Electronics > Beginners
transistor flip flop
Zero999:
--- Quote from: tggzzz on December 27, 2019, 11:57:08 pm ---
--- Quote from: Kleinstein on December 27, 2019, 03:18:35 pm ---The main resistors to effect the time constant should be R42 and R43. However there is a certain ration of R42/R40 and R43/R41 needed. The ration of 10 looks about good. So the main adjustment of the time constant to the lenght of the trigger pulse would be the capacitors.
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The purpose of the capacitors is to speedily inject some current into the transistor base, to get the switching started faster. There is no relevant RC time constant per se, other than the capacitors should have completed the charge injection before switching in the other direction needs to occur.
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I don't see how those capacitors will do much to speed it up. The base voltage already goes below zero, reversing the base current, when the input pulse goes low.
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