CN107830945A - A kind of hypersensitive temperature sensor - Google Patents

A kind of hypersensitive temperature sensor Download PDF

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Publication number
CN107830945A
CN107830945A CN201711412555.7A CN201711412555A CN107830945A CN 107830945 A CN107830945 A CN 107830945A CN 201711412555 A CN201711412555 A CN 201711412555A CN 107830945 A CN107830945 A CN 107830945A
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CN
China
Prior art keywords
temperature
circuit
amplifier
sensitive
resistance
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
Application number
CN201711412555.7A
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Chinese (zh)
Inventor
崔建国
宁永香
韩俊芳
米娟芳
石昊
崔建峰
付渊
岳俊梅
李莉
段新娥
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Shanxi Engineering Institute
Shanxi Institute of Technology
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Shanxi Engineering Institute
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shanxi Engineering Institute filed Critical Shanxi Engineering Institute
Priority to CN201711412555.7A priority Critical patent/CN107830945A/en
Publication of CN107830945A publication Critical patent/CN107830945A/en
Pending legal-status Critical Current

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K3/00Thermometers giving results other than momentary value of temperature
    • G01K3/08Thermometers giving results other than momentary value of temperature giving differences of values; giving differentiated values
    • G01K3/14Thermometers giving results other than momentary value of temperature giving differences of values; giving differentiated values in respect of space

Abstract

The invention discloses a kind of hypersensitive temperature sensor based on slicing operation amplifier, and it is made up of a temperature-sensitive point circuit, a clipping amplifier circuit, a temperature-compensation circuit, transducer sensitivity regulation circuit, a warning circuit., it is necessary to which we make temperature-sensitive element by oneself, two temperature-sensitive points A, B relative position can arbitrarily change described temperature-sensitive point circuit.Described clipping amplifier circuit, by operational amplifier N1And peripheral cell composition, actually constitute a voltage comparator.Described temperature-compensation circuit, by voltage-regulator diode V1(temperature compensation type bandgap voltage reference:1.23V) and its peripheral resistor network composition operational amplifier inverting input biasing circuit.The transducer sensitivity adjusts circuit, and the sensitivity of sensor circuit can be adjusted by potentiometer POT, comparator is had certain hysteresis by adjusting sensitivity.The warning circuit, by transistor V2And direct current piezoelectric buzzer HA compositions.

Description

A kind of hypersensitive temperature sensor
Technical field
The present invention relates to a kind of technology of temperature control sensor, especially a kind of hypersensitive temperature difference based on slicing operation amplifier Sensor, the sensor can both test thermoelectric voltage, also can output switch amount, composition as common temperature-sensitive element it is automatic Temperature control system, such as " draught detector ".
Background technology
In routine work and life, it is sometimes desirable to detect the temperature difference of water inlet pipe and outlet pipe in cooling circulating water;For Mitigate the harm of draught, it is necessary to judge that door and window is to open or should close;People need to monitor combustion site(Such as Gas flame), prevent fray-out of flame.
General industry is by the way of, and using two parameter identical thermistors, and two in same temperature strip The metalfilmresistor as thermistor is measured under part, their bridge-types are connected, as long as regulating the compensation of lead, output It is exactly the temperature difference;Or two identical thermocouples are directly used, two kinds of environment are respectively placed in, then a secondary meter is coupled and carries out Computing can indicates the temperature difference.
Thermocouple is a kind of temperature sensor, and thermocouple output is millivolt signal, therefore the above method can be used as temperature Indicator or calculating temperature difference, but output temperature or the temperature difference cannot function as switching stage application.If in thermoelectricity occasionally thermal resistance temperature Spend in excursion, the artificial voltage given in loop or curent change look for a correspondence in 4 ~ 20mA electric currents, and sensor is just It is sent in the form of this corresponding current in transmitter, the effect of transmitter is exactly that the current signal for transmitting sensor is handled Host computer, or display instrument or executing agency or warning device are transmitted in the form of data signal afterwards.
But the program general user of transmitter can not modify, to be carried out by producer, therefore this is extremely inconvenient. So if a kind of sensor that can directly test the temperature difference be it is fabulous, the temperature sensor can direct output switch amount, enter The corresponding Industry Control of row, design below it is a kind of using Limiting Amplifier Design can be in the one kind used in wide temperature range very much Temperature responsive unit --- temperature control sensor, the output of this temperature control sensor can realize the demand for control of the above.
The content of the invention
The technical problems to be solved by the invention be to provide it is a kind of it is simple in construction, cheap, using it is reliable, can survey automatically The equipment for measuring the temperature difference of local environment diverse location, i.e. temperature sensor, sensor can both test thermoelectric voltage, Can as common temperature-sensitive element output switch amount, form auto temperature controlled system, such as " draught detector ".
To achieve the above object, the present invention provides a kind of hypersensitive temperature sensor based on slicing operation amplifier, its By a temperature-sensitive point circuit, a clipping amplifier circuit, a temperature-compensation circuit, a transducer sensitivity regulation electricity Road, a warning circuit composition;The temperature-sensitive point circuit is used as temperature sensing device using our self-designed thermocouples, hot Quick sharp circuit is by resistance R2 connection amplifiers N1 normal phase input end, while temperature-sensitive point circuit passes through resistance R3 connection amplifiers N1's Inverting input, the faint temperature signal that temperature-sensitive point circuit is sensed are amplified by the clipping amplifier circuit;The temperature Spend compensation circuit, connection discharge circuit N1 inverting input, the inverting input biasing circuit of composition slicing operation amplifier; The transducer sensitivity adjusts circuit, the same inverting input for connecting discharge circuit N1, exports slicing operation amplifier With certain hysteresis;Slicing operation amplifier output signal passes through resistance R9 connection transistors V2Base stage, as crystalline substance Body pipe V2Base bias voltage, transistor V2The conducting of C-E poles ,+4.5V power supplys are sequentially connected direct current buzzer HA, resistance R10, transistor V2 form loop with ground, drive direct current buzzer warning.
, it is necessary to which we make temperature-sensitive element by oneself, this temperature-sensitive element is made up of described temperature-sensitive point circuit copper cash and resistive conductor, And no matter the relative position of profile, size or two temperature-sensitive points A, B can arbitrarily change, and adapt to extremely severe ring Border.
Described clipping amplifier circuit, by operational amplifier N1And peripheral cell composition, actually constitute an electricity Press comparator.
Described temperature-compensation circuit, described temperature-compensation circuit, resistance R7, voltage stabilizing are sequentially connected by+4.5V power supplys Diode V1And ground forms loop, a burning voltage+1.23V is formed at V1 both ends, the burning voltage passes through resistance R5, electricity Position device POT, resistance R4 connection amplifiers N1 inverting input, form operational amplifier inverting input biasing circuit.
The transducer sensitivity adjusts circuit, and+1.23V burning voltages are connected by resistance R5, potentiometer POT, resistance R4 Amplifier N1 inverting input is connect, the sensitivity of sensor circuit can be adjusted by changing potentiometer POT resistances, sensitive by adjusting Degree makes comparator have certain hysteresis.
The warning circuit, by transistor V2And direct current piezoelectric buzzer HA compositions.
Brief description of the drawings
Accompanying drawing 1, accompanying drawing 2, accompanying drawing 3 are used for providing a further understanding of the present invention, form the part of the application, accompanying drawing 1 is designed temperature difference sensor electrical schematic diagram of the present invention.Accompanying drawing 2 is the structure for making temperature-sensitive element by oneself.Accompanying drawing 3 is4.5V become Parallel operation.
Embodiment
Accompanying drawing 1 is designed temperature difference sensor electrical schematic diagram of the present invention, by a temperature-sensitive point circuit, a limiting amplifier Circuit, a temperature-compensation circuit, a transducer sensitivity regulation circuit, a warning circuit composition, are described in detail below The present invention.
Slicing operation amplifier passes through laser-adjusting, better than common amplifier, it is allowed to amplify minimum input voltage without by Biasing effect.Thermocouple is for measurement temperature(Essence and the measurement temperature difference, but arrived cold-point temperature compensation by compensation circuit 0℃), due to the limitation of its volume, profile, material, it is impossible to which flexible adaptation can not possibly be used alone in various complex environments " the real temperature difference " is measured, it is necessary to which we make temperature-sensitive element by oneself.
Temperature-sensitive point makes:For the minimum temperature difference, a kind of temperature-sensitive element can be designed, this temperature-sensitive element is by copper cash and electricity Hinder line to form, and no matter the relative position of profile, size or two temperature-sensitive points A, B can also arbitrarily change, and adapt to extremely Rugged environment, the harmful effect of environment can be suppressed by suitable circuit, as shown in Figure 2.This temperature-sensitive element its A kind of real and thermocouple, it is the temperature-sensitive element for being specifically used to measure the temperature difference rather than measurement temperature, therefore need not specially be referred to Bright cool and heat ends.
The characteristic of operational amplifier:ICL7650, in open loop operational pattern, is not provided with negative anti-as operational amplifier Feedback, therefore sensitivity is very high.The current potential of this voltage comparator circuit output end and the electric potential relation of input are:In-phase input end During more than anti-phase input terminal voltage, output voltage is close to positive voltage;When in-phase input end is less than anti-phase input terminal voltage, Output voltage is close to negative supply voltage.This necessary input voltage difference of operational amplifier is in millivolt rank, zero load amplification Rate is higher, and this voltage difference is smaller.
It means that although with the mutually voltage difference very little between inverting input, many times can be also exaggerated.Therefore appoint What voltage difference can all make amplifier output depend entirely on input voltage for the level of the both positive and negative polarity of power supply and be above or below base Quasi- voltage.Required for this comparing function is exactly us.
Transducer sensitivity adjusts:In electrical principle Fig. 1, slicing operation amplifier N1Actually constitute a voltage Comparator, by the adjunct circuit of comparator inverting input, thus it is possible to vary in-phase input end causes the input that comparator inverts The threshold voltage of signal, the threshold values is in zero crossings sensitivity highest.
By voltage-regulator diode V1(temperature compensation type bandgap voltage reference:1.23V) and its peripheral resistor network composition is transported Amplifier inverting input biasing circuit is calculated, the DC component of the signal of inverting input can be adjusted, final change computing is put The threshold voltage of big device output signal upset.
The sensitivity of sensor circuit can be adjusted by potentiometer POT in figure, sensitivity not adjust too high, Yi Mian electricity Occur vibrating in road or the input voltage of very little is poor(Such case is constantly present in practice)Just make comparator N1Upset, passes through tune Section sensitivity makes comparator have certain hysteresis.
By the pin of ICL7650 the 9th(Clamped end)Operational amplifier inverting input is connected on, is defeated in order to improve operational amplifier Go out signal DC component.That is operational amplifier output depends not only on external input with inputting actual electric potential relation Voltage, and depend on the bias voltage related to input, ICL7650 typical input bias current only 2pA, such input Outer meeting resistance resistance can it is very big, such as 1 μ V disturbance voltage is corresponding:
R==500KΩ
The design chooses inverting input outer meeting resistance R3Resistance is 1.2M Ω.
Sensor application:Thermo detector circuit shown in Fig. 1 primes can provide 1k(Fahrenheit temperature)The temperature difference, so by Test sample can be remained due to being influenceed caused by the temperature difference with unit voltage of different sizes, therefore this circuit can be suitable Used in small temperature range.
" thermocouple " that this temperature sensor is designed using us is used as temperature sensing device, and the two are communicating together Temperature-sensitive point is made up of identical material, they or the different monitoring points related as two, there is provided thermoelectric voltage;Or as normal The temperature-sensitive element seen is used as " auto temperature controlled system " sensor like that.It is used for example as " draught detector ", exactly house yin, yang Both sides have the temperature difference just to cause draught, and the temperature difference is bigger, wind speed is bigger, thus can by the detection of the temperature difference so as to automatically turning on or Close the doors and windows, in order to avoid cause human body to be damaged by draught.
This practical circuit, it is suitable for a variety of monitoring tasks, if event occurs to send alarm by piezoelectric buzzer HA, Amplifier is through a transistor driving buzzer.Transistor V2Base stage there is no bias voltage, therefore be likely to occur such a phenomenon: There is no the output current potential determined during Amplifier ON, thus input signal is not reacted.As long as in V2Base stage and colelctor electrode it Between plus a negative-feedback electric capacity C3, this shortcoming can be overcome.
Test this detector(Temperature sensor)When, a small-pulse effect is first sent, such as touch temperature-sensitive point joint Place, a check pulse is just produced, buzzer can sound.Due to buzzer direct current supply, therefore use direct current buzzer.
When detector does not have input signal, the interference signal of external electrical network frequency can enter circuit, send out buzzer Go out cackle, detector has this cackle can be covered during signal voltage.So in order to prevent the alternating voltage in environment from coupling Into detector, compensation circuit must be accessed between output end and inverting input, due to the high resistant characteristic of operational amplifier, Most of application scenarios, use 2.7pF feedback capacity C7It is enough as compensation circuit.
A S can be added again on circuit1Switch, so as to which bigger electric capacity can be accessed when needed.But which increase Response time and turn-off time.For example, still by taking draught detector as an example, it is harmful to postpone the turn-off time, such as causes interior The illnesss such as people's anemopyretic cold, scapulohumeral periarthritis.
Function Extension:Temperature sensor after Function Extension, the temperature difference can be indicated using digital voltmeter;Its output stage Switching stage is can also act as, such as switch ventilation or heating system.Temperature-sensitive element inertia very little is advantageous to quick response, by this biography Sensor can also monitor bulk goods, prevent their spontaneous combustions;Another significant application is to be carried out by optical element remote Temperature detection, detector is arranged in focus.
Power supply:This design uses4.5V powers, and can be provided by power frequency 220V through over commutation, voltage stabilizing;For the ease of The AC influence of line voltage is carried and reduced, 9V laminated cells can be used, by voltage changer ICL7660, by 9v Cell voltage is converted to symmetrically4.5V, as shown in Figure 3.
The temperature sensor works in limiter comparator working condition using operational amplifier ICL7650, by us certainly The temperature-sensitive element of system(Itself it is also thermocouple), a temperature control sensor is formed, the sensor can be used as temperature indicator; Can be as the sensor of the output switch data signal of general significance, can be with the unlatching of control device using its output switch amount Or close, complete Industry Control.The circuit design is novel, simple for structure, and cost of manufacture is very cheap, is advantageous to marketing.

Claims (5)

  1. A kind of 1. hypersensitive temperature sensor, it is characterised in that:By a temperature-sensitive point circuit, clipping amplifier circuit, one Individual temperature-compensation circuit, a transducer sensitivity regulation circuit, a warning circuit composition;The temperature-sensitive point circuit uses me Self-designed thermocouple as temperature sensing device, the positive that temperature-sensitive point circuit passes through resistance R2 connection amplifiers N1 inputs End, while the faint temperature difference that temperature-sensitive point circuit is sensed by resistance R3 connection amplifiers N1 inverting input, temperature-sensitive point circuit Signal is amplified by the clipping amplifier circuit;The temperature-compensation circuit, connection discharge circuit N1 inverting input, Form the inverting input biasing circuit of slicing operation amplifier;The transducer sensitivity adjusts circuit, equally connects amplifier Circuit N1 inverting input, make the output of slicing operation amplifier that there is certain hysteresis;Slicing operation amplifier exports Signal passes through resistance R9 connection transistors V2Base stage, as transistor V2Base bias voltage, transistor V2C-E poles lead Logical ,+4.5V power supplys are sequentially connected direct current buzzer HA, resistance R10, transistor V2 and ground and form loop, drive direct current buzzer Alarm.
  2. 2. hypersensitive temperature sensor according to claim 1, it is characterised in that:Described temperature-sensitive point circuit is, it is necessary to certainly Temperature-sensitive element processed, this temperature-sensitive element are made up of copper cash and resistive conductor, and no matter profile, size or two temperature-sensitive points A, B Relative position can arbitrarily change, and adapt to extremely rugged environment.
  3. 3. hypersensitive temperature sensor according to claim 1, it is characterised in that:Described clipping amplifier circuit, by Operational amplifier N1And peripheral cell composition, actually constitute a voltage comparator.
  4. 4. hypersensitive temperature sensor according to claim 1, it is characterised in that:Described temperature-compensation circuit, by+ 4.5V power supplys are sequentially connected resistance R7, voltage-regulator diode V1, with ground formed loop, V1 both ends formed a burning voltage+ 1.23V, the burning voltage by resistance R5, potentiometer POT, resistance R4 connection amplifiers N1 inverting input, composition computing put Big device inverting input biasing circuit.
  5. 5. hypersensitive temperature sensor according to claim 1, it is characterised in that:The transducer sensitivity regulation electricity Road ,+1.23V burning voltages by resistance R5, potentiometer POT, resistance R4 connection amplifiers N1 inverting input, change potentiometer POT resistances can adjust the sensitivity of sensor circuit, comparator is had certain hysteresis by adjusting sensitivity.
CN201711412555.7A 2017-12-24 2017-12-24 A kind of hypersensitive temperature sensor Pending CN107830945A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711412555.7A CN107830945A (en) 2017-12-24 2017-12-24 A kind of hypersensitive temperature sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711412555.7A CN107830945A (en) 2017-12-24 2017-12-24 A kind of hypersensitive temperature sensor

Publications (1)

Publication Number Publication Date
CN107830945A true CN107830945A (en) 2018-03-23

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711412555.7A Pending CN107830945A (en) 2017-12-24 2017-12-24 A kind of hypersensitive temperature sensor

Country Status (1)

Country Link
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109119931A (en) * 2018-08-06 2019-01-01 四川大学 Transmission line of electricity anti-icing ice-melt heat Calculation method online based on self-control thermal wire

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109119931A (en) * 2018-08-06 2019-01-01 四川大学 Transmission line of electricity anti-icing ice-melt heat Calculation method online based on self-control thermal wire
CN109119931B (en) * 2018-08-06 2020-01-24 四川大学 Power transmission line online anti-icing and de-icing heat quantity calculation method based on self-made thermal conductor

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