CN2172470Y - Digital thermograph - Google Patents
Digital thermograph Download PDFInfo
- Publication number
- CN2172470Y CN2172470Y CN 93217991 CN93217991U CN2172470Y CN 2172470 Y CN2172470 Y CN 2172470Y CN 93217991 CN93217991 CN 93217991 CN 93217991 U CN93217991 U CN 93217991U CN 2172470 Y CN2172470 Y CN 2172470Y
- Authority
- CN
- China
- Prior art keywords
- converter
- temperature
- voltage
- digital
- circuit
- 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.)
- Expired - Fee Related
Links
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- Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)
Abstract
The utility model discloses a digital thermograph, comprising a constant source circuit 2, a PN junction temperature sensor 1 which is connected with the constant source circuit 2 and outputs a voltage signal which is relative to temperature, an A/D converter 5 which converts the voltage signal which is relative to the temperature into a digital signal, a digital display 6 which can display digital temperature value, an isolating circuit 3 which can make a measurement converting circuit and the A/D converter isolated to supply power, and a voltage changer 4 which can provides a floating zero voltage B and a reference voltage VR so as to cause the A/D converter 5 to work with floating. The utility model has the advantages of simple line, high precision because of adopting a unipolarity power supply to supply power, and low cost.
Description
The utility model relates to a kind of digital measuring apparatus, and particularly adopting PN junction is the digital measurement of temperature instrument of temperature sensor.
There is following shortcoming in the existing digital temperature measuring set:
Complex circuit, thereby cost is higher;
Need to adopt the bipolar power supply power supply,
Poor linearity, thereby the measurement temperature accuracy is reduced.
The purpose of this utility model is a kind of A/D of employing transducer will be provided and only need the circuit of single power supply simple, and the linearity is good, the digital measurement of temperature instrument that precision is high.
For reaching this purpose, the technical scheme that the utility model adopted is to adopt constant current source and a PN junction temperature sensor to be in series, PN junction output supplied with the input signal of A/D converter with the voltage signal of temperature change, and convert digital signal to by A/D converter and export to digital indicator and demonstrate Temperature numerical, in order to reduce signaling conversion circuit that constant current source and sensor be composed in series with the influence in the A/D converter power supply, adopt a voltage follower of forming by operational amplifier that the two power supply is isolated, A/D converter adopts floating ground working method, complete machine adopts single power supply, also comprise automatic compensation, the buffering buffer circuit.
Fig. 1 is the circuit block diagram of digital measurement of temperature instrument of the present utility model;
Fig. 2 is a physical circuit figure of digital measurement of temperature instrument of the present utility model.
Below in conjunction with accompanying drawing scheme of the present utility model is described.
In Fig. 1, PN junction temperature sensor 1 with constant current source 2 series connection converts temperature signal to be measured to signal electronegative potential input end INHI that voltage signal is input to the A/D transducer, this signal converts the digital signal rear feed to for A/D converter device and demonstrates the measurement Temperature numerical to digital indicator 6, respectively to constant current source 2, power by PN junction and electric pressure converter 4 through power isolation circuit (voltage follower) 3 for power supply module 7.Power supply module 7 also directly shows 6 power supplies to A/D converter 5 and numeral.The reference voltage V of A/D converter
R, signal input low pressure end INLO supplies with through electric pressure converter 4.
In Fig. 2, by transistor T, resistance R
1, R
2, R
3Be connected and form constant current source 2, by amplifier A
1, resistance R
6, R
7Constitute power isolation circuit 3, electric pressure converter 4 comprises by potentiometer W
1, resistance R
4Amplifier A
2The voltage follower that connects into and by resistance R
5With amplifier A
3The voltage follower that connects into.Power isolation circuit 3 makes A/D converter 5 with constant current source 2, the power supply of electric pressure converter 4 and PN junction temperature sensor 1 is isolated, thereby has reduced A/D converter 4, with the influence in power supply of constant current source 2, electric pressure converter 4 and PN junction sensor 1.Constant current source 2 provides a suitable steady current for PN junction temperature sensor 1, and electric current is crossed the precision that the conference influence is measured, and the too small meeting of electric current reduces temperature-responsive speed and measurement sensitivity is reduced.In order under the single power supply condition, to make the circuitry operate as normal and to reach enough measuring accuracy, and A/D converter 5 is worked under floating ground mode, even the signal electronegative potential input end INLO of A/D converter 5 floats, the zero potential B of A/D converter 5 is by (W
2Sliding contact hypomere resistance+R
5Resistance) voltage (as A
3The input of in-phase end) through A
3Output is provided to input end INLO, and even the actual potential that A is ordered when being used for compensating measured temperature automatically and being 0 ℃ is applied signal voltage U 0 ℃ the time
X=U
A-U
BPotentiometer W
1Sliding contact on voltage, through operational amplifier A
2Export to the reference voltage terminal VREF of A/D, make reference voltage, by adjusting W
2Resistance can adjust full scale.Amplifier A
1, A
2All connect into voltage follower circuit 1, thus realize buffer compartment from function.
The circuit of digital measurement of temperature instrument of the present utility model is simple, and cost is low, linearity height, the high power supply of saving a negative polarity of precision, when temperature-measuring range at 0-100 ℃, precision can reach 0.5, promotes in being suitable for producing.
Claims (2)
1, a kind of digital measurement of temperature instrument is characterized in that comprising:
A constant-current source circuit (2); The PN junction temperature sensor (1) that a same constant current source (2) is in series, synthermal relevant voltage signal of its output of PN junction sensor (1); An A/D commentaries on classics device (5) that the above-mentioned voltage signal relevant with temperature is converted to digital signal; Thereby the output terminal with the A/D transducer is connected and the digital signal relevant with temperature of A/D converter output is demonstrated the digital indicator (6) of temperature value; Signal to A/D converter is imported low side (INLO) provides the change-over circuit (4) that floats ground O current potential (B) and reference voltage V REF, so that make A/D converter be operated under the floating ground state and the full-scale adjusting of realization temperature; The power isolation circuit (3) that the power supply that makes constant current source (2), PN junction temperature sensor (1) and voltage conversion circuit (4) is isolated with A/D converter, and one respectively to the power supply module (7) of each circuit supply.
2, digital measurement of temperature instrument as claimed in claim 1 is characterized in that described constant current source (2) by transistor T, resistance R
1, R
3, R
2Connect to form described voltage conversion circuit (4) bag potentiometer W
1Resistance R
4Operational amplifier A
2The voltage follower that connects and by potentiometer (W
2) resistance (R
5) amplifier A
3The voltage follower that connects into, wherein amplifier A
2Output be provided to the VREF input end as the reference voltage of A/D converter, by adjusting potentiometer W
1Change reference voltage and can adjust the temperature full scale.Operational amplifier A
3Export a zero potential (B) that A/D converter (5) is worked floatingly, offer the signal electronegative potential input end INLO of A/D converter (5).By adjusting potentiometer W
2Can adjust the zero point of temperature; Described power isolation circuit (3) is by resistance R
6, R
7With amplifier A
1Connect and compose.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93217991 CN2172470Y (en) | 1993-07-13 | 1993-07-13 | Digital thermograph |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93217991 CN2172470Y (en) | 1993-07-13 | 1993-07-13 | Digital thermograph |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2172470Y true CN2172470Y (en) | 1994-07-20 |
Family
ID=33797773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 93217991 Expired - Fee Related CN2172470Y (en) | 1993-07-13 | 1993-07-13 | Digital thermograph |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2172470Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102589734A (en) * | 2012-01-31 | 2012-07-18 | 钜泉光电科技(上海)股份有限公司 | Temperature sensor |
| CN108254091A (en) * | 2016-12-29 | 2018-07-06 | 财团法人工业技术研究院 | Microelectromechanical device with measurement range selector |
| CN114720009A (en) * | 2022-06-09 | 2022-07-08 | 中国船舶重工集团公司第七0七研究所 | Digital high-precision temperature measurement system and method for relative gravimeter |
-
1993
- 1993-07-13 CN CN 93217991 patent/CN2172470Y/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102589734A (en) * | 2012-01-31 | 2012-07-18 | 钜泉光电科技(上海)股份有限公司 | Temperature sensor |
| CN102589734B (en) * | 2012-01-31 | 2013-10-23 | 钜泉光电科技(上海)股份有限公司 | Temperature sensor |
| CN108254091A (en) * | 2016-12-29 | 2018-07-06 | 财团法人工业技术研究院 | Microelectromechanical device with measurement range selector |
| CN108254091B (en) * | 2016-12-29 | 2020-09-01 | 财团法人工业技术研究院 | Microelectromechanical device with measurement range selector |
| CN114720009A (en) * | 2022-06-09 | 2022-07-08 | 中国船舶重工集团公司第七0七研究所 | Digital high-precision temperature measurement system and method for relative gravimeter |
| CN114720009B (en) * | 2022-06-09 | 2022-09-16 | 中国船舶重工集团公司第七0七研究所 | Digital high-precision temperature measurement system and method for relative gravimeter |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |