【正文】 display circuit, such as group into. temperature sampling circuit Temperature sampling circuit using AD590 currentmode temperaturesensitive device of its stability and linearity are better. When in AD590 for the current , temperature increase 1℃ , the current increase in 1uA. The current is converted to voltage signal by analogtodigital converter ADC0809, AT89C51 singlechip temperature monitoring and conversion. One resistor R measurement using a low temperature coefficient of resistance, temperature coefficient of 10 x l0_6 / ℃ . When monitoring the temperature of lO0 ℃ when generated in the resistor voltage about, when the temperature is 0 ℃ when generated in the resistance of about 1 voltage, that is, at a temperature of 0 ~ 1O0 ℃ in resistance on pressure drop 2 resulting from bad to 5v. However, when the temperature is 0 ℃ demodulation IC2 potential output allows for OV, the time when 1O0 ℃ for IC2 output 5v, in the constant temperature water tank 3 installed AD590, which are located under the sink in the various parts, using its monitoring of temperature changes in the market tank in order to control the stirring motor to ensure uniform temperature sink. thermostat control circuit Constant temperature control circuit from heating thermostat temperature setting and the position of the two parts of the circuit. The thermostat circuit settings temperature to provide the working conditions of the heating circuit, the circuit set by the keyboard bination of software programming to achieve mon. In addition to each button and set the IO port connected to 8255, but also through a door with the AT89C51 and T0 timer connected so that when the button is depressed immediately after the interruption to the application AT89C51, 8255 inquiry, and at the same time the functions of the corresponding control . One set is the key type from the set and the AT89C51, D / A converter analog voltage measurement is the AD590, after the detection signal AT89C51, D / A converter provides analog, IC3 constitute a parison amplifier, IC4 ratio amplifier , BG1, BG2, T constitutes a thyristor conduction angle control circuit, a single bipolar transistor oscillator circuit the lower the frequency, SCR39。其中設(shè)定量是由設(shè)定鍵鍵入并經(jīng) AT89C5 D／ A 轉(zhuǎn)換的電壓模擬量，測量 是 AD590 的檢測信號經(jīng)過 AT89C5 D／ A 轉(zhuǎn)換提供的模擬量， IC3 構(gòu)成比較放大器， IC4 構(gòu)成比例放大器， BG BG T 構(gòu)成可控硅導(dǎo)通角控制電路，單結(jié)晶體管振蕩電路的頻率越低，可控硅的導(dǎo)通時間越短加熱功率越小，相反則高。 4)在零件上創(chuàng)建微小的變化，不必使用關(guān)系去改變模型。在充分考慮本沖壓設(shè)備性能參數(shù)和典型沖壓件的前提下，都可以用同樣的解決方案來建立標(biāo)準(zhǔn)模架庫。運(yùn)用上述方法。初始化完成系統(tǒng)加電后對 8255 的復(fù)位和軟件的初始化并將恒溫水域預(yù)置為等待進(jìn)水工作狀態(tài)，打開進(jìn)水電磁閥，當(dāng)有鍵按下時 AT89C51 相應(yīng)中斷，讀取 8255 的口狀態(tài)，判斷按鍵的功能，以便調(diào)用相應(yīng)的子程 序。在 0~C 時 AD590 的電流為 ，溫度每增加 1℃ ，電流增加 1uA。s onthe shorter the time the smaller the heating power, on the contrary higher. Singlejunction transistors and the