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基于便捷式电子显微镜的LED调光器的研制
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作者 蔡金洋 王磊 《机电一体化》 2013年第10期14-17,94,共5页
以同某公司合作开发的便捷式电子显微镜项目为背景,设计了一套LED环形光源的亮度等级调节和区域选择的控制模块。该模块利用51单片机、数字电位器、带施密特触发器的反相器、电容、场效应管等几种并不复杂的电子元器件,实现PWM脉冲波的... 以同某公司合作开发的便捷式电子显微镜项目为背景,设计了一套LED环形光源的亮度等级调节和区域选择的控制模块。该模块利用51单片机、数字电位器、带施密特触发器的反相器、电容、场效应管等几种并不复杂的电子元器件,实现PWM脉冲波的产生和调制,以及LED光源的亮度控制;通过软件控制的方法,代替手动拨码开关,完成光源区域的选择。实验结果表明,该模块能实现LED光源32个等级的亮度控制及各个区域的开关选择,性能稳定,耗电量低,达到了实际应用的要求。 展开更多
关键词 便捷式电子显微镜 led调光器 脉冲宽度 区域选择
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Numerical analysis on an OOK-NRZ visible light communication system based on a single white LED 被引量:7
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作者 贾永坡 叶玮琳 +4 位作者 田崇文 全相印 王嘉琪 宋占伟 郑传涛 《Optoelectronics Letters》 EI 2011年第5期376-379,共4页
An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the de... An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the detector's output signals under OOK modulation is deduced. With the selected LED, detector and other related parameters, the designed communication system is optimized and its performance is analyzed. The optimized communication distance between the LED and the detector is 0.54 m at the communication bit rate of 1 Mbit/s. With the best communication distance, when the signal-to-noise ratio (SNR) is larger than 6.5 dB, the bit error rate (BER) can drop to 10-4. The analytical model and theory presented in this paper can be of certain practical meanings in the design of similar communication systems. 展开更多
关键词 Bit error rate Communication systems Detectors Light Mathematical models Numerical analysis Optical communication Optimization Signal to noise ratio
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