CN210294391U - Current measurement circuit based on I-F conversion - Google Patents
Current measurement circuit based on I-F conversion Download PDFInfo
- Publication number
- CN210294391U CN210294391U CN201920753731.1U CN201920753731U CN210294391U CN 210294391 U CN210294391 U CN 210294391U CN 201920753731 U CN201920753731 U CN 201920753731U CN 210294391 U CN210294391 U CN 210294391U
- Authority
- CN
- China
- Prior art keywords
- circuit
- current
- charging
- charging circuit
- operational amplifier
- 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
- 238000005259 measurement Methods 0.000 title claims abstract description 22
- 238000006243 chemical reaction Methods 0.000 title claims description 8
- 238000012545 processing Methods 0.000 claims abstract description 13
- 230000005540 biological transmission Effects 0.000 claims abstract description 5
- 239000003990 capacitor Substances 0.000 claims description 14
- 238000004364 calculation method Methods 0.000 claims description 4
- 230000001939 inductive effect Effects 0.000 claims description 3
- 231100000673 dose–response relationship Toxicity 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 4
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000012360 testing method Methods 0.000 abstract description 3
- 230000033228 biological regulation Effects 0.000 abstract description 2
- 238000007493 shaping process Methods 0.000 description 6
- 230000003321 amplification Effects 0.000 description 5
- 238000003199 nucleic acid amplification method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003904 radioactive pollution Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Images
Landscapes
- Measurement Of Radiation (AREA)
Abstract
The utility model discloses a current measurement circuit based on I-F transform, this measuring circuit is including the charging circuit who is used for induced-current for enlarge the high resistance operational amplifier circuit of the electric current that charging circuit sensed and convert to voltage, a multichannel selection circuit for data transmission, reverse charging circuit, and data processing circuit. The utility model provides a measuring circuit and measuring method form closed-loop control, can come real-time regulation according to the current variation on the charging circuit, have satisfied the test of high range promptly, have improved low dose response sensitivity again.
Description
Technical Field
The utility model relates to a measuring circuit especially relates to a current measurement circuit based on I-F transform.
Background
In radio frequency measurements it is often necessary to measure slowly changing and very weak electrical signals (10)-7～10-15A or even less) are measured, e.g., current signal output by the ionization chamber, current signal output by the photomultiplier, and charged ionization provided by the acceleratorThe sub-beam current and the like and the reradiation field mainly measure the radiation of the seeds for the purposes of controlling the dosage of a working site, detecting the radioactive pollution of the environment and the like, and belong to the measurement of weak current. Obviously, the ordinary ammeter cannot measure the smiling current, so the current to be measured needs to be amplified or converted for measurement, and at present, the measurement of the small current mostly adopts the following two modes:
1. the direct voltage amplification measurement mode adopts the circuit principle as shown in fig. 1, and mainly comprises: the circuit comprises a high-resistance, front-amplifying high-resistance amplifier, an analog shaping circuit, a main-amplifying high-resistance amplifier, a comparator and a TTL shaping circuit; the measurement principle is as follows: the input small current I is converted into voltage V through a high-resistance pre-amplifier, the voltage V is amplified to a measurable amplitude through an analog shaping circuit and a main amplifier, and the voltage V is converted into a digital signal through a comparator and a TTL shaping circuit and is output, so that the measurement of the small current is achieved.
2. The I-F conversion current frequency measuring mode, the measuring circuit adopts the circuit principle as shown in figure 2, mainly comprises: the circuit comprises a charging capacitor, a front-end high-impedance amplifier, a discharge control circuit, a comparator and a TTL shaping circuit. The measurement principle is as follows: the input small current I reaches a certain amplitude through the charging capacitor after passing through the front-end high-impedance amplifier, the comparator is turned over, the TTL shaping circuit triggers two paths of outputs after detecting the turning over of the comparator, one path of feedback is used for controlling the discharging circuit, and the other path of signal is finally output, namely the current to be measured.
Both of the above methods can measure small currents, but have the following problems:
1. the direct voltage amplification measurement mode has the disadvantages of large amplification factor, difficult noise suppression, large temperature influence on high resistance, large volume and low measurement precision.
2. The I-F conversion current frequency measurement mode overcomes all the defects of the first direct voltage amplification measurement mode, and has the advantages of stable test and wide range, but the defects of high range, insensitive low-dose response and high requirements on production debugging environment.
SUMMERY OF THE UTILITY MODEL
In order to solve the problems existing in the prior art, the utility model aims to provide a current measuring circuit based on I-F conversion, which has high measuring range, low dosage and high sensitivity.
To achieve the objective of the present invention, the current measuring circuit based on I-F conversion provided herein comprises:
a charging circuit for inducing current;
the high-resistance operational amplifier circuit is used for amplifying the current sensed by the charging circuit and converting the current into voltage;
the multi-path selection circuit is used for data transmission and divides the high-resistance operational amplifier output signal into two paths, one path is output to the data processor, the other path is used for the reverse charging circuit, and meanwhile, the data processor controls reverse charging through the multi-path selection circuit;
a reverse charging circuit for performing reverse charging on the charging circuit; and
and the data processing circuit receives the data input by the multi-path selection circuit, performs ADC (analog to digital converter) processing and calculation on the data to obtain current, generates logic level and charges the charging circuit through the multi-path selection circuit and the reverse charging circuit.
The utility model has the advantages that: the utility model provides a measuring circuit and measuring method form closed-loop control, can come real-time regulation according to the current variation on the charging circuit, have satisfied the test of high range promptly, have improved low dose response sensitivity again.
Drawings
FIG. 1 is a schematic block diagram of a conventional direct voltage amplification measurement method;
FIG. 2 is a schematic block diagram of a conventional I-F conversion current frequency measurement;
fig. 3 is a schematic circuit block diagram of a current measuring circuit provided by the present invention;
fig. 4 is a circuit diagram of a current measuring circuit provided by the present invention.
Detailed Description
The claimed invention will now be described in further detail with reference to the accompanying drawings and examples.
In order to solve the insensitive problem of low dose response of the existing small current measuring circuit, the utility model provides a high-range, sensitive high current measuring circuit based on I-F transform of low dose response here.
The circuit principle of the measuring circuit provided herein is shown in fig. 3, which includes a charging circuit for inducing current, a high-impedance operational amplifier circuit for amplifying the current induced by the charging circuit and converting the current into voltage, a multiplexing circuit for data transmission, an inverse charging circuit, and a data processing circuit. The method comprises the steps of switching on a power supply, when an ionization chamber detects that rays generate a certain amount of negative current to be loaded on a charging circuit, slowly reducing the voltage on the charging circuit due to weak current to form a slowly-reduced charging oblique line, generating a slowly-increased charging oblique line after the rays are reversely reflected by a high-resistance operational amplifier circuit, transmitting the charging oblique line to a data processing circuit through a multi-path selection circuit, carrying out ADC (analog to digital converter) processing and calculation on received data by the data processing circuit to obtain current, generating a logic level, and controlling the reverse charging circuit to reversely charge the charging circuit to enable a cyclic sawtooth wave charging voltage to be formed on the charging circuit.
The utility model provides a measuring circuit can be used for measuring the current signal of ionization chamber output, the current signal of photomultiplier output, the charged ion's that the accelerator provided beam current, radiometric measurement etc for when measuring the radiant quantity, when the slope of charging the slash changes, detect relevant undercurrent promptly (there is the ray promptly), calculate through data processing circuit and can obtain corresponding radiation dose.
The utility model discloses charging circuit, high resistance operational amplifier circuit, multichannel selection circuit, reverse charging circuit and data processing circuit among the recording measuring circuit can adopt any one kind that has now, adopts following circuit structure here respectively:
the charging circuit is composed of a capacitor C1, the high-resistance operational amplifier circuit is composed of a high-resistance operational amplifier U1, the reverse charging circuit is composed of a switch tube Q1, the multiplexer is composed of a U2, the data processing circuit is composed of a programmable singlechip U3, and the specific circuit connection relation is shown in figure 4.
A first polar plate of the capacitor C1 is connected with a high-resistance operational amplifier U1 and serves as an input end lin, a second polar plate of the capacitor C1 is grounded through a resistor R18 and is also connected with the multiplexer U2 through a capacitor C17, and an output end of the high-resistance operational amplifier U1 is also grounded through a resistor R18; and the multiplexer U2 is in communication connection with the singlechip U3 to realize data transmission. The signal output terminal of the multiplexer U2 is also connected to the first plate of the capacitor C1 through a transistor Q1.
After power-on work, when the ionization chamber detects that rays exist, a certain amount of negative current is loaded on the input end lin, the capacitor C1 and the resistor R18 are used for reversely charging the capacitor C1, the voltage of the capacitor C1 is slowly reduced from +0V due to weak current, the charging inclined line slowly rising from +0V is generated after being reversely rotated by the high-resistance operational amplifier U1, the charging inclined line is transmitted to the internal ADC of the singlechip U3 through the multiplexer U2 for real-time sampling and analysis, when the inclination of the charging inclined line changes, related rays are detected, equivalent radiation dose is obtained through a corresponding algorithm of the singlechip, meanwhile, the singlechip U3 generates a logic level, the slowly rising charging inclined line is loaded on the first plate of the capacitor C1 through the multiplexer U2, the switch tube Q1 and the resistor R18 to reversely charge the capacitor C1, therefore, a cyclic sawtooth wave charging voltage is formed on the first plate of the capacitor C1, the ionization chamber generates charging curves with different slopes according to the detected amount of rays, and the corresponding dose is obtained through analysis and calculation of the slopes of the charging curves, so that radiation detection is completed.
In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.
Claims (4)
1. A current measurement circuit based on I-F conversion is characterized in that: the circuit comprises a first circuit and a second circuit,
a charging circuit for inducing current;
the high-resistance operational amplifier circuit is used for amplifying the current sensed by the charging circuit and converting the current into voltage;
the multi-path selection circuit is used for data transmission and divides the high-resistance operational amplifier output signal into two paths, one path is output to the data processor, the other path is used for the reverse charging circuit, and meanwhile, the data processor controls reverse charging through the multi-path selection circuit;
a reverse charging circuit for performing reverse charging on the charging circuit; and
and the data processing circuit receives the data input by the multi-path selection circuit, performs ADC (analog to digital converter) processing and calculation on the data to obtain current, generates logic level and reversely charges the charging circuit through the multi-path selection circuit and the reverse charging circuit.
2. The I-F transform based current measurement circuit of claim 1, wherein: the charging circuit is a capacitor C1.
3. The I-F transform based current measurement circuit of claim 1, wherein: the high-resistance operational amplifier circuit comprises a high-resistance operational amplifier.
4. The I-F transform based current measurement circuit of claim 1, wherein: the data processing circuit is a single chip microcomputer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920753731.1U CN210294391U (en) | 2019-05-23 | 2019-05-23 | Current measurement circuit based on I-F conversion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920753731.1U CN210294391U (en) | 2019-05-23 | 2019-05-23 | Current measurement circuit based on I-F conversion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210294391U true CN210294391U (en) | 2020-04-10 |
Family
ID=70070646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920753731.1U Active CN210294391U (en) | 2019-05-23 | 2019-05-23 | Current measurement circuit based on I-F conversion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210294391U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110058078A (en) * | 2019-05-23 | 2019-07-26 | 上海仁机仪器仪表有限公司 | A kind of current measurement circuit and measurement method based on I-F transformation |
| CN112987076A (en) * | 2021-02-07 | 2021-06-18 | 中国科学院近代物理研究所 | A Current Intensity Detection System for Weak Beams |
-
2019
- 2019-05-23 CN CN201920753731.1U patent/CN210294391U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110058078A (en) * | 2019-05-23 | 2019-07-26 | 上海仁机仪器仪表有限公司 | A kind of current measurement circuit and measurement method based on I-F transformation |
| CN112987076A (en) * | 2021-02-07 | 2021-06-18 | 中国科学院近代物理研究所 | A Current Intensity Detection System for Weak Beams |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101799496B (en) | Capacitor measurement device and method thereof | |
| WO2017097148A1 (en) | Apparatus, device and method for measuring breakdown voltage | |
| CN210294391U (en) | Current measurement circuit based on I-F conversion | |
| WO2020211515A1 (en) | High-accuracy temperature sensor | |
| CN201532446U (en) | A battery internal resistance testing device | |
| CN108918980A (en) | A kind of capacitance signal measuring circuit and measurement method | |
| CN101963634A (en) | Integrated optical isolation lightning electric field measurement apparatus | |
| CN110058078A (en) | A kind of current measurement circuit and measurement method based on I-F transformation | |
| CN111024761A (en) | Ignition energy measurement method based on high voltage discharge peak detection | |
| CN107688048A (en) | Reverse addition type potentiostat and IV converted measurement circuit available for electrochemical measurement | |
| CN107490585B (en) | It is a kind of to eliminate method and device of the temperature to Si-PIN detectors ɑ energy spectral peak drift effects | |
| CN109743025A (en) | A Wide Input Charge Sensitive Amplifier Based on Charge Distribution Network | |
| Comerma et al. | Front end ASIC design for SiPM readout | |
| CN110618309A (en) | Semiconductor detector leakage current measuring device and measuring method | |
| CN106092147A (en) | A kind of digital integrator for superconducting cyclotron magnetic-field measurement | |
| CN207263686U (en) | A kind of high-precision reversely addition type potentiostat and IV converted measurement circuits | |
| CN212460065U (en) | On-line self-checking device for PET detector front-end circuit based on SiPM | |
| Blanco et al. | A new front-end electronics chain for timing RPCs | |
| CN103472422A (en) | Checking method of geoelectrical wave detecting instrument | |
| Ye et al. | A new capacitance measuring system for capacitive sensor for moving target detection | |
| CN109387691A (en) | The atomic low current linear measuring circuit of femto-ampere grade | |
| CN110133708B (en) | Nuclear pulse signal measuring device and measuring method | |
| CN210835177U (en) | Battery detection circuit | |
| CN112987070A (en) | Detection signal processing method, device and circuit | |
| CN207882426U (en) | A kind of system for being calibrated to the absolute delay time |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |