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Kai Klaas
12/29/05 09:07
Read: 568 times

#106169 - Changes nothing
Responding to: Erik Malund's previous message
Erik said:
then add a footnote "this assumes ideal behaviour of the components"

It still doesn't work, even with ideal components. Grounding of input B will still result in a turn-on of transistor, at least partially!
Also, what a stupid assumption, that inputs can actually be grounded, means connected to exactly 0V. If this circuit is driven by another DTL-modul, then the voltage drop across a turned-on collector emitter junction must be taken into consideration, which can be up to 0.4V, as we know from TTL. So, even with low ohmic germanium or Schottky diodes, this circuit will not work!

Where is the sense to let students perform a test, which is totally absurd? Why not giving them a working DTL-circuit?
So, either the test maker is stupid, or sadistic. I had enough of these idiots in my life...

The best remedy would be to ask the supervisor, whether germanium diodes can be assumed, though. Maybe he can clear the situation then. Give it a try, before you loose everything...


List of 32 messages in thread
CET Exam Chaper 9 Questions        Charles Bannister      12/24/05 15:30      
   Answers      Steve M. Taylor      12/24/05 15:50      
      Answers provide later by myself.      Charles Bannister      12/24/05 16:02      
         See Q5      Steve M. Taylor      12/24/05 16:09      
         Vintage?????      Ian Bell      12/28/05 09:58      
            No signs of senility      Steve M. Taylor      12/28/05 10:38      
               Ah, well      Ian Bell      12/28/05 12:22      
                  An achievement      Steve M. Taylor      12/28/05 12:36      
   Q3      J. Guy      12/28/05 10:11      
      yes      Erik Malund      12/28/05 10:27      
      Depends      Ian Bell      12/28/05 12:26      
         If Q3 did not have a clear answer, neith      Erik Malund      12/28/05 12:32      
         What a messy circuit...      Kai Klaas      12/28/05 19:57      
            Tough      Steve M. Taylor      12/29/05 04:31      
            assume the stupidity of the test maker      Erik Malund      12/29/05 06:47      
               Changes nothing      Kai Klaas      12/29/05 09:07      
                  germanium diodes silicon transistors or      Erik Malund      12/29/05 09:26      
                     Nice link!      Kai Klaas      12/29/05 09:36      
                        I googled      Erik Malund      12/29/05 10:28      
            Germanium and Silicon      Ian Bell      12/29/05 14:47      
               in my first job the ICs were PCBs using      Erik Malund      12/29/05 15:00      
                  DTL      J. Guy      12/29/05 15:15      
                     Appeal ?      Steve M. Taylor      12/29/05 16:25      
               cet test      Terry Lingle      12/29/05 21:41      
               From a contemporary source...      Andy Neil      12/30/05 04:12      
                  Top Marks      Steve M. Taylor      12/30/05 06:28      
                     To Charles!      Andy Neil      12/30/05 06:31      
   ANSWERS      Charles Bannister      01/05/06 18:00      
      Conclusion      Kai Klaas      01/06/06 05:25      
         Germanium diodes are      Terry Lingle      01/06/06 06:43      
            silly concept      Erik Malund      01/06/06 07:12      
               yes      Terry Lingle      01/06/06 08:37      

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