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.
標簽： Wide-input modules offer dc
上傳時間： 2014-12-24
上傳用戶：dragonhaixm
Features: High efficiency, high reliability, low cost AC input range selected by switch 100% full load burn-in test Protections: Short circuit / Over load Fixed switching frequency at 25KHz Cooling by free air convection 1 year warranty Dimensions: 199*98*38mm (L*W*H)
標簽： Switchin Output Single SKS
上傳時間： 2013-10-30
上傳用戶：taa123456
The P89LPC912/913/914 are single-chip microcontrollers in low-cost 14-pin packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system level functions have been incorporated into the P89LPC912/913/914 in order to reduce component count, board space, and system cost.
上傳時間： 2013-10-12
上傳用戶：司令部正軍級
為提高溫度測量效率，降低系統的成本，擴展傳輸距離，設計出一種新型溫度采集系統。單片機通過控制具有單總線方式的溫度傳感器DS18B20實現對溫度的測量，同時單片機通過控制具有單總線方式300～450MHz頻率范圍內的MAX7044與MAX7033無線發射與接收芯片實現溫度數據的無線傳輸。與傳統溫度采集系統相比，該系統利用單總線方式連接，采用無線傳輸方式實現遠距離通信，易于系統的集成與擴展。實驗結果表明，該系統結構簡單、方便移植，能夠同時實現多達上百點溫度的測量與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.
上傳時間： 2013-10-29
上傳用戶：515414293
設計一種基于AT89C52的語音錄放系統，利用單片機、ISD2560語音錄放器件、麥克風、揚聲器等元器件實現硬件電路的設計，并利用C51高級語言設計ISD2560器件控制字的寫入和定時中斷程序。經軟硬件調試，結果表明該系統錄放效果良好，具有一定的工程實用價值。 Abstract: Voice recording and playback system based on AT89C52is designed in this paper.Using the single-chip microcomputer，voice recording and playback chip ISD2560，microphone and speaker to realize the hardware circuit design.Writing ISD2560control words and timing interrupt procedures are designed by C51advanced language.Through the hardware and software test,voice recording and playback system play better voice,and this system has some engineering practical values.
上傳時間： 2013-10-20
上傳用戶：ywcftc277
該系統由單片機89S52控制模塊，程控寬帶放大模塊，整形模塊，FPGA內頻率、相位差測量模塊等構成，采用等精度測頻法測出頻率和周期，可測量有效值為0.01～5V，頻率范圍1Hz～20MHz信號的頻率、周期信號，精度高達10-6。采用計數法測量相位差，該系統可測量有效值0.5～5V，頻率10Hz～100kHz信號的相位差，精度為1°。系統功能由按鍵控制，測量結果實時顯示，人機界面友好。 Abstract: The system consists of the following functional blocks:89S52microcontroller controlling module,programmable amplifier module,comparator module,frequency and phase difference testing module in the FPGA.The system use the equal accuracy frequency-examining technique it measures frequency and circle of signal which its ranges is from1Hz to20MHz and the amplitude of which its range is from0.01Vrms to5Vrms,precision is up to10-6.Using of count method,the system detects the phase difference of signal,the amplitude of whic its range is from0.5Vrms to5Vrms and the frequency of which its ranges is from10Hz to100kHz,precision is up to1°,The system functions is controlled by certain keys,measurement results are displayed in real-time and it is friendly interface.
上傳時間： 2013-11-04
上傳用戶：CHINA526
以89S52單片機和EP1C6Q240C8型FPGA為控制核心的多功能計數器，是由峰值檢波、A/D轉換、程控放大、比較整形、移相網絡部分組成,可實現測量正弦信號的頻率、周期和相位差的功能。多功能計數器采用等精度的測量方法，可實現頻率為1Hz～10MHz、幅度為0.01～5Vrms的正弦信號的精確測頻，以及頻率為10Hz～100kHz、幅度為0.5～5Vrms的正弦信號精確測相。液晶顯示器能夠實時顯示當前信號的頻率、周期和相位差。該多功能計數器精度高，界面友好，實用性強。 Abstract: A multi-function counter，which uses89S52MCU and EP1C6Q240C8FPGA as a control core，consists of peak detector，A/D conversion，program-controlled amplification，compared shaping and phase-shifting network part.The counter measures the frequency，period and phase of sinusoidal signal.With the equal precision method,the multi-function counter achieves the precise frequency measurement of the sinusoidal signal which its frequency is from1Hz to10MHz，its amplitude is from0.01Vrms to5Vrms，as well as the accurate phase measurement of the sinusoidal signal which its frequency is from10Hz to100kHz，its amplitude is from0.5Vrms to5Vrms.The LCD monitor real-time displays the frequency，period and phase difference of current signal.The multi-function counter features high precision，friendly interface，and strong practical.
上傳時間： 2013-11-15
上傳用戶：gy592333
介紹了當前普通標記機控制系統現狀及其存在缺點，給出氣動標記機及相頻修正PWM模式的工作原理。采用ATmega16單片機和USB轉換RS232接口器件CH341T實現驅動控制系統與PC的實時通訊，標記控制系統可升級到USB接口。采用基于ATmega16的相頻修正PWM替換555振蕩電路產生的PWM，可直接通過軟件調整PWM信號。使用達林頓三極管TIP122替代直流繼電器驅動高頻電磁閥，使得電磁閥驅動電路簡單，成本低廉。該控制系統已成功應用于氣動標記機。 Abstract: In this paper,the actuality and demerit of the common gas marking machine control systems are described.The operation principle of the gas marking machine and the phase and frequency correct PWM of ATmega16is introduced.The real-time communication between the driving control system and PC by CH341T which its function is translated USB to RS232is realized,the control systems is updated grade to USB interface.The PWM signal can be adjustable by software for the555surge circuit was substituted by the phase and frequency.The high frequency electromagnetic value’s driving circuit by DC relay is replaced by TIP122,therefore,the circuit is become simple and the cost cheap.The control systems has been widely used in gas marking machine.
上傳時間： 2013-10-18
上傳用戶：1427796291
提出一種基于C8051F040的炮塔方位角測試系統的設計方案，給出測試系統的各個模塊軟硬件設計。炮塔方位角測試系統集數據采集，數據傳輸和數據顯示等功能于一體，實現了炮塔方位角裝置的離線檢測。系統軟件采用C51編寫，對單片機進行有效電源管理，保證了系統的穩定性，可靠性。 Abstract: This paper puts forwards a design of artillery position system based on C8051F040，describes all modules hardware and software design of measurement system.The system has the function of information collection，transmission，and display.It can measure artillery position system in offline.The system software using C51can manage the power of single chip microcomputer，guarantee the stability，reliability.
上傳時間： 2014-12-27
上傳用戶：7891
介紹一種多功能音樂播放器，它是以AT89S52單片機為核心，并輔有一些外圍器件，采用匯編語言編寫程序，實現多功能音樂播放，歌曲自動循環播放和使用琴鍵自編曲目功能。此外，彩燈顯示歌曲節奏，按鍵跳轉到喜愛曲目，液晶顯示當前播英文曲目。并給出了系統軟硬件設計。 Abstract: It introduces a multifunctional music player,taking AT89S52 single-chip microcomputer as hardware control core and using some peripheral elements.Programmes are compiled in assembly language to act as expected.There are two functional modes in this system.One is to make the music play automatically and consecutively,the other is to compose new songs through keys.In addition,lights show the pace of music and the English names can be displayed in the liquid crystal screen.With perfect combination of hardware and software,the music player can meet many music lovers’needs for multifunctional music player.And the hardware and software of the system are given.
上傳時間： 2013-11-18
上傳用戶：xiaodu1124
