CN209459786U - Temperature transmitter - Google Patents

Abstract

The utility model discloses a kind of temperature transmitters comprising central integrated chip, thermistor R_t, resistance R_CM, zero potentiometer R_Z, resistance R_Z1, amplitude modulation potentiometer R_G, resistance R_G1, the end V+IN of the center integrated chip connects the thermistor R_tOne end, the thermistor R_tThe other end through resistance R_CMThe end IRET of the central integrated chip is connected, the end VIN of the center integrated chip connects the zero potentiometer R_ZCrus secunda, the zero potentiometer R_ZThird foot through the resistance R_Z1And the resistance R_CMThe end IRET of the central integrated chip is connected, the end RG1 of the center integrated chip connects the amplitude modulation potentiometer R_GCrus secunda, the amplitude modulation potentiometer R_GThird foot through resistance R_G1Connect the end RG2 of the central integrated chip.Temperature transmitter provided by the utility model can weaken output signal drift phenomenon, to improve the precision and stability of temperature transmitter.

Description

Temperature transmitter

Technical field

The utility model relates to temperature acquisition gage work fields, and in particular to a kind of temperature transmitter.

Background technique

With the development of electronic technology with the application of microcomputer measuring and controlling technology, skill using platinum resistance as temperature-sensing element Art is increasingly mature.Temperature transmitter currently on the market is typically all to be built by discrete component, and circuit is more complicated and smart Degree and stability are not good enough.In the severe environment applications that epidemic disaster changes greatly, easily there is the phenomenon that upper and lower limit drift, make Measurement result inaccuracy, causes entire transmitter accuracy of measurement to decline.

Utility model content

The utility model is to solve the severe environment applications that temperature transmitter is changed greatly in epidemic disaster in the prior art In, easily there is the problem of upper and lower limit drift, the utility model provides a kind of new temperature transmitter, provided by the utility model Temperature transmitter can weaken output signal drift phenomenon, to improve the precision and stability of temperature transmitter.

The technical solution of the utility model is as follows:

A kind of temperature transmitter, including central integrated chip, thermistor R_t, resistance R_CM, zero potentiometer R_Z, resistance R_LIN, resistance R_Z1, amplitude modulation potentiometer R_G, resistance R_G1, the end V+IN of the center integrated chip connects the thermistor R_tOne End, the thermistor R_tThe other end through resistance R_CMConnect the end IRET of the central integrated chip, the integrated core in center The end VIN of piece connects the zero potentiometer R_ZCrus secunda, while the end VIN of the central integrated chip connects the center The end IR1 of integrated chip, the end IR2 of the center integrated chip is through resistance R_LINConnect the end VLIN, the zero potentiometer R_Z's Third foot is through the resistance R_Z1And the resistance R_CMConnect the end IRET of the central integrated chip, the center integrated chip The end RG1 connect the amplitude modulation potentiometer R_GCrus secunda, the amplitude modulation potentiometer R_GThird foot through resistance R_G1Described in connection The end RG2 of central integrated chip.

The temperature transmitter further includes triode, and the collector of the triode connects the end Input voltage terminal VH, described The emitting stage of triode connects the end E of the central integrated chip, the base stage connection of the triode central integrated chip The end B.

Further, the central integrated chip uses XTR105.

Further, the thermistor R_tUsing PT100.

Further, the model 9013 that the triode uses.

The utility model has the beneficial effects that

1, the utility model passes through in zero potentiometer R_Z, amplitude modulation potentiometer R_GThe electricity of upper each series connection high-precision, high stability Hinder R_G1, resistance R_Z1, to reduce zero potentiometer R_Z, amplitude modulation potentiometer R_GStandard resistance range, increase the sensitivity of adjusting, drop The low degree for adjusting contact and being subjected to displacement, to weaken drift phenomenon；

2, the utility model enormously simplifies original electricity by using a high-precision central integrated chip XTR105 Road reduces the element for influencing temperature transmitter precision and stability；

3, the utility model is by using capacitor C₁, capacitor C₂, capacitor C₃Weaken or eliminate negative connecting wire in current loop The wireless electromagnetic of longer generation interferes, to keep output signal more stable.

Detailed description of the invention

It, below will be to required in embodiment description in order to illustrate more clearly of the technical solution of the utility model embodiment The attached drawing used is briefly described, it should be apparent that, the accompanying drawings in the following description is only some implementations of the utility model Example, for those of ordinary skill in the art, without creative efforts, can also be according to these attached drawings Obtain other accompanying drawings.

Fig. 1 is the circuit structure diagram of temperature transmitter provided by the embodiment of the utility model.

Specific embodiment

The exemplary embodiment of the utility model is more fully described below with reference to accompanying drawings.Although showing this in attached drawing The exemplary embodiment of utility model, it being understood, however, that may be realized in various forms the utility model without should be by here The embodiment of elaboration is limited.It is to be able to thoroughly understand the utility model, and energy on the contrary, providing these embodiments It is enough to be fully disclosed to those skilled in the art the scope of the utility model.

Fig. 1 is the circuit structure diagram of temperature transmitter provided by the embodiment of the utility model, during which includes Integrated chip is entreated, the model XTR105 of the chip, it is high-precision IC system, with the following functions:

The excitation of thermistor；Complete temperature and resistance value linear compensation；Resistance error of lead compensation；Output signal turns It changes, amplify；Wave protection and anti-interference is realized with add ons；Especially its internal linearizer provides thermistor Second order correction, makes to linearize in quality and improves 40 times；Internal amplifier gain can be directed to the broad range of temperature measuring equipment It is configured；Entire current converter includes whole errors of the linearisation of thermistor in full scale -40~+85 DEG C work model It is less than ± 1% in enclosing.So being not required to be reconfigured other compensators and amplifier in transmitter circuit composition, thus significantly simple Change circuit in the prior art, reduces the element for influencing temperature transmitter precision and stability.

In order to be acquired to temperature signal, temperature transmitter provided by the utility model further includes thermistor R_t, should Thermistor R_tThe model Pt100 of use, thermistor R_tOne end connect the end V+IN of central integrated chip, the temperature-sensitive Resistance R_tThe other end through resistance R_CMConnect the end IRET of central integrated chip.

Further, temperature transmitter further includes zero potentiometer R_Z, amplitude modulation potentiometer R_G, zero potentiometer R_ZFor- 200 DEG C of lowest temperatures (zero point) adjust potentiometer, amplitude modulation potentiometer R_GPotentiometer is adjusted for temperature upper limit (full scale), is passed through Adjust zero potentiometer R_Z, amplitude modulation potentiometer R_GResistance value realize the adjustment of the upper and lower limit value of transmitter, specifically, zeroing electricity Position device R_Z, amplitude modulation potentiometer R_GSelection mode is as follows:

Zero potentiometer R_ZTo be artificially arranged, specific resistance value can be learnt by looking into phasing meter, amplitude modulation potentiometer R_GAccording to Lower calculation acquires:

R_G=2R₁{(R₂+R_Z)-4(R₂R_Z)}/(R₂-R₁), R in the calculation formula₁For the temperature-sensitive of the specified range of half Resistance R_tResistance value, R₂For the thermistor R of the specified range upper limit_tValue (R1, R2 can look into phasing meter and acquire).

Zero potentiometer R_Z, amplitude modulation potentiometer R_GSpecific connection type it is as follows:

Zero potentiometer R_ZCrus secunda connect the end VIN of central integrated chip, zero potentiometer R_ZThird foot through electricity Hinder R_CMConnect the end IRET of central integrated chip, amplitude modulation potentiometer R_GCrus secunda connect the end RG1 of central integrated chip, adjust Width potentiometer R_GThird foot connect the end RG2 of central integrated chip.

Preferably, which further includes resistance R_Z1And resistance R_G1, resistance R_Z1, resistance R_G1It is electric with zeroing respectively Position device R_Z, amplitude modulation potentiometer R_GCentral integrated chip, specifically, resistance R are connected after series connection_Z1One end connect zero potentiometer R_ZThird foot, resistance R_Z1The other end through resistance R_CMConnect the end IRET of central integrated chip, resistance R_G1One end connection Amplitude modulation potentiometer R_GThird foot, resistance R_G1The other end connects the end VIN of central integrated chip, passes through zero potentiometer R_Z, adjust Width potentiometer R_GSeries resistance R_Z1And resistance R_G1To reduce zero potentiometer R_Z, amplitude modulation potentiometer R_GStandard resistance range, increase adjust The sensitivity of section reduces the degree that contact is subjected to displacement that adjusts, to weaken drift phenomenon.

It further, is the central integrated chip of cooperation to thermistor R_tThe signal of acquisition carries out linearisation adjustment, this reality Temperature transmitter with novel offer further includes resistance R_LIN, resistance R_LINOne end connect the end VLIN of central integrated chip, Resistance R_LINThe other end connect the end IR2 of central integrated chip, resistance R_LINSelection be to be determined by the temperature-measuring range designed, Resistance R_LINResistance value calculation are as follows:

R_LIN=R_CM(R_G-R₁)/2(2R₁-R_G-R_Z)。

Further, which further includes triode, the model 9013 which uses, the triode Collector connects Input voltage terminal VH, and the base stage of triode connects the end B of central integrated chip, in the emitting stage connection of triode The end E of integrated chip is entreated, which is equivalent to an external amplifier, can isolate most of central integrated chips from defeated Enter gain to the loss of power of reference voltage, to improve the load-carrying ability of converter temperature, and ensure that temperature becomes Send the precision of device.If do not use it, can due to the additional internal loss of power and making precision to a certain extent reduces, this shadow It rings particularly evident in the design of lower thermometric range (input high-gain).

Preferably, to protect temperature transmitter, the utility model also configures diode D₁, diode D₁The model of use For 1N4148, diode D₁Anode connect Input voltage terminal VH, diode D₁Cathode connect the V+ of central integrated chip End vises the supply voltage of central integrated chip under the standard of certain safety, in order to avoid destroy thermistor R_t；Circuit reversal connection When, it prevents big loop current from entering, and plays the role of wave protection.

Preferably, to make circuit provided by the utility model preferably work, which also configures capacitor C₁、 Capacitor C₂, capacitor C₃, capacitor C₁One end connect the end IR2 of central integrated chip, capacitor C₁The other end through resistance R_CMIn connection Entreat the end IRET of integrated chip, capacitor C₂One end connect the end V+ of central integrated chip, capacitor C₂The other end connect centralized At the end IG of chip, capacitor C₃One end be connected in parallel on resistance R_CMBoth ends will if the connecting wire in current loop is longer Wireless electromagnetic interference is generated, to influence the stability of output signal, passes through capacitor C₁, capacitor C₂, capacitor C₃Weaken or eliminates this Kind interference.

Working principle of the utility model is:

The utility model utilizes thermistor R_tResistance value vary with temperature and the characteristic that changes, thermistor R_tResistance value Variation, so that the variation of voltage signal is brought, by thermistor R_tThe end V+IN of the voltage input center integrated chip at both ends leads to The V/I conversion circuit for crossing the integrated chip interior in center is converted, to make output current signal DC4~20mA.

In conclusion temperature transmitter provided by the utility model can weaken output signal drift phenomenon, subtract simultaneously Few wireless electromagnetic interference, to improve the precision and stability of temperature transmitter.

While there has been shown and described that the embodiments of the present invention, for the ordinary skill in the art, It is understood that these embodiments can be carried out with a variety of variations in the case where not departing from the principles of the present invention and spirit, repaired Change, replacement and variant, the scope of the utility model is defined by the appended claims and the equivalents thereof.

Claims (5)

1. temperature transmitter, which is characterized in that including central integrated chip, thermistor R_t, resistance R_CM, zero potentiometer R_Z, electricity Hinder R_LIN, resistance R_Z1, amplitude modulation potentiometer R_G, resistance R_G1, the end V+IN of the center integrated chip connects the thermistor R_t's One end, the thermistor R_tThe other end through resistance R_CMThe end IRET of the central integrated chip is connected, the center is integrated The end VIN of chip connects the zero potentiometer R_ZCrus secunda, while the central integrated chip the connection of the end VIN it is described in The end IR1 of integrated chip is entreated, the end IR2 of the center integrated chip is through resistance R_LINConnect the end VLIN, the zero potentiometer R_Z Third foot through the resistance R_Z1And the resistance R_CMConnect the end IRET of the central integrated chip, the integrated core in center The end RG1 of piece connects the amplitude modulation potentiometer R_GCrus secunda, the amplitude modulation potentiometer R_GThird foot through resistance R_G1Connection institute State the end RG2 of central integrated chip.

2. temperature transmitter according to claim 1, which is characterized in that the temperature transmitter further includes triode, institute The collector connection end Input voltage terminal VH of triode is stated, the emitting stage of the triode connects the E of the central integrated chip End, the base stage of the triode connect the end B of the central integrated chip.

3. temperature transmitter according to claim 1, which is characterized in that the center integrated chip uses XTR105.

4. temperature transmitter according to claim 1, which is characterized in that the thermistor R_tUsing PT100.

5. temperature transmitter according to claim 2, which is characterized in that the model 9013 that the triode uses.