Re: Power supplies keep crapping out on me

["Luke Forat" <iceman@nospam.digidude.homeip.net>]

  Sorry, that was supposed to be a 4.7uF, and the value is just indicatory, 
not precise. Values for this trigger cap in switching PSUs vary a lot 
actually, some have over the 10uF value actually while others are as small 
as 1uF.

  Luke

"Michael J. Mahon" <mjmahon@aol.com> ha scritto nel messaggio 
edGdnU7XMYx-VkfZnZ2dnUVZ_uidnZ2d@comcast.com">news:edGdnU7XMYx-VkfZnZ2dnUVZ_uidnZ2d@comcast.com...
> Luke Forat wrote:
>>     Scott,
>>
>>     it looks like your "power up trigger" cap is leaking. This is usually 
>> a
>> small electrolythic cap used in switching transformers to trigger the
>> oscillator so it will powerup and start oscillating. It is a common 
>> defect
>> in switching PSUs because these caps are continuously powered when not in
>> use and eventually fail - but you don't notice it until you power off for
>> some time and let it "die". Usually it's a 47uF cap or around that value.
>
> I'd expect a much smaller value for this capacitor--like around 1uF--but
> there were several different designs used over the Apple II/II+/IIe
> production history.
>
> -michael
>
> New, faster SUDOKU v2.0 solver for Apple II's!
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>
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