Servomotors are available as AC or DC motors. Early servomotors were generally DC motors because the only type of control for large currents was through SCRs for many years. As transistors became capable of controlling larger currents and switching the large currents at higher frequencies, the AC servomotor became used more often. Early servomotors were specifically designed for servo amplifiers. Today a class of motors is designed for applica-tions that may use a servo amplifier or a variable-frequency controller, which means that a motor may be used in a servo system in one application, and used in a variable-frequency drive in another application. Some companies also call any closed-loop system that does not use a stepper motor a servo system, so it is possible for a simple AC induction motor that is connected to a velocity controller to be called a servomotor.
標(biāo)簽： motors Servomotors servomotors available
上傳時(shí)間： 2014-08-10
上傳用戶(hù)：源碼3
為適應(yīng)雙向DC/DC功率變換的電流采樣需求,一種高精度高邊電流采樣電路被提出。其基本思想是在功率電路的高邊串入采樣電阻,借助電流鏡原理并引入偏置電流電路,將雙向電流均轉(zhuǎn)換為正向電壓輸出。通過(guò)理論分析與仿真結(jié)合的方法對(duì)電流鏡采樣原理及4種不同的偏置電流電路方案進(jìn)行對(duì)比,最后通過(guò)實(shí)驗(yàn)數(shù)據(jù)驗(yàn)證了高精度高邊電流采樣電路的有效性。實(shí)驗(yàn)數(shù)據(jù)表明,該采樣電路可在-25~75℃的溫度工作范圍內(nèi),針對(duì)-10~＋10 A范圍內(nèi)的電流采樣實(shí)現(xiàn)優(yōu)于5%的采樣精度。Current sensing plays an important role in controlling,monitoring or protection functions of power systems.To meet the current sensing requirement of bidirectional DC/DC converters,a high-accuracy bidirectional current sensing circuit is proposed.The proposed current sensing circuit inserts a resistor in the path of the current to be sensed,while the current mirror and biased current circuit are introduced.Therefore,the bidirectional current can be expressed by positive voltage.By theoretical analysis and simulation,the sampling theory is analyzed and four biased current circuits are compared.At last,experimental results verified the proposed method.It is demonstrated that the proposed current sensing circuit can achi...
上傳時(shí)間： 2022-04-22
上傳用戶(hù)：
電源基礎(chǔ)知識(shí)DC-DC
標(biāo)簽： DC-DC 電源 基礎(chǔ)知識(shí)
上傳時(shí)間： 2013-05-25
上傳用戶(hù)：eeworm
專(zhuān)輯類(lèi)-開(kāi)關(guān)電源相關(guān)專(zhuān)輯-119冊(cè)-749M 電源基礎(chǔ)知識(shí)DC-DC-47頁(yè).ppt
上傳時(shí)間： 2013-05-16
上傳用戶(hù)：yare
專(zhuān)輯類(lèi)-開(kāi)關(guān)電源相關(guān)專(zhuān)輯-119冊(cè)-749M MC34063廉價(jià)的DC-DC變換器.pdf
上傳時(shí)間： 2013-05-21
上傳用戶(hù)：dylutao
專(zhuān)輯類(lèi)-開(kāi)關(guān)電源相關(guān)專(zhuān)輯-119冊(cè)-749M 脈寬調(diào)制DC-DC全橋變換器的軟開(kāi)關(guān)技術(shù)-140頁(yè)-3.3M.pdf
上傳時(shí)間： 2013-06-11
上傳用戶(hù)：ddddddos
專(zhuān)輯類(lèi)-實(shí)用電子技術(shù)專(zhuān)輯-385冊(cè)-3.609G 兩種雙管反激型DC-DC變換器的研究和比較.pdf
上傳時(shí)間： 2013-05-28
上傳用戶(hù)：Yukiseop
dsp2812下CCS3的DC-DC-PWM波形調(diào)制程序
標(biāo)簽： DC-DC-PWM 2812 CCS3 dsp
上傳時(shí)間： 2013-07-10
上傳用戶(hù)：LSPSL
中大尺寸液晶電視AC-DC電源架構(gòu)及最新LED背光方案
上傳時(shí)間： 2013-07-01
上傳用戶(hù)：liu_yuankang
電源是電子設(shè)備的重要組成部分，其性能的優(yōu)劣直接影響著電子設(shè)備的穩(wěn)定性和可靠性。隨著電子技術(shù)的發(fā)展，電子設(shè)備的種類(lèi)越來(lái)越多，其對(duì)電源的要求也更加靈活多樣，因此如何很好的解決系統(tǒng)的電源問(wèn)題已經(jīng)成為了系統(tǒng)成敗的關(guān)鍵因素。 本論文研究選取了BICMOS工藝，具有功耗低、集成度高、驅(qū)動(dòng)能力強(qiáng)等優(yōu)點(diǎn)。根據(jù)電流模式的PWM控制原理，研究設(shè)計(jì)了一款基于BICMOS工藝的雙相DC-DC電源管理芯片。本電源管理芯片自動(dòng)控制兩路單獨(dú)的轉(zhuǎn)換器工作，兩相結(jié)構(gòu)能提供大的輸出電流，但是在開(kāi)關(guān)上的功耗卻很低。芯片能夠精確的調(diào)整CPU核心電壓，對(duì)稱(chēng)不同通道之間的電流。本電源管理芯片單獨(dú)檢測(cè)每一通道上的電流，以精確的獲得每個(gè)通道上的電流信息，從而更好的進(jìn)行電流對(duì)稱(chēng)以及電路的保護(hù)。 文中對(duì)該DC-DC電源管理芯片的主要功能模塊，如振蕩器電路、鋸齒波發(fā)生電路、比較器電路、平均電流電路、電流檢測(cè)電路等進(jìn)行了設(shè)計(jì)并給出了仿真驗(yàn)證結(jié)果。該芯片只需外接少數(shù)元件就可構(gòu)成一個(gè)高性能的雙相DC-DC開(kāi)關(guān)電源，可廣泛應(yīng)用于CPU供電系統(tǒng)等。 通過(guò)應(yīng)用Hspice軟件對(duì)該變換器芯片的主要模塊電路進(jìn)行仿真，驗(yàn)證了設(shè)計(jì)方案和理論分析的可行性和正確性，同時(shí)在芯片模塊電路設(shè)計(jì)的基礎(chǔ)上，應(yīng)用0.8μmBICMOS工藝設(shè)計(jì)規(guī)則完成了芯片主要模塊的版圖繪制，編寫(xiě)了DRC、LVS文件并驗(yàn)證了版圖的正確性。所設(shè)計(jì)的基于BICMOS工藝的DC-DC電源管理芯片的均流控制電路達(dá)到了預(yù)期的要求。
上傳時(shí)間： 2013-06-06
上傳用戶(hù)：dbs012280
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