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怎么就沒人幫忙一下呢?

先祝賀你一下!
494最好再接一級圖騰柱再去驅動MOS.
把R34 C18那吸收位置改小點試試.

看來原因大家也已經給你找到了.
MOS管的驅動不好,
吸收電路不好,尖峰太大.

樓主,我也在設計車載電源,也是推挽的,推挽變壓器如何計算啊,苦苦等待  我的QQ729454923   郵箱PADS2005PCB@126.COM

大家能否給出:494最好再接一級圖騰柱再去驅動MOS.....這個電路我看一下啊!

pads2005pcb兄弟,這樣吧,你把你的參數要求給我,我幫你算出來,然后你再去做樣品試,因為我也是頭一次做,現在我所用的方法不知道對不對!要是不對的話只會讓大伙笑話.

車載逆變電源,變壓器,推挽
輸入12V,輸出300V1A   開關頻率40KHZ,效率不低于0.8
占空比我不知道取多少,請你作決定,由于是急著開發的市場機,請大俠仔細幫我算好,萬分感謝.如果能提供你的公式則更佳.

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!這是我所幫你算的推挽式開關變壓器,供你參考,如果能用的話我再告訴你是如何計算的.我也是頭一回做,權當是拋磚引玉吧!
初級請用銅帶繞,開關管選用IRF3205就行了,輸出為橋式整流.如有不妥,也請各位高手指正!
            謝謝!

謝謝,過兩天我給你回復實驗結果.