【正文】 直流調(diào)速器就是調(diào)節(jié)直流電動(dòng)機(jī)速度的設(shè)備，上端和交流電源連接，下端和直流電動(dòng)機(jī)連接，直流調(diào)速器將交流電轉(zhuǎn)化成兩路輸出直流電源，一路輸入給直流電機(jī)礪磁（定子），一路輸入給直流電機(jī)電樞（轉(zhuǎn)子），直流調(diào)速器通過(guò)控制電樞直流電壓來(lái)調(diào)節(jié)直流電動(dòng)機(jī)轉(zhuǎn)速。電動(dòng)機(jī)的電樞電壓受單片機(jī)輸出脈沖控制，實(shí)現(xiàn)了利用脈沖寬度調(diào)制技術(shù)（ PWM）進(jìn)行直流電機(jī)的變速。 我們討論的是可以正轉(zhuǎn)反轉(zhuǎn)的，如果只按一個(gè)方向轉(zhuǎn)，我們就只要把 PWM1置為高電平或低電平，只改變另一個(gè) PWM2電平的脈沖變化即可。 行車方向檢 測(cè)電路，采用反射接收原理配置了一對(duì)紅外線發(fā)射、接收傳感器。正常行駛時(shí)，發(fā)射管發(fā)射紅外光照射地面，光線經(jīng)白紙反射后被接收管接收，輸出高電平信號(hào)；電動(dòng)車經(jīng)過(guò)黑線時(shí)，發(fā)射端發(fā)射的光線被黑線吸收，接收端接收不到反射光線，傳感器輸出低電平信號(hào)后送 80C51單片機(jī)處理，判斷執(zhí)行哪一種預(yù)先編制的程序來(lái)控制 車的行駛狀態(tài)。//高電平的占空比 bit Flag = 1。 //電機(jī)換向 sbit PWM1=P1^0。 void Motor_speed_high(void)。 /****************延時(shí)處理 **********************/ void Delay(int i) { int j。 if(Key_add==0)//消抖 { count0 += 5。 if(Key_dec==0) { count0 = 5。 if(Key_turn == 0) { Flag = ~Flag。 TL0=TH0_TL0%256。 } /*********主函數(shù) ********************/ void main(void) { Timer0_init()。 } } /**************定時(shí) 0 中斷處理 ******************/ void Timer0_int(void) interrupt 1 using 1 { TR0 = 0。 if(Time_delay != 0)//延時(shí)函數(shù)用 { Time_delay。 if(count1 = 100) { count1=0。 if(count1 = 100) { count1=0。外中斷 1入口 LJMP INTEX1 。中斷返回 *************************** * 初始化程序 * **************************** CLEARMEMIO: MOV R0, 70H 。下一地址 DJNZ R7, ML0 。50毫秒定時(shí)用初值 MOV TH1,3CH MOV 20H,00H 。開(kāi)總中斷允許 RET 。轉(zhuǎn) MAIN循環(huán) NOP 。關(guān)外中斷 1 INC 20H 。滿 6圈清 0進(jìn)位（ 6圈為 1米） INC 21H 。 滿 10清 0進(jìn) 1位 INC 22H 。 滿 10清 0進(jìn) 1位 INC 24H 。 滿 10清 0 LLL: MOV 74H,21H ?；謴?fù)堆棧 POP ACC SETB EX1 。 顯示程序 。掃描字 PLAY: MOV A,R5 。取段碼表首址 MOVC A,A+DPTR 。指向下顯示數(shù)地址 MOV A,R5 。放回 A AJMP PLAY 。子程序結(jié)束 TAB: DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH 第 19 頁(yè) 結(jié)論 本設(shè)計(jì)完成了自動(dòng)往返行駛汽車，使用 MCS8031 單片機(jī)，并且用七段數(shù)碼管顯示里程。根據(jù)所選用的硬件及芯片，設(shè)計(jì)電路并編程實(shí)現(xiàn)要求內(nèi)容。 通過(guò)這次課程設(shè)計(jì)使我懂得了理論與實(shí)際相結(jié)合是很重要的，只有理論知識(shí)是遠(yuǎn)遠(yuǎn)不夠的，只有把所學(xué)的理論知識(shí)與實(shí)踐相結(jié)合起來(lái)，從理論中得出結(jié)論，才能真正為社會(huì)服務(wù)，從而提高自己的實(shí)際動(dòng)手能力和獨(dú)立思考的能力。t agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly. For more informu, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. ation about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。s antiracism taskforce, is in London for the Football Association39。s 21 win. Michel Platini, president of European football39。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life 第 22 頁(yè) trajectory deeply shallow, suddenly feel something, do it. 一字開(kāi)頭的年齡已經(jīng)到了尾聲。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候，自己的想法總是特別地清晰。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說(shuō)，是自以為是的精神寄托罷了。 Have declared the end of the encounter that haven39。 instead of letting the world soften us, we let it drive us deeper into ourselves. We try to deflect the hurt and pain by pretending it doesn’t exist, but although we can try this all we want, in the end, we can’t hide from ourselves. We need to learn to open our hearts to the potentials of life and let the world soften us. 生活發(fā)生不幸時(shí)，我們常常會(huì)關(guān)上心門(mén)；世界不僅沒(méi)能慰藉我們，反 倒使我們更加消沉。 Whenever a painful situation arises in your life, try to embrace it instead of running away or trying to mask the hurt. When the sadness strikes, take a deep breath and lean into it. When we run away from sadness that’s unfolding in our lives, it gets stronger and more real. We take an emotion that’s fleeting and make it a solid event, instead of something that passes through us. 當(dāng)生活中出現(xiàn)痛苦的事情時(shí)，別再逃跑或隱藏痛苦，試著擁抱它吧；當(dāng)悲傷 來(lái)襲時(shí)，試著深呼吸，然后直面它。其實(shí)，我們有能力面對(duì)這些痛苦的感受，從中領(lǐng)悟到出路。與其一味顧慮重重，不如從局外人的角度看待決策之事。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there