CN2524231Y

CN2524231Y - Temperature sampler

Info

Publication number: CN2524231Y
Application number: CN 02225467
Authority: CN
Inventors: 张利; 高亮; 戴全平
Original assignee: SHUNDE SPECIAL TRANSFORMER FACTORY
Current assignee: SHUNDE SPECIAL TRANSFORMER FACTORY
Priority date: 2002-01-24
Filing date: 2002-01-24
Publication date: 2002-12-04
Anticipated expiration: 2012-01-24

Abstract

The utility model relates to a temperature sampler which is characterized in that the temperature sampler comprises a DC/DC isolating auxiliary power source which is used for providing direct-current working voltage for the other units introduced as follow; a CPU control unit; a temperature collecting device used for receiving the sine wave driving signal which is output by the CPU control unit, and sampling and then enlarging the external temperature signal, the inputting the external temperature signal to the CPU control unit, and an isolating serial port communicator used for receiving the actual temperature signal which is sent by the CPU control unit and outputting the actual temperature signal. The utility model has the advantages of high temperature survey precision, simple electric circuit and reliable work.

Description

Temperature sampler

(1) technical field

The utility model relates to a kind of Temperature sampler.

(2) background technology

Because temperature one resistive performance of PT100 is fine, interchangeability good, low price, it is used widely, as temperature sensor in the high-precision temperature measurement mechanism.Drive PT100 with the high-precision current source, produce the voltage signal corresponding at the PT100 two ends with temperature.Because PT100's is non-linear, need to add correcting circuit, carry out the ADC analog to digital conversion again; As contain single chip circuit, and can directly carry out the ADC conversion, proofread and correct with software.It is to use thermometry, owing to directly get the magnitude of voltage at PT100 two ends, requires precision height, the good temp characteristic of the hardware such as voltage-reference, resistance of current source, ADC, and these all will increase the complicacy and the cost of circuit.

(3) summary of the invention

The purpose of this utility model provides that a kind of to measure temperature accuracy high, the simple Temperature sampler of circuit.

In order to achieve the above object, the utility model is achieved in that and it is characterized in that: being included as following each unit provides the DC/DC of direct-current working volts to isolate accessory power supply; One CPU control module; After amplifying its voltage difference, the sine wave drive signal of one reception CPU control module output and the external temperature signal of sampling input to the temperature collecting device of CPU control module again; One receives the actual temperature value signal of CPU control module output and with the isolated serial port communicator of its output.

Of the present utility modelly further be improved to, above-mentioned DC/DC isolates accessory power supply and comprises dc voltage conversion module P1, P2, capacitor C 1-C7, inductance L 1 and resistance R 1; 1,2 pin of module P1 connect an end of direct supply, and 7,8 pin connect the other end of direct supply; 5,6 pin of a termination module P1 after capacitor C 3, the C4 parallel connection, this end also is the output terminal of voltage Vdd, other end ground connection; Connect 5,6 pin of the circuit one termination module P1 after its series connection, other end ground connection after capacitor C 6, the C7 parallel connection with resistance R 1 and inductance L 1; Capacitor C 5 one terminations connect the series connection point of inductance L 1 and resistance R 1, other end ground connection, and the other end of resistance R 1 is the output terminal of voltage Vaa; 5,6 pin of 7, the 8 pin connection module P1 of module P2,3,4 pin of 1, the 2 pin connection module P1 of module P2,5,6 pin of a termination module P2 after capacitor C 1, the C2 parallel connection, 3,4 pin of other end connection module P2.Above-mentioned CPU control module comprises ic chip 1, resetting block U4, operational amplifier U2a, crystal Y1, capacitor C 17-C25 and resistance R 30-R32; Be connected on after capacitor C 17, the C18 parallel connection between 5,6 pin of ic chip 1; 7 pin of capacitor C 19, C20 series connection back one termination ic chip 1,8 pin of another termination ic chip 1, its concatenation points connects 6 pin of ic chip 1; 3 pin of operational amplifier U2a are 9 pin of positive input termination ic chip 1, its 4 pin connects voltage Vaa end, this pin is also by capacitor C 21 ground connection, its 2 pin is that negative input end passes through resistance R 31 ground connection, resistance R 30 is connected between 1,2 pin of operational amplifier U2a, and 1 pin of operational amplifier U2a is an output terminal sine wave output drive signal; 2 pin of resetting block U4 connect 15 pin of ic chip 1, its 1 pin ground connection, and 3 pin connect voltage Vdd end; Crystal Y1, capacitor C 24, C25 form ∏ shape circuit, and two of crystal Y1 terminates between 32,33 pin of ic chip 1, and capacitor C 23 is connected between 34,35 pin of

ic chip

1, and 34 pin connect voltage Vdd end, its 35 pin ground connection; Capacitor C 22 is connected between 47,48 pin of ic chip 1,47 pin ground connection, and 48 pin connect voltage Vdd end; An end ground connection after resistance R 32 is connected with switch LK1,41 pin of another termination ic chip 1, capacitor C 26 is connected between 20,21 pin of ic chip 1, and 20 pin connect voltage Vdd end, 21 pin ground connection.The said temperature harvester comprises temperature sensor PT1A-PT4A, resistance R 2-R45, capacitor C 8-C31, operational amplifier U1a-U1d; 1 pin of resistance R 3, R4 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT1A; 3 pin of resistance R 2 one termination PT1A, 1 pin of another termination operational amplifier U2a is an output terminal; 2 pin of operational amplifier U1a are the series connection point that negative input end passes through resistance R 6 connecting resistance R3, R4, its 3 pin is positive input terminal meets PT1A by resistance R 53 pin, its 1 pin connects 1 pin of ic chip 1 by resistance R 37, and 4 pin of operational amplifier U1a connect voltage Vaa end; 2 pin of capacitor C 10 1 termination operational amplifier U1a are negative input end, other end ground connection; 3 pin of resistance R 7, capacitor C 9 back one end operational amplifier U1a in parallel are positive input terminal, other end ground connection; 4 pin of capacitor C 8 one termination operational amplifier U1a, other end ground connection; Resistance R 8 is connected between 1,2 pin of operational amplifier U1a; 1 pin of capacitor C 28 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 10, R11 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT2A; 3 pin of resistance R 9 one termination PT2A, 1 pin of another termination operational amplifier U2a is an output terminal; 6 pin of operational amplifier U1b are the series connection point that negative input end passes through resistance R 13 connecting resistance R10, R11, and to be positive input terminal connect 3 pin of PT2A by resistance R 12 to its 5 pin, and its 7 pin connects 2 pin of ic chip 1 by resistance R 38; 6 pin of capacitor C 12 1 termination operational amplifier U1b are negative input end, other end ground connection; 5 pin of resistance R 14, capacitor C 11 back one end operational amplifier U1b in parallel are positive input terminal, other end ground connection; Resistance R 15 is connected between 6,7 pin of operational amplifier U1b, 2 pin of capacitor C 29 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 17, R18 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT3A; 3 pin of resistance R 16 1 termination PT3A, 1 pin of another termination operational amplifier U2a is an output terminal; 9 pin of operational amplifier U1c are the series connection point that negative input end passes through resistance R 20 connecting resistance R17, R18, and to be positive input terminal connect 3 pin of PT3A by resistance R 19 to its 10 pin, and its 8 pin connects 3 pin of ic chip 1 by resistance R 45; 9 pin of capacitor C 14 1 termination operational amplifier U1c are negative input end, other end ground connection; 10 pin of resistance R 21, capacitor C 13 back one end operational amplifier U1c in parallel are positive input terminal, other end ground connection; 3 pin of capacitor C 30 1 termination ic chips 1, other end ground connection; Resistance R 22 is connected between 8,9 pin of operational amplifier U1c; 1 pin of resistance R 24, R25 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT4A; 3 pin of resistance R 23 1 termination PT4A, 1 pin of another termination operational amplifier U2a is an output terminal; 13 pin of operational amplifier U1d are the series connection point that negative input end passes through resistance R 27 connecting resistance R24, R25, and its 12 pin is positive input terminal meets PT4A by resistance R 26 3 pin; 13 pin of capacitor C 16 1 termination operational amplifier U1d are negative input end, other end ground connection; 12 pin of resistance R 28, capacitor C 15 back one termination operational amplifier U1d in parallel are positive input terminal, other end ground connection; Resistance R 29 is connected between 13,14 pin of operational amplifier U1d, 4 pin of capacitor C 31 1 termination ic chips 1, other end ground connection.The isolated serial port communicator comprises photoelectricity isolated tube U5a, U5b, U6, serial interface chip U7, resistance R 33-R43 and capacitor C 27; 2 pin of photoelectricity isolated tube U5a connect 22 pin of ic chip 1 by resistance R 33, and its 1 pin connects voltage Vdd end, its 7 pin ground connection, and 8 pin connect 2,3 pin of serial interface chip U7, and this pin also meets voltage+5V by resistance R 36; The 3 pin ground connection of photoelectricity isolated tube U6,4 pin connect 16 pin of ic chip 1, and 2 pin connect 1 pin of serial interface chip U7 by resistance R 39, and 1 pin meets voltage+5V; 3 pin of photoelectricity isolated tube U5b connect voltage Vdd end, and 4 pin connect 17 pin of ic chip 1 by resistance R 35,5 pin ground connection, and 6 pin connect 4 pin of serial interface chip U7, and 6 pin also meet voltage+5V by resistance R 40; 6,7 pin of serial interface chip U7 are the output pin of temperature value, its 7 pin of resistance R 41 1 terminations, other end ground connection, its 6 pin of one termination of resistance R 43, other end ground connection, resistance R 42 is connected between its 6,7 pin, its 5 pin ground connection, 8 pin meet voltage+5V, and this end is also by capacitor C 27 ground connection.

The utility model compared with prior art has following advantage:

1, measures the temperature accuracy height;

2, circuit is simple, reliable operation.

(4) description of drawings

Fig. 1 is a circuit block diagram of the present utility model;

Fig. 2 is circuit theory diagrams of the present utility model.

(5) embodiment

Below in conjunction with drawings and Examples the utility model is done further detailed description:

As shown in Figure 1, it is a kind of Temperature sampler, and being included as following each unit provides the DC/DC of direct-current working volts to isolate accessory power supply (4); One CPU control module (2); After amplifying its voltage difference, the sine wave drive signal of one reception CPU control module (2) output and the external temperature signal of sampling input to the temperature collecting device (1) of CPU control module (2) again; One receives the actual temperature value signal of CPU control module (2) output and with the isolated serial port communicator (3) of its output.

As shown in Figure 2, above-mentioned DC/DC isolates accessory power supply (4) and comprises dc voltage conversion module P1, P2, capacitor C 1-C7, inductance L 1 and resistance R 1; 1,2 pin of module P1 connect an end of direct supply, and 7,8 pin connect the other end of direct supply; 5,6 pin of a termination module P1 after capacitor C 3, the C4 parallel connection, this end also is the output terminal of voltage Vdd, other end ground connection; Connect 5,6 pin of the circuit one termination module P1 after its series connection, other end ground connection after capacitor C 6, the C7 parallel connection with resistance R 1 and inductance L 1; Capacitor C 5 one terminations connect the series connection point of inductance L 1 and resistance R 1, other end ground connection, and the other end of resistance R 1 is the output terminal of voltage Vaa; 5,6 pin of 7, the 8 pin connection module P1 of module P2,3,4 pin of 1, the 2 pin connection module P1 of module P2,5,6 pin of a termination module P2 after capacitor C 1, the C2 parallel connection, 3,4 pin of other end connection module P2.Above-mentioned CPU control module (2) comprises ic chip 1, resetting block U4, operational amplifier U2a, crystal Y1, capacitor C 17-C25 and resistance R 30-R32; Be connected on after capacitor C 17, the C18 parallel connection between 5,6 pin of ic chip 1; 7 pin of capacitor C 19, C20 series connection back one termination ic chip 1,8 pin of another termination ic chip 1, its concatenation points connects 6 pin of ic chip 1; 3 pin of operational amplifier U2a are the positive input termination

9 pin of ic chip 1, its 4 pin connect voltage Vaa end, and this pin is also by capacitor C 21 ground connection; Its 2 pin is that negative input end passes through resistance R 31 ground connection, and resistance R 30 is connected between 1,2 pin of operational amplifier U2a, and 1 pin of operational amplifier U2a is an output terminal sine wave output drive signal; 2 pin of resetting block U4 connect 15 pin of ic chip 1, its 1 pin ground connection, and 3 pin connect voltage Vdd end; Crystal Y1, capacitor C 24, C25 form ∏ shape circuit, and two of crystal Y1 terminates between 32,33 pin of ic chip 1, and capacitor C 23 is connected between 34,35 pin of

ic chip

1, and 34 pin connect voltage Vdd end, 35 pin ground connection; Capacitor C 22 is connected between 47,48 pin of ic chip 1,47 pin ground connection, and 48 pin connect voltage Vdd end; An end ground connection after resistance R 32 is connected with switch LK1,41 pin of another termination ic chip 1, capacitor C 26 is connected between 20,21 pin of ic chip 1, and 20 pin connect voltage Vdd end, 21 pin ground connection.Said temperature harvester (1) comprises temperature sensor PT1A-PT4A, resistance R 2-R45, capacitor C 8-C31, operational amplifier U1a-U1d; 1 pin of resistance R 3, R4 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT1A; 3 pin of resistance R 2 one termination PT1A, 1 pin of another termination operational amplifier U2a is an output terminal; 2 pin of operational amplifier U1a are the series connection point that negative input end passes through resistance R 6 connecting resistance R3, R4, its 3 pin is positive input terminal meets PT1A by resistance R 53 pin, its 1 pin connects 1 pin of ic chip 1 by resistance R 37, and 4 pin of operational amplifier U1a connect voltage Vaa end; 2 pin of capacitor C 10 1 termination operational amplifier U1a are negative input end, other end ground connection; 3 pin of resistance R 7, capacitor C 9 back one end operational amplifier U1a in parallel are positive input terminal, other end ground connection; 4 pin of capacitor C 8 one termination operational amplifier U1a, other end ground connection; Resistance R 8 is connected between 1,2 pin of operational amplifier U1a; 1 pin of capacitor C 28 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 10, R11 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT2A; 3 pin of resistance R 9 one termination PT2A, 1 pin of another termination operational amplifier U2a is an output terminal; 6 pin of operational amplifier U1b are the series connection point that negative input end passes through resistance R 13 connecting resistance R10, R11, and to be positive input terminal connect 3 pin of PT2A by resistance R 12 to its 5 pin, and its 7 pin connects 2 pin of ic chip 1 by resistance R 38; 6 pin of capacitor C 12 1 termination operational amplifier U1b are negative input end, other end ground connection; 5 pin of resistance R 14, capacitor C 11 back one end operational amplifier U1b in parallel are positive input terminal, other end ground connection; Resistance R 15 is connected between 6,7 pin of operational amplifier U1b, 2 pin of capacitor C 29 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 17, R18 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT3A; 3 pin of resistance R 16 1 termination PT3A, 1 pin of another termination operational amplifier U2a is an output terminal; 9 pin of operational amplifier U1c are the series connection point that negative input end passes through resistance R 20 connecting resistance R17, R18, and to be positive input terminal connect 3 pin of PT3A by resistance R 19 to its 10 pin, and its 8 pin connects 3 pin of ic chip 1 by resistance R 45; 9 pin of capacitor C 14 1 termination operational amplifier U1c are negative input end, other end ground connection; 10 pin of resistance R 21, capacitor C 13 back one termination operational amplifier U1c in parallel are positive input terminal, other end ground connection; 3 pin of capacitor C 30 1 termination ic chips 1, other end ground connection; Resistance R 22 is connected between 8,9 pin of operational amplifier U1c; 1 pin of resistance R 24, R25 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT4A; 3 pin of resistance R 23 1 termination PT4A, 1 pin of another termination operational amplifier U2a is an output terminal; 13 pin of operational amplifier U1d are the series connection point that negative input end passes through resistance R 27 connecting resistance R24, R25, and its 12 pin is positive input terminal meets PT4A by resistance R 26 3 pin; 13 pin of capacitor C 16 1 termination operational amplifier U1d are negative input end, other end ground connection; 12 pin of resistance R 28, capacitor C 15 back one termination operational amplifier U1d in parallel are positive input terminal, other end ground connection; Resistance R 29 is connected between 13,14 pin of operational amplifier U1d, 4 pin of capacitor C 31 1 termination ic chips 1, other end ground connection.Above-mentioned isolated serial port communicator (3) comprises photoelectricity isolated tube U5a, U5b, U6, serial interface chip U7, resistance R 33-R43 and capacitor C 27; 2 pin of photoelectricity isolated tube U5a connect 22 pin of ic chip 1 by resistance R 33, and its 1 pin connects voltage Vdd end, its 7 pin ground connection, and 8 pin connect 2,3 pin of serial interface chip U7, and this pin also meets voltage+5V by resistance R 36; The 3 pin ground connection of photoelectricity isolated tube U6,4 pin connect 16 pin of ic chip 1, and 2 pin connect 1 pin of serial interface chip U7 by resistance R 39, and 1 pin meets voltage+5V; 3 pin of photoelectricity isolated tube U5b connect voltage Vdd end, and 4 pin connect 17 pin of ic chip 1 by resistance R 35,5 pin ground connection, and 6 pin connect 4 pin of serial interface chip U7, and 6 pin also meet voltage+5V by resistance R 40; 6,7 pin of serial interface chip U7 are the output pin of temperature value, and resistance R 41 connects its 7 pin, other end ground connection, its 6 pin of one termination of resistance R 43, other end ground connection, resistance R 42 is connected between its 6,7 pin, its 5 pin ground connection, 8 pin meet voltage+5V, and this end is also by capacitor C 27 ground connection.During work, the temperature signal that the sine wave signal of ic chip 1 output and PT1A-PT4A gather inputs to ic chip 1 after superposeing and amplifying, this signal wherethrough reason, only extract useful single frequency point (being sine wave freuqency) temperature signal, and other frequency interferences signal is suppressed, particularly more serious power frequency is disturbed, and adds software filtering, antijamming capability is significantly improved, and this temperature signal exports exterior display screen to through isolated serial port communicator (3) and shows.

Claims

1, a kind of Temperature sampler is characterized in that: being included as following each unit provides the DC/DC of direct-current working volts to isolate accessory power supply (4); One CPU control module (2); After amplifying its voltage difference, the sine wave drive signal of one reception CPU control module (2) output and the external temperature signal of sampling input to the temperature collecting device (1) of CPU control module (2) again; One receives the actual temperature value signal of CPU control module (2) output and with the isolated serial port communicator (3) of its output.

2, Temperature sampler according to claim 1 is characterized in that: DC/DC isolates accessory power supply (4) and comprises dc voltage conversion module P1, P2, capacitor C 1-C7, inductance L 1 and resistance R 1; 1,2 pin of module P1 connect an end of direct supply, and 7,8 pin connect the other end of direct supply; 5,6 pin of a termination module P1 after capacitor C 3, the C4 parallel connection, this end also is the output terminal of voltage Vdd, other end ground connection; Connect 5,6 pin of the circuit one termination module P1 after its series connection, other end ground connection after capacitor C 6, the C7 parallel connection with resistance R 1 and inductance L 1; Capacitor C 5 one terminations connect the series connection point of inductance L 1 and resistance R 1, other end ground connection, and the other end of resistance R 1 is the output terminal of voltage Vaa; 5,6 pin of 7, the 8 pin connection module P1 of module P2,3,4 pin of 1, the 2 pin connection module P1 of module P2,5,6 pin of a termination module P2 after capacitor C 1, the C2 parallel connection, 3,4 pin of other end connection module P2.

3, Temperature sampler according to claim 1 is characterized in that: CPU control module (2) comprises ic chip 1, resetting block U4, operational amplifier U2a, crystal Y1, capacitor C 17-C25 and resistance R 30-R32; Be connected on after capacitor C 17, the C18 parallel connection between 5,6 pin of ic chip 1; 7 pin of capacitor C 19, C20 series connection back one termination ic chip 1,8 pin of another termination ic chip 1, its concatenation points connects 6 pin of ic chip 1; 3 pin of operational amplifier U2a are 9 pin of positive input termination ic chip 1, its 4 pin connects voltage Vaa end, this pin is also by capacitor C 21 ground connection, its 2 pin is that negative input end passes through resistance R 31 ground connection, resistance R 30 is connected between 1,2 pin of operational amplifier U2a, and 1 pin of operational amplifier U2a is an output terminal sine wave output drive signal; 2 pin of resetting block U4 connect 15 pin of ic chip 1, its 1 pin ground connection, and 3 pin connect voltage Vdd end; Crystal Y1, capacitor C 24, C25 form ∏ shape circuit, and two of crystal Y1 terminates between 32,33 pin of ic chip 1, and capacitor C 23 is connected between 34,35 pin of ic chip 1, and 34 pin connect voltage Vdd end, 35 pin ground connection; Capacitor C 22 is connected between 47,48 pin of ic chip 1,47 pin ground connection, and 48 pin connect voltage Vdd end; An end ground connection after resistance R 32 is connected with switch LK1,41 pin of another termination ic chip 1, capacitor C 26 is connected between 20,21 pin of ic chip 1, and 20 pin connect voltage Vdd end, 21 pin ground connection.

4, Temperature sampler according to claim 1 is characterized in that: temperature collecting device (1) comprises temperature sensor PT1A-PT4A, resistance R 2-R45, capacitor C 8-C31, operational amplifier U1a-U1d; 1 pin of resistance R 3, R4 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT1A; 3 pin of resistance R 2 one termination PT1A, 1 pin of another termination operational amplifier U2a is an output terminal; 2 pin of operational amplifier U1a are the series connection point that negative input end passes through resistance R 6 connecting resistance R3, R4, its 3 pin is positive input terminal meets PT1A by resistance R 53 pin, its 1 pin connects 1 pin of ic chip 1 by resistance R 37, and 4 pin of operational amplifier U1a connect voltage Vaa end; 2 pin of capacitor C 10 1 termination operational amplifier U1a are negative input end, other end ground connection; 3 pin of resistance R 7, capacitor C 9 back one end operational amplifier U1a in parallel are positive input terminal, other end ground connection; 4 pin of capacitor C 8 one termination operational amplifier U1a, other end ground connection; Resistance R 8 is connected between 1,2 pin of operational amplifier U1a; 1 pin of capacitor C 28 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 10, R11 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT2A; 3 pin of resistance R 9 one termination PT2A, 1 pin of another termination operational amplifier U2a is an output terminal; 6 pin of operational amplifier U1b are the series connection point that negative input end passes through resistance R 13 connecting resistance R10, R11, and to be positive input terminal connect 3 pin of PT2A by resistance R 12 to its 5 pin, and its 7 pin connects 2 pin of ic chip 1 by resistance R 38; 6 pin of capacitor C 12 1 termination operational amplifier U1b are negative input end, other end ground connection; 5 pin of resistance R 14, capacitor C 11 back one end operational amplifier U1b in parallel are positive input terminal, other end ground connection; Resistance R 15 is connected between 6,7 pin of operational amplifier U1b, 2 pin of capacitor C 29 1 termination ic chips 1, other end ground connection; 1 pin of resistance R 17, R18 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT3A; 3 pin of resistance R 16 1 termination PT3A, 1 pin of another termination operational amplifier U2a is an output terminal; 9 pin of operational amplifier U1c are the series connection point that negative input end passes through resistance R 20 connecting resistance R17, R18, and to be positive input terminal connect 3 pin of PT3A by resistance R 19 to its 10 pin, and its 8 pin connects 3 pin of ic chip 1 by resistance R 45; 9 pin of capacitor C 14 1 termination operational amplifier U1c are negative input end, other end ground connection; 10 pin of resistance R 21, capacitor C 13 back one termination operational amplifier U1c in parallel are positive input terminal, other end ground connection; 3 pin of capacitor C 30 1 termination ic chips 1, other end ground connection; Resistance R 22 is connected between 8,9 pin of operational amplifier U1c; 1 pin of resistance R 24, R25 series connection back one termination operational amplifier U2a is an output terminal, 2 pin of another termination PT4A; 3 pin of resistance R 23 1 termination PT4A, 1 pin of another termination operational amplifier U2a is an output terminal; 13 pin of operational amplifier U1d are the series connection point that negative input end passes through resistance R 27 connecting resistance R24, R25, and its 12 pin is positive input terminal meets PT4A by resistance R 26 3 pin; 13 pin of capacitor C 16 1 termination operational amplifier U1d are negative input end, other end ground connection; 12 pin of resistance R 28, capacitor C 15 back one termination operational amplifier U1d in parallel are positive input terminal, other end ground connection; Resistance R 29 is connected between 13,14 pin of operational amplifier U1d, 4 pin of capacitor C 31 1 termination ic chips 1, other end ground connection.

5, Temperature sampler according to claim 1 is characterized in that: isolated serial port communicator (3) comprises photoelectricity isolated tube U5a, U5b, U6, serial interface chip U7, resistance R 33-R43 and capacitor C 27; 2 pin of photoelectricity isolated tube U5a connect 22 pin of ic chip 1 by resistance R 33, and its 1 pin connects voltage Vdd end, its 7 pin ground connection, and 8 pin connect 2,3 pin of serial interface chip U7, and this pin also meets voltage+5V by resistance R 36; The 3 pin ground connection of photoelectricity isolated tube U6,4 pin connect 16 pin of ic chip 1, and 2 pin connect 1 pin of serial interface chip U7 by resistance R 39, and 1 pin meets voltage+5V; 3 pin of photoelectricity isolated tube U5b connect voltage Vdd end, and 4 pin connect 17 pin of ic chip 1 by resistance R 35,5 pin ground connection, and 6 pin connect 4 pin of serial interface chip U7, and 6 pin also meet voltage+5V by resistance R 40; 6,7 pin of serial interface chip U7 are the output pin of temperature value, its 7 pin of resistance R 41 1 terminations, other end ground connection, its 6 pin of one termination of resistance R 43, other end ground connection, resistance R 42 is connected between its 6,7 pin, its 5 pin ground connection, 8 pin meet voltage+5V, and this end is also by capacitor C 27 ground connection.