VSS importance

[Bruce Plecan]

-----Original Message-----
From: jdzura at csc.com <jdzura at csc.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Monday, September 28, 1998 5:23 PM
Subject: Re: VSS importance

OK, next question, where does one find application notes on a
4046, or CD4046BC?.  Can a CD4046BC be used in lieu of a 4046?.  Can someone
scan an application note, send it to me, and I'll get a 2x done so we can
put it at 332 incoming so, all can find it.  Questlink/National don't have
them.
If ya can't scan, can you send me the exact address,  mom + pop
bright.net still are playing games, and searching is next to impossible.
Cheers
Bruce




>The problem with doing a one-shot solution is the analog nature of the
frequency
>multiplication. Over time and temperature there will most likely be
problems. The
>classic way to do this is to implement a phase locked loop with a divide by
2
>(D-FF) in the feedback path to the phase comparator. The output of the PLL
before
>the flip flop will be exactly 2x the input frequency. I  can't remember the
>series, but there used to be a 4000 series Cmos PLL that had great
application
>notes.
>
>The other purely "digital" way requires an oscillator to run a series of
Flip
>flops that can be used to do the 2x frequency multiplication. This is
essentially
>a zero order PLL. In either digital case, the circuit will take a few chips
and
>some additional power. I believe I have read where someone sells an adapter
for
>$50-60 already done. If it has been done and is only $50, you should
probably buy
>it. Designing one will probably cost at least half that by the time you
consider
>packaging, connectors, and a wirewrap board. Just my humble opinion and I
have
>been an electronic designer for more than 15 years. If you still insist,
let me
>know, and I will look up the reference to the cmos PLL chip. CMOS has the
>advantage of being run from 12 VDC and won't incur the overhead of voltage
>regulation.
>
>Joe D
>
>
>
>
>
>"Bruce Plecan" <nacelp at bright.net> on 09/28/98 01:48:00 PM
>
>Please respond to diy_efi at efi332.eng.ohio-state.edu
>
>To:   diy_efi at efi332.eng.ohio-state.edu
>cc:    (bcc: Joe Dzura/SED/CSC)
>Subject:  Re: VSS importance
>
>
>
>
>
>-----Original Message-----
>From: Mike Hoenes <MHoenes at dhr.state.nc.us>
>To: Jake Sternberg <chickens at ccwf.cc.utexas.edu>;
>diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
>Date: Monday, September 28, 1998 1:00 PM
>Subject: RE: VSS importance
>
>>anyone figure out how to get a 730  with a 91 L98 eprom to accept input
>from
>>a 2000ppm vss?
>
>Been figuring but not done yet.
>I'm assuming you want a 4000ppm, and only have a 2000ppm.
>What I think will work is use two 555 as monostables.  Trigger
>one off the - edge of the input signal, and one off of the + edge,
>then combine the two signals with a 4011 or some such, tie
>that to a Mosfet, and a resistor off of that and use the resistor's
>input as the VSS signal.
>______            ______            ______            ______
>             I_____I             I_____I             I_____I
>______   ___    ____    _____    ____   ____    ____
>             I_I      I_I          I_I           I_I         I_I
I_I
>Hard to type with Doc laughing at my wave patterns
>Maybe some EE has input?.
>Cheers
>Bruce
>
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