共查询到18条相似文献,搜索用时 187 毫秒
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介绍了一款车载调光大功率LED驱动电路,电路采用单片机MSP430F1232为核心控制器,集成调光控制模块LM3404,论述调光电路的硬件方案和软件方案的设计。电路可以实现对车载大功率LED照明灯具进行调光,并且具有参数记忆功能,方便了车内阅读需要。 相似文献
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PT4107是一款针对高功率LED照明的PWM恒流控制器,输入电压既町以是传统的110V/220V交流电,义可以是不低于18V的直流电。该芯片采用峰值电流检测方式,为大功率LED提供恒定的供电电流,并具有数字脉冲调光和线性调光功能.整体供电效率可达88%,且可靠性高,主要用于离线式LED驱动、LED日光灯、LED环境照明、LED交通信号灯等电路中。 相似文献
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LED作为新一代绿色固体冷光源,对其驱动与调光问题的研究一直是近年来照明界关注的焦点,在节能环保领域具有广阔的发展前景。针对当前办公照明能耗偏高、光源利用率偏低问题,提出基于MSP430单片机控制的LED智能调光系统,即通过传感器进行光敏检测和动静探测,将反馈信号输送给单片机,改变单片机输出的脉冲信号占空比,从而实现PWM调光功能。选用带有调光功能的专用LED驱动芯片XL6003带动负载,并通过实验对该系统的性能进行量化分析,实现LED照明系统在办公区域的智能化和集约化应用,达到节能高效的目的。 相似文献
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LED路灯驱动及智能调光系统的研究与设计 总被引:1,自引:0,他引:1
大功率LED灯有节能高效等诸多优点,很有发展前景,其驱动与调光是近年来研究的热点,因此本文对LED路灯进行了深入研究,针对其特性设计了LED路灯的驱动电路和智能调光电路,进而构成了LED路灯系统。驱动电路是由HV9931控制的Buck-Boost-Buck电路,直接由市电供电实现恒流驱动且带有PFC功能;调光方式采用PWM调光,用TLS2561作为光强度传感器,由PIC16C62控制产生PWM调光信号控制HV9931实现智能调光。实验结果表明该电路转换效率高,功率因数高,输入电流的THD小,白光LED路灯光色纯正而且节能,很有市场前景而且有进一步研究的价值。 相似文献
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高亮度LED可提供足够的照明亮度,成为新一代照明产品的解决方案.本文首先介绍一款基于NCP1200P60的开关电源的设计;然后介绍基于DW8501的LED恒流驱动电路的实现;最后介绍以PIC12F615单片机为控制器,实现红外遥控调光功能的电路设计及程序开发.本文介绍的LED调光灯具有使用安全电压、高效率、节能、环保、健康等诸多优势,可用于家居照明. 相似文献
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LED 智能照明系统逐渐应用到室内照明,具有智能控制、高效节能、绿色的特点。国内 LED 智能照明系统仍不完善,存在不易控制、能源浪费、功率因数低、谐波干扰大等问题,使得 LED 照明的优势没有很好的体现出来,并阻碍其推广。对智能调光控制技术进行研究,设计单级 PFC 反激式恒流驱动电路和蓝牙调光方案,Android 智能手机作为客户端以蓝牙无线技术传输调光控制信号,对 LED 恒流驱动电路进行开关、调光控制实现智能照明,具有便捷可靠、电源转换效率和功率因数高、电流总谐波低的性能。 相似文献
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在调查分析现有室内照明LED调光技术和产品的基础上,设计了墙壁开关式的LED调光器与调光驱动电源。为降低对电网的干扰,设计中避免了可控硅导通角控制模式,调光器通过分压方式沿单根电力线(火线)发送2~5 k Hz小幅值(~15 V)电压脉冲调光信号,由驱动电源接收电路检测并解调后改变驱动电路的PWM调光亮度级,调光操作结束后可稳定保持调光亮度级而调光器维持全角导通。调光器工作电流在导通和关断时分别通过单根电力线的电流耦合和分压方式提供,具有静态功耗低、电功率效率和功率因数高、输入电流谐波失真低的特点。 相似文献
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Yu‐Liang Lin Chung‐Ming Leng Jian‐Min Wang 《International Journal of Circuit Theory and Applications》2016,44(3):683-692
This paper aims to investigate the low dimming switch stress of a light‐emitting diode (LED) driver. Most dimmable LED drivers contain a series dimming switch with a LED string to implement a pulse‐width modulation‐dimming function. However, this setup causes the dimming switch to suffer from high voltage stress in the dimming interval. To reduce the voltage stress of a dimming switch, a low switch stress scheme is presented. The dimming circuit is parallel with the LED string. Using proper arrangement and design of the parameters, the dimming circuit changes the feedback status, which results in the output driving voltage varying between a constant current and a fixed voltage operation. These two operating conditions also make the LED string turn on/off alternately and consequently and perform the dimming function. The dimming switch acts by altering the feedback path instead of cutting off the main power flow; hence, it does not need a power level switch. Details of the operating principles and design considerations are discussed in this study. A prototype boost converter was developed to verify the feasibility of the proposed low dimming switch stress LED driver. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Chun‐An Cheng Tsung‐Yuan Chung 《International Journal of Circuit Theory and Applications》2016,44(11):1942-1958
This paper proposes a single‐stage light‐emitting diode (LED) driver that offers power‐factor correction and digital pulse–width modulation (PWM) dimming capability for streetlight applications. The presented LED streetlight driver integrates an alternating current–direct current (AC–DC) converter with coupled inductors and a half‐bridge‐type LLC DC–DC resonant converter into a single‐stage circuit topology. The sub‐circuit of the AC–DC converter with coupled inductors is designed to be operated in discontinuous‐conduction mode for achieving input‐current shaping. Zero‐voltage switching of two active power switches and zero‐current switching of two output‐rectifier diodes in the presented LED driver decrease the switching losses; thus, the circuit efficiency is increased. A prototype driver for powering a 144‐W‐rated LED streetlight module with input utility‐line voltages ranging from 100 to 120 V is implemented and tested. The proposed streetlight driver features cost‐effectiveness, high circuit efficiency, high power factor, low levels of input‐current harmonics, and a digital PWM dimming capability ranging from 20% to 100% output rated LED power, which is fulfilled by a micro‐controller. Satisfying experimental results, including dimming tests, verify the feasibility of the proposed LED streetlight driver. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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介绍一款采用AT9933芯片的PWM恒流LED汽车前照灯驱动电路,其驱动、拓扑和调光方式分别采用开关型变换器、Boost—buck拓扑和PWM调光方式。负载采用8颗1W大功率白光LED串联。实验结果表明,当输入电压在9~16V之间变化时,输出恒流大小为342mA,电流精度达2.3%;当输入电压为12V时,输出电压为25.12V,电路转换效率达80.44%。 相似文献
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LED的驱动电源性能会直接影响LED的使用性能和寿命,优化驱动电源性能是提高LED普及率的关键因素之一。本文基于LT3964芯片设计了LED驱动电源电路,利用LTspice软件对电路进行仿真测试,仿真结果显示该电路为恒流驱动方式,31~36 V电压输入下工作效率不低于94.73%。利用Altium Designer绘制PCB板并制作驱动电路实物,利用脉冲宽度调制(PWM)实现了100 W RGBW灯珠阵列的调光调色。实测中,在34V电压输入下电路实际工作效率为95.37%,与仿真结果相近。 相似文献
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Huang‐Jen Chiu Yu‐Kang Lo Yu‐Liang Lin Gwan‐Chi Jane 《International Journal of Circuit Theory and Applications》2015,43(3):307-317
This paper presents a novel cost‐effective pulse‐width‐modulation (PWM) dimming method for light‐emitting diode (LED) lighting applications. High efficiency, high power factor, circuit simplicity, and low cost can be achieved by a Flyback power factor correction converter with the studied adaptive PWM dimming method. The operation principles and design considerations of the proposed LED dimming method are analyzed and discussed. A 45 W laboratory prototype has been built and tested to verify the feasibility of the proposed scheme. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献