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公司), LM表示美國(guó) IVEC公司, MC為美國(guó) MOTROL公司。 ⑥ 施密特觸發(fā)器 在調(diào)光電路中,為了能夠調(diào)節(jié)光的亮度,就必須控制交流電的電壓,電壓強(qiáng) 26 則燈光亮,所以在雙向可控硅導(dǎo)通的時(shí)間來(lái)確定交流電的有效值是實(shí)現(xiàn)調(diào)光的重要過(guò)程。要實(shí)現(xiàn)這過(guò)程,就必須給單片機(jī)輸入交流的同步檢測(cè)信號(hào),從而來(lái)確定脈沖的發(fā)送時(shí)間,來(lái)導(dǎo)通可控硅,實(shí)現(xiàn)燈光亮度控制。所以系統(tǒng)就需要一個(gè)提供同步信號(hào)的電路。而 施密特觸發(fā)器 就能提供這功能,它的重要功能就是能夠把變化非常緩慢的輸入脈沖波形,整形成為適合于電路需要的矩形脈沖,而且由于具有滯回能力特性,所以抗干擾能力很強(qiáng)。圖 21為 用施密特觸發(fā)器實(shí)現(xiàn)波形變換。 本系統(tǒng)采用的是 74HC7014, 74HC7014 高速 Si 門(mén) CMOS 設(shè)備。它被指定依從JEDEC 標(biāo)準(zhǔn)第 7A 。 74HC7014 提供六精確度 施密特 觸發(fā)器以非倒置緩沖。它是能變換慢慢地改變的輸入信號(hào)入尖銳被定義的 , jitterfree 產(chǎn)品信號(hào)。這使電路適當(dāng)操作在一個(gè)高度喧鬧的環(huán)境里。輸入短褲被允許對(duì) V 和 16 V 沒(méi)有干擾其它渠道。特點(diǎn) : 工作電壓 3 到 6 V。 圖 21 施密特觸發(fā)器實(shí)現(xiàn)波形變換 ⑥遙控接收及控制調(diào)光電路總圖 前面介紹了電源設(shè)計(jì)電路,調(diào)光控制電路,下面我就設(shè)計(jì)一個(gè)總圖,通過(guò)單片機(jī)來(lái)實(shí)現(xiàn)。我先畫(huà)個(gè)總體框圖,如圖 22所示。具體詳圖請(qǐng)見(jiàn)附圖 2。其 — 口作為數(shù)碼管的二進(jìn)制數(shù)據(jù)輸出,顯示數(shù)字為 “0 — 7” , “0” 表示最暗, “7”表示最亮,采用帶鎖存功能的七段譯碼電路 74HC4511集成塊譯碼顯示數(shù)值,以 4地址輸入 (D1 對(duì) D4),七活躍高段產(chǎn)品 (Qa對(duì) Qg) 。 4511 的 LE 端接 89c51 的 30 腳(地址鎖存允許控制); — P0 .7 以及 — 作為 14個(gè)電器的電源控制輸出,接口用繼電器隔離輸出。 口為調(diào)光脈沖 輸出 ,輸出脈沖由三極管 9012 放大后經(jīng)光電耦合器 MOC3021 驅(qū)動(dòng)雙向可控硅控制負(fù)載; 口為交流 50Hz同步檢測(cè)信號(hào)輸入。系統(tǒng)對(duì)市電進(jìn)行變壓、整流、并經(jīng)施密特觸發(fā)器整形后得到 100Hz 的方波(周期 10ms),作為發(fā)送調(diào)光脈沖的同步信號(hào),系統(tǒng)采用 10ms 為一個(gè) “ 單 U1 VT+ VT t UOH UOL O t 27 位時(shí)間 ” 的長(zhǎng)度,燈的亮度越高,則可控硅導(dǎo)通時(shí)間的占空比越大; 口為紅外遙控碼輸入,采用集成紅外線(xiàn)接收路 SFH50638, 此集成元件體積小、抗干擾性好、并且價(jià)格低廉。它僅有三個(gè)腳,分別是電源正極、電源負(fù)極以及信號(hào)輸出端,其工作電壓為 5V 左右,它的主要功能包括放大、選頻、解調(diào)幾大部分,要求輸入是已經(jīng)被調(diào)制的信號(hào),經(jīng)過(guò)它的接收放大和解調(diào)會(huì)在輸出端直接輸出原始信號(hào)至 腳。這款紅外線(xiàn)接收電路接收距離可以達(dá) 8 米左右,完全可以滿(mǎn)足室內(nèi)的遙控距離; 腳為外部中斷 0 輸入腳,采用下降沿觸發(fā),有信號(hào)時(shí),第一位碼的低電平啟動(dòng)中斷程序,實(shí)時(shí)接收數(shù)據(jù)幀。第 9 腳為單片機(jī)的復(fù)位腳,采用 RC上電復(fù)位電路; 1 19 腳接 12M 晶振。 圖 22 遙控接收控制電路總框圖 ⑦遙控發(fā)射器的造型設(shè)計(jì)要求 這里我只簡(jiǎn)單介紹下發(fā)射器的設(shè)計(jì)要求,具體實(shí)物將不再設(shè)計(jì)。造型設(shè)計(jì)的宗旨是處理好人與產(chǎn)品、人與環(huán)境之間的關(guān)系,既滿(mǎn)足人們對(duì)物質(zhì)功能的需求,又滿(mǎn)足人們對(duì)審美的精神需求。在兼顧合理性、經(jīng)濟(jì)性、審美性、實(shí)用性、獨(dú)創(chuàng)性的基礎(chǔ)上,還要考慮對(duì)產(chǎn)品的功能、構(gòu)造、工藝、色彩、裝潢、表面處理和人機(jī)關(guān)系等許多因素。在不同的產(chǎn)品中這些因素的地位是不均等的。這就要求針對(duì)產(chǎn)品的各自特點(diǎn)進(jìn)行設(shè) 計(jì),造型設(shè)計(jì)可以確定和提高電子產(chǎn)品的外形質(zhì)量,創(chuàng)造出功能與美感,技術(shù)和藝術(shù)相統(tǒng)一的藝術(shù)形象,反映出新一代產(chǎn)品的科技面貌和時(shí)代風(fēng)格。 從使用角度來(lái)看,紅外線(xiàn)遙控發(fā)射器應(yīng)該是手持式的。其操作按鍵分布在遙控發(fā)射器的面板上。遙控發(fā)射器的尺寸及按鍵之間的間隔與排列應(yīng)從生理學(xué)的角度,按照人手掌的大下,手指的長(zhǎng)短的調(diào)查統(tǒng)計(jì)數(shù)據(jù)來(lái)確定。 單片機(jī) 七段譯碼電路 數(shù)碼顯示器 紅外線(xiàn)接收電路 斯密特觸發(fā)器 電源電路 控制 14 個(gè)燈具的電源輸出 調(diào)光電路 28 結(jié) 論 通過(guò)這次畢業(yè)設(shè)計(jì),提升了我的自學(xué)能力,通過(guò)不斷的查閱資料,通過(guò)老師的不斷講解,來(lái)解決其中遇到的困難,比如如何解決無(wú)線(xiàn)通信問(wèn)題,如何解決控制問(wèn)題等。 我在設(shè)計(jì)中改變了比較傳統(tǒng)的固 定式開(kāi)關(guān)元件,利用單片機(jī)無(wú)線(xiàn)遙控控制室內(nèi)燈光取得了良好的效果,為人們提供了很大的方便,在社會(huì)生活越來(lái)越現(xiàn)代化的同時(shí),我認(rèn)為燈具電器等家具實(shí)現(xiàn)智能化控制是一個(gè)很大的趨勢(shì),同時(shí)也應(yīng)總結(jié)經(jīng)驗(yàn),逐步完善室內(nèi)燈光智能控制,例如可以增加室內(nèi)燈具的自動(dòng)巡檢與電腦聯(lián)網(wǎng)功能,燈具故障即可自動(dòng)發(fā)出報(bào)修信號(hào),燈具的各種使我們第一時(shí)間得知燈具的工作狀況,還可以對(duì)燈具加入很多的場(chǎng)景模式等。在設(shè)計(jì)中也體會(huì)到我的知識(shí)面還是很狹窄,作為電子系的畢業(yè)生,在學(xué)好本專(zhuān)業(yè)的基礎(chǔ)前提下,還要不斷的學(xué)習(xí)其他領(lǐng)域的科學(xué)技術(shù)知識(shí),拓寬自己的知識(shí)面,才能勝 任新設(shè)備、新技術(shù)的工作,更好發(fā)揮本專(zhuān)業(yè)的作用。 29 參 考 文 獻(xiàn) [1] 王俊峰 薛鴻德 .現(xiàn)代遙控技術(shù)及其應(yīng)用 .人民郵電出版社 .2022 [2] 馬家辰 孫玉德 張穎 .MCS51單片機(jī)原理及接口技術(shù) .哈爾濱工業(yè)大學(xué)出版社 .1998 [3] 科林 孫人杰 . TTL、高速 CMOS 手冊(cè) .電子工業(yè)出版社 .2022 [4] 周雪 .模擬電子技術(shù) .西安電子科技大學(xué)出版社 .2022 [5] 殷際英 林宋 方建軍 .光機(jī)電一體化 .化學(xué)工業(yè)出版社 .2022 [6] 齊寶林 .電工快速識(shí)圖 .福建科學(xué)技術(shù)出版社 .2022 g an employment tribunal clai Employment tribunals sort out disagreements between employers and employees. You may need to make a claim to an employment tribunal if: ? you don39。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 information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept i. If you are worried about how the time limits apply to you, 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. If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。re clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s antiracism taskforce, is in London for the Football Association39。s 150th anniversary 30 celebrations and will attend City39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s 21 win. Michel Platini, president of European football39。s governing body, has also ordered an immediate investigation into the referee39。s actions.