關(guān)于燒機(jī)問題的分析

我看了看燒機(jī)的許多話題,想談?wù)勗趺礃尤シ治?
1.出現(xiàn)電流飽和的信號(hào),例如以下的波形.

1150508607.tif
2.Vceo is very marginal,almost or over 700V when power on

    If You want to see the waveform ,pls wait for a moment ,
3. the Junction temperature is very marginal ,or the power stree is over 85%

   eg, if the power Diss is 0.5W ,and the Case temperature of the Q1 is 120C ,the R(jc)is 54 (c/W),then it is very easy to damage the Q1

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sunry

LV.2

2006-06-17 09:54

then ,how to fix the above the three issue?

  gived solution as below

  1. descrease the Ton time ,avoid the saturation.

  later reply !

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sunry

LV.2

2006-06-17 16:06

@sunry

then,howtofixtheabovethethreeissue? givedsolutionasbelow 1.descreasetheTontime,avoidthesaturation. laterreply!

看到?jīng)]人回,繼續(xù)講完

  減小Ton ,無非就是改變變壓器和開關(guān)管的外圍電路,例如:Rzcd,and Czcd
    應(yīng)該說具體電路具體分析

  有興趣的,請(qǐng)和我討論.

2 .也就驅(qū)動(dòng)不好造成的.
  例如,晶體管驅(qū)動(dòng)不夠或者過驅(qū)動(dòng),這就要求設(shè)計(jì)人員懂的晶體管的特性.

  有興趣的,請(qǐng)和我討論.

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sunry

LV.2

2006-06-17 16:17

@sunry

看到?jīng)]人回,繼續(xù)講完減小Ton,無非就是改變變壓器和開關(guān)管的外圍電路,例如:Rzcd,andCzcd 應(yīng)該說具體電路具體分析有興趣的,請(qǐng)和我討論.2.也就驅(qū)動(dòng)不好造成的. 例如,晶體管驅(qū)動(dòng)不夠或者過驅(qū)動(dòng),這就要求設(shè)計(jì)人員懂的晶體管的特性. 有興趣的,請(qǐng)和我討論.

3,這種情形,大部分出現(xiàn)在熱設(shè)計(jì)上.

  一種是降低成本,用功率小的管子,而沒用預(yù)防措施去散熱
   另一種就開關(guān)時(shí),功耗太大,,

   這種問題在不少新手發(fā)生過.

  講完上面的,請(qǐng)有興趣的回復(fù),繼續(xù)討論.

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