Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!lll-lcc!rzh
From: rzh@lll-lcc.llnl.gov (Roger Hanscom)
Newsgroups: sci.electronics
Subject: 1Hz signals
Keywords: counters, TTL, CD4566
Message-ID: <2006@lll-lcc.llnl.gov>
Date: 13 Oct 88 00:05:39 GMT
Distribution: na
Organization: Lawrence Livermore Labs, LCC, Livermore Ca
Lines: 33


   This question should be really easy for you guys!  I do OK with
digital stuff, but most things in the analog domain are "mysteries
of the universe".  I'm building a TTL digital counter, and I need a
1Hz pulse train to feed it.  I'd like to use the 60Hz signal on the
power transformer, and a MINIMUM of components to condition it and
divide it down.  The transformer I'm using is nominally a 9v
wall-plug type.  How can I convert that to some thing I can work
with (read reduce the ~20v p-p to something like 5v p-p).  I know
how to divide it with TTL, if I could just make the AC more well
behaved to feed it to TTL.  I tried a 4566 IC like this (working
from memory here, pls forgive lapses):

                               o---o
                               |   |
                        ---------------------
                        |      14  2      16|--Vcc (5v)
  60Hz o----100K--o--o--|15?                |
		  |  |  |          CD4566   |
		  |  |  |    2,8,?          |
		  C  Z  ---------------------
		  |  |         |       C is 1Mfd 25v tant.
     G  <|--------o--o---------|       Z is 5.1v, 1w zener

but both the 10Hz and 1Hz outputs of the 4566 are dead.  Should
Vcc be closer to the p-p voltage of the 60Hz signal?? How can I
reduce the p-p voltage on the 60Hz signal??  Is there a better
way?  Comments appreciated.
Roger
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