resistor, the comparator circuit comprises a comparator, a sixth resistor, a seventh sampling resistor and an eighth sampling resistor, the LED driving circuit comprises a ninth resistor, a thirteenth resistor and a transistor switch tube, the first indicator light comprises three first LED lights, a second LED light and a third LED light which are connected in parallel, and the second indicator light comprises three fourth LED lights, a fifth LED light and a sixth LED light which are connected in series; the output end of the circuit for outputting the 4-20mA current signal by the 4-20mA ultraviolet probe is connected with a second resistor to the positive input end of an operational amplifier, the positive input end of the operational amplifier is connected with a fourth resistor to a ground end, the output end of the circuit for outputting the 4-20mA current signal by the 4-20mA ultraviolet probe is connected with a first sampling resistor to a 4-20mA Out output end in series, the 4-20mA Out output end is connected with a third resistor to the negative input end of the operational amplifier, a fifth resistor is connected between the negative input end and the output end of the operational amplifier, the output end of the operational amplifier is connected with a sixth resistor to the positive input end of a comparator, the negative input end of the comparator is respectively connected with a seventh sampling resistor, an eighth sampling resistor to a 24V direct current and a ground end, and the output end of the comparator is connected with a ninth resistor to the base electrode of a transistor switch tube, the collector of the transistor is sequentially connected with a parallel circuit consisting of a first LED lamp, a second LED lamp and a third LED lamp, a parallel circuit consisting of a tenth resistor, an eleventh resistor and a twelfth resistor to 24V direct current, a node between the two parallel circuits is sequentially connected with a fourth LED lamp, a fifth LED lamp, a sixth LED lamp, a thirteenth resistor to the emitting electrode of the transistor in series, and the emitting electrode of the transistor is grounded.
Preferably, the 4-20mA current signal output line of the 4-20mA current signal output circuit of the 4-20mA ultraviolet probe is separated and independent from the current sampling comparison circuit and the power supply ground wire of the LED driving circuit, so that the two circuit loops can work in a matched mode and cannot generate large influence between the two circuit loops.
The invention has the beneficial effects that: the circuit adopts a three-wire circuit structure, realizes the functions of transmitting and supplying 4-20mA current signals and the function of LED indicating more than or less than a specific threshold value, judges the size of ultraviolet intensity through the LED threshold value indicating lamp and has wide application prospect.
Drawings
The invention is described in detail below with reference to the drawings and the detailed description;
FIG. 1 is a functional block diagram of the present invention;
fig. 2 is a circuit diagram of the present invention.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.
Referring to fig. 1-2, the following technical solutions are adopted in the present embodiment: the circuit for realizing threshold LED indication by the 4-20mA ultraviolet probe comprises a 4-20mA current signal circuit UA output by the 4-20mA ultraviolet probe, a differential operational amplifier circuit 1, a comparator circuit 2 and an LED drive circuit 3, wherein the input end of the 4-20mA current signal circuit UA output by the 4-20mA ultraviolet probe is connected with 24V direct current, the output end of the 4-20mA current signal circuit UA output by the 4-20mA ultraviolet probe is connected with the differential operational amplifier circuit 1, the output end of the 4-20mA current signal circuit UA output by the 4-20mA ultraviolet probe is also connected with a first sampling resistor R1 to a 4-20mA Out output end in series, the output end of the differential operational amplifier circuit 1 is connected with the comparator circuit 2, the differential operational amplifier circuit 1 and the comparator circuit 2 form a current sampling comparator circuit, and the output end of the comparator circuit 2 is connected with a first indicator LED1 through the LED drive circuit 3, The second light LED 2.
It is worth noting that the differential operational amplifier circuit 1 is composed of an operational amplifier OPA, a second resistor R2-a fifth resistor R5, the comparator circuit 2 is composed of a comparator COM, a sixth resistor R6, a seventh sampling resistor R7 and an eighth sampling resistor R8, the LED driving circuit 3 includes a ninth resistor R9-a thirteenth resistor R13 and a transistor switching tube Q1, the first indicator light LED1 is composed of three first LED lamps DB1, a second LED lamp DB2 and a third LED lamp DB3 which are connected in parallel, and the second indicator light LED2 is composed of three fourth LED lamps DR1, fifth LED lamps DR2 and sixth LED lamps DR3 which are connected in series.
The output end of the circuit UA outputting 4-20mA current signals by the 4-20mA ultraviolet probe is connected with a second resistor R2 to the positive input end of an operational amplifier OPA, the positive input end of the operational amplifier OPA is connected with a fourth resistor R4 to the ground terminal, the output end of the circuit UA outputting 4-20mA current signals by the 4-20mA ultraviolet probe is connected with a first sampling resistor R1 to a 4-20mA Out output end in series, the 4-20mA Out output end is connected with a third resistor R3 to the negative input end of the operational amplifier OPA, a fifth resistor R5 is connected between the negative input end and the output end of the operational amplifier OPA, the output end of the operational amplifier OPA is connected with a sixth resistor R6 to the positive input end of a comparator COM, the negative input end of the comparator COM is respectively connected with a seventh sampling resistor R7, an eighth sampling resistor R8 to 24V direct current and the ground terminal, the output end of the comparator COM is connected with a ninth resistor R9 to the base of a crystal switch tube Q1, the collector of the transistor Q1 is connected in sequence with the parallel circuit composed of the first LED lamp DB1, the second LED lamp DB2 and the third LED lamp DB3, the parallel circuit of the tenth resistor R10, the eleventh resistor R11 and the twelfth resistor R12 to 24V dc, the node between the two parallel circuits is connected in sequence with the emitter of the transistor Q1 in series from the fourth LED lamp DR1, the fifth LED lamp DR2, the sixth LED lamp DR3 and the thirteenth resistor R13, and the emitter of the transistor Q1 is grounded.
The working principle of the specific embodiment is as follows: the first sampling resistor R1 is connected in series between the 4-20mA current signal circuit UA output by the 4-20mA ultraviolet probe and the 4-20mA Out output terminal, voltages U1 and U2 are respectively generated at two ends of the first sampling resistor R1 and are sent to the differential operational amplifier circuit 1, and the amplified voltage Uo = (R2+ R5). times.R 4. times.U 2/[ (R3+ R5). times.R 2] -R5. times.U 1/R2. Uo is fed into a comparator circuit 2, the compared voltage Uc = VCC/(R7+ R8) × R8, the comparator circuit 2 compares Uc with Uo:
firstly, when the measured ultraviolet irradiation value is large, 4-20mA current signals output by a 4-20mA current signal circuit UA output by a 4-20mA ultraviolet probe are large, at the moment, the output voltage value UO of a differential operation amplifying circuit 1 is larger than a compared voltage value Uc, Ur outputs high level to an LED driving circuit 3, at the moment, a crystal switch tube Q1 is conducted, and as a first LED lamp DB1, a second LED lamp DB2 and a third LED lamp DB3 are connected in parallel, the conducting voltage is VF; the fourth LED lamp DR1, the fifth LED lamp DR2 and the sixth LED lamp DR3 are connected in series, and the on-voltage is 3VF, so that the first LED lamp DB1, the second LED lamp DB2 and the third LED lamp DB3 are turned on, and the fourth LED lamp DR1, the fifth LED lamp DR2 and the sixth LED lamp DR3 are turned off, indicating that the ultraviolet radiation value is greater than the threshold value.
And secondly, when the measured ultraviolet radiation value is smaller, the 4-20mA current signal output by the 4-20mA ultraviolet probe output 4-20mA current signal circuit UA is smaller, the voltage value UO output by the differential operation amplifying circuit 1 is smaller than the compared voltage value Uc, then Ur outputs a low level to the LED driving circuit 3, the crystal switching tube Q1 is cut off, the first LED lamp DB1, the second LED lamp DB2 and the third LED lamp DB3 are turned off, the fourth LED lamp DR1, the fifth LED lamp DR2 and the sixth LED lamp DR3 are turned on, and the ultraviolet radiation value is indicated to be smaller than the threshold value.
The specific embodiment adds a current sampling comparison circuit and an LED drive circuit on the basis of a traditional two-wire ultraviolet probe circuit outputting 4-20mA current signals, and sets a power ground wire independently to separate a 4-20mA current signal output line from the current sampling comparison circuit and the power ground wire of the LED drive circuit, so that two circuit loops can work in a matched manner and cannot generate large influence with each other; VCC and 4-20mA Out provide power for the ultraviolet probe circuit and form a loop of 4-20mA current signals, VCC and GND provide power loops for the current sampling comparison circuit and the LED drive circuit, thus the current sampling comparison circuit and the LED drive circuit can obtain stable power and work normally, the loop current of the current sampling comparison circuit and the LED drive circuit is greatly reduced to flow into the loop of 4-20mA current signals, and the influence on 4-20mA current output signals is avoided. The circuit simultaneously realizes the functions of transmitting and supplying 4-20mA current signals and the indicating function of being larger than or smaller than a specific threshold value through three lines of a 4-20mA ultraviolet probe, the larger or smaller than the specific threshold value can be judged through the color of an LED, and the size of the ultraviolet intensity is judged through an LED threshold value indicating lamp, so that the circuit is practical and reliable and has wide application prospect.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (2)
- The circuit for realizing threshold LED indication by the 1.4-20mA ultraviolet probe is characterized by comprising a 4-20mA ultraviolet probe output 4-20mA current signal circuit (UA), a differential operation amplification circuit (1), a comparator circuit (2) and an LED drive circuit (3), wherein the input end of the 4-20mA current signal circuit (UA) output by the 4-20mA ultraviolet probe is connected with 24V direct current, the output end of the 4-20mA current signal circuit (UA) output by the 4-20mA ultraviolet probe is connected with the differential operation amplification circuit (1), the output end of the 4-20mA current signal circuit (UA) output by the 4-20mA ultraviolet probe is also connected with a first sampling resistor (R1) to a 4-20mA Out output end in series, the output end of the differential operation amplification circuit (1) is connected with the comparator circuit (2), and the differential operation amplification circuit (1) and the comparator circuit (2) form a current sampling comparison circuit, the output end of the comparator circuit (2) is connected with the first indicator light (LED1) and the second indicator light (LED2) through the LED driving circuit (3).
- 2. The 4-20mA ultraviolet probe of claim 1 implementing threshold LED indication circuitry, characterized in that the differential operational amplifier circuit (1) is composed of an operational amplifier (OPA), a second resistor (R2) -a fifth resistor (R5), the comparator circuit (2) consists of a Comparator (COM), a sixth resistor (R6), a seventh sampling resistor (R7) and an eighth sampling resistor (R8), the LED driving circuit (3) comprises a ninth resistor (R9) -a thirteenth resistor (R13) and a transistor switching tube (Q1), the first road indicator lamp (LED1) consists of three first LED lamps (DB1), a second LED lamp (DB2) and a third LED lamp (DB3) which are connected in parallel, and the second road indicator lamp (LED2) consists of three fourth LED lamps (DR1), a fifth LED lamp (DR2) and a sixth LED lamp (DR3) which are connected in series;the output end of the 4-20mA ultraviolet probe output 4-20mA current signal circuit (UA) is connected with a second resistor (R2) to the positive input end of an operational amplifier (OPA), the positive input end of the operational amplifier (OPA) is connected with a fourth resistor (R4) to the ground end, the output end of the 4-20mA ultraviolet probe output 4-20mA current signal circuit (UA) is connected with a first sampling resistor (R1) to a 4-20mA Out output end in series, the 4-20mA Out output end is connected with a third resistor (R3) to the negative input end of the operational amplifier (OPA), a fifth resistor (R5) is connected between the negative input end and the output end of the operational amplifier (OPA), the output end of the operational amplifier (OPA) is connected with a sixth resistor (R6) to the positive input end of a Comparator (COM), and the negative input end of the Comparator (COM) is respectively connected with a seventh sampling resistor (R7), An eighth sampling resistor (R8) is connected with a 24V direct current, the output end of the Comparator (COM) is connected with a base electrode of a ninth resistor (R9) to a transistor switch tube (Q1), a collector electrode of the transistor switch tube (Q1) is sequentially connected with a parallel circuit consisting of a first LED lamp (DB1), a second LED lamp (DB2) and a third LED lamp (DB3), a parallel circuit consisting of a tenth resistor (R10), an eleventh resistor (R11) and a twelfth resistor (R12) is connected with the 24V direct current, a node between the two parallel circuits is sequentially connected with an emitter electrode of the fourth LED lamp (1), the fifth LED lamp (DR2), the sixth LED lamp (DR3), a thirteenth resistor (R13) to the transistor switch tube (Q1), and an emitter electrode of the transistor switch tube (Q1) is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011113997.3A CN114390748A (en) | 2020-10-18 | 2020-10-18 | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011113997.3A CN114390748A (en) | 2020-10-18 | 2020-10-18 | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114390748A true CN114390748A (en) | 2022-04-22 |
Family
ID=81193574
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011113997.3A Pending CN114390748A (en) | 2020-10-18 | 2020-10-18 | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114390748A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4279254A (en) * | 1978-10-30 | 1981-07-21 | Paul B. Elder Company | Ultraviolet light control |
| RU2154811C2 (en) * | 1998-11-04 | 2000-08-20 | Закрытое акционерное общество "Лаборатория импульсной техники" | Circuit diagram of unit processing signal from sensor of intensity of ultraviolet radiation |
| CN103323109A (en) * | 2013-06-21 | 2013-09-25 | 中国科学院上海技术物理研究所 | Light intensity detecting system for mobile phone sterilizer ultraviolet lamp tube |
| CN207991690U (en) * | 2018-04-02 | 2018-10-19 | 河南佳玉宝厨房设备有限公司 | The UV-C uitraviolet intensity detection circuits of smoke purifier |
| CN213244413U (en) * | 2020-10-18 | 2021-05-18 | 北京东方百士电子有限公司 | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe |
-
2020
- 2020-10-18 CN CN202011113997.3A patent/CN114390748A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4279254A (en) * | 1978-10-30 | 1981-07-21 | Paul B. Elder Company | Ultraviolet light control |
| RU2154811C2 (en) * | 1998-11-04 | 2000-08-20 | Закрытое акционерное общество "Лаборатория импульсной техники" | Circuit diagram of unit processing signal from sensor of intensity of ultraviolet radiation |
| CN103323109A (en) * | 2013-06-21 | 2013-09-25 | 中国科学院上海技术物理研究所 | Light intensity detecting system for mobile phone sterilizer ultraviolet lamp tube |
| CN207991690U (en) * | 2018-04-02 | 2018-10-19 | 河南佳玉宝厨房设备有限公司 | The UV-C uitraviolet intensity detection circuits of smoke purifier |
| CN213244413U (en) * | 2020-10-18 | 2021-05-18 | 北京东方百士电子有限公司 | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN213244413U (en) | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe | |
| CN107677606B (en) | Detection circuit based on photometry | |
| CN114390748A (en) | Circuit for realizing threshold LED indication by 4-20mA ultraviolet probe | |
| CN215893785U (en) | Result-visualized portable photoelectric detector | |
| CN105044625A (en) | LED lamp multi-parameter detection device | |
| CN202652655U (en) | Led constant current drive circuit | |
| CN108598858B (en) | Laser light source light intensity automatic control system for front scattering sample gas cell | |
| CN201196673Y (en) | Multifunctional DC pen | |
| CN103091634A (en) | Battery level indicating circuit and indicating device and lamp | |
| CN204666800U (en) | A kind of LED Multi-parameter detection device | |
| CN213812717U (en) | Underground pressure alarm device | |
| CN214278404U (en) | Non-contact infrared pulse detection device for intelligent electric meter | |
| CN202634851U (en) | Constant-current driving circuit for LEDs in system test | |
| CN102175688A (en) | Colour code detector | |
| CN204903713U (en) | Novel logical state test pen device | |
| CN210129002U (en) | Laser light power efficiency ratio measuring device of carbon dioxide laser | |
| CN112710453A (en) | LED lamp illumination detection circuit | |
| CN208190971U (en) | A kind of the lamp bead string detection circuit and LED street lamp of lamp plate | |
| CN220874521U (en) | Three-wire system proximity sensor | |
| CN206411008U (en) | A kind of dust amount detecting device of the screen pack of VMC | |
| CN221002984U (en) | Automobile ignition test pen | |
| CN209327497U (en) | A kind of pen type testing device | |
| CN221746172U (en) | Test pencil circuit and test pencil | |
| CN105246212A (en) | Novel LED (Light Emitting Diode) dimming circuit | |
| CN221598182U (en) | LED driving circuit |
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 |