VSS importance

T Hergen thergen at svn.net
Tue Sep 29 01:11:53 GMT 1998


The x2 or /2 is half the puzzle.  I'm don't know what the vss sensor
outputs or the ecm vss input expects.  Does anyone know what range of
voltages a vss sensor will produce?  Does anyone know what the minimum AC
voltage swing is needed on the various vss inputs?

These same questions will come up if a phase locked loop is used.

Bruce, in your 555 thru a cap to vss experiment, was the 555 powered by
12v or 5v?

Thanks,
Tom

On Mon, 28 Sep 1998, Bruce Plecan wrote:

> 
> -----Original Message-----
> From: T Hergen <thergen at svn.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Monday, September 28, 1998 6:23 PM
> Subject: Re: VSS importance
> 
> 
> >If the ecm doesn't care about the duty cycle, you may be able to use
> >something simple (view with fixed width font):
> >
> >    Output will generate a pulse for each edge on the input.
> >    This doubles the average frequency.  The duty cycle will
> >    not be 50-50.
> >
> >I haven't taken the time to calculate the resistor and cap values,
> >but can if you're interested.
> 
> If you would, I'd appreciate it.  I'll breadboard it, and after verifing
> it, I'll have it posted at 332 incoming so anyone needing a 4000ppm
> signal off of a 2000ppm can do it.
> 
> By the same token, if someone would do a flip flop for going 4000ppm to
> 2000ppm, then we'd have this knocked, for lots
> of applications.
> Cheers
> Bruce
> >
> >
> >Tom
> >
> >
> >
> >On Mon, 28 Sep 1998 jdzura at csc.com wrote:
> >
> >> 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

<snip>




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