电流型PWM控制器UC3844及其在微机电源中的应用

针对电压型脉宽调制器(PWM)控制器只有电压控制环、电流变化滞后电压变化、系统响应速度慢、稳定性差等固有缺点,介绍了既有电压控制环、又有电流控制环的新型电流型PWM控制器.分析了电流型PWM控制器与电压型PWM控制器的控制原理,比较了二者之间的优缺点;介绍了电流型PWM控制器UC3844的工作原理,并应用电流型PWM控制器UC3844设计了微机电源,指出了设计中应该注意的问题.结果表明,由电流型PWM控制器构成的微机电源具有良好的电压调整率、负载调整率和系统稳定性等优点.     

电流型PWM控制器在电源中的应用

介绍了双环电流型脉宽调制(PWM)控制器UC3842的工作原理、特点以及使用中的功率因数校正和斜坡补偿方法.双环电流型PWM控制器是在普通电压反馈PWM控制环内部增加了电流反馈的控制环节,因而除了包含电压型PWM控制器的功能外,还能检测开关电流或电感电流,实现电压电流的双环控制.     

基于UC28600控制器的开关电源设计

提出一种基于UC28600的脉冲宽度调制（PWM）控制器的开关电源设计方案。UC28600是TI公司的一款高性能的准谐振PWM控制器。该方案选用UC28600采用多模式控制以提高全负载条件下的开关转换效率,并达到减少电磁干扰,降低待机损耗的目的。     

基于AP3710的高性价比电源适配器方案

着重描述了基于PWM控制器AP3710的电源适配器解决方案的特点,给出了AP3710整体方案的实际测试结果.     

MSP430单片机定时噐设计应用

通过探索基于MSP430在温度控制、PWM控制、串口通信等系统的开发实例,提供了一套如何在控制系统设计中使用MSP430的开发思路和方案,该方案具有较好的参考实用价值.     

高性价比的电源适配器解决方案——AP3710及其应用电路

低功率电源适配器的方案 低功率电源适配器主要针对输出功率5～15瓦的电源系统.主要有两类方案,即集成PWM控制器方案和分立PWM控制器方案.     

工作在不同频率的脉宽调制器

许多应用需要脉宽调制(PWM)电路,如:电压调节器、功率控制、风扇速度控制等.图1所示电路利用三个运算放大器构成了PWM电路,由于运算放大器选择的灵活性,该方案能够满足各种应用的要求,例如,对于低功耗系统,可以选择微功耗运放;而高频运放则可用来实现高频PWM.图1电路还可用于产生三角波.     

基于CAN总线的四路舵机控制器的研究

本文设计了一种基于CAN通信总线的新型舵机控制器.该控制器考虑了谐波传动的随速度波动和低阻尼特点,以提高舵机系统控制品质为目标,采用增量式分段PID算法产生PWM信号,对舵机随动系统进行实时精准控制,并通过CAN2.0总线接口实现了微型计算机与CPU之间的实时变量传送,方便了程序的调试.测试结果表明,该控制系统具有抗干扰性能好、控制品质优等特点.     

三相电压型PWM整流器的数字化控制

介绍了一种采用TMS320F240DSP芯片的控制方案，该方案基于矢量控制的思想实现了三相电压型PWM整流器的控制，实验证明了该控制方案的可行性。     

一种数字可调的升压型开关电源的设计与实现

针对数字化的广泛应用,提出了一种数字控制、电压可调节的升压型开关电源的实现方案.该方案硬件设计采用Boost升压拓扑,MOS管驱动器件IR2110控制开关管IRF540.软件设计选用CPLD和51系列单片机构成数字控制模块,生成PWM控制信号,调节输出电压.PI算法实现快速稳压功能.通过MATLAB仿真和实验验证,该方案是行之有效的.     

A Carrier-Based Unipolar PWM Current Controller That Minimizes the PWM-Cycle Average Current-Error Using Internal Feedback of the PWM Signals

A carrier-based unipolar pulsewidth modulation (PWM) current controller is described using a one-phase PWM rectifier bridge as a test circuit. The controller PWM signal generator uses a sawtooth carrier signal to obtain both synchronized PWM waveforms and a constant switching frequency. A current-error signal and an amplitude modulation depth signal are used to create the input reference signal to the PWM signal generator. The amplitude modulation depth signal is obtained from the PWM-cycle average of the PWM signal generator output signals. This internal feedback is illustrated using a second-order low pass Butterworth filter. With an appropriately designed low-pass filter, the current-error signal is forced to be centered on zero over a PWM cycle. The maximum peak-peak magnitude of the current-error signal is used as a design guideline for deciding an appropriate gain constant in the controller current feedback loop. The low pass filter design is examined to determine a suitable gain and 20-dB attenuation frequency to minimize the current-error signal. The steady-state and transient operation of the proposed current controller is compared with a proportional-integral controller and an average current-error controller. SPICE simulations and experimental results are used to demonstrate the characteristics of the controller.     

一种电流模式多输入可控PWM比较器设计

提出了一种用于PWM(Pulse Width Modulation)控制器的比较器输出电路的设计,该电路基于电流模式控制,能够同时对三路输入信号进行比较输出并对输出信号进行锁存。为了在PWM控制电路启动的时候让输出脉冲占空比从小到大逐渐变化,比较器电路设计采用了一个反相输入端,两个同相输入端,其中一个同相输入端控制PWM比较器是否产生输出信号,从而可以降低开关频率,对PWM控制电路起到保护作用。仿真和测试结果显示该比较器能有效地控制PWM输出,并且占空比范围宽、延迟时间短。     

一种用于汽车电磁阀质量测试电源的设计

设计一种用于模拟汽车电磁阀工作状态的PWM电源,该电源以单片机为控制核心,采用DDS芯片AD9851和PWM控制芯片SG3525为波形发生设备,键盘和液晶显示作为人机接口,输出频率在O～25000Hz,占空比在0～100％,幅度在0～36V范围内可任意设置和实时显示的PWM信号。该电源运行稳定、精度高,已成功应佣到汽车、电磁阀的生产企业。     

High-performance programmable AC power source with low harmonicdistortion using DSP-based repetitive control technique

This paper proposes a new control scheme based on a two-layer control structure to improve both the transient and steady-state responses of a closed-loop regulated pulse-width-modulated (PWM) inverter for high-quality sinusoidal AC voltage regulation. The proposed two-layer controller consists of a tracking controller and a repetitive controller. Pole assignment with state feedback has been employed in designing the tracking controller for transient response improvement, and a repetitive control scheme was developed in synthesizing the repetitive controller for steady-state response improvement. A design procedure is given for synthesizing the repetitive controller for PWM inverters to minimize periodic errors induced by rectifier-type nonlinear loads. The proposed control scheme has been realized using a single-chip digital signal processor (DSP) TMS320C14 from Texas Instruments. A 2-kVA PWM inverter has been constructed to verify the proposed control scheme. Total harmonic distortion (THD) below 1.4% for a 60-Hz output voltage under a bridge-rectifier RC load with a current crest factor of 3 has been obtained. Simulation and experimental results show that the DSP-based fully digital-controlled PWM inverter can achieve both good dynamic response and low harmonics distortion     

工业智能仪表标准电流信号输出电路设计

为了给工业智能仪表提供廉价的标准电流信号输出接口,可以使用微处理器输出标准PWM电压信号,低通滤波器从PWM信号中分离出与PWM电压信号脉宽成正比的电压信号,此电压信号经过由放大器和三极管组成的V/I转换电路转换产生稳定的标准电流信号。用软件技术实现了电流输出范围的自动校准功能,并且系统采用单电源供电和信号隔离技术使整个标准电流输出电路对所用元件的参数不敏感且成本低、结构简单、校准方便,在电动直线行程控制器的设计过程中得以广泛应用。     

A Design and Experiment of Speed Controller with PI-Plus Bang-Bang Action for a DC Servomotor with Transistorized PWM Drives

A speed controller with proportional-integral (PI)-plus bang-bang action is proposed for dc servomotors with transistorized pulse width modulated (PWM) drives. The controller employs the PI-action when the magnitude of the error between the reference signal and the speed output signal is smaller than some precribed value. Otherwise, the controller produces the maximum allowable control signal with the integrator reset. Specifically, a mathematical analysis of the motor system with the proposed speed controller is presented and a rule of thumb for parameter design is provided.     

A robust hysteresis current-controlled PWM inverter for linear PMSMdriven magnetic suspended positioning system

Hysteresis current-controlled pulsewidth modulation (PWM) is very robust but it possesses nonconstant switching frequency, and it is difficult to use for high-performance position servo applications. This paper presents a robust hysteresis current-controlled PWM scheme for a magnetic suspended positioning system driven by an inverter-fed linear permanent-magnet synchronous motor having improved performance in these two areas. In the proposed control scheme, the conventional hysteresis PWM mechanism is augmented by a robust harmonic spectrum-shaping controller. The error signal, which represents the switching frequency deviated from the set one, is detected using a notching filter inverse model. Then, the current command is adjusted by a robust compensation signal. The hysteresis band can be equivalently varied to let the dominant harmonic frequency of inverter output be constant, wherein the frequency can easily be changed by tuning the center frequency of the notch filter. The gating signal of switches is not needed to be sensed for making the proposed control. The constant-frequency control performance yielded by the proposed controller is rather insensitive to the system disturbances and the neutral voltage variation due to isolated Y connection. Through applying the proposed PWM inverter, satisfactory position control requirements can be achieved by properly setting the dominant harmonic frequency according to the electromechanical model of the positioning system     

降压型DC/DC开关电源中的电压前馈技术

介绍了一种应用于降压型DC/DC开关电源的电压前馈技术,通过调整内部三角波的中心电压,使PWM信号占空比跟随输入电源电压快速改变。该技术能有效抑制输入电源电压变化对输出电压的影响,增强输出电压的稳定性。