一個不錯的降壓芯片
標簽： PG_IC-ON-line LNK 306 CN
上傳時間： 2014-01-02
上傳用戶：ssj927211
高的工作電壓高達100V N雙N溝道MOSFET同步驅動 The D810DCDC is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
上傳時間： 2013-10-24
上傳用戶：wd450412225
The LTC®3569 is a compact power solution for handhelddevices. Its tiny 3mm × 3mm QFN package includesthree buck regulators with individually programmableoutput voltages. One regulator supports load currentsup to 1200mA, while the other two support currents to600mA. Two regulators can be paralleled for increasedload capability. Each current-mode regulator is internallycompensated with excellent load and line regulation. Acomplete 2- or 3-output solution requires a minimumof external passive components.
上傳時間： 2013-10-11
上傳用戶：yxgi5
為了改變目前電網現場作業管理的變電巡檢、變電檢修試驗、輸電線路巡檢檢修等管理系統各自獨立運行，信息不能共享，功能、效率受限，建設和維護成本高的現狀，提出了采用B/S+C/S構架模式，將各現場作業管理模塊和生產MIS（管理系統）集成為一體的現場作業管理系統的設計方案，做到各子系統和生產MIS軟硬資源共享，做到同一數據唯一入口、一處錄入多處使用。各子系統設備人員等基礎信息來源于生產管理系統，各子系統又是生產管理系統的作業數據、缺陷信息的重要來源。經過研究試用成功和推廣應用，目前該系統已在江西電網220 kV及以上變電站全面應用。 Abstract: In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
上傳時間： 2013-11-15
上傳用戶：han_zh
The latest generation of Texas Instruments (TI) boardmountedpower modules utilizes a pin interconnect technologythat improves surface-mount manufacturability.These modules are produced as a double-sided surfacemount(DSSMT) subassembly, yielding a case-less constructionwith subcomponents located on both sides of theprinted circuit board (PCB). Products produced in theDSSMT outline use the latest high-efficiency topologiesand magnetic-component packaging. This providescustomers with a high-efficiency, ready-to-use switchingpower module in a compact, space-saving package. Bothnonisolated point-of-load (POL) switching regulators andthe isolated dc/dc converter modules are being producedin the DSSMT outline.TI’s plug-in power product line offers power modules inboth through-hole and surface-mount packages. The surfacemountmodules produced in the DSSMT outline use asolid copper interconnect with an integral solder ball fortheir
上傳時間： 2013-10-10
上傳用戶：1184599859
單相橋式逆變電路為例：S1～S4是橋式電路的4個臂，由電力電子器件及輔助電路組成。S1、S4閉合，S2、S3斷開時，負載電壓uo為正S1；S1、S4斷開，S2、S3閉合時，uo為負，把直流電變成了交流電。改變兩組開關切換頻率，可改變輸出交流電頻率。圖5-1 逆變電路及其波形舉例電阻負載時，負載電流io和uo的波形相同，相位也相同。阻感負載時，io滯后于uo，波形也不同（圖5-1b）。t1前：S1、S4通，uo和io均為正。t1時刻斷開S1、S4，合上S2、S3，uo變負，但io不能立刻反向。io從電源負極流出，經S2、負載和S3流回正極，負載電感能量向電源反饋，io逐漸減小，t2時刻降為零，之后io才反向并增大 （2）換流方式分類換流——電流從一個支路向另一個支路轉移的過程，也稱換相。開通：適當的門極驅動信號就可使其開通。關斷：全控型器件可通過門極關斷。半控型器件晶閘管，必須利用外部條件才能關斷，一般在晶閘管電流過零后施加一定時間反壓，才能關斷。研究換流方式主要是研究如何使器件關斷。本章換流及換流方式問題最為全面集中，因此在本章講述1、器件換流利用全控型器件的自關斷能力進行換流（Device Commutation）。2、電網換流由電網提供換流電壓稱為電網換流（line Commutation）。可控整流電路、交流調壓電路和采用相控方式的交交變頻電路，不需器件具有門極可關斷能力，也不需要為換流附加元件。3、負載換流由負載提供換流電壓稱為負載換流（Load Commutation）。負載電流相位超前于負載電壓的場合，都可實現負載換流。負載為電容性負載時，負載為同步電動機時，可實現負載換流。
上傳時間： 2013-10-15
上傳用戶：qingdou
一、 main.c(35): warning: #128-D: loop is not reachable from preceding code 原因，前面有一個while(1){ …….} 二、 main.c(54): warning: #1-D: last line of file ends without a newline 少了一個回車在}之后
上傳時間： 2014-12-26
上傳用戶：sjb555
為解決當前計算機串行通訊接口只有USB，難以滿足舊型號設備或某些單片機要求RS232通訊的問題，設計出兩款RS232/USB電路。采用CH341A與MAX223集成電路芯片構建標準9線RS232/USB通用接口轉換器，無需編程。采用CH341A與PIC16F877A構建單片機與計算機之間的USB通訊電路，軟件遵循RS232通訊協議，硬件進行電平轉換。實際使用表明，這兩款產品與計算機端Windows 操作系統下的串口應用程序完全兼容，且通訊過程中無握手失敗現象。 Abstract: To solve the problem that current computer serial communication only with USB interface can not satisfy with the old type equipments or MCU to communicate with RS232， two kinds of RS232/USB circuit were designed.CH341A and MAX223 integrated circuit chips were used to create a standard 9-line RS232/USB universal interface convertor without programme. CH341A and PIC16F877A chips were adopted to build the USB communication circuit between computers and MCU. The software follows RS232 communication protocol， and the hardware converts electrical levels. Actual practices indicate that the two manufactures are compatible with serial application program of Windows operation system completely，and get avoid of handshake lost.
上傳時間： 2013-11-03
上傳用戶：siying
提出一種基于凌陽單片機的步進電機加減速的控制方法。采用凌陽科技推出的16位結構工控單片機SPMC75F2413A為控制器，由Allegro公司生產的兩相步進電機專用驅動器件SLA7042M構成步進電機的驅動電路，在傳統的3段直線加減速控制算法基礎上增加至7段S形曲線加減速過程，控制步進電機的啟動和停止。實驗結果表明，該控制方法克服了直線加減速中不連續、易造成系統沖擊的問題，整個系統實現柔性控制，電機啟動、停止連續性能提高30%。 Abstract: The method of controlled stepping motor is referred based on SPMC75F2413A MCU， which adopts the 16 knots SPMC75F2413A MCU as the controller. The special-purpose actuation chip SLA7042M of two stepping motor produced by Allegro Corporation constituted to actuation electric circuit. The purpose of increasing to seven section of S shape curve based on the traditional three sections of straight line is to control the start and stop process of stepping motor. The experimental results show that the control method solves easy to pull-out and overshot problems. The overall system realizes flexible control， and the performance of motor start or stop continuity is increased 30%
上傳時間： 2013-12-08
上傳用戶：jiangfire
單片機作為一種微型計算機，其內部具有一定的存儲單元（8031除外），但由于其內部存儲單元及端口有限，很多情況下難以滿足實際需求。為此介紹一種新的擴展方法，將數據線與地址線合并使用，通過軟件控制的方法實現數據線與地址線功能的分時轉換，數據線不僅用于傳送數據信號，還可作為地址線、控制線，用于傳送地址信號和控制信號，從而實現單片機與存儲器件的有效連接。以單片機片外256KB數據存儲空間的擴展為例，通過該擴展方法，僅用10個I/O端口便可實現，與傳統的擴展方法相比，可節約8個I/O端口。 Abstract: As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
上傳時間： 2014-12-26
上傳用戶：adada
