CN88203185U - Thermistor linearized device - Google Patents
Thermistor linearized device Download PDFInfo
- Publication number
- CN88203185U CN88203185U CN 88203185 CN88203185U CN88203185U CN 88203185 U CN88203185 U CN 88203185U CN 88203185 CN88203185 CN 88203185 CN 88203185 U CN88203185 U CN 88203185U CN 88203185 U CN88203185 U CN 88203185U
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- CN
- China
- Prior art keywords
- thermistor
- voltage
- amplifier
- temperature
- output
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Abstract
The utility model belongs to the class of instrument control. After a thermistor passes through a follower, an inverter amplifier, a voltage comparator and an integrated amplifier, the output of theintegrated amplifier feeds back to the thermistor through a feedback resistance, and a non-linear relationship between the resistance value of the thermistor and the temperature of the thermistor is converted into a linear relation between the output voltage of the amplifier output and the measured temperature. The thermistor linearized device is used in the digital temperature display and control, and the accuracy of temperature measurement can reach 1 DEG C. The thermistor linearized device has the advantages of sensitive reaction and stable and reliable work.
Description
The utility model belongs to instrument control class.
Food, chemical industry, rubber, plastics, electronics and agricultural in poultry hatching, the temperature survey of equipment such as microbe growth in medical belong to mostly in the temperature survey in normal temperature district (50 ℃ to 270 ℃).At this warm area, thermistor because the sensitivity of thermometry height, be swift in response, interchangeability is good, and obvious superiority is arranged, be other temperature sensor as platinum resistance, thermopair, semiconductor etc. can't be obtained.But the relation of thermistor and temperature exists severe nonlinear, the method that has a strong impact on numeral realizes accurate the measurement and control, adopted the method for simulated pointer in the past, the demonstration of temperature is realized by the non-linear of analog dial scale, if will realize numeral shows, can not adopt the method, for digitized measurement, the linear relationship of voltage and resistance realizes easily, analog to digital converter as monolithic, the digital value that shows and the relation of voltage are linear, also are that the numeral of resistance value shows it is to realize easily.But because thermistor and temperature exist severe nonlinear, the temperature that thermistor be reflected realizes that it is difficult that numeral shows.
The purpose of this utility model is to realize that in wider temperature range the temperature and the linearizer output voltage of thermistor reaction are linear.
The utility model is achieved in that by constant voltage and through a fixed resistance thermistor is powered, take off voltage at the thermistor two ends, through follower, group amplifier, feed back on the thermistor, then can realize that in certain limit the temperature and the voltage drop on the thermistor of thermistor reaction are linear.Its principle is seen accompanying drawing 1, U
SBe to add fixed voltage, amplifier 1 is as follower, and group amplifier 9 is done to amplify and used.Fixed resistance R
SWith R
fAfter selecting, the enlargement factor of group amplifier 9 is:
K=R
f(n- 1/(R
s) - 1/(R
f) )= (R
8)/(R
7) (1)
N=(Rt wherein
1+ Rt
3-2Rt
2)/((Rt
1+ Rt
3) Rt
2-2Rt
1Rt
3)
Rt
1, Rt
2, Rt
3Be that thermistor is in temperature t
1, t
2, t
33 resistance value.
t
1, t
2, t
3Relation be: t
2-t
1=t
3-t
2
In view of the above, select the enlargement factor K of group amplifier 9, can realize within the specific limits that then the temperature of voltage drop on the thermistor and its reaction is linear.
Realize the linearization in the wide temperature range,, realize linearization, do following processing then for every section at first with the temperature range segmentation:
Because of the voltage drop on the thermistor
When temperature equalled zero, the resistance value of thermistor did not equal zero, the voltage drop U on the thermistor
tWith the pass of temperature t be: U
t=a-bt (3)
A is a constant in the formula, and the b value is different to different linearization sections.
If add the one-level operational amplifier in addition, add bias voltage after, can make its output voltage
U
0=K
2bt (4)
Though each linearization section b value is different, as long as the value of the amplification coefficient K2 of corresponding this operational amplifier of change just can make K
2B becomes constant, then the output voltage U of this operational amplifier
0In wide temperature range and temperature line relationship.
The utility model is described in further detail below in conjunction with embodiment and accompanying drawing.
Fig. 1 is thermistor linearizer ultimate principle figure
Fig. 2 is a thermistor linearizer circuit diagram
Us is a constant impressed voltage, is added on the thermistor Rt by R1, and the output of group amplifier 9 feeds back on the thermistor by feedback resistance Rf.Amplifier 1 is a follower, and it follows the variation of voltage on the thermistor, passes through inverting amplifier 3 again, is added to the input end of group amplifier 9 then by resistance.Take off dividing potential drop through resistance R 2, R3, R4, R5, compare by the output voltage of 4,5,6 voltage comparators (be actually by operational amplifier and form) with phase inverter 3.4, the effect of the diode on 5,6 voltage comparators is not have voltage when making amplifier positive output, voltage is arranged during negative output, this negative voltage increases along with the increase of two input voltage difference on the voltage comparator, can reach like this, for different linearization sections, 4, the output voltage of 5,6 voltage comparators to change the enlargement factor of different linearization sections, is realized piece-wise linearization along with the rising of temperature progressively is added on each input resistance of group amplifier 9.
Above piece-wise linearization, desirable 50 ℃ of every section temperature range, in order to realize the linearization of (250 ℃) output voltage and temperature in the wide temperature range, each linearization section difference of K value and b value as can be known from formula (1), (2), (3) increases by an operational amplifier 8, in different linearization sections for this reason, 4,5,6 voltage comparators have different output,, according to formula (4) as can be known, change K2 and make K to change its enlargement factor K2 by the different input resistance of operational amplifier 8
2B becomes a constant, makes the output voltage U of operational amplifier 8
0Linear with temperature t in wider temperature range.
Above thermistor linearizer is used for digital temperature and shows controller, and temperature measurement accuracy can reach 1 ℃, is quick on the draw, and working stability is reliable.
Claims (2)
1, thermistor linearizer is characterized in that it comprises:
(1) follower, its output voltage is followed the variation of voltage on the thermistor, outputs to inverting amplifier and voltage comparator.
(2) inverting amplifier, its output voltage and input voltage equal and opposite in direction, polarity are opposite, make voltage comparator and group amplifier obtain correct polarity by it.
(3) voltage comparator, it with voltage that changes on the thermistor and the given voltage ratio of fixing supplies with group amplifier.
(4) group amplifier, its input is connected with the output of voltage comparator, inverting amplifier, to realize the different enlargement factor of different linearization sections.
2, linearizer according to claim 1, it is characterized in that described voltage comparator passes through operational amplifier and different input resistances thereof with group amplifier, change its enlargement factor, realize the linear relationship of interior output voltage of wide temperature range and temperature.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 88203185 CN88203185U (en) | 1988-02-22 | 1988-02-22 | Thermistor linearized device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 88203185 CN88203185U (en) | 1988-02-22 | 1988-02-22 | Thermistor linearized device |
Publications (1)
Publication Number | Publication Date |
---|---|
CN88203185U true CN88203185U (en) | 1988-10-05 |
Family
ID=4838053
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN 88203185 Withdrawn CN88203185U (en) | 1988-02-22 | 1988-02-22 | Thermistor linearized device |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN88203185U (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101430231B (en) * | 2007-10-31 | 2010-12-29 | 凹凸电子(武汉)有限公司 | Temperature detection method and system |
CN105953938A (en) * | 2016-04-22 | 2016-09-21 | 安徽京师方圆信息技术有限公司 | Method for measuring temperature of equipment cabinet |
EP3309525A1 (en) | 2016-10-13 | 2018-04-18 | Yeditepe Universitesi | Analog circuit for wide range sensor linearization optimal in uniform norm |
CN110044508A (en) * | 2018-01-15 | 2019-07-23 | 佛山市顺德区美的电热电器制造有限公司 | Electromagnetic heating system and its temp measuring method, device |
CN111141986A (en) * | 2020-01-14 | 2020-05-12 | 湖北民族大学 | Weak current control monitoring system and method based on Internet of things |
-
1988
- 1988-02-22 CN CN 88203185 patent/CN88203185U/en not_active Withdrawn
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101430231B (en) * | 2007-10-31 | 2010-12-29 | 凹凸电子(武汉)有限公司 | Temperature detection method and system |
TWI382162B (en) * | 2007-10-31 | 2013-01-11 | O2Micro Int Ltd | Thermistor-based temperature detection apparatus and the temperature detection method thereof |
CN105953938A (en) * | 2016-04-22 | 2016-09-21 | 安徽京师方圆信息技术有限公司 | Method for measuring temperature of equipment cabinet |
EP3309525A1 (en) | 2016-10-13 | 2018-04-18 | Yeditepe Universitesi | Analog circuit for wide range sensor linearization optimal in uniform norm |
CN110044508A (en) * | 2018-01-15 | 2019-07-23 | 佛山市顺德区美的电热电器制造有限公司 | Electromagnetic heating system and its temp measuring method, device |
CN110044508B (en) * | 2018-01-15 | 2021-02-26 | 佛山市顺德区美的电热电器制造有限公司 | Electromagnetic heating system and temperature measuring method and device thereof |
CN111141986A (en) * | 2020-01-14 | 2020-05-12 | 湖北民族大学 | Weak current control monitoring system and method based on Internet of things |
CN111141986B (en) * | 2020-01-14 | 2022-04-05 | 湖北民族大学 | Weak current control monitoring system and method based on Internet of things |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
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 |