温度控制外文文献

1、The Application of The One-chip Computer DuringTemperature ControlAbstractPractical application of one-chip computer in heat-treatment furnace is listed,and detailed i ntroduction is given to the compositions and the main functions of WDY-1temperature co ntrol meter.Keywords ：One-chip computer; cont

2、rol;temperature.1、ForewordThe monolithic microcomputer is, because it which is born along with the ultra large scale integrated circuit technology development has the volume young, the function is strong, the price compared to the higher characteristic, therefore widely applies to the electronic ins

3、trument, the domestic electric appliances, the energy conservation installment, the military installment, the robot, the industry control and so on many domains, causes the product miniaturization, the intellectualization, both enhanced the product function and the quality, and reduced the cost, sim

4、plified the design. This article mainly introduces the monolithic integrated circuit in temperature control application.The east wind car company gear box factory hot engineering course does not have the muffle furnace, mainly uses in the gear box gear, the axis class components cementation heat tre

5、atment working procedure. Originally with the XWB self-balancing recording instrument control temperature, two types controls the warm way, enables to have the big inertia non-muffle furnace temperature fluctuation to be big, the error reaches ±10about. And the measuring appliance use environme

6、nt teaches badly, the oil smoke, the dust often cause the measuring appliance the mechanical drive partial deactivation, not only service work load big, moreover the product quality is not easy to guarantee. Along with the national economy development, the automobile industry unceasingly expands, th

7、e produce market competition is intense, superior win and the inferior wash out. From this, we pass through the earnest investigation and study and the design, sought one kind tocontrol the warm method well, that is this article introduced WDY-1warm controlled the meter to substitute for the XWB sel

8、f-balancing recording instrument.2、The WDY-1temperature bomb introductionThe WDY-1temperature bomb introduced this instrument uses the American Intel Corporation eight monolithic integrated circuits to take the control core, matches by other import integrated circuits, in addition to the software de

9、sign, has carefully realized the measuring appliance intellectualization. May with sensor coordination use and so on the thermo-element, thermal resistance, carry on the precision measurement to in the 01600scope each electric heating stove temperature, simultaneously, four LED monitor direct tracki

10、ng demonstration is controlled the object the temperature value, the accuracy high, the demonstration clear, stable is reliable, easy to operate.The entire measuring appliance principle of work is:By 8,031monolithic integrated circuits controls, according to the procedure which establishes in advanc

11、e to the thermo-element signal (namelywas fixed time measured signal carries on the sampling, and automatically carries on zero to float the adjustment, finally demonstrated measured the temperature value, simultaneously presses supposes the definite value, measured the temperature value, the temper

12、ature change speed, automatically carries on the PID parameter from and the operation, and outputs the 010mAcontrolling current, matches by the host return route realization temperature control.3、WDY-1warm controls the meter the survey and the control actionThis warm controls the meter to be the int

13、ellectualized measuring appliance, the measuring accuracy 0.2level, demonstrated resolution 1, the control precision 0.5level, the control mode is the PID algorithm, the hypothesis way for the direct temperature value hypothesis, simultaneously has ultra heats and breaks the partner to report to the

14、 police, thus the internal electric circuit quite are many, under the main circuit and each link function introduced on this measuring instrument in.（1）Thermo-elementModel WRN, divides number K, measured warm scope 01300, may the long-firing operation in 01000, the short time work to 1300, is one ki

15、nd of survey temperature signal sensor, its positive electrode is the nickel alloy, the cathode is the nickel silicon alloy. When use directly admits according to the request without the muffle furnace, the nickel -nickel silicon took one kind of standard thermo-element, in measured when takes, its

16、cold end temperature T0=0(inpractical application must through compensate realization, according to obtains through looks up the table, may the direct readout hot end temperature value. Obviously, the thermo-element in stove position certainly is not free, its hot end locates the position must accur

17、ately reflect the furnace temperature. Moreover, thermo-element performance quality direct influence heat treatment work piece quality, therefore, must regularly carry on the inspection, the replacement to the thermo-element. （2）Pretreats the electric circuitIts function includes:Compensates to the

18、thermo-element signal cold end; Breaks the partner to report to the police the protection; Three extremely filters. The cold end compensating circuit mainly for always flows the electric bridge, Rt is the copper resistance, is a standard thermal resistance, when temperature change, the Rt resistance

19、 number will change, therefore will lay aside Rt in the thermo-element cold end, will let its feeling cold end temperature the change. When temperature =0, the bridge pressure outputs U0=0V,if temperature increment, then Rt changes in a big way, causes the bridge to press the output to be bigger tha

20、n zero, presses the output value from this the bridge is the thermo-element cold end temperature corresponds 热电势. Breaks the partner to report to the police through 8,031outputs controls four LED monitor simultaneously to glitter demonstrated "E" or the buzzer reports to the police.（3）enla

21、rges and the cut electric circuit is composed by the 4066B four double throw switches and two levels of operational amplifiers.First, under 8,031controls, the simulation signal enlarges after two levels enters A/Dto transform, completes the simulation and the digital place transformation in 8031. Th

22、en, thesignal prepares for, the final thermo-element signal input enlarges, delivers the A/D transformation. Obviously, this electric circuit function is:Signal enlargement collects which the thermo-element, as well as transforms the simulation under the monolithic integrated circuit control into th

23、e digital place.（4）the a/dconversion electric circuit is composed by the 4066B four double throw switches and the LM358low power losses double operational amplifier.The transformation principle is the fraction transforms, the entire process divides into three stages, (1stops the time:Eliminates on t

24、he integrator the zero-bias voltage. (2:Will enlarge after the simulation voltage signal in time T1(T1will be definite value in the integral; (3counter:To the standard voltage reverse integral, the simulation voltage which like this inputs transforms if the mean value to have the direct ratio the ti

25、me-gap, finally will use the clock pulse and the counter this time is separated transforms the digital signal 1.（5）the driving plate definite value electric circuit uses for to establish the craft temperature. 8,243is composed by 3driving plates and the special-purpose I/Oexpansions chip, 3have cove

26、red the actual temperature use scope, through the driving plate direct hypothesis temperature value, using the driving plate interior electronic contact, separately the temperature which on, ten, hundred, thousand initializes sends in 8,243chips, then the basis monolithic integrated circuit instruct

27、ion, supposes the definite value to send in 8,031 memories.（6）the display circuit by the 74LS247seven sections of decoders, a 74LS139pair of 24 decoder, 74LS05six each piece of and four LED monitor is composed. 8,031monolithic integrated circuits the thermo-element temperature signal which must demo

28、nstrate through the P1.0P1.3mouth deliver 74LS247, delivers seven sections of digital monitors after the decoding, then by 8,031P1.4P1.5mouth output position gating signal, chooses the position again which passes must demonstrate. Four monitors take turns from the units place to thousand to lighten

29、in turn, each demonstration time 1ms, demonstrated the actual（7）the digital-analog conversion electric circuit transforms the PID operation digital quantity the corresponding simulation quantity, transforms after the enlargement and V/I obtains 010mAthe electric current continuous signal to take the

30、 output control.（8）the RS-232communication connection the monolithic integrated circuit front end took machine carries on the data acquisition or the pretreatment, obtains after the level switching circuit with the TTL level compatible signal voltage, finally information storage which will gather th

31、rough the RS-232communication connection electric circuit to system machine in 2,in order to next inquiry or backup.4、controls rules choice and analyzes（1）to measure the object the characteristic this article temperature request all maintains the definite value in any time (orin stipulation erroneou

32、s scope, but as a result of the outside influence, for example, the material joins, the supply voltage undulation and so on, can enable the furnace temperature to have the certain degree the change.（2）controls the rule the choice basis to measure the object the characteristic, must choose one kind o

33、f control rule, enable the furnace temperature to have the change tendency to limit from time to time, this system uses from the PID adjustment. When WDY-1warm controlled the meter just the thrust build-up, some will fly upwards the opportunity, the instrument outputs 100%,caused the stove temperature according to compare the steep slope to rise to about given value 80%(satisfiesrapid request, then acted according to the stove the temperature rate of change, the temperature deviation as well as the pure lag characteristic, directly according to beforehan