干脆自己设计吧~
为了实现这个想法,找了很多资料,开始时想用boost升压,但是发现升压倍数太高,电路的占空比达到了80%以上,电感量太大,难以实现,就转而想用反激变换器或者推挽变换器。
计算了一下,变换器带24W节能灯,启动电流是正常工作电流的1.5倍以上,也就是说40W以上的电源勉强能带的起,先找够大的磁芯吧。
从一开始就想diy,所以就没有想去买那些不好买的东东,那就拆吧~找来找去,发现家里的废电动车48V-12V变换器输出电感挺合适,查了一下参数是EI28磁芯,这个磁芯中柱有气隙,用来做48V电源的推挽可能会因为漏磁严重产生过高的电压尖峰,刚好反激变换器都需要留一定的气隙,就用它做反激变换器吧。
设计思路是取自《单管变换器及其应用》中宽电源电压范围变换器设计的二级48V-5V部分。
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267144963-178004.gif)
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267144988-178005.gif)
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267144994-178006.gif)
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267145000-178007.gif)
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267145006-178008.gif)
按上面的公式我编了个excel表格
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267145985-178020.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
变压器一次绕组选外径0.66漆包线2股并绕13匝、二次绕组选外径0.39漆包线单股绕67匝、控制绕组选外径0.39漆包线绕4匝
看看半成品,还有一个4.7k电阻和几根线没有装上
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146307-178030.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146313-178031.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
反面
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146418-178036.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
装到外壳里看看
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146433-178037.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
设计图纸
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146439-178038.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
电路图
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146445-178039.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
印板简图和零件表,零件表中漏了个4.7欧电阻
![](http://u.dianyuan.com/upload/bbs/2010/02/26/1267146450-178040.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)