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Erik Malund
03/06/12 07:31
Modified:
  03/06/12 07:33
Read: 185 times
Mt Airy, Nc
USA


 		 #186445 - you are still in trouble
Responding to: Kai Klaas's previous message
while there are many 'tricks' for when a scope is not available, the "running blinnd" is still, at best, cumbersome.

"the pulse at pin X looks like this" is 1000 times better than "I think there is a pulse at pin X"

I do not think I'm the only one that on a non-technical visit (bringing no instruments) have been asked "now you are here can you have a look at this" and, in some cases I have been succesful. NOTE "in some cases", there are many cases that can not be solved in a reasonable time without proper instrumentation.

Now on a totally different track, I recall an incident in the old minicomputer/TTL days when a brit I consider smarter than myself and yours truly spent more than a month hunting an intermittent which turned out to be a pulse too narrow for the scope of the day to show and we had to resort to the "DNA scope" (loop: reasoning what it COULD be, trying it, back to loop:). We finally, by sheer reasoning, found that when chip x was in the high side of the range, but still within the parameters, under certain circumstances a ~2ns pulse could slip through and the equipmenta would fail ~once a day.

so, yes a scope is essential, but, if you have a month, you can, probably, reason your way to the cause of theproblem.

Erik

List of 18 messages in thread
TopicAuthorDate
ultrasonic receiver problem      Raju M      03/03/12 05:40      
   You really, really need to get an oscilloscope!      Andy Neil      03/03/12 06:12      
      The joys of working blind        Kalpak Dabir      03/03/12 20:21      
   The same way ...      Joseph Hebert      03/04/12 08:07      
      How do you fry an egg with a sledge hammer?      Andy Neil      03/04/12 12:25      
         First?      Michael Karas      03/04/12 23:05      
            First, and always.      Joseph Hebert      03/07/12 21:29      
   If you cannot afford a scope...        Kai Klaas      03/05/12 06:38      
      This is a kind of dip meter      KONSTANTINOS L. ANGELIS      03/06/12 04:24      
      you are still in trouble      Erik Malund      03/06/12 07:31      
      On-line simulator      Joseph Hebert      03/06/12 10:26      
      You need to save up for a scope!      Andy Neil      03/07/12 00:33      
         Microcontroller      Per Westermark      03/07/12 00:51      
         re You need to save up for a scope!      Erik Malund      03/07/12 07:21      
            Yes, perhaps that's the solution      Richard Erlacher      03/07/12 08:56      
            %$#@! -- it happened again!      Richard Erlacher      03/07/12 08:56      
   Multimeters can't troubleshoot everything      Andy Neil      03/23/12 15:41      
      Yes, and you need ...      Richard Erlacher      03/24/12 08:35      

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