Abstract: Electrolytic capacitors are notorious for short lifetimes in high-temperature applications such asLED light bulbs. The careful selection of these devices with proper interpretation of their specifications isessential to ensure that they do not compromise the life of the end product. This application notediscusses this problem with electrolytic capacitors in LED light bulbs and provides an analysis that showshow it is possible to use electrolytics in such products.
上傳時間： 2013-11-17
上傳用戶：asdfasdfd
Abstract: Investment in smart meters and smart grid end equipment continues to grow worldwide as countriestry to make their electric delivery systems more efficient. However, as critical as the electric deliveryinfrastructure is, it is normally not secured and thus subject to attack. This article describes the concept oflife-cycle security—the idea that embedded equipment in the smart grid must have security designed into theentire life of the product, even back to the contract manufacturer. We also talk about how life-cycle securityapplies to embedded equipment in the smart grid. Potential threats are discussed, as are potential solutionsto mitigate the risks posed by those threats.
上傳時間： 2014-12-24
上傳用戶：熊少鋒
Abstract: Field-programmable gate arrays (FPGAs) are used in a wide variety of applications and end markets, including digital signalprocessing, medical imaging, and high-performance computing. This application note outlines the issues related to powering FPGAs.It also discusses Maxim's solutions for powering Altera® FPGAs.
上傳時間： 2013-11-02
上傳用戶：zhaoman32
Automotive power systems are unforgiving electronicenvironments. Transients to 90V can occur when thenominal voltage range is 10V to 15V (ISO7637), along withbattery reversal in some cases. It’s fairly straightforwardto build automotive electronics around this system, butincreasingly end users want to operate portable electronics,such as GPS systems or music/video players,and to charge their Li-Ion batteries from the automotivebattery. To do so requires a compact, robust, effi cientand easy-to-design charging system
上傳時間： 2013-11-04
上傳用戶：wfl_yy
Each year Vishay releases thousands of new components that enable our customers to create new and superior end products. We recognize that offering unique component solutions helps improve the performance of next-generation devices, overcome technical barriers, and create new markets.
上傳時間： 2013-12-14
上傳用戶：ming529
The design of battery-powered equipment can often bequite challenging. Since few ICs can operate directly fromthe end-of-life voltage from a 2-cell battery (about 1.8V),most systems require a DC/DCconverter. The systemdesigner often has a limited area in which to place the DC/DC converter; associated inductors and capacitors must be
上傳時間： 2013-11-23
上傳用戶：wys0120
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.”)
標簽： Circuitry Operation Single Cell
上傳時間： 2013-10-30
上傳用戶：hz07104032
以C8051F020為核心處理器，設計無線傳感器網絡數據采集系統。系統采用SZ05-ADV型無線通訊模塊組建Zigbee無線網絡，結合嵌入式系統的軟硬件技術，完成終端節點的8路傳感器信號的數據采集。現場8路信號通過前端處理后，分別送入C8051F020的12位A/D轉換器進行轉換。經過精確處理、存儲后的現場數據，通過Zigbee無線網絡傳送到上位機，系統可達到汽車試驗中無線測試的目的。 Abstract: This paper designs a wireless sensor network system for data acquisition with C8051F020 as core processors.The system used SZ05-ADV wireless communication module，set up a Zigbee wireless network， combined with hardware and software technologies of embedded systems，completed the end-node 8-locale sensor signal data acquisition.Eight locale signals were sent separately into the 12-bit ADC of C8051F020 for conversion through front treatment.After accurate processing and storage，the locale data was transmitted to the host computer through Zigbee wireless.The system achieves the purpose of wireless testing in vehicle trial.
標簽： C8051F020 Zigbee 汽車測試 系統設計
上傳時間： 2013-11-23
上傳用戶：dsgkjgkjg
I2C interface, is a very powerful tool for system designers. Theintegrated protocols allow systems to be completely software defined.Software development time of different products can be reduced byassembling a library of reusable software modules. In addition, themultimaster capability allows rapid testing and alignment ofend-products via external connections to an assembly-line computer.The mask programmable 87LPC76X and its EPROM version, the87LPC76X, can operate as a master or a slave device on the I2Csmall area network. In addition to the efficient interface to thededicated function ICs in the I2C family, the on-board interfacefacilities I/O and RAM expansion, access to EEPROM andprocessor-to-processor communications.
標簽： microcontro Using 76X LPC
上傳時間： 2013-12-30
上傳用戶：Artemis
//芯片資料請到www.elecfans.com查找 //DS1820 C51 子程序//這里以11.0592M晶體為例，不同的晶體速度可能需要調整延時的時間//sbit DQ =P2^1;//根據實際情況定義端口 typedef unsigned char byte;typedef unsigned int word; //延時void delay(word useconds){ for(;useconds>0;useconds--);} //復位byte ow_reset(void){ byte presence; DQ = 0; //pull DQ line low delay(29); // leave it low for 480us DQ = 1; // allow line to return high delay(3); // wait for presence presence = DQ; // get presence signal delay(25); // wait for end of timeslot return(presence); // presence signal returned} // 0=presence, 1 = no part //從 1-wire 總線上讀取一個字節byte read_byte(void){ byte i; byte value = 0; for (i=8;i>0;i--) { value>>=1; DQ = 0; // pull DQ low to start timeslot DQ = 1; // then return high delay(1); //for (i=0; i<3; i++); if(DQ)value|=0x80; delay(6); // wait for rest of timeslot } return(value);} //向 1-WIRE 總線上寫一個字節void write_byte(char val){ byte i; for (i=8; i>0; i--) // writes byte, one bit at a time { DQ = 0; // pull DQ low to start timeslot DQ = val&0x01; delay(5); // hold value for remainder of timeslot DQ = 1; val=val/2; } delay(5);} //讀取溫度char Read_Temperature(void){ union{ byte c[2]; int x; }temp; ow_reset(); write_byte(0xCC); // Skip ROM write_byte(0xBE); // Read Scratch Pad temp.c[1]=read_byte(); temp.c[0]=read_byte(); ow_reset(); write_byte(0xCC); //Skip ROM write_byte(0x44); // Start Conversion return temp.x/2;}
上傳時間： 2013-11-03
上傳用戶：hongmo
