Square wave ingition triggers

[Bruce Plecan]

Subject: Re: Square wave ingition triggers


>Not sure, but it looked like a standard late 70's pickup for a Ford
>V8. matter of fact, a guy I knew told me he used one after cutting
>off the Ford plug on a Chevy MSD dist that had been in a fire. been
>awhile since I worked in the performance industry, so can't help
>more than that. Guy I know is trying to adapt MSD dist to 747 ECM
>controlled spark (yep, gotta lockout the timing next). 
>So what does the Ford type pickup put out? Square wave? or more of a
>ramp? Will the GM EST understand this signal correctly?
>Tom
>
I'll say this.  If the reluctor's coil is 800-1200 ohms resistance, and
the reluctor has 8 "tangs to it", it probably will work.  If connected to
the gm module.  The wave form is a sine type wave with very steep
ramps, and quite pointed.  The polarity is right when the timing is
most retarded when running.  Being a "sine" wave it can got either
+, or - first, so polarity matters.
HTH
Bruce