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Date: Tue, 5 Jun 2007 21:33:56 -0600
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Renesis Tach pick up
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Hi Ben,

Tracy's EM2 uses the primary injector pulse to measure RPM.  Trouble is
it only provides one pulse per revolution.  A tack is usually expecting
at least 2 pulses per revolution (set up for a 4 cylinder 4 stroke
engine).  The coil signals are more sensitive than the injector signals
so connecting external stuff to them is more likely to cause a problem.

If the GRT can handle one pulse per rev, you can use the injector signal
and you're all set.  I built a small box with an op amp in it to
combine the rotor 1 and rotor 2 injector pulses to get 2 pulses per
rev for one of my customers, but it hasn't been tested with his engine
yet. He's driving a standard auto tach with it.

Bob W. 

On Tue, 5 Jun 2007 20:12:27 -0700 (PDT)
Ben Schneider <plumberben@yahoo.com> wrote:

> This may seem a silly question, but I was thinking today, and perhaps I
> read it in one of my books or in a post or something. But I have a GRT EIS
> for engine monitoring, and was wondering about the tach. How do I hook it
> up so it will read RPM. I know it is going to read engine RPM, but there
> is no mag, does it use a coil? If so, which one?  Probably a simple
> solution that I am missing, but I have drawn a blank. 
> 
> BTW, I have a Renesis with LS1 coils and an EC2.
> 
> Thanks...
> 
> Ben Schneider
> 
> --
> Homepage:  http://www.flyrotary.com/
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