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/33/1125921046.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">关于低压差三端稳压器7805的疑问??请指教,谢谢!!!
小弟为了减小DC-DC的纹波,在输出端串联集成三端稳压.是否接三端稳压前的输出电压要高一点,如要求输出+5V;接7805"至少要高2V---如下图的介绍",那就是说我的前级电路要输出至少7V才行,感觉不妥啊,变压器都要重新算匝数???还是我理解错误????请指教.谢谢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/33/1125921046.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">
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/33/1125921046.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">全部回复(8)
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@skyfish
看来大哥对变压器很熟悉,请帮助看看我这个DC-DC用什么现成的变压器合适呢(我只买5~10个做实验,成了再买)?请看我的电源要求:输入:9V~18V三路输出:OUTput(1)=+12v/1A 纹波电压峰峰值
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/33/1125923307.jpg');}" onmousewheel="return imgzoom(this);">
附上我的电路图,请大哥看看这样离实现要求还有多远?如何改进.小弟是新人,一个产品都还没做过.求助!!!嘿嘿
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