CN109839534B - Power current isolation acquisition circuit - Google Patents
Power current isolation acquisition circuit Download PDFInfo
- Publication number
- CN109839534B CN109839534B CN201711211886.4A CN201711211886A CN109839534B CN 109839534 B CN109839534 B CN 109839534B CN 201711211886 A CN201711211886 A CN 201711211886A CN 109839534 B CN109839534 B CN 109839534B
- Authority
- CN
- China
- Prior art keywords
- unit
- isolation
- power supply
- sampling resistor
- power
- 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
Images
Landscapes
- Arrangements For Transmission Of Measured Signals (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention belongs to the technical field of airborne analog quantity acquisition, and particularly relates to a power current isolation acquisition circuit based on floating ground power supply. The circuit comprises an isolation power supply unit, a sampling resistor, a signal conditioning unit, an A/D conversion unit and an isolation optocoupler unit, wherein the sampling resistor is connected in series with the power circuit, the voltage at two ends of the sampling resistor is conditioned by the signal conditioning unit and then is sent to the A/D conversion unit, and the conversion result of the A/D conversion unit is transmitted to the electromechanical management computer through the isolation optocoupler unit; one end of the isolation optocoupler unit is powered by an isolation power supply unit, and the other end of the isolation optocoupler unit is powered by a digital power supply; the A/D conversion unit and the signal conditioning unit are powered by the isolation power supply unit; the positive end of the isolation power supply unit is connected with the current input end of the sampling resistor. The power current isolation acquisition circuit is provided, and high-precision isolation acquisition of power current is realized.
Description
Technical Field
The invention belongs to the technical field of airborne analog quantity acquisition, and particularly relates to a power current isolation acquisition circuit based on floating ground power supply.
Background
The aircraft electromechanical system comprises a large amount of requirements for detecting interface power current, a sampling resistor is generally connected in series before the interface power current is converged into a ground wire in the conventional method, the interface power current is calculated by collecting resistor voltage, when each interface is not in one device at the same time, an independent power current loop needs to be set, so that the cable design is heavy, and meanwhile, due to mutual interference and coupling of ground planes, the analog quantity collection precision is reduced and the signal processing complexity is increased; in another conventional method, a sampling resistor is connected in series before a power current flows into an interface, and an analog voltage is transmitted to an a/D conversion module after being converted by an isolation operational amplifier, but the isolation operational amplifier causes the a/D conversion module to lose 2-3 bits of acquisition precision, and reduces the accuracy of power current acquisition.
Disclosure of Invention
The technical problems solved by the invention are as follows: the power current isolation acquisition circuit is provided, and high-precision isolation acquisition of power current is realized.
The technical scheme of the invention is as follows: a power galvanic isolation acquisition circuit, characterized by: the circuit comprises an isolation power supply unit, a sampling resistor, a signal conditioning unit, an A/D conversion unit and an isolation optocoupler unit, wherein the sampling resistor is connected in series with the power circuit, the voltage at two ends of the sampling resistor is conditioned by the signal conditioning unit and then is sent to the A/D conversion unit, and the conversion result of the A/D conversion unit is transmitted to the electromechanical management computer through the isolation optocoupler unit;
one end of the isolation optocoupler unit is powered by an isolation power supply unit, and the other end of the isolation optocoupler unit is powered by a digital power supply;
the A/D conversion unit and the signal conditioning unit are powered by the isolation power supply unit;
the positive end of the isolation power supply unit is connected with the current input end of the sampling resistor.
Preferably, the isolation power supply unit adopts an isolation power supply module or a discrete device isolation mode to realize isolation power supply conversion.
Preferably, the resistance value of the sampling resistor is selected to ensure that the voltage drop of the power current generated by the sampling resistor is not greater than the output voltage of the isolation power supply unit, so that the design complexity of the signal conditioning unit is reduced.
Preferably, the output interface of the a/D conversion unit is an SPI interface.
The invention has the beneficial effects that: the working power supply of the signal conditioning unit, the A/D conversion unit and the signal isolation unit adopts a floating power supply mode, so that the cable loop arrangement is omitted, the A/D conversion precision loss caused by isolation operational amplifier is avoided, the isolation of an analog quantity system and a digital signal processing system is realized, the coupling interference between a power circuit and a digital circuit is eliminated, the anti-interference strength of the system is increased, and the power current acquisition precision is improved.
Drawings
Fig. 1 is a schematic diagram of the principle of the present invention.
FIG. 2 is a schematic view of a 28V bus current collection
Detailed Description
The invention is further described with reference to the following detailed description and accompanying drawings.
Fig. 1 is a functional block diagram of a power galvanic isolation acquisition circuit. Referring to fig. 1, the circuit comprises an isolation power supply unit, a sampling resistor, a signal conditioning unit, an a/D conversion unit and an isolation optocoupler unit, wherein the sampling resistor is connected in series with the power circuit, the voltage at two ends of the sampling resistor is conditioned by the signal conditioning unit and then sent to the a/D conversion unit, and the conversion result of the a/D conversion unit is transmitted to an electromechanical management computer through the isolation optocoupler unit, so that the resolution of the power current value is completed.
Fig. 2 is a schematic diagram showing current collection of a 28V bus, a 5V digital power supply generates a 3.3V power supply through an isolation DC/DC power supply chip DCP020503P, the a/D converter and an isolation optocoupler unit work, the positive terminal of the 3.3V power supply is connected with the 28V bus power supply, and at this time, the voltage of the negative terminal of the 3.3V power supply is actually 24.7V. The power current flows through the sampling resistor of 0.1 omega, is input into the A/D conversion unit after being regulated by the RC resistor network signal, and the input voltage of the A/D conversion unit is Vin3.3-i 0.1, i is the current flowing through the sampling resistor, so the maximum sampling current of the circuit design is 33A, the A/D conversion unit adopts an AD7691 chip of ADI company, the A/D conversion result is sent to the isolation optical coupling unit through an SPI interface, the isolation optical coupling converts the signal into digital logic and sends the digital logic to the electromechanical management computer, and therefore the acquisition and the calculation of power current are completed.
Claims (1)
1. A power galvanic isolation acquisition circuit, characterized by: the circuit comprises an isolation power supply unit, a sampling resistor, a signal conditioning unit, an A/D conversion unit and an isolation optocoupler unit,
the isolation power supply unit adopts an isolation DC/DC power supply chip DCP 020503P; the resistance value of the sampling resistor is 0.1 omega;
the 5V digital power supply generates a 3.3V power supply after passing through a DC/DC power supply chip DCP020503P, and the power supply is used for an A/D conversion unit and an isolation optocoupler unit to work;
the positive end of the 3.3V power supply is connected with a 28V bus power supply, and the voltage of the negative end of the 3.3V power supply is actually 24.7V at the moment;
the power current flows through a sampling resistor of 0.1 omega, is processed by a signal conditioning unit and then is input into an A/D conversion unit, the input voltage Vin of the A/D conversion unit is 3.3-i 0.1, and i is the current flowing through the sampling resistor;
the output end of the A/D conversion unit is sent to the isolation optocoupler unit through the SPI interface, and the isolation optocoupler unit converts the signal into digital logic and sends the digital logic to the electromechanical management computer so as to finish the acquisition and the calculation of power current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711211886.4A CN109839534B (en) | 2017-11-27 | 2017-11-27 | Power current isolation acquisition circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711211886.4A CN109839534B (en) | 2017-11-27 | 2017-11-27 | Power current isolation acquisition circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109839534A CN109839534A (en) | 2019-06-04 |
| CN109839534B true CN109839534B (en) | 2021-08-03 |
Family
ID=66879425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711211886.4A Active CN109839534B (en) | 2017-11-27 | 2017-11-27 | Power current isolation acquisition circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109839534B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112304466B (en) * | 2020-10-20 | 2023-02-28 | 武汉微环控技术有限公司 | Multichannel scanning formula temperature measuring device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560682A (en) * | 2013-07-31 | 2014-02-05 | 佟炳然 | Power driving system |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201497776U (en) * | 2009-09-27 | 2010-06-02 | 哈尔滨理工大学 | Device for realizing power measurement based on resistance sampling by adopting linear photoelectric coupler |
| CN102353825B (en) * | 2011-06-03 | 2014-02-19 | 清华大学 | Resistor sampling isolation current detection circuit |
| CN102944737B (en) * | 2012-11-22 | 2014-12-24 | 中国科学院电工研究所 | Intelligent sensor for measuring high current |
| CN203037722U (en) * | 2013-01-24 | 2013-07-03 | 北京优科利尔能源设备有限公司 | Current sampling circuit |
| CN203117697U (en) * | 2013-01-30 | 2013-08-07 | 桂林风得控科技有限公司 | Current monitoring module |
| CN204065209U (en) * | 2014-06-09 | 2014-12-31 | 厦门乐人电子有限公司 | A kind of electric current isolation detection circuit |
| CN204348191U (en) * | 2014-12-29 | 2015-05-20 | 湖州市埭溪中学 | Intelligent teaching circuit contact performance tester |
| CN206411185U (en) * | 2017-01-09 | 2017-08-15 | 苏州大学 | A kind of automatic switching range high-current detector |
-
2017
- 2017-11-27 CN CN201711211886.4A patent/CN109839534B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560682A (en) * | 2013-07-31 | 2014-02-05 | 佟炳然 | Power driving system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109839534A (en) | 2019-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1819522B (en) | M-Bus host interface device | |
| CN105141491B (en) | RS485 communication circuit and method for realizing spontaneous self-receiving | |
| CN106208369A (en) | A kind of on-line monitoring device of intelligent type low-voltage circuit breaker | |
| CN101957806A (en) | Peripheral component interconnection standard acquisition device for synchronous serial interface signal | |
| CN109839534B (en) | Power current isolation acquisition circuit | |
| CN201035557Y (en) | Switch capacity signal interface circuit | |
| CN206313786U (en) | MBUS principal and subordinate's monitoring devices | |
| CN110850761B (en) | High-precision analog quantity acquisition circuit | |
| CN209842605U (en) | Bus type isolator | |
| CN203812008U (en) | Analog signal collector | |
| CN215954178U (en) | Current equalizing circuit of parallel power supply | |
| CN207703935U (en) | Wide-range voltage harvester is mutually isolated in a kind of multichannel | |
| CN107273330B (en) | Three-wire system serial communication interface isolation circuit module | |
| CN101662372B (en) | Serial bus system of party-line transmitting of information and power | |
| CN201885822U (en) | Acquisition module for configurable thermal resistance | |
| CN109302194B (en) | Mbus host receiving circuit | |
| CN113608016A (en) | AC115V current conditioning and collecting circuit based on effective value chip | |
| CN205209560U (en) | No line type low -power consumption flow sensor | |
| CN206673846U (en) | A kind of high-performance electric source module | |
| CN207369032U (en) | A kind of consumption detection device based on broadband power line carrier communication unit | |
| CN216252793U (en) | Small signal acquisition and transmission system | |
| CN214200424U (en) | Four-wire system temperature acquisition and self-checking circuit | |
| CN211504231U (en) | Water and electricity energy consumption monitoring system | |
| CN217902298U (en) | Multi-interface high-speed acquisition card | |
| CN213482327U (en) | Current test 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |