CN204535873U - A kind of low-cost and high-precision thermometer - Google Patents
A kind of low-cost and high-precision thermometer Download PDFInfo
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- CN204535873U CN204535873U CN201520184052.9U CN201520184052U CN204535873U CN 204535873 U CN204535873 U CN 204535873U CN 201520184052 U CN201520184052 U CN 201520184052U CN 204535873 U CN204535873 U CN 204535873U
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Abstract
The utility model discloses a kind of low-cost and high-precision thermometer, comprises diode D1, potentiometer RP1, potentiometer RP2, chip IC 1 and voltage table P.The principle that the utility model thermometer utilizes the rising of diode forward pressure drop temperature and linearly reduces, utilize cheap diode as temperature element, the thermometer measure precision produced is 0.01 DEG C, and whole circuit structure is simple, components and parts are few, and cost of manufacture is low.
Description
Technical field
The utility model relates to a kind of thermometer, specifically a kind of low-cost and high-precision thermometer.
Background technology
The most serviceability temperature sensor of electronic thermometer common in the market or thermistor are as temperature sensing original paper, but the precision of thermistor is lower, the thermometer precision produced is short of to some extent, at some, temperature accuracy is required that high place is inapplicable, and the precision of temperature sensor is very high, but price is high, therefore this kind of high-precision thermometer price is higher.
Utility model content
The purpose of this utility model is to provide the thermometer that a kind of cost of manufacture is low, precision is high, to solve the problem proposed in above-mentioned background technology.
For achieving the above object, the utility model provides following technical scheme:
A kind of low-cost and high-precision thermometer, comprises diode D1, potentiometer RP1, potentiometer RP2, chip IC 1 and voltage table P, it is characterized in that, the pin 1 of described chip IC 1 connects the port 2 of electric capacity C1 and rectifier bridge T, the port one connecting valve S1 of rectifier bridge T, the winding N2 of the other end connection transformer W of switch S 1, the other end of the winding N2 of transformer W connects the port 3 of rectifier bridge T, the two ends of the winding N1 of transformer W connect the two ends of 220V alternating current respectively, the other end contact resistance R2 of electric capacity C1, electric capacity C2, the port 4 of rectifier bridge T, the pin 2 of chip IC 1 and the pin 1 of chip IC 2, the pin 3 contact resistance R1 of chip IC 1, resistance R3, the other end of electric capacity C2, the pin 8 of chip IC 2 and the pin 8 of chip IC 4, the other end of other end contact resistance R2 of resistance R1 and the pin 3 of chip IC 2, the pin 2 contact resistance R4 of chip IC 2, resistance R5, resistance R8, resistance R10, the interface 2 of voltage table P and the pin 7 of chip IC 2, the other end contact resistance R6 of resistance R3 and a stiff end of potentiometer RP1, the sliding end of potentiometer RP1 connects the pin 3 of chip IC 3, the other end of another stiff end contact resistance R4 of potentiometer RP1, the pin 2 of chip IC 3 connects the negative electrode of diode D1 and the other end of resistance R5, pin 1 ground connection of chip IC 3, the pin 7 contact resistance R7 of chip IC 3 and the anode of diode D4, the other end of other end contact resistance R8 of resistance R6 and the pin 3 of chip IC 4, the other end of the pin 2 contact resistance R7 of chip IC 4 and resistance R9, the other end of resistance R9 connects a stiff end of potentiometer RP1 and the pin 7 of chip IC 4, the sliding end of potentiometer RP1 connects the interface 1 of voltage table P, the other end of another stiff end contact resistance R10 of potentiometer RP1.
As preferred version of the present utility model: described chip IC 1 is 7,809 three sections of voltage stabilizers, and chip IC 2, chip IC 3 and chip IC 4 are LM311 voltage comparator.
As preferred version of the present utility model: the model of described diode D1 is IN4148.
Compared with prior art, the beneficial effects of the utility model are: the principle that the utility model thermometer utilizes the rising of diode forward pressure drop temperature and linearly reduces, utilize cheap diode as temperature element, the thermometer measure precision produced is 0.01 DEG C, whole circuit structure is simple, components and parts are few, and cost of manufacture is low.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of low-cost and high-precision thermometer.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
Refer to Fig. 1, a kind of low-cost and high-precision thermometer, comprise diode D1, potentiometer RP1, potentiometer RP2, chip IC 1 and voltage table P, it is characterized in that, the pin 1 of described chip IC 1 connects the port 2 of electric capacity C1 and rectifier bridge T, the port one connecting valve S1 of rectifier bridge T, the winding N2 of the other end connection transformer W of switch S 1, the other end of the winding N2 of transformer W connects the port 3 of rectifier bridge T, the two ends of the winding N1 of transformer W connect the two ends of 220V alternating current respectively, the other end contact resistance R2 of electric capacity C1, electric capacity C2, the port 4 of rectifier bridge T, the pin 2 of chip IC 1 and the pin 1 of chip IC 2, the pin 3 contact resistance R1 of chip IC 1, resistance R3, the other end of electric capacity C2, the pin 8 of chip IC 2 and the pin 8 of chip IC 4, the other end of other end contact resistance R2 of resistance R1 and the pin 3 of chip IC 2, the pin 2 contact resistance R4 of chip IC 2, resistance R5, resistance R8, resistance R10, the interface 2 of voltage table P and the pin 7 of chip IC 2, the other end contact resistance R6 of resistance R3 and a stiff end of potentiometer RP1, the sliding end of potentiometer RP1 connects the pin 3 of chip IC 3, the other end of another stiff end contact resistance R4 of potentiometer RP1, the pin 2 of chip IC 3 connects the negative electrode of diode D1 and the other end of resistance R5, pin 1 ground connection of chip IC 3, the pin 7 contact resistance R7 of chip IC 3 and the anode of diode D4, the other end of other end contact resistance R8 of resistance R6 and the pin 3 of chip IC 4, the other end of the pin 2 contact resistance R7 of chip IC 4 and resistance R9, the other end of resistance R9 connects a stiff end of potentiometer RP1 and the pin 7 of chip IC 4, the sliding end of potentiometer RP1 connects the interface 1 of voltage table P, the other end of another stiff end contact resistance R10 of potentiometer RP1.
Chip IC 1 is 7,809 three sections of voltage stabilizers, and chip IC 2, chip IC 3 and chip IC 4 are LM311 voltage comparator.
The model of diode D1 is IN4148.
Principle of work of the present utility model is: any one common diode, can as the sensing element of excellent, that there is a certain precision electronic thermometer, because well-known, diode is when temperature often raises 1 degree, and its forward voltage drop will reduce 2mV.In circuit, a constant reference voltage is added in the pin 2 of chip IC 3, pin 2 access diode D1 and resistance R5 of chip IC 3.The electric current flowing through diode D1 also flows through resistance R5 simultaneously, therefore on resistance R5, maintains constant pressure drop.Like this when IC3 output end voltage changes, it may be only cause because of temperature variation caused by the change of diode D1 forward voltage drop, and namely the change of IC3 output voltage is proportional to the temperature variation of diode D1.The reference voltage of IC3 is provided by three terminal regulator IC1.The output voltage of IC3 amplifies through IC4 again.IC4 with IC3 is identical, and its 3 pin also keeps constant level.The selection of resistance R5 and resistance R8 resistance should make the 0V of voltage table P correspond to environment temperature 0 degree.More than 0 degree and following temperature can be measured to make thermometer. this circuit does not adopt symmetrical powering power supply, but has first used an integrated regulator IC1, and it provides the reference voltage of quite stable to IC3 and IC4.It is the voltage of+2.5V that chip IC 1 produces one relative to negative power line together with resistance R1, resistance R2.The power lead of this+2.5V is just as " ground wire " of thermometer.The adjustment method of circuit is as follows: first adjust potentiometer RP1, make output voltage during temperature 0 degree be 0V.Then adjust W2, when making 99.9 degree, output voltage is 0.999V.
Claims (3)
1. a low-cost and high-precision thermometer, comprises diode D1, potentiometer RP1, potentiometer RP2, chip IC 1 and voltage table P, it is characterized in that, the pin 1 of described chip IC 1 connects the port 2 of electric capacity C1 and rectifier bridge T, the port one connecting valve S1 of rectifier bridge T, the winding N2 of the other end connection transformer W of switch S 1, the other end of the winding N2 of transformer W connects the port 3 of rectifier bridge T, the two ends of the winding N1 of transformer W connect the two ends of 220V alternating current respectively, the other end contact resistance R2 of electric capacity C1, electric capacity C2, the port 4 of rectifier bridge T, the pin 2 of chip IC 1 and the pin 1 of chip IC 2, the pin 3 contact resistance R1 of chip IC 1, resistance R3, the other end of electric capacity C2, the pin 8 of chip IC 2 and the pin 8 of chip IC 4, the other end of other end contact resistance R2 of resistance R1 and the pin 3 of chip IC 2, the pin 2 contact resistance R4 of chip IC 2, resistance R5, resistance R8, resistance R10, the interface 2 of voltage table P and the pin 7 of chip IC 2, the other end contact resistance R6 of resistance R3 and a stiff end of potentiometer RP1, the sliding end of potentiometer RP1 connects the pin 3 of chip IC 3, the other end of another stiff end contact resistance R4 of potentiometer RP1, the pin 2 of chip IC 3 connects the negative electrode of diode D1 and the other end of resistance R5, pin 1 ground connection of chip IC 3, the pin 7 contact resistance R7 of chip IC 3 and the anode of diode D4, the other end of other end contact resistance R8 of resistance R6 and the pin 3 of chip IC 4, the other end of the pin 2 contact resistance R7 of chip IC 4 and resistance R9, the other end of resistance R9 connects a stiff end of potentiometer RP1 and the pin 7 of chip IC 4, the sliding end of potentiometer RP1 connects the interface 1 of voltage table P, the other end of another stiff end contact resistance R10 of potentiometer RP1.
2. a kind of low-cost and high-precision thermometer according to claim 1, is characterized in that, described chip IC 1 is 7,809 three sections of voltage stabilizers, and chip IC 2, chip IC 3 and chip IC 4 are LM311 voltage comparator.
3. a kind of low-cost and high-precision thermometer according to claim 1, is characterized in that, the model of described diode D1 is IN4148.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520184052.9U CN204535873U (en) | 2015-03-30 | 2015-03-30 | A kind of low-cost and high-precision thermometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520184052.9U CN204535873U (en) | 2015-03-30 | 2015-03-30 | A kind of low-cost and high-precision thermometer |
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| Publication Number | Publication Date |
|---|---|
| CN204535873U true CN204535873U (en) | 2015-08-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520184052.9U Expired - Fee Related CN204535873U (en) | 2015-03-30 | 2015-03-30 | A kind of low-cost and high-precision thermometer |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105491258A (en) * | 2016-01-15 | 2016-04-13 | 鲁爱武 | Remote affection interaction control system and near affection interaction control system |
| CN106949898A (en) * | 2016-01-07 | 2017-07-14 | 天津普正动力科技有限公司 | A kind of intelligent vehicle-carrying navigation system |
| CN108120929A (en) * | 2017-12-23 | 2018-06-05 | 郑州默尔电子信息技术有限公司 | A kind of stirring motor running safety monitoring device |
-
2015
- 2015-03-30 CN CN201520184052.9U patent/CN204535873U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106949898A (en) * | 2016-01-07 | 2017-07-14 | 天津普正动力科技有限公司 | A kind of intelligent vehicle-carrying navigation system |
| CN105491258A (en) * | 2016-01-15 | 2016-04-13 | 鲁爱武 | Remote affection interaction control system and near affection interaction control system |
| CN108120929A (en) * | 2017-12-23 | 2018-06-05 | 郑州默尔电子信息技术有限公司 | A kind of stirring motor running safety monitoring device |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150805 Termination date: 20160330 |
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| CF01 | Termination of patent right due to non-payment of annual fee |