| I did sound nasty in my defense of Scott, and didn't mean to be. The "scary" comment had to do with possibility of damage to the Pertronix. Any ignition coil, (transformer that it is) works by storage of energy in the field, and then kickback from the collapse of the field when disconnected from the power source. That's where the spark comes from as the secondary field collapses. But the primary has kickback too, and that voltage spike comes right out and hits the ballast. The scary part is hooking a solid state device to such a transient laden power source.
On the issue of 12v or 24v, I'd suggest the box your Pertronix came in might have been a 12v unit. Thus the understandable confusion. Way back when, in the '90's, when we were first seeing 404's come into the country, someone (John Wessels? or others in parallel efforts?) approached Pertronix to design a unit for our trucks in 24v. I really don't think Scott would have said the units need 12v. He's been around these special 24v Pertronix from the beginning.
As for the Pertronix box specifying connecting to the coil for power, coils have a "batt" terminal tied to vehicle power. That establishes the 'high' end for the coil's primary, and the Pertronix, or points, grounds the 'low' end then ungrounds it when a spark is needed. BTW, the period of time the points held the primary charging is the Dwell time, measured in portions of 360 degrees.
That coil 'batt' voltage suffers some spiky variation too, so why take a chance?
(once a ham, always a ham)
Bob |