CN112698066A - Acquisition and measurement circuit for temperature compensation based on thermistor - Google Patents
Acquisition and measurement circuit for temperature compensation based on thermistor Download PDFInfo
- Publication number
- CN112698066A CN112698066A CN202011510375.4A CN202011510375A CN112698066A CN 112698066 A CN112698066 A CN 112698066A CN 202011510375 A CN202011510375 A CN 202011510375A CN 112698066 A CN112698066 A CN 112698066A
- Authority
- CN
- China
- Prior art keywords
- circuit
- thermistor
- operational amplifier
- resistor
- 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.)
- Pending
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 28
- 239000003990 capacitor Substances 0.000 claims abstract description 34
- 238000005070 sampling Methods 0.000 claims abstract description 25
- 230000008878 coupling Effects 0.000 claims abstract description 15
- 238000010168 coupling process Methods 0.000 claims abstract description 15
- 238000005859 coupling reaction Methods 0.000 claims abstract description 15
- 239000000463 material Substances 0.000 claims description 4
- 230000007613 environmental effect Effects 0.000 abstract description 9
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/44—Modifications of instruments for temperature compensation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Amplifiers (AREA)
Abstract
The invention provides a thermistor-based acquisition and measurement circuit for temperature compensation, which comprises a sampling circuit, an amplifying circuit and a coupling circuit which are sequentially connected in series, wherein the sampling circuit comprises a B2424S-1W power module, the positive electrode of the input end of the B2424S-1W power module is connected with a direct-current power supply A, the negative electrode of the input end of the B2424S-1W power module is grounded, the negative electrode of the output end of the B2424S-1W power module is grounded, the positive electrode of the output end of the B2424S-1W power module is sequentially connected in series with a compensation circuit formed by connecting a resistor R3 and a thermistor R4 in parallel, the compensation circuit is connected with the first end of a capacitor C4, the second end of a capacitor C4 is grounded, the first end of the capacitor C4 is further connected with the first end of a sampling source through a resistor R. By adopting the technical scheme of the invention, the resistor and the thermistor are connected in parallel to form the compensation circuit, thereby compensating the drift voltage generated due to the change of the environmental temperature and ensuring the measurement precision of the whole measurement circuit.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a thermistor-based acquisition and measurement circuit for temperature compensation.
Background
Sampling circuits are a large type of circuit in electronic circuits, typically having an analog signal input, a control signal input and an analog signal output. The effect is to receive the input voltage at a given moment and hold it at the output until the next sampling begins. In recent years, with the development of electronic technology, the requirement of electronic measurement technology for measurement accuracy is increasing. Especially, in the application of some electronic products, an electronic measurement circuit is needed, and generally, the electronic measurement circuit is connected with a sampling circuit through an amplifying circuit and a coupling circuit so as to obtain a sampling signal through the sampling circuit, the sampling signal is amplified through the amplifying circuit and then is connected into the corresponding measurement circuit through the coupling circuit, for example, an intelligent distribution box acquires a grounding resistor, the distribution box belongs to absolute electric equipment, when the insulation of the distribution box is broken, a metal shell can be electrified, and the equipment can protect an operator contacting the equipment through ground energy. Therefore, monitoring the grounding of the equipment is important. However, when some sampling circuits operate under severe air temperature conditions, the collection of the ground resistance in the sampling circuits is inevitably affected, which affects the precision of the whole measuring circuit, and in addition, the severe air temperature conditions can cause the parameters of some electronic components to change, age, power voltage fluctuation, temperature change and the like, which all cause the change of the output voltage.
Disclosure of Invention
In order to solve the technical problem, the invention provides an acquisition and measurement circuit for temperature compensation based on a thermistor.
The invention is realized by the following technical scheme.
The invention provides a thermistor-based acquisition and measurement circuit for temperature compensation, which comprises a sampling circuit, an amplifying circuit and a coupling circuit, wherein the sampling circuit comprises a B2424S-1W power module, the positive electrode of the input end of the B2424S-1W power module is connected with a direct current power supply A, the negative electrode of the input end of the B2424S-1W power module is grounded, the negative electrode of the output end of the B2424S-1W power module is grounded, the positive electrode of the output end of the B2424S-1W power module is sequentially connected in series with a compensation circuit formed by connecting a resistor R3 and a thermistor R4 in parallel, the compensation circuit is connected with a first end of a capacitor C4, the second end of a capacitor C4 is grounded, the first end of a capacitor C4 is further connected with a first end of a sampling source through a resistor R7, the second end of a capacitor C4 is further connected with a second end of the sampling source, one end of a resistor R1 is connected in series with a parallel circuit formed by connecting a thermistor R4 and, The coupling circuits are connected in series.
The grounding resistor R3 is 5.1k omega.
The thermistor R4 material constant is 3950.
The compensation resistor R1 is 270k omega.
And a pole capacitor C1 is connected between the positive pole of the input end of the B2424S-1W power supply module and the negative pole of the input end of the B2424S-1W power supply module.
And a pole capacitor C2 is connected between the positive pole of the output end of the B2424S-1W power supply module and the negative pole of the output end of the B2424S-1W power supply module.
The amplifying circuit comprises an operational amplifier A, an operational amplifier B and a potentiometer RP, wherein the power supply end of the operational amplifier A is connected with the positive electrode of the output end of the B2424S-1W power supply module, the ground end of the operational amplifier A is grounded, the non-inverting input end of the operational amplifier A is connected with the first end of a capacitor C4, the inverting input end of the operational amplifier A is connected with the non-inverting input end of the operational amplifier B after being connected with the output end in parallel, the inverting input end of the operational amplifier B is connected with the first end of the potentiometer RP and then is connected with the positive electrode of the output end of the B2424S-1W power supply module through a resistor R, and a resistor R5 is connected between the second end of the potentiometer RP and the output end of the operational amplifier B, the inverting input end of the operational amplifier B is also connected with the third end of the potentiometer RP, and the output end of the operational amplifier B is used as the output end of the amplifying circuit.
The operational amplifier A is an LM158 integrated operational amplifier chip.
The operational amplifier A is an LM158 integrated operational amplifier chip.
The coupling circuit comprises an EN357N photoelectric coupler, the anode of the input end of the EN357N photoelectric coupler is connected with the output end of the amplifying circuit in series through a resistor R2, the cathode of the input end of the EN357N photoelectric coupler is grounded, the anode of the output end of the EN357N photoelectric coupler is connected with a direct-current power supply B, the cathode of the output end of the EN357N photoelectric coupler is used as the output end of the coupling circuit and is grounded through a resistor R6, and two ends of the resistor R6 are also connected with a capacitor C3 in parallel.
The invention has the beneficial effects that: by adopting the technical scheme of the invention, the compensation resistor is connected in series after the thermistor is connected in parallel at the two ends of the grounding resistor, so that the effective total resistance value of the compensation circuit consisting of the compensation resistor, the grounding resistor and the thermistor presents the characteristic of linear change along with the change of the environmental temperature, thereby compensating the drift voltage generated by the change of the environmental temperature.
Drawings
Fig. 1 is a circuit diagram of the present invention.
Detailed Description
The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the described.
The invention provides a thermistor-based acquisition and measurement circuit for temperature compensation, which comprises a sampling circuit, an amplifying circuit and a coupling circuit, wherein the sampling circuit comprises a B2424S-1W power module, the positive electrode of the input end of the B2424S-1W power module is connected with a direct current power supply A, the negative electrode of the input end of the B2424S-1W power module is grounded, the negative electrode of the output end of the B2424-1W power module is grounded, the positive electrode of the output end of the B2424S-1W power module is sequentially connected in series with a compensation circuit formed by connecting a resistor R3 and a thermistor R4 in parallel, the compensation circuit is connected with the first end of a capacitor C S, the second end of the capacitor C4 is grounded, the first end of the capacitor C4 is further connected with the first end of a sampling source through a resistor R7, the second end of the capacitor C4 is further connected with the second end of the sampling source, one end of a resistor R1 is connected in series with, and the first end of the capacitor C4 is used as the output end of the sampling circuit and is sequentially connected with the amplifying circuit and the coupling circuit in series.
Further, it is preferable that the ground resistance R3 has a resistance value of 45k Ω to 55k Ω. The thermistor R4 material constant is 3950. The compensation resistor R1 is 270k omega. And a pole capacitor C1 is connected between the positive pole of the input end of the B2424S-1W power supply module and the negative pole of the input end of the B2424S-1W power supply module. And a pole capacitor C2 is connected between the positive pole of the output end of the B2424S-1W power supply module and the negative pole of the output end of the B2424S-1W power supply module. The voltage of the direct-current power supply A is 24V, the capacity of the capacitor C4 is 2.2 muF/400V, the capacity of the electrode capacitor C1 is 2.2 muF/50V, and the capacity of the electrode capacitor C2 is 4.7 muF/25V.
In addition, the amplifying circuit comprises an operational amplifier A, an operational amplifier B and a potentiometer RP, wherein the power supply end of the operational amplifier A is connected with the positive electrode of the output end of the B2424S-1W power module, the ground end of the operational amplifier A is grounded, the non-inverting input end of the operational amplifier A is connected with the first end of the capacitor C4, the inverting input end of the operational amplifier A is connected with the non-inverting input end of the operational amplifier B after being connected with the output end thereof in parallel, the inverting input end of the operational amplifier B is connected with the positive electrode of the output end of the B2424S-1W power module through a resistor R8 after being connected with the first end of the potentiometer, and a resistor R5 is connected between the second end of the potentiometer RP and the output end of the operational amplifier B, the inverting input end of the operational amplifier B is also connected with the third end of the potentiometer RP, and the output end of the operational amplifier B is used as the output end of the amplifying circuit. The operational amplifier A is an LM158 integrated operational amplifier chip. The operational amplifier A is an LM158 integrated operational amplifier chip. The resistance value of the resistor R5 is 10k omega, the resistance value of the potentiometer RP is 10k omega, and the resistance value of the resistor R8 is 5.1k omega.
In addition, the coupling circuit comprises an EN357N photoelectric coupler, the positive electrode of the input end of the EN357N photoelectric coupler is connected with the output end of the amplifying circuit in series through a resistor R2, the negative electrode of the input end of the EN357N photoelectric coupler is grounded, the positive electrode of the output end of the EN357N photoelectric coupler is connected with a direct-current power supply B, the negative electrode of the output end of the EN357N photoelectric coupler is used as the output end of the coupling circuit and is grounded through a resistor R6, and two ends of the resistor R6 are further connected with a capacitor C3 in parallel. The voltage of the direct current power supply B is 3.3V, the resistance value of the resistor R2 is 1k omega, the resistance value of the resistor R6 is 10k omega, and the capacity of the capacitor C3 is 47 muF.
By adopting the technical scheme of the invention, the compensation resistor is connected in series after the thermistor is connected in parallel at the two ends of the grounding resistor, so that the effective total resistance value of the compensation circuit consisting of the compensation resistor, the grounding resistor and the thermistor presents the characteristic of linear change along with the change of the environmental temperature, thereby compensating the drift voltage generated by the change of the environmental temperature.
By adopting the technical scheme of the invention, as shown in fig. 1, the equivalent total resistance of a temperature compensation circuit consisting of a compensation resistor R1, a grounding resistor R3 and a thermistor R4 is as follows:
wherein R isTIs the resistance of the thermistor R4, the resistance of the thermistor R4 has the following characteristics:
in the above formula, B is the material constant of the thermistor, RTIs the resistance value, R, of the thermistor at the ambient temperature T0Is the ambient temperature T0Thermistor value of time, wherein the ambient temperature T, T0By adopting Kelvin measurement, because the NTC thermistor belongs to a sintered semiconductor, characteristic parameters of the NTC thermistor have certain discreteness, the discreteness rate of the same batch of products with the same nominal value also reaches about 20%, and the discreteness rate of B also reaches about 20%The above formula is linearized, and can be transformed approximately into:
when the compensation resistor R1 and the thermistor R4 are not adopted, and the resistance at two ends of RE and BE is more than 50K, the voltage at the pins 5, 6 and 7 of the LM158 comparator is measured, and the measurement results are shown in the table 1:
TABLE 1 LM158 comparator environmental test data
After the compensation resistor R1 and the thermistor R4 are adopted, when the resistance at two ends of RE and BE is more than 50K, the voltage at the pins 5, 6 and 7 of the LM158 comparator is respectively measured, and the measurement results are shown in Table 1:
TABLE 2 LM158 comparator environmental test data after temperature compensation
Comparing the output voltage results in tables 1 and 2, it can be seen that the fluctuation of the output voltage of the whole circuit is large before the compensation circuit is not connected, obviously, different environmental temperatures have large influence on the output voltage of the whole circuit, so the measurement accuracy of the whole measurement circuit is influenced, the thermistor R4 is connected in parallel at two ends of the grounding resistor R3, after the compensation resistor R1 is connected in series, the output voltage change of the whole circuit is kept stable no matter the circuit is in the environmental temperature range of-40 ℃ to 55 ℃, and the compensation effect of the compensation circuit on the temperature drift is very obvious.
Claims (10)
1. The utility model provides a carry out temperature compensation's collection measuring circuit based on thermistor which characterized in that: comprises a sampling circuit, an amplifying circuit and a coupling circuit, wherein the sampling circuit comprises a B2424S-1W power module, the positive electrode of the input end of the B2424S-1W power supply module is connected with a direct current power supply A, the negative electrode of the input end of the B2424S-1W power supply module is grounded, the negative electrode of the output end of the B2424S-1W power supply module is grounded, the positive electrode of the output end of the B2424S-1W power supply module is sequentially connected in series with a compensation circuit formed by connecting a resistor R3 and a thermistor R4 in parallel, the first end of the capacitor C4 is connected with the first end of the capacitor C4, the second end of the capacitor C4 is grounded, the first end of the capacitor C4 is also connected with the first end of the sampling source through a resistor R7, the second end of the capacitor C4 is also connected with the second end of the sampling source, one end of the resistor R1 is connected in series with a parallel circuit consisting of a thermistor R4 and a resistor R3, and the first end of the capacitor C4 is used as the output end of the sampling circuit and is sequentially connected in series with the amplifying circuit and the coupling circuit.
2. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: the grounding resistor R3 is 5.1k omega.
3. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: the thermistor R4 material constant is 3950.
4. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: the compensation resistor R1 is 270k omega.
5. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: and a pole capacitor C1 is connected between the positive pole of the input end of the B2424S-1W power supply module and the negative pole of the input end of the B2424S-1W power supply module.
6. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: and a pole capacitor C2 is connected between the positive pole of the output end of the B2424S-1W power supply module and the negative pole of the output end of the B2424S-1W power supply module.
7. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: the amplifying circuit comprises an operational amplifier A, an operational amplifier B and a potentiometer RP, wherein the power supply end of the operational amplifier A is connected with the positive electrode of the output end of the B2424S-1W power supply module, the ground end of the operational amplifier A is grounded, the non-inverting input end of the operational amplifier A is connected with the first end of a capacitor C4, the inverting input end of the operational amplifier A is connected with the non-inverting input end of the operational amplifier B after being connected with the output end in parallel, the inverting input end of the operational amplifier B is connected with the first end of the potentiometer RP and then is connected with the positive electrode of the output end of the B2424S-1W power supply module through a resistor R, and a resistor R5 is connected between the second end of the potentiometer RP and the output end of the operational amplifier B, the inverting input end of the operational amplifier B is also connected with the third end of the potentiometer RP, and the output end of the operational amplifier B is used as the output end of the amplifying circuit.
8. The thermistor-based acquisition measurement circuit of claim 7, characterized in that: the operational amplifier A is an LM158 integrated operational amplifier chip.
9. The thermistor-based acquisition measurement circuit of claim 7, characterized in that: the operational amplifier A is an LM158 integrated operational amplifier chip.
10. The thermistor-based acquisition measurement circuit of claim 1, characterized in that: the coupling circuit comprises an EN357N photoelectric coupler, the anode of the input end of the EN357N photoelectric coupler is connected with the output end of the amplifying circuit in series through a resistor R2, the cathode of the input end of the EN357N photoelectric coupler is grounded, the anode of the output end of the EN357N photoelectric coupler is connected with a direct-current power supply B, the cathode of the output end of the EN357N photoelectric coupler is used as the output end of the coupling circuit and is grounded through a resistor R6, and two ends of the resistor R6 are also connected with a capacitor C3 in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011510375.4A CN112698066A (en) | 2020-12-18 | 2020-12-18 | Acquisition and measurement circuit for temperature compensation based on thermistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011510375.4A CN112698066A (en) | 2020-12-18 | 2020-12-18 | Acquisition and measurement circuit for temperature compensation based on thermistor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112698066A true CN112698066A (en) | 2021-04-23 |
Family
ID=75507545
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011510375.4A Pending CN112698066A (en) | 2020-12-18 | 2020-12-18 | Acquisition and measurement circuit for temperature compensation based on thermistor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112698066A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114295885A (en) * | 2021-12-29 | 2022-04-08 | 东莞市长工微电子有限公司 | Current detection circuit and driving device |
| CN117907675A (en) * | 2024-03-07 | 2024-04-19 | 斯比泰电子（嘉兴）有限公司 | High-precision voltage and current measurement circuit |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87209231U (en) * | 1987-06-19 | 1987-12-30 | 核工业部北京第五研究所 | Pulse width-modulation & photoelectric coupled analogue signal isolator |
| CN202455267U (en) * | 2011-07-08 | 2012-09-26 | 西安天照伟成电气有限公司 | Power supply circuit |
| CN103344813A (en) * | 2013-07-10 | 2013-10-09 | 深圳市航天新源科技有限公司 | Direct current voltage isolation sampling circuit |
| CN103913610A (en) * | 2014-04-23 | 2014-07-09 | 英迪迈智能驱动技术无锡有限公司 | Current sampling circuit with temperature drifting compensation function |
| CN204575214U (en) * | 2015-04-07 | 2015-08-19 | 佛山市柏克新能科技股份有限公司 | A kind of maximum temperature sample circuit |
| CN106248240A (en) * | 2016-08-15 | 2016-12-21 | 成都众山科技有限公司 | A kind of temperature transmitter with temperature-compensating |
| CN107462767A (en) * | 2017-09-18 | 2017-12-12 | 广州城市职业学院 | plasma probe measurement and control system |
| CN109286315A (en) * | 2018-11-12 | 2019-01-29 | 港芝（东莞）电子制造厂有限公司 | A kind of intelligent power supply circuit of digital equipment |
| CN109730691A (en) * | 2019-01-11 | 2019-05-10 | 河南鑫安利职业健康科技有限公司 | Detect the signal compensation apparatus of special operating personnel body index instrument |
| CN209558246U (en) * | 2019-03-30 | 2019-10-29 | 贵州航天风华实业有限公司 | Warning lamp |
-
2020
- 2020-12-18 CN CN202011510375.4A patent/CN112698066A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87209231U (en) * | 1987-06-19 | 1987-12-30 | 核工业部北京第五研究所 | Pulse width-modulation & photoelectric coupled analogue signal isolator |
| CN202455267U (en) * | 2011-07-08 | 2012-09-26 | 西安天照伟成电气有限公司 | Power supply circuit |
| CN103344813A (en) * | 2013-07-10 | 2013-10-09 | 深圳市航天新源科技有限公司 | Direct current voltage isolation sampling circuit |
| CN103913610A (en) * | 2014-04-23 | 2014-07-09 | 英迪迈智能驱动技术无锡有限公司 | Current sampling circuit with temperature drifting compensation function |
| CN204575214U (en) * | 2015-04-07 | 2015-08-19 | 佛山市柏克新能科技股份有限公司 | A kind of maximum temperature sample circuit |
| CN106248240A (en) * | 2016-08-15 | 2016-12-21 | 成都众山科技有限公司 | A kind of temperature transmitter with temperature-compensating |
| CN107462767A (en) * | 2017-09-18 | 2017-12-12 | 广州城市职业学院 | plasma probe measurement and control system |
| CN109286315A (en) * | 2018-11-12 | 2019-01-29 | 港芝（东莞）电子制造厂有限公司 | A kind of intelligent power supply circuit of digital equipment |
| CN109730691A (en) * | 2019-01-11 | 2019-05-10 | 河南鑫安利职业健康科技有限公司 | Detect the signal compensation apparatus of special operating personnel body index instrument |
| CN209558246U (en) * | 2019-03-30 | 2019-10-29 | 贵州航天风华实业有限公司 | Warning lamp |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114295885A (en) * | 2021-12-29 | 2022-04-08 | 东莞市长工微电子有限公司 | Current detection circuit and driving device |
| CN114295885B (en) * | 2021-12-29 | 2023-10-13 | 东莞市长工微电子有限公司 | Current detection circuit and driving device |
| CN117907675A (en) * | 2024-03-07 | 2024-04-19 | 斯比泰电子（嘉兴）有限公司 | High-precision voltage and current measurement circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112698066A (en) | Acquisition and measurement circuit for temperature compensation based on thermistor | |
| CN103837253B (en) | A kind of CMOS temperature transmitter | |
| CN209327890U (en) | A kind of voltage regulator circuit, power supply and electrical equipment | |
| CN102735362B (en) | Astronautic programmable thermocouple temperature transmitter | |
| CN103913249A (en) | Temperature monitoring circuit device and method | |
| CN114062900A (en) | Operational amplifier circuit offset voltage testing method | |
| CN115060962A (en) | Source meter capable of rapidly switching measuring range and temperature compensation method thereof | |
| CN108304023B (en) | High-load stability compensation circuit of switching power supply | |
| US20130043892A1 (en) | Resistance measurement circuit | |
| CN203870150U (en) | Isolation type power grid detector | |
| CN204649327U (en) | A kind of thermal resistance signal change-over circuit | |
| CN206020612U (en) | A kind of power amplifier parallel connection debugging apparatus | |
| CN201936215U (en) | Novel high-precision constant current source circuit | |
| CN110440945B (en) | High-precision low-temperature drift discrete type double-matching constant current source temperature measuring circuit | |
| CN103293386B (en) | A kind of proving installation of insulation resistance and method | |
| CN203657927U (en) | Precise adjustable thermocouple cold end temperature compensation instrument | |
| CN113804959B (en) | High-precision high-speed weak current measurement circuit and measurement method based on transimpedance amplification | |
| CN205879391U (en) | Pt100 resistance wire sexualization temperature measurement treatment circuit | |
| CN203337310U (en) | Atmospheric pressure measurement electric circuit | |
| CN203084063U (en) | Measurement circuit module | |
| CN113701911B (en) | Electric energy meter terminal temperature detection circuit and method | |
| CN221652466U (en) | Voltage stabilizing circuit for current detection and energy storage BMS system | |
| CN212988631U (en) | Temperature acquisition circuit, control panel and electrical equipment | |
| CN219085028U (en) | Resistance measuring device and source meter | |
| CN217484782U (en) | High-precision high-temperature-resistant voltage-controlled alternating-current constant-current source 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 |