用UC3842的電源,空載MOS管溫升略高,如何降低功率管溫升?

一款用UC3842的開(kāi)關(guān)電源,12V 2A、5V2A(USB外置盒用)空載時(shí)MOS功率管溫升略高,有點(diǎn)燙手,而我用過(guò)別的UC3842電源功率管幾乎無(wú)溫升,如何降低功率管溫升呢?

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keenfeng

LV.4

2005-01-13 12:51

how many degree?

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陳芳

LV.4

2005-01-13 12:54

@keenfeng

howmanydegree?

空載大概在40度左右

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jxmlhy

LV.4

2005-02-10 21:53

@陳芳

空載大概在40度左右

40度會(huì)燙手???
我的都到80多了

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hjjk

LV.6

2005-02-12 18:16

MOS管的波形是不是正常的?如正常,加大散熱片吧,呵呵呵

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陳芳

LV.4

2005-02-12 23:25

@hjjk

MOS管的波形是不是正常的?如正常,加大散熱片吧,呵呵呵

另一款電路幾乎一樣的電源,空載時(shí)MOS卻很涼…

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cleu39

LV.1

2005-02-12 23:43

You can operate with a lower switching frequency with no load condition. It will reduce the switching loss. Someone has done in this way.
Check the lower MOSFET temparature module, find out the timing R and C subcircuit in its control circuit. Please post it if you have some results.

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