基于MC34063A的LED用恒流驱动电路

本文对LED的驱动方式进行了探讨,并基于一单片双极型线性集成电路MC34063A设计了一个开关恒流驱动电路,用以实现大功率LED的驱动。在对驱动电路原理进行分析后,实际制作了电路并进行了LED的点亮调试,实验结果表明所设计的驱动电路能保证LED的稳定发光。     

光学仪器照明用的大功率LED驱动电源设计

据光学仪器照明系统的要求并结合大功率LED的特性,设计了一种可调光的大功率LED恒流驱动电路.既可对LED进行PWM调光,又能有效解决大功率LED的散热问题.与卤素灯等传统光源的驱动电路相比,它还具有体积小,低成本等优势,故可广泛应用于光学仪器的照明系统中.     

功率数控跳频滤波器

大功率跳频滤波器是超短波通信中常用部件，其优点是抗干扰性强，保密性好，t调谐速度快，文章介绍了用于超短波跳频通讯的一种具有数字调谐功能的大功率数控跳频滤波器的设计原理，内部驱动电路，并重点讨论了开关及驱动电路的工作原理，最后给出测试结果。     

大功率晶体管GTR驱动电路的设计

介绍了大功率开关晶体管GTR基极驱动电路的设计，分析了基极驱动电路的要求及其设计方法，并给出一种实用的驱动电路。     

大功率LED智能化照明控制系统设计

在绿色照明领域,既要体现节能,又要具备较高的光效,大功率LED驱动设计显得越来越重要。针对大功率LED的特性,研究设计了适用于不同参数指标的白光LED的驱动与控制系统。该系统以单片机C8051F040为核心,结合外围电路,用数字控制技术代替模拟电路控制,对大功率LED的恒流驱动电流进行高精度控制,以及对LED亮度进行自动调节控制,实现了多种大功率LED智能化照明。     

基于AVR单片机的大功率LED驱动和控制电路的设计与分析

本文就大功率LED在照明领域中的应用情况进行了分析,提出了一种基于AVR单片机的大功率LED驱动和控制电路,详细分析了电路的工作原理、软件设计和元件选型等问题。     

高效LED照明驱动及智能调光电路设计

介绍一种用市电供电的高效大功率LED照明用驱动芯片及其应用电路和LED的智能调光控制。驱动芯片用的是大功率恒流驱动芯片SMD802,智能调光电路主要是由测光模块和ATMEGA16单片机现实,经实验测试可以实现LED灯的高效节能优点和智能调光控制。     

KW9135P互锁轻触电子开关集成电路

KW9135P是六位互锁式和双三位互锁式轻触电子开关集成电路。它采用先进的CMOS集成电路工艺和标准16引脚双列直插式封装，具有高输入阻抗、低输出电阻、低功耗、工作电压范围大等特点。该电路可直接驱动LED、小型继电器和各种逻辑电路，外围辅以晶体管则可驱动较大功率的继电器和电路工作。该电路适用于各种仪器、仪表、家用电器、微机、录音录像等音视频设备，可替代波段开关、琴键开关及各种机械开关。     

基于CLL谐振的大功率多路输出LED驱动器

针对大功率LED驱动电源需要实现多路均流的特点,提出了一种基于CLL谐振的多路输出LED驱动方案。驱动电路前级采用临界模式下的Boost拓扑实现功率因数校正(PFC)功能,后级采用CLL谐振拓扑实现LED负载恒流。首先对CLL谐振变换器的电路原理进行了分析,通过将副边四路输出等效为单路输出,采用基波近似法分析加平衡电容的CLL谐振变换器,求得该变换器的直流电压增益公式和恒流公式。讨论了CLL谐振变换器和Boost型PFC电路的主要参数设计。在此基础上制作了样机,实验结果表明,采用CLL谐振的两级结构电路能高效地驱动LED电源,且各LED串之间具有较好的均流效果。     

一种高效单级变换式LED驱动电源设计

论文介绍了一种高效单级功率因数校正LED驱动电源。该电源采用SEPIC拓扑在临界导通模式下实现了功率因数校正和对LED灯的恒流驱动,电路采用单级PFC结构简化了电路结构,采用零电压开关技术降低了开关管的开关损耗。实验结果表明,该电源功率因数高、损耗小、输出稳定,可以高效率驱动LED灯工作。     

无源无损软开关变换器对比分析

高频化是电力电子装置提高功率密度的有效手段,高频化引起电力电子开关器件的开关损耗增加,无源无损软开关电路可有效降低电力电子开关器件的开关损耗。以最小电压应力（MVS）无源无损软开关电路、非最小电压应力（NMVS）无源无损软开关电路及最小电压电流应力（MVCS）无源无损软开关电路等3种主流的无源无损软开关Buck变换器为对象进行研究,从拓扑结构、占空比、电压电流应力、开关损耗及转换效率等几个方面进行比较研究。搭建了硬件实验环境,经理论分析和实验验证得出MVCS软开关电路具有更加良好的性能,为无源无损软开关电路的应用提供设计依据。     

On the stability of DC-to-DC converters in photovoltaic systems undergoing sliding motions

This paper deals with the dynamic behaviour of different DC-to-DC switching electronic converters in photovoltaic applications. In particular, the ability of the DC-to-DC converters to accomplish regulation of certain circuit variables, which are related to the control objectives, is examined. This task is addressed from a variable structure system approach. With this aim, the feasibility of establishing stable sliding regimes on different state co-ordinate surfaces is investigated. Differences in the dynamic behaviour of the DC-to-DC switching converters between photovoltaic and conventional power-supply applications are stressed.     

A new variable-mode control strategy for LLC resonant converters operating in a wide input voltage range

This paper proposes a new variable-mode control strategy that is applicable for LLC resonant converters operating in a wide input voltage range. This control strategy incorporates advantages from full-bridge LLC resonant converters, half-bridge LLC resonant converters, variable-frequency control mode, and phase-shift control mode. Under this control strategy, different input voltages determine the different operating modes of the circuit. When the input voltage is very low, it works in a full-bridge circuit and variable frequency mode (FB_VF mode). When the input voltage rises to a certain level, it shifts to a full-bridge circuit and phase-shifting control mode (FB_PS mode). When the input voltage further increases, it shifts into a half-bridge circuit and variable frequency mode (HB_VF mode). Such shifts are enabled by the digital signal processor (DSP), which means that no auxiliary circuit is needed, just a modification of the software. From light load to heavy load, the primary MOSFET for the LLC resonant converter can realize zero-voltage switching (ZVS), and the secondary rectifier diode can realize zero-current switching (ZCS). With an LLC resonant converter prototype with a 300 W rated power and a 450 V output voltage, as well as a resonant converter with 20–120 V input voltage, the experiments verified the proposed control strategy. Experimental results showed that under this control strategy, the maximum converter efficiency reaches 95.7% and the range of the input voltage expands threefold.     

同步BUCK型开关电源效率分析简法

对于同步整流BUCK型开关电源的转换效率,传统的分析方法得出的结果比较精确,然而过程相当繁琐,无法快捷预知其结果和预先对设计电路进行技术评估。本文通过建立其考虑了寄生电阻的大信号平均模型以及它的直流(DC)模型,从而导出它的效率计算公式。该计算公式得出结果虽然不精确,但方便快捷,与实际值相比,差别不大。     

Analysis of complex intermittency in Boost converter from a bifurcation control viewpoint

Due to undesirable interference via unintended coupling paths, switching converters may exhibit complex intermittency, which appears as a form of bifurcation undergoing regular operation, subharmonics, and chaos orderly and repeatedly for a long period of time. Such intermittent operation, being an unwanted operating state, should normally be avoided in power converters. This paper expounds the mechanism and conditions for the emergence of intermittency in a common current-mode controlled Boost converter. It is found that interference at frequencies near the switching frequency or its rational multiples may induce intermittent operation. The strengths and frequencies of the interfering signals determine the type and period of intermittency. The problem is analyzed by transforming the time-bifurcation analysis to a conventional parameter-bifurcation analysis. Based on this transformation, intermittency can be investigated from the bifurcation control viewpoint. Furthermore, the critical circuit parameter conditions for the emergence of intermittency can be predicted and compared with those from circuit simulation.     

LQ optimal control for a class of pulse width modulated systems

We consider linear quadratic optimal control for a class of pulse width modulated systems. The problem is motivated from a practical application—digital control of switching power converters. The control synthesis problem is posed based on a sampled data model of the original switching dynamics and a linear quadratic criterion that takes the intersampling behavior into account.     

Improved self-oscillating control of a quadratic buck converter for constant voltage applications

A great number of switching power supplies are used to provide a variable voltage for resistive-inductive loads. However, some applications in industry, require a regulated current with a constant voltage such as battery charging systems, LED drivers, and laboratory equipment for power converters connected to PV cells. Additionally, some constant voltage systems are intrinsically unstable, and therefore, they cannot be used without a closed-loop compensatory circuit. Hence, this article describes a novel smooth starter system behaving as a current source for constant voltage applications. The proposed technology is implemented by a quadratic buck converter, and then, a self-oscillating control technique is applied for performing the output current regulation of the converter, which is capable of aiding to improve the system performance, stabilize the overall system, protect the converter from transient current oscillations, and provide an acceptable control performance. In addition to practical aspects, soft starter methods and limitation of the constant voltage power converter are mentioned and described in this article. The designed structure has not only the advantages of smooth response and simplicity to construct but also performs a nearly zero steady-state error regulation. The power stage, the control scheme, and the modulator are explained in detail and validated by experiments.     

单级BOOST型APFC电路控制方法的研究及仿真

有源功率校正技术(APFC)在解决开关电源功率因数方面得到了很好地应用。本文采用单相有源功率校正技术来提高开关电源的功率因数,主电路采用Boost型电路,控制采用电流模式控制的电压、电流双闭环。用Simulink软件对电路进行仿真分析,取得了很好的结果。     

永磁同步电机驱动器开关电源系统的设计

水磁同步电机驱动器通常采采用四个相互独立的DC/DC变换器进行供电,增加了驱动控制系统的成夺和体积.本文采用降压斩波电路将电源电压变换至5V,一部分给驱动器中的有源器件进行供电,另一部分通过全桥式开关电源变换电路,生成四路相互隔离的商流电源,用于驱动三相桥式逆变器功率开关器件的通断.实验表明,当输入电源电压在8-30V...     

DC-DC变换器分段线性系统的最小投影法切换律

采用分段线性系统分析方法, DC-DC变换器的稳定性研究和控制器设计变得十分简单和有效. 本文首先基于分段线性系统的稳定性原理, 建立实现系统全局稳定的最小投影法切换律. 其次提出基于最小投影法的收敛率分析方法, 揭示了分段线性系统在整个状态邻域收敛率快慢的本质, 为改善最小投影法切换律的收敛率提供理论依据. 最后以Boost DC-DC变换器为例说明以上理论研究的正确性, 并以实验验证最小投影法切换律在DC-DC变换器实际应用中的可行性.