Alt-BEAM Archive
Message #05218
To: beam@sgiblab.sgi.com
From: Steven Bolt sbolt@xs4all.nl
Date: Sat, 10 Jul 1999 11:02:50 +0200 (CEST)
Subject: [alt-beam] Re: Something funny with the 1382 voltage triggers?
On Fri, 9 Jul 1999, Bob Shannon wrote:
> > Btw, if you are sure they are the same, why bother comparing them
> > with a curve tracer? Am I missing something?
>
> Yes, your missing the fact that I physically swapped parts
> between a working thru-hole photovore that used the same
> electrical configuration.
>
> So with the same physical solar cell, motors and capacitors, the
> thru-hole SE's work while the SMT ones lock up.
Ok, perhaps there is a language barrier here. You swapped the
parts; that means you took the thru-hole parts from the working SE
and put them into the SMT SE, which still didn't work?
And the SMT transistors did fine in the thru-hole SE?
In that case, you have proved that the SMT transistors are not the
culprits. No need to bother with that curve tracer. Continue
swapping, I'd say - there isn't much left. Basically just the
storage cap and the voltage trigger. If those from the SMT SE also
work well in the thru-hole version, you'd have to look for the rare
broken resistor or contaminated pcb.
> Its just that simple.
Your suspecting the SMT devices put me on the wrong foot, it seems.
This phrase in particular:
> I heard today that SOT23 transistors are not made from the same
> dies used for the TO92 packages, due to bonding wire attachement
> issues. It seems that they are not quite the same parts.
Anyway, I still wonder what you expected from that curve tracer, if
you were diagnosing by swap.
Best,
Steve
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# sbolt@xs4all.nl # Steven Bolt # popular science monthly KIJK #
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