VSS problems

[steve ravet]

> >OK, here's the stupid question:  What is a mfd disc (microferrad?) and what
> >will this do?
> >I'm willing to try anything to get the VSS controlled functions working
> >(doesn't have to be particularly accurate) but my specific knowledge of
> >electronics is limited to Ohms law I'm afraid! :)
> >Could you give the dummy explanation please?

Bruce is referring to a capacitor, one of the little brown disc types. 
You can get a pack of them at Radio Shack for a buck or so.  If your VSS
sender is the 2000 ppm DC type it has a waveform like this (always
positive):


        ___       _____       _____
           |     |     |     |     |
0v    _____|_____|_____|_____|_____|___________

The capacitor in there blocks the DC portion of the signal which centers
the waveform around the 0v line like this:


        ___       _____       _____
0v   ______|_____|_____|_____|_____|_______________
           |_____|     |_____|     |

The frequency will still be wrong, but the ECM will at least see a
signal that it likes. (If it likes an A/C signal, that is).


-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com