What would happen if someone connected 24V to your12V circuits? If the power and ground lines were inadvertentlyreversed, would the circuits survive? Does yourapplication reside in a harsh environment, where the inputsupply can ring very high or even below ground? Evenif these events are unlikely, it only takes one to destroya circuit board.
光伏發(fā)電是未來(lái)新能源發(fā)電重要方向之一，而光伏變流器是光伏發(fā)電系統(tǒng)的核心。介紹一種基于微網(wǎng)理念的光伏變流器設(shè)計(jì)。以該變流器為核心的光伏發(fā)電系統(tǒng)可以看做一個(gè)小型的微網(wǎng)系統(tǒng)。該系統(tǒng)能根據(jù)外部電網(wǎng)情況，工作于并網(wǎng)模式和離網(wǎng)模式。介紹了該系統(tǒng)的各個(gè)組成部件的設(shè)計(jì)以及變流器主電路部分器件的選型。最后，由實(shí)驗(yàn)樣機(jī)進(jìn)行測(cè)試。試驗(yàn)結(jié)果驗(yàn)證了電路拓?fù)浣Y(jié)構(gòu)及控制方案的可行性，也說(shuō)明了系統(tǒng)參數(shù)設(shè)計(jì)方法的正確性。
Abstract:
Solar Photovoltaic generation is an important direction of new energy power generation in the future，while photovoltaic converter is the core of photovoltaic generation system. This paper deals with a study on photovoltaic inverter based on the concept of microgrid. This paper describes a system whose core component is the photovoltaic inverter，can work on grid-connected mode or run independently according to the external situation. The paper simply describes the main components of the system. At last，the prototype was produced and tested. Test result has proved feasibility of circuit topology structure and controlling scheme and shown correctness of system parameters.Key words: PV inverter； microgrid； off-grid； storage battery
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.
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 relatively
easy to write custom software for receiving,
recording, and analyzing ambient temperature data.
Best of all, Digitemp Jr. requires no external power supplies
or batteries. It is powered directly by the RS-232
port.
提出了一種以S3C2440A為核心處理器的銀行評(píng)價(jià)器的設(shè)計(jì)方案，并結(jié)合XILINX公司的XL95144XL型CPLD，輔助S3C2440A，實(shí)現(xiàn)該銀行評(píng)價(jià)器的各部分功能以及系統(tǒng)信號(hào)之間的相互協(xié)調(diào)。該評(píng)價(jià)器在系統(tǒng)設(shè)計(jì)上采用液晶屏顯示，代替了以往簡(jiǎn)單的數(shù)碼管電路的顯示模式，在視覺(jué)上給人以全新的享受。同時(shí)，評(píng)價(jià)器增加了新的網(wǎng)絡(luò)供電方式，只要將評(píng)價(jià)器連接上網(wǎng)絡(luò)就可以正常工作，方便了客戶的使用。總之，此款銀行評(píng)價(jià)器采用了嵌入式系統(tǒng)的設(shè)計(jì)方案，大大豐富了系統(tǒng)功能，實(shí)現(xiàn)一個(gè)銀行評(píng)價(jià)器設(shè)計(jì)的新突破。
Abstract: S3C2440A of SamSung company is the core component of the embedded system. A design of bank assessor based on S3C2440A was provided in this paper. It used XL95144XL combined with S3C2440A to realize all the functions and coordination with system signals. This bank assessor used LCD to display instead of the former simple digital display and provided a new seusuous enjoment. Meanwhile，it provided a new method of network power supply，that the bank assessor could regularly work once it connected to the network，which is convenient for customers to use. In a word，this assessor takes embedded system，enriches the system’s functions and reclizes a new breakout.
為提高溫度測(cè)量效率，降低系統(tǒng)的成本，擴(kuò)展傳輸距離，設(shè)計(jì)出一種新型溫度采集系統(tǒng)。單片機(jī)通過(guò)控制具有單總線方式的溫度傳感器DS18B20實(shí)現(xiàn)對(duì)溫度的測(cè)量，同時(shí)單片機(jī)通過(guò)控制具有單總線方式300～450MHz頻率范圍內(nèi)的MAX7044與MAX7033無(wú)線發(fā)射與接收芯片實(shí)現(xiàn)溫度數(shù)據(jù)的無(wú)線傳輸。與傳統(tǒng)溫度采集系統(tǒng)相比，該系統(tǒng)利用單總線方式連接，采用無(wú)線傳輸方式實(shí)現(xiàn)遠(yuǎn)距離通信，易于系統(tǒng)的集成與擴(kuò)展。實(shí)驗(yàn)結(jié)果表明，該系統(tǒng)結(jié)構(gòu)簡(jiǎn)單、方便移植，能夠同時(shí)實(shí)現(xiàn)多達(dá)上百點(diǎn)溫度的測(cè)量與500m范圍的傳輸。
Abstract:
To improve the temperature measurement efficiency and reduce system cost,expansion of transmission distance,a new type of temperature acquisition system is designed.Microcontroller controlled temperature sensor DS18B20which has a single-bus achieves temperature measurement,while microcontroller by controlled the MAX7044and MAX7033chip with a single-bus and having300~450MHz radiofrequency to achieve the wireless transmission of temperature data.Compared with conventional temperature acquisition system,the system uses single-bus connected,and uses wireless transmission means to achieve long-distance communications,easy-to-system integration and expansion.The experimental results show that the system is simple,convenient transplantation,and can be implemented in as many as a hundred-point temperature measure-ment and the transmission range of500meters.
C8051F020單片機(jī)通過(guò)SPI接口驅(qū)動(dòng)四線電阻式觸摸屏控制器TSC2046，利用中斷方式驅(qū)動(dòng)TSC2046設(shè)計(jì)軟件。介紹了觸摸屏的工作原理、TSC2046工作方式以及典型應(yīng)用電路。
Abstract:
The C8051F020 MCU is connected with the TSC2046 which is a 4-wire touch screen controller. The TSC2046 is controlled by interrupt mode, the? operation principle of touch screen is introduced. The operation mode of TSC2046 and typical application circuit are also discussed.
對(duì)于傳統(tǒng)的跑步機(jī)無(wú)法聯(lián)機(jī)組網(wǎng)，保存歷史數(shù)據(jù)，實(shí)時(shí)調(diào)試等問(wèn)題，介紹了一個(gè)由多臺(tái)跑步機(jī)通過(guò)RS-232串行總線與上位機(jī)相連組成的跑步機(jī)聯(lián)網(wǎng)系統(tǒng)。系統(tǒng)采用W77E58作為下位機(jī)核心控制器件，它具有雙串行通訊端口，其中一個(gè)串口用于與變頻器通訊，另一個(gè)串口則與上位機(jī)相連，構(gòu)成跑步機(jī)網(wǎng)絡(luò)。
Abstract:
The traditional running machine can not be connected to a network, saving historical data, real time debug etc.In this paper,a new network system which is composed of running machines connected by a RS-232 communication bus is introduced.In the system,W77E58 is used as a core control unit.W77E58 has two serial ports,one is connected to the inverter and the other is connected to the PC. Thus a network appears.
The SN65LBC170 and SN75LBC170 aremonolithic integrated circuits designed forbidirectional data communication on multipointbus-transmission lines. Potential applicationsinclude serial or parallel data transmission, cabledperipheral buses with twin axial, ribbon, ortwisted-pair cabling. These devices are suitablefor FAST-20 SCSI and can transmit or receivedata pulses as short as 25 ns, with skew lessthan 3 ns.These devices combine three 3-state differentialline drivers and three differential input linereceivers, all of which operate from a single 5-Vpower supply.The driver differential outputs and the receiverdifferential inputs are connected internally to formthree differential input/output (I/O) bus ports thatare designed to offer minimum loading to the buswhenever the driver is disabled or VCC = 0. Theseports feature a wide common-mode voltage rangemaking the device suitable for party-lineapplications over long cable runs.
