L6562做T8-40W一拖二有图论谈!

各位同仁,我现在做一款L6562+磁环电路的T8-40W一拖二镇流器,想做到85-265V恒功率,现在只能达到100V-265V恒功率.电压低于100伏功率就下降很多,如图:
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各位同仁请帮忙指点一下:先谢!500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/68/914361218546592.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">