推挽式电源请教

空载时MOS管控制极波形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/70/2901511224233568.jpg');}" onmousewheel="return imgzoom(this);">

满载时MOS管控制极波形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/70/2901511224233638.jpg');}" 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/70/2901511224233665.jpg');}" onmousewheel="return imgzoom(this);">

满载时次级整流二极管波形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/70/2901511224233887.jpg');}" onmousewheel="return imgzoom(this);">

怎么就没人帮忙一下呢?

先祝贺你一下!
494最好再接一级图腾柱再去驱动MOS.
把R34 C18那吸收位置改小点试试.

看来原因大家也已经给你找到了.
MOS管的驱动不好,
吸收电路不好,尖峰太大.

楼主,我也在设计车载电源,也是推挽的,推挽变压器如何计算啊,苦苦等待  我的QQ729454923   邮箱PADS2005PCB@126.COM

大家能否给出:494最好再接一级图腾柱再去驱动MOS.....这个电路我看一下啊!

pads2005pcb兄弟,这样吧,你把你的参数要求给我,我帮你算出来,然后你再去做样品试,因为我也是头一次做,现在我所用的方法不知道对不对!要是不对的话只会让大伙笑话.

车载逆变电源,变压器,推挽
输入12V,输出300V1A   开关频率40KHZ,效率不低于0.8
占空比我不知道取多少,请你作决定,由于是急着开发的市场机,请大侠仔细帮我算好,万分感谢.如果能提供你的公式则更佳.

300W push-pull? except you use UC3846 current mode chips,if you use TL494/SG3525 you will be trapped at magnet bias, which often does not show up in experiments but blow up transistors several months after sold.

Recommend to build hard switched half-bridge topology and use UC3825/A as the main controller and IR2110 as the gate driver, with MOSFET 90N02, 90N03 or even 70N02 is enough.

set the UC3825 clock freq to 600Khz and so the PC40/PC44 transformer runs at its best matched freq 300Khz. A small FeAlSi toroid is recommended as the output inductor.

The transformer is very easy to build, EI28 core with only 2 windings--- PRI 1 : SEC 58( 5.5V -> (302/0.95=319V), assume maximum transistor and Cap ESR voltage down is 0.5V, in fact smaller as 0.3V or such)

maximum Duty to as large as possible in your experiment, My value is 95% largest.

2901511224636919.doc
pads2005pcb你好!这是我所帮你算的推挽式开关变压器,供你参考,如果能用的话我再告诉你是如何计算的.我也是头一回做,权当是抛砖引玉吧!
初级请用铜带绕,开关管选用IRF3205就行了,输出为桥式整流.如有不妥,也请各位高手指正!
            谢谢!

谢谢,过两天我给你回复实验结果.