【正文】 the rectification bridge, the filter resistance, the pressure sensitive resistance and integration voltagestabilizer circuit MC7812T and MC7805T, which can provide +5V and the +12V power source for the controller. OutsideOSC1 and OSC2, 8 kHz crystal oscillator is connected with the circuit. The Keyboard The function of controlling and the enactment of parameters are realized by the pressing the keys. The two keys of the system’s main controller plete directly the functions of heating and the inquiring of the water level, using the keyboard severance pattern and PTA2, PTA3 as the input entrance of the pressing. The keyboard of the remote controller is designed into matrix type. The pressing of the keys will initiate the keyboard severance, by scanning from line to line。就中國的具體情況而言 ， 由于太陽能熱水器的使用受天氣原因的限制 ， 使用范圍狹窄，燃氣熱水器由于以石油、天然氣為燃料 ， 而燃料供應(yīng)量又難以滿足人們?nèi)找嬖鲩L的需求，且不利于環(huán)境，因此電熱水器越來越受到消費者的青睞。 電源與時鐘電路。采用 SPI主方式擴展兩片 74LS164，作為七段顯示器靜態(tài)顯示的段數(shù)據(jù)輸出口。在正常情況下，流過磁環(huán)的電流大小相等，方向相反，磁環(huán)檢測線圈無感應(yīng)電流信號，漏電檢測集成電路輸出低電平。 遙控器 遙控部分采用簡單控制電路，又不會減少功能，將有些硬件電路用軟件實現(xiàn)，并且充分考慮到了抗干擾問題。中斷主要有定時中斷，鍵盤輸入中斷，TIM輸入捕捉中斷， TBM模塊中斷等。有按鍵按下進入鍵中斷置標志位，等松開后再進行相應(yīng)的處理。發(fā)送：當遙控器按鍵按下，設(shè)置標志位，并通過動 態(tài)掃描方式讀取鍵號，之后按標志位及鍵號利用輸出比較進行編碼發(fā)送。 5. 設(shè)計擴展 隨著信息技術(shù)的發(fā)展，智能化的家用電器將逐漸走進人們的家庭。 安全保護子程序。之后依流程進行處理。之后系統(tǒng)主程序循環(huán)調(diào)用各個功能模塊子程序。紅外信號輸出采用軟件編碼方式，主控制器軟件解碼。 CPU自動判斷是否為自檢信號以及自檢是否合格，有信號則自檢合格，繼續(xù)執(zhí)行程序；無信號則自檢不合格，自動停止加熱保溫及鍵盤操作，結(jié)束工作程序并發(fā)出報警信號，電源指示燈閃爍警示，蜂鳴器 連續(xù)嗚響，從而確保電熱水器的安全使用。水位檢測為三個并聯(lián)的不同阻值的電阻，電路的電極電流較小 (幾個微安 )，電腐蝕小，適用水電阻變化范圍大 (10 K一 100K歐 )。 控制器的功能及參數(shù)設(shè)定都是通過按鍵來實現(xiàn)，本系統(tǒng)主控制器兩個按鍵完成直接加熱及查詢水位的功能，采用鍵盤中斷模式， PTA2， PTA3作為按鍵的輸入口。由于考慮到熱水器的潮濕的工作環(huán)境對單片機的特殊要求，我們采用了摩托羅拉新推出 MC68HC08系列的單片機作為控制中心。 when the waterlevel arrives, the three resistances are linked into parallel connection. The information of waterlevel can be judged by transforming voltages from different resistances through PTB1 (high, middle, low and burning). The Detecting of Electricity Leaking and Alarming Circuit Since the working environment of waterheater is humid, the controller should be able to detect the electricity leaking to ensure the safety of the user. Under normal circumstance, the electric current passing the magic circle is the same but with opposite directions. The magic detecting circle wouldn’t sense any signal of electric current and the integrated circuit of electricity leaking detecting will output low electric level. When the electric current leaks, the electric current passing the magic circle is lopsided. The detecting circuit will detect the signal of electricity leaking and magnify the electric level output through the integrated circuit M54123L and then will be output into CPU after inverting by audion. Receiving the signal of electricity leaking, the CPU will stop heating and preservation and the operation of keyboards, ends the operation and sends alarming signal. The electricity light will flicker to warn and the buzzer will buzz continuously. Generally speaking, CPU will send out a reliable pulse for leaking protection every 10ms to replace the ordinary detecting switch and control the connection of crystal tube. So the electric current passing the magic circle is larger than 10 MA, which will be detected by the detecting magic circle as stimulant signal for leaking, magnified by M54123L and inverted by audion and then output to will judge whether the detection is eligible. If there is signal, the detection is eligible and can go on working。 if there is no signal, the detection is not eligible and