由James E.Kettler所描述的使用三色发光二极管的演示装置,已经在课堂里使用多时.对学生这是一个便宜的装置,其他人也是感兴趣的.发光二极管具有发红光或者绿光的性质,这个性质取决于给它供电的6V直流电源的极性.给它加上6V交流电时,它的发光是黄的.正因为它具有发三种颜色光的能力,所以把它命名为三色发光二极管. The demonstration device using three-color light-emitting diodes described by James E. Kettler has been used in the classroom for a long time. This is a cheap device for students, and other people are also interested. Light-emitting diodes have a red or green light Nature, this property depends on the polarity of the 6V DC power supply that powers it. When it is supplied with 6V AC, its glow is yellow. Because it has the ability to send light of three colors, so it is named as three Light-emitting diodes.