This Section covers the design of power transformers used in buck-derived topologies: forward converter, bridge, half-bridge, and full-wave centertap. Flyback transformers (actually coupled inductors) are covered in a later Section. For more specialized applications, the principles discussed herein will generally apply.
以STC12C5A60S2單片機(jī)為控制核心,采用2.4G(JF24D)無(wú)線遙控模塊進(jìn)行無(wú)線發(fā)射與接收,設(shè)計(jì)了一種雙電機(jī)遙控船模控制系統(tǒng).該系統(tǒng)通過(guò)切換檔桿實(shí)現(xiàn)前進(jìn)后退,方向盤(pán)左右轉(zhuǎn)動(dòng)、暫停按鈕等控制直流電機(jī)的正轉(zhuǎn)、反轉(zhuǎn)、暫停,使得電機(jī)驅(qū)動(dòng)的遙控船模實(shí)現(xiàn)前進(jìn)后退、左右轉(zhuǎn)向、暫停等功能,有效解決了驅(qū)動(dòng)功率小和船模之間相互干擾等問(wèn)題,可廣泛應(yīng)用于遙控船模領(lǐng)域.Using STC12C5A60S2 single-chip microcomputer as the controller and 2.4 G(JF24D)wireless remote control module for wireless transmission and reception, a dual-motor remote control ship model control system is designed. The system realizes forward and backward by switching the gear lever. The steering wheel rotates left and right and the pause button controls the forward, reverse and pause of the dc motor. The remote controller of ship model driven by the motor realizes forward and backward, left and right steering, pause and other functions. The ship model control system can effectively solve the problems of small driving power and mutual interference between ship models, and can be widely used in the field of remote controller of ship model.
設(shè)計(jì)功率MOSFET驅(qū)動(dòng)電路時(shí)需重點(diǎn)考慮寄生參數(shù)對(duì)電路的影響。米勒電容作為MOSFET器件的一項(xiàng)重要參數(shù),在驅(qū)動(dòng)電路的設(shè)計(jì)時(shí)需要重點(diǎn)關(guān)注。重點(diǎn)觀察了MOSFET的開(kāi)通和關(guān)斷過(guò)程中柵極電壓、漏源極電壓和漏源極電流的變化過(guò)程,并分析了米勒電容、寄生電感等寄生參數(shù)對(duì)漏源極電壓和漏源極電流的影響。分析了柵極電壓在米勒平臺(tái)附近產(chǎn)生振蕩的原因,并提出了抑制措施,對(duì)功率MOSFET的驅(qū)動(dòng)設(shè)計(jì)具有一定的指導(dǎo)意義。When designing the drive circuit of power MOSFET,the influence of parasitic parameters on the circuit should be concerned.As an important parameter of MOSFET device,Miller capacitance should be considered in the design of drive circuit.The variation of gate voltage,drain source voltage and drain source current during the turn-on and turn-off of MOSFET were observed.The influences of parasitic parameters such as Miller capacitance and parasitic inductance on drain source voltage and drain source current were analyzed.The reasons of gate voltage oscillation nearby Miller plateau were analyzed,and the restraining measures were put forward.This research was instructive for the drive design of power MOSFET.
以單片機(jī)控制A/D轉(zhuǎn)換器TLC549為例,對(duì)A/D轉(zhuǎn)換器的主要技術(shù)指標(biāo)進(jìn)行了分析研究,在Proteus平臺(tái)下,完成了A/D轉(zhuǎn)換電路的構(gòu)建,采用器件工作時(shí)序方式進(jìn)行程序編寫(xiě),借助仿真圖表、虛擬儀器等工具對(duì)A/D轉(zhuǎn)換的數(shù)據(jù)進(jìn)行測(cè)量并對(duì)失調(diào)誤差、增益誤差、微分非線性、積分非線性和轉(zhuǎn)換時(shí)間等重要參數(shù)進(jìn)行了詳細(xì)分析。結(jié)果表明:使用Proteus軟件可對(duì)A/D轉(zhuǎn)換過(guò)程進(jìn)行定性分析,將抽象的A/D轉(zhuǎn)換器技術(shù)指標(biāo)直觀化、形象化展現(xiàn)出來(lái),有助于學(xué)生更好地理解A/D轉(zhuǎn)換過(guò)程。The main technical indicators of A/D converter were analyzed and studied with an example from A/D converter TLC2543 which is controlled by using SCM.It was completed the construction of the A/D converter circuit under the Proteus software.The programming based on the operation sequence of the chip is put forward.With the aid of the simulation tools such as virtual instrument,simulation charts provided by Proteus,the important parameters of circuit such as offset error,gain error,differential nonlinearity(DNL),integral nonlinearity (INL) and conversion time are analyzed detailedly.Simulation results show that the A/D conversion process can be qualitatively analyzed and visualized the abstract indicators of A/D.The system can help students better to understand the SCM conversion process.
搶答器是一種智力競(jìng)賽常用的器件,搶答器的設(shè)計(jì)方法千差萬(wàn)別,文章利用常用的數(shù)字電子器件,設(shè)計(jì)了八路搶答器電路的設(shè)計(jì)、仿真及實(shí)現(xiàn)的全過(guò)程,提出兩種可行的設(shè)計(jì)方案:方案1采用74ls373實(shí)現(xiàn)電路鎖存,74ls148實(shí)現(xiàn)電路編碼,74ls74及數(shù)碼管實(shí)現(xiàn)電路顯示;方案二采用CD4511BCN和LMC555CM集成電路及數(shù)碼管實(shí)現(xiàn)搶答器的控制和顯示。本文設(shè)計(jì)用的器件簡(jiǎn)單,容易理解,適用于初學(xué)電子技術(shù)的人員。Answer scrambler is a common device in intelligence competition, and its design methods vary greatly. This paper designs the whole process of design, simulation and Realization of the circuit of eight-way answer scrambler by using common digital electronic devices, and puts forward two feasible design schemes: scheme 1 uses 74 ls373 to realize circuit latching, 74 ls148 to realize circuit coding,74 ls74 and digital tube to realize circuit. The second scheme uses CD4511 BCN, LMC555 CM integrated circuit and digital tube to control and display the answerer. The device designed in this paper is simple and easy to understand, and it is suitable for the beginners of electronic technology.
le flows through MOS channel while Ih flows across PNP transistor Ih= a/(1-a) le, IE-le+lh=1/(1-a)' le Since IGBT has a long base PNP, a is mainly determined by ar si0 2ar= 1/cosh(1/La), La: ambipolar diff length a-0.5 (typical value)p MOSFET channel current (saturation), le=U"Cox"W(2"Lch)"(Vc-Vth)le Thus, saturated collector current Ic, sat=1/(1-a)"le=-1/(1-a)"UCox"W/(2Lch)"(Vo-Vth)2Also, transconductance gm, gm= 1/(1-a)"u' Cox W/Lch*(Vo-Vth)Turn-On1. Inversion layer is formed when Vge>Vth2. Apply positive collector bias, +Vce3. Electrons flow from N+ emitter to N-drift layer providing the base current for the PNP transistor4. Since J1 is forward blased, hole carriers are injected from the collector (acts as an emitter).5. Injected hole carriers exceed the doping level of N-drift region (conductivity modulation). Turn-Off1. Remove gate bias (discharge gate)2. Cut off electron current (base current, le, of pnp transistor)
3-phase Sensor-less Fan Motor DriverAM2355NThe AM2355N is a 3-phase sensor-less DC fan motor driver IC. It senses the BEMF (BackElectro-Motive Force) of the motor in rotation and provides corresponding commutation current tothe motor. Rotation speed can be controlled by PWM input signal. The drivers include LockDetection, Thermal Shutdown, and Over-current Protection. Forward and Reverse control.www.junmintech.com
