Size, output flexibility and efficiency advantages havemade switching regulators common in electronic apparatus.The continued emphasis on these attributes hasresulted in circuitry with 95% efficiency that requiresminimal board area. Although these advantages are welcome,they necessitate compromising other parameters
Most portable computers have built-in sockets to acceptsmall PC cards for use as extended memories, fax modems,network interfaces, wireless communicators and awide assortment of other functions. The Personal ComputerMemory Card International Association (PCMCIA)has released specifications that outline the general powerrequirements for these cards.
Portable, battery-powered operation of electronic apparatushas become increasingly desirable. Medical, remotedata acquisition, power monitoring and other applicationsare good candidates for batteryoperation. In some circumstances,due to space, power or reliability considerations,it is preferable to operate the circuitry from a single 1.5Vcell. Unfortunately, a 1.5V supply eliminates almost alllinear ICs as design candidates. In fact, the LM10 opamp-reference and the LT®1017/LT1018 comparators arethe only IC gain blocks fully specifi ed for 1.5V operation.Further complications are presented by the 600mV dropof silicon transistors and diodes. This limitation consumesa substantial portion of available supply range, makingcircuit design diffi cult. Additionally, any circuit designedfor 1.5V operation mustfunction at end-of-life batteryvoltage, typically 1.3V. (See Box Section, “Componentsfor 1.5V Operation.”)
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.
When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.
應用 APPLICATIONS·電視機、錄像機、音頻設備、顯示器、復印機、打印裝置、游戲機及計算機等?！び糜陂_關電源線性濾波器?！は鞒?TV、VTR、VCR及監聽器泄漏雜音?！び糜贠A 設備、通信設備和其它器件?！V set, recorder, sound-frequency equipment, show-scope, photocopy-scope, typewrite equipment, recreation-scope, computer etc.·For line filters of switching power supplies.·Eliminates incoming/leaking noise of TVs, VTRs/VCRs and audio equipment .·For OA equipment, communications equipment and other electronic devices.
Designing read/write device (RWD) units for industrial RF-Identification
applications is strongly facilitated by the NXP Semiconductors HITAG
Reader Chip HTRC110. All needed function blocks, like the antenna
driver, modulator demodulator and antenna diagnosis unit, are integrated
in the HTRC110. Therefore only a minimum number of additional passive
components are required for a complete RWD.
This Application Note describes how to design an industrial
RF-Identification system with the HTRC110. The major focus is
dimensioning of the antenna, all other external components including
clock and power supply, as well as the demodulation principle and its
implementatio
Digitemp Junior – An RS-232 Port-Powered Digital Thermometer
Digitemp Jr. is a device that is designed to measure
and report ambient temperature. When connected to
an RS-232 port on any PC, it will periodically measure
and report in ASCII form the ambient temperature in
degrees Celsius. These temperature readings can be
monitored with any terminal program. If the terminal
program supports capture to disk, the temperature
readings can be saved to disk for further analysis with
a spreadsheet program or other data analysis tool. The
simple ASCII output format of Digitemp Jr. makes it rel-
atively easy to write custom software for receiving,
recording, and analyzing ambient temperature data.
Best of all, Digitemp Jr. requires no external power sup-
plies or batteries. It is powered directly by the RS-232 port.
針對煤礦井下調度及緊急救援系統的需求，以DTMF編解碼模塊為核心，設計了具有自動撥號功能的新型電話系統。該系統利用MT8880對DTMF信號的編解碼功能實現一鍵撥號和遠程設置，通過檢測振鈴和忙音信號，完成自動摘機和掛機過程，配合AGC等外圍電路達到話音清晰流暢的效果。
Abstract:
To meet the demand for mine scheduling and emergency rescue system， with using DTMF signal codec as the core， a new telephone system was designed with automatic dialing function. In the system， the DTMF signal encoding and decoding function of MT8880 was used to achieve one-touch dialing and remote setting. The circuit detects the ringing and busy signal， and then completes automatic off-hook and hangup. With AGC(Automatic Gain Control) and other peripheral circuits， the voice was regulated to a clear and smooth effect.
為了使音頻信號分析儀小巧可靠，成本低廉，設計了以2片MSP430F1611單片機為核心的系統。該系統將音頻信號送入八階巴特沃茲低通濾波器，對信號進行限幅放大、衰減、電平位移、緩沖，并利用一單片機負責對前級處理后的模擬信號進行采樣，將采集得到的音頻信號進行4 096點基2的FFT計算，并對信號加窗函數提高分辨率，另一單片機負責對信號的分析及控制顯示設備。此設計精確的測量了音頻信號的功率譜、周期性、失真度指標，達到較高的頻率分辨率，并能將測量結果通過紅外遙控器顯示在液晶屏上。
Abstract:
o make the audio signal analyzer cheaper， smaller and more reliable， this system sends the audio signal to the eight-order butterworth filter， and then amplifies， attenuates， buffers it in a limiting range， transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum， periodicity， power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.
