CN204085732U - Temperature sensing circuit - Google Patents
Temperature sensing circuit Download PDFInfo
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- CN204085732U CN204085732U CN201420616225.5U CN201420616225U CN204085732U CN 204085732 U CN204085732 U CN 204085732U CN 201420616225 U CN201420616225 U CN 201420616225U CN 204085732 U CN204085732 U CN 204085732U
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- 238000005516 engineering process Methods 0.000 description 1
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Abstract
The utility model discloses a kind of temperature sensing circuit, it uses double bridge, temperature collection circuit built by differential integrated operational amplifier, and adopt thermistor as a brachium pontis of double bridge, when the temperature is changed, the resistance that thermistor is corresponding also can change, electric bridge can produce differential pressure, by differential integrated operational amplifier, differential pressure signal is amplified, and give hysteresis loop comparator and carry out voltage compare, thus determining the output potential of hysteresis loop comparator, whether the startup of control alarm unit to be.Said temperature testing circuit structure is simple, cost is lower, and stability is higher.
Description
Technical field
The utility model relates to a kind of testing circuit, particularly a kind of circuit for detected temperatures.
Background technology
Along with the raising of city safety-protection system Construction and management demand, originally single video monitoring system to be met an urgent need prevention and control system upgrade and development to digitizing, and front-end equipment also integrates application development by single analog video camera to plurality of devices such as digital high-definition web camera, video intercom, emergent alarm buttons.Because more safety-protection system is all installed on open air, therefore, the impact of humidity on safety-protection system of surrounding enviroment can not be ignored.Existing humidity measuring circuit is all comparatively complicated, and cost is higher.
Utility model content
For above-mentioned the deficiencies in the prior art, technical problem to be solved in the utility model is: provide a kind of temperature sensing circuit, comprises double bridge, differential integrated operational amplifier, hysteresis loop comparator and alarm unit;
Described double bridge comprises resistance R1, thermistor R2, and described hysteresis loop comparator comprises comparer U2 and U3;
Voltage source V CC is successively by resistance R1 and thermistor R2 ground connection, described resistance R1 is connected with the normal phase input end of differential integrated operational amplifier with the node between thermistor R2, and the inverting input of described differential integrated operational amplifier is directly connected with its output terminal, the output terminal of described differential integrated operational amplifier is also successively by resistance R3 and adjustable resistor R9 ground connection, the resistance R3 of described series connection and adjustable resistor R9 also with connect after resistance R4 and R8 be connected in parallel, described resistance R3 is connected with the normal phase input end of comparer U2 by resistance R6 with the node between adjustable resistor R9, node between described resistance R4 and R7 is connected with the inverting input of comparer U2 by resistance R5, the normal phase input end of described comparer U2 is also by resistance R7 ground connection, the inverting input of described comparer U2 is also connected with the output terminal of comparer U2 by resistance R10,
The output terminal of described comparer U2 is also direct to be connected with the inverting input of comparer U3, and the normal phase input end of described comparer U3 is also connected with the output terminal of comparer U3 by resistance R11; The described output terminal of comparer U3 is connected with one end of alarm unit, the other end ground connection of described alarm unit;
Described voltage source V CC is successively by resistance R15 and adjustable resistor R14 ground connection, and described resistance R15 is connected with the normal phase input end of comparer U3 by resistance R13 with the node between adjustable resistor R14.
Further, described alarm unit comprises light emitting diode, and the wherein said output terminal of comparer U3 is connected with the anode of light emitting diode, the plus earth of described light emitting diode.
Further, described alarm unit comprises hummer, and the wherein said output terminal of comparer U3 is connected with one end of hummer, the other end ground connection of described hummer.
Further, also comprise an electric capacity C1, described electric capacity C1 is connected between the node of resistance R1 and thermistor R2 and the earth.
Described temperature sensing circuit uses double bridge, temperature collection circuit built by differential integrated operational amplifier, and adopt thermistor R2 as a brachium pontis of double bridge, when the temperature is changed, the resistance that thermistor R2 is corresponding also can change, electric bridge can produce differential pressure, by differential integrated operational amplifier, differential pressure signal is amplified, and give hysteresis loop comparator and carry out voltage compare, thus determining the output potential (" height " or " low ") of hysteresis loop comparator, whether the startup of control alarm unit to be.Meanwhile, by the convertible critical temperature of the adjustment of adjustable resistor R9 and R14.Said temperature testing circuit structure is simple, cost is lower, and stability is higher.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiments more of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the circuit diagram of the better embodiment of the utility model temperature sensing circuit.
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.
First, before embodiment is described, be necessary that some terms to occurring make an explanation herein.Such as:
Use the term such as " first ", " second " to describe various element if occur herein, but these elements should not limited by these terms.These terms are only used for differentiation element and another element.Therefore, " first " element also can be called as " second " element and not depart from instruction of the present utility model.
In addition, should be understood that, when mentioning an element " connection " or " connection " to another element, it can directly connect or directly be connected to another element or also can there is intermediary element.On the contrary, when mentioning that an element " directly connection " or " directly connecting " are to another element, then there is not intermediary element.
The various terms occurred in this article are only not intended to conduct to restriction of the present utility model for describing the object of concrete embodiment.Unless context is clearly pointed out in addition, then singulative intention also comprises plural form.
" comprise " when using term in this manual and/or " including " time, these terms specify the existence of described feature, entirety, step, operation, element and/or parts, but also do not get rid of more than one other features, entirety, step, operation, element, the existence of parts and/or its group and/or additional.
About embodiment:
Refer to Fig. 1, the better embodiment of temperature sensing circuit of the present utility model comprises double bridge, differential integrated operational amplifier U1, hysteresis loop comparator and alarm unit.
Concrete, described double bridge comprises resistance R1, thermistor R2, and described hysteresis loop comparator comprises comparer U2 and U3, and described alarm unit comprises LED 1.
Voltage source V CC is successively by resistance R1 and thermistor R2 ground connection, node between described resistance R1 and thermistor R2 is by electric capacity C1 ground connection, also the normal phase input end of direct and differential integrated operational amplifier U1 is connected, and the inverting input of described differential integrated operational amplifier U1 is directly connected with its output terminal.The output terminal of described differential integrated operational amplifier U1 is also successively by resistance R3 and adjustable resistor R9 ground connection.The resistance R3 of described series connection and adjustable resistor R9 also with connect after resistance R4 and R8 be connected in parallel.Described resistance R3 is connected with the normal phase input end of comparer U2 by resistance R6 with the node between adjustable resistor R9, node between described resistance R4 and R7 is connected with the inverting input of comparer U2 by resistance R5, the normal phase input end of described comparer U2 is also by resistance R7 ground connection, and the inverting input of described comparer U2 is also connected with the output terminal of comparer U2 by resistance R10.
The output terminal of described comparer U2 is also direct to be connected with the inverting input of comparer U3, and the normal phase input end of described comparer U3 is also connected with the output terminal of comparer U3 by resistance R11.The output terminal of described comparer U3 is connected with the anode of LED 1, the plus earth of described LED 1.
Described voltage source V CC is successively by resistance R15 and adjustable resistor R14 ground connection, and described resistance R15 is connected with the normal phase input end of comparer U3 by resistance R13 with the node between adjustable resistor R14.
In the utility model, described temperature sensing circuit uses double bridge, differential integrated operational amplifier U1 builds temperature collection circuit, and adopt thermistor R2 as a brachium pontis of double bridge, when the temperature is changed, the resistance that thermistor R2 is corresponding also can change, electric bridge can produce differential pressure, by differential integrated operational amplifier U1, differential pressure signal is amplified, and give hysteresis loop comparator and carry out voltage compare, thus determine the output potential (" height " or " low ") of hysteresis loop comparator, control the light on and off of LED 1.Meanwhile, by the convertible critical temperature of the adjustment of adjustable resistor R9 and R14 (i.e. the critical temperature values of LED 1 light on and off).Said temperature testing circuit structure is simple, cost is lower, and stability is higher.
Certainly, in other embodiments, described alarm unit also can comprise other suggestion device, and such as hummer also can.
These are only embodiment of the present utility model; not thereby the scope of the claims of the present utility model is limited; every utilize the utility model instructions and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present utility model.
Claims (4)
1. a temperature sensing circuit, is characterized in that: described temperature sensing circuit comprises double bridge, differential integrated operational amplifier, hysteresis loop comparator and alarm unit;
Described double bridge comprises resistance R1, thermistor R2, and described hysteresis loop comparator comprises comparer U2 and U3;
Voltage source V CC is successively by resistance R1 and thermistor R2 ground connection, described resistance R1 is connected with the normal phase input end of differential integrated operational amplifier with the node between thermistor R2, and the inverting input of described differential integrated operational amplifier is directly connected with its output terminal, the output terminal of described differential integrated operational amplifier is also successively by resistance R3 and adjustable resistor R9 ground connection, the resistance R3 of described series connection and adjustable resistor R9 also with connect after resistance R4 and R8 be connected in parallel, described resistance R3 is connected with the normal phase input end of comparer U2 by resistance R6 with the node between adjustable resistor R9, node between described resistance R4 and R7 is connected with the inverting input of comparer U2 by resistance R5, the normal phase input end of described comparer U2 is also by resistance R7 ground connection, the inverting input of described comparer U2 is also connected with the output terminal of comparer U2 by resistance R10,
The output terminal of described comparer U2 is also direct to be connected with the inverting input of comparer U3, and the normal phase input end of described comparer U3 is also connected with the output terminal of comparer U3 by resistance R11; The described output terminal of comparer U3 is connected with one end of alarm unit, the other end ground connection of described alarm unit;
Described voltage source V CC is successively by resistance R15 and adjustable resistor R14 ground connection, and described resistance R15 is connected with the normal phase input end of comparer U3 by resistance R13 with the node between adjustable resistor R14.
2. temperature sensing circuit as claimed in claim 1, it is characterized in that: described alarm unit comprises light emitting diode, the wherein said output terminal of comparer U3 is connected with the anode of light emitting diode, the plus earth of described light emitting diode.
3. temperature sensing circuit as claimed in claim 1, it is characterized in that: described alarm unit comprises hummer, the wherein said output terminal of comparer U3 is connected with one end of hummer, the other end ground connection of described hummer.
4. temperature sensing circuit as claimed in claim 1, is characterized in that: also comprise an electric capacity C1, and described electric capacity C1 is connected between the node of resistance R1 and thermistor R2 and the earth.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420616225.5U CN204085732U (en) | 2014-10-23 | 2014-10-23 | Temperature sensing circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420616225.5U CN204085732U (en) | 2014-10-23 | 2014-10-23 | Temperature sensing circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204085732U true CN204085732U (en) | 2015-01-07 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420616225.5U Expired - Fee Related CN204085732U (en) | 2014-10-23 | 2014-10-23 | Temperature sensing circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN204085732U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105784168A (en) * | 2016-04-01 | 2016-07-20 | 浪潮电子信息产业股份有限公司 | Temperature transmitter |
| CN105911953A (en) * | 2016-06-23 | 2016-08-31 | 李玉盛 | Novel control system for intelligent home |
| TWI579544B (en) * | 2015-06-17 | 2017-04-21 | 台灣積體電路製造股份有限公司 | Thermal detection circuit and method |
| CN106644114A (en) * | 2017-01-06 | 2017-05-10 | 四川埃姆克伺服科技有限公司 | Temperature sensor signal processing circuit |
| CN107167262A (en) * | 2017-06-19 | 2017-09-15 | 江苏师范大学 | A kind of digital temperature detection circuit based on DSP |
| CN109342797A (en) * | 2018-08-24 | 2019-02-15 | 维沃移动通信有限公司 | A backlight source detection circuit, terminal and backlight source detection method |
-
2014
- 2014-10-23 CN CN201420616225.5U patent/CN204085732U/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI579544B (en) * | 2015-06-17 | 2017-04-21 | 台灣積體電路製造股份有限公司 | Thermal detection circuit and method |
| US9841326B2 (en) | 2015-06-17 | 2017-12-12 | Taiwan Semiconductor Manufacturing Co., Ltd. | Thermal detection circuit |
| US10508957B2 (en) | 2015-06-17 | 2019-12-17 | Taiwan Semiconductor Manufacturing Co., Ltd. | Thermal detection circuit |
| US11067453B2 (en) | 2015-06-17 | 2021-07-20 | Taiwan Semiconductor Manufacturing Co., Ltd. | Thermal detection circuit |
| US11609126B2 (en) | 2015-06-17 | 2023-03-21 | Taiwan Semiconductor Manufacturing Co., Ltd. | Thermal detection circuit |
| CN105784168A (en) * | 2016-04-01 | 2016-07-20 | 浪潮电子信息产业股份有限公司 | Temperature transmitter |
| CN105911953A (en) * | 2016-06-23 | 2016-08-31 | 李玉盛 | Novel control system for intelligent home |
| CN106644114A (en) * | 2017-01-06 | 2017-05-10 | 四川埃姆克伺服科技有限公司 | Temperature sensor signal processing circuit |
| CN106644114B (en) * | 2017-01-06 | 2023-06-20 | 四川埃姆克伺服科技有限公司 | Temperature sensor signal processing circuit |
| CN107167262A (en) * | 2017-06-19 | 2017-09-15 | 江苏师范大学 | A kind of digital temperature detection circuit based on DSP |
| CN109342797A (en) * | 2018-08-24 | 2019-02-15 | 维沃移动通信有限公司 | A backlight source detection circuit, terminal and backlight source detection method |
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| C14 | Grant of patent or utility model | ||
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| CF01 | Termination of patent right due to non-payment of annual fee |
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| CF01 | Termination of patent right due to non-payment of annual fee |