求简单的PWM调光电路.非常感谢!
5V输入的PWM调光电路,要求不高,频率1K以上都可以,实现用电位器调节占空比.非常感谢!!
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@iqhome
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R2用来调整duty,如果R5用1k可以在2%到98%调整,但最好按图中的值来获得最好的亮度.Q1与Q2组合成达林顿管,用以减少对U1的电流获取与提高放倍数,并U1最好用CMOS型的,这样电压低到2V时还能工作.L1与D1升压后给LED供电,C2决定频率,改变R2不会改变频率.
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