【導(dǎo)讀】術(shù)實(shí)驗(yàn)等科研領(lǐng)域。由于輸出波形的頻率較低，所以決定使用AT89C52作為控制電路，用。中斷查表法形成波形的數(shù)據(jù)輸出，再用D/A轉(zhuǎn)換器輸出需要的波形信號(hào)。1HZ--10KHZ的方波以及頻率從1HZ--5000HZ的正弦波（三角波）。于初學(xué)者將其作為一學(xué)習(xí)板使用，系統(tǒng)價(jià)格低廉，功能實(shí)用。尤其隨著70年代微。處理器的嶄露頭角，更促使信號(hào)發(fā)生器向著智能化、自動(dòng)化方向發(fā)展。

　　

【正文】 理、原理圖設(shè)計(jì)、 PCB 設(shè)計(jì)、信號(hào)完整性分析等技術(shù)進(jìn)行完美融合，為用戶提供了全面的設(shè)計(jì)解決方案，使用戶可以輕松進(jìn)行各種復(fù)雜的電路板設(shè)計(jì)。 以下是 信號(hào)發(fā)生器的 Protel Dxp 制版過(guò)程的簡(jiǎn)要介紹： 第三章 可調(diào)低頻信號(hào)發(fā)生器的設(shè)計(jì) 第一， 創(chuàng)建設(shè)計(jì)工程：新建一個(gè)文件夾命名為 Signal,選擇 FileNewPCB Project菜單，創(chuàng)建一個(gè) PCB 的工程文件，選擇 File Save Project菜單，打開 Save As 對(duì)話框，將所創(chuàng)建的工程名為 Signal. PrjPCB。 第二， 繪制原理圖：選擇 FileNewSchematic 菜單，創(chuàng)建新原理圖文件，并啟動(dòng)原理圖編輯器，單擊標(biāo)準(zhǔn)工具欄的保存活動(dòng)文檔工具，在彈出的保存文件對(duì)話框中選擇 Signal 文件夾，輸入 文件名后單擊“保存”按鈕，執(zhí)行菜單命令 DesignOptions,打開 Document Options 對(duì)話框。在 Standard styles 選項(xiàng)的下拉列表中選擇 A4,設(shè)置圖紙規(guī)格，其他選項(xiàng)均采用默認(rèn)值，然后點(diǎn)擊 OK 按鈕確認(rèn)。選擇 ViewFit Document 菜單，使文檔在窗口中最大化顯示，單擊標(biāo)準(zhǔn)工具欄的縮放區(qū)按鈕，在繪圖區(qū)單擊并拖動(dòng)定義希望放大的區(qū)域。最后單擊編輯區(qū)右側(cè)的 Libraries 標(biāo)簽，打開 Libraries 庫(kù)文件面板，打開元件庫(kù)下拉列表，選擇 Miscellaneous 集成庫(kù)，搜索所需要的元件，雙擊選中，然后用導(dǎo)線將它們連接成原理圖，如下圖所示： 第三章 可調(diào)低頻信號(hào)發(fā)生器的設(shè)計(jì) 圖 315 可調(diào)低頻信號(hào)發(fā)生器原理圖 第三， 進(jìn)行原理圖校驗(yàn)與分析：在完成原理圖的繪制以后，根據(jù)先前設(shè)定的設(shè)計(jì)規(guī)則對(duì)原理圖進(jìn)行校驗(yàn)，或者通過(guò)電路仿真對(duì)電路的可行性進(jìn)行分析，對(duì)電路的結(jié)構(gòu)進(jìn)行優(yōu)化。 第四， 設(shè)計(jì)印制電路板：?jiǎn)?dòng) PCB 編輯器，加載根據(jù)原理圖創(chuàng)建的網(wǎng)絡(luò)連接和元件封裝，對(duì)電路板進(jìn)行自動(dòng)布局并進(jìn)行手工調(diào)整，對(duì)電路板進(jìn)行手工布線，布線結(jié)束后對(duì)改圖進(jìn)行覆銅操作，得到最后的實(shí)驗(yàn)板如下圖： 圖 316可調(diào)低頻信號(hào)發(fā)生器 PCB圖 第五，制板：將最后得到的 PCB 圖作為模版進(jìn)行制板，并將準(zhǔn)備好的器件焊接至 該板子上。 第三章 可調(diào)低頻信號(hào)發(fā)生器的設(shè)計(jì) 測(cè)試與調(diào)試 將保存的 hex 程序文件燒錄進(jìn)單片機(jī) AT89C52 中，并按照原理圖正確接線，接好后進(jìn)行測(cè)試，結(jié)果應(yīng)該與 預(yù)測(cè)的 效果相同，若有異常則檢查故障并對(duì) 仿真 進(jìn)行修正。 心得體會(huì) 通過(guò)這次對(duì)可調(diào)低頻信號(hào)發(fā)生器的設(shè)計(jì)與制作，讓我了解了設(shè)計(jì)電路的程序，也讓我明白了關(guān)于信號(hào)發(fā)生器的原理與設(shè)計(jì)理念，要設(shè)計(jì)一個(gè)電路首先要用仿真軟件進(jìn)行仿真，成功之后才實(shí)際接線的。但是最后的成品卻不一定與仿真時(shí)完全一樣，因?yàn)樵趯?shí)際的應(yīng)用中有著各種各樣的條件制約著，理論和實(shí)踐是有差距的，反復(fù)的修改和測(cè)試 能給我們較多寶貴的經(jīng)驗(yàn)。所以，在設(shè)計(jì)時(shí)應(yīng)考慮兩者的差異，結(jié)合器件的實(shí)際情況從中找出最適合的設(shè)計(jì)方法?？偠灾?，這次的課程設(shè)計(jì)讓我對(duì)電路設(shè)計(jì)和各種軟件都有了較深入的了解，使我鞏固了上課時(shí)候?qū)W習(xí)的知識(shí)，并且對(duì)這些知識(shí)的實(shí)際運(yùn)用有了新的認(rèn)識(shí)。所以說(shuō)，坐而言不如立而行，通過(guò)自己動(dòng)手實(shí)際操作我受益匪淺，但是在設(shè)計(jì)的過(guò)程中還是犯了許多的錯(cuò)誤，希望能在老師的教導(dǎo)和自己的練習(xí)中得到糾正和提高。 致謝 參考文獻(xiàn) [1] 張毅剛，彭喜元，董繼成．單片機(jī)原理及應(yīng)用 [M]．北京：高等教育出社 ,2021:6794. [2] 李剛、林凌 . 新概念單片機(jī)教程 [M]. 天津：天津大學(xué)出版社， [3] 李金平，沈明山，姜余祥．電子系統(tǒng)設(shè)計(jì) [M]．北京：電子工業(yè)出版社，2021： 19,180196,398440. [4] 甘登岱． 跟我學(xué) Protel Dxp 電路設(shè)計(jì)與制版 [M]．北京：人民郵電出版社，2021： 196214. 致謝 致謝 這次畢業(yè)設(shè)計(jì)能夠制作成功，和許多人對(duì)我的幫助是分不開的，首先我要感謝我的畢設(shè)指導(dǎo)老師盧金平老師，是他對(duì)我設(shè)計(jì)的思路提供幫助，在制作困難的時(shí)候，也是他給了我鼓勵(lì)。其次我還要感謝學(xué)校提供給 我們圖書館這樣一個(gè)好地方讓我們查閱相關(guān)資料，我所做的畢設(shè)中很多信息均來(lái)自圖書館中的書籍。這些書中的珍貴信息對(duì)我的幫助非常巨大。最后我想感謝在我做畢業(yè)設(shè)計(jì)中那些在身邊幫助我的各位同學(xué)，本來(lái)我對(duì) DXP， PROTUES,以及 KEIL 這三款軟件不是非常熟悉，是身邊的同學(xué)在關(guān)鍵時(shí)候給予我耐心的幫助，讓我現(xiàn)在對(duì)這些軟件更加熟悉，也使我畢業(yè)設(shè)計(jì)中的制版和仿真能夠成功。 附錄：外文翻譯 In Wang Zuoliang?s translation practices, he translated many poems, especially the poems written by Robert Burns. His translation of Burn?s “A Red, Red Rose” brought him fame as a verse translator. At the same time, he published about ten papers on the translation of poems. Some argue that poems cannot be translated. Frost stresses that poetry might get lost in translation. According to Wang, verse translation is possible and necessary, for “The poettranslator brings over some exciting work from another culture and in doing so is also writing his own best work, thereby adding something to his culture. In this transmission and exchange, a richer, more colorful world emerges. ”(Wang, 1991:112). Then how can we translate poems? According to Wang?s understanding, the translation of poems is related to three aspects: A poem?s meaning, poetic art and language. （ 1） A poem?s meaning “Sociocultural differences are formidable enough, but the matter is made much more plex when one realizes that meaning does not consist in the meaning of words only, but also in syntactical structures, speech rhythms, levels of style.” (Wang, 1991:93). （ 2） Poetic art According to Wang, “Bly?s point about the ?marvelous translation? being made possible in the United States only after Whitman, Pound and Williams Carlos Williams posed poetry in speech rhythms shows what may be gained when there is a genuine revolution in poetic art.” (Wang, 1991:93). （ 3） Language “Sometimes language stays static and sometimes language stays active. When language is active, it is beneficial to translation” “This would require this kind of intimate understanding, on the part of the translator, of its genius, its idiosyncrasies, its past and present, what it can do and what it choose not to do.” (Wang, 1991:94). Wang expresses the difficulties of verse translation. Frost?s ment is sufficient to prove the difficulty a translator has to grapple with. Maybe among literary translations, the translation of poems is the most difficult thing. Poems are the crystallization of wisdom. The difficulties of poetic prehension lie not only in lines, but also in structure, such as cadence, rhyme, metre, rhythm, all these conveying information. One point merits our attention. Wang not only talks about the times? poetic art, but also the impact language?s activity has produced on translation. In times when the language is active, translation is prospering. The reform of poetic art has improved 致謝 the translation quality of poems. For example, around May Fourth Movement, Baihua replaced classical style of writing, so the translation achieved earthshaking success. The relation between the state of language and translation is so