To add even more trivia to a beat to = death subject:

Yes, Pertronix are Hall effect = based. A hall sensor turns on based on the strength of the magnetic field that they = see, thus, it is logical to conclude that you can effect the dwell by changing the = distance from the collar (with the magnets in it) and the sensor. ie... the = closer the pick-up is to the collar (magnets) , the longer the sensor will see it. Obviously, if you get too much of a gap, the pulse will be shorter.

Personal experience: Don't get you hand = anywhere near the business side of one of these (coil output). Not only = does the module decide when to fire the coil, it gives it a sustained = spark. It hurts lots more than when you get hit by points. I ran one in a = beetle that I circle track raced for years and it brought home more = than one trophe. It later went into a '73 bus and ran fine. In case = it matters, I also carried a set of points and a condenser in the = bus just in case.

Mark Rokus
'87 Syncro = (wifie's)
'87 Syncro Westy: Mine :-)
'81 Westy
'82 Diesel Rabbit
'72 = Karmann Ghia

----- Original Message -----

From: jeff crane

Sent: Saturday, May 13, 2000 = 10:54 PM

Yes = dwell angle is still a factor in transistorized ignitions. It is = no longer adjustable but through software it is possible in = distributorless ignitions, but no the service tech cannot do so.

Dwell is expressed in degrees of distributor shaft = rotation. 30*dwell on an eight cylinder engine would leave = 120* of cumulative rotation for the coil to be off charge and = therefore cooling somewhat. 45* on a four cylinder engine would leave 180* = to cool, and 180* to charge the coil cumulatively. Simply = because the distributor shaft rotates 360* of course. If you have a = transistorized ignition, breakerless whatever, you can still measure the dwell angle. If the system is weak chances are you will find = a shorter dwell angle when you test it. I have done this and I = know it works. In fact, transistorized ignitions can and do have = variable dwell periods factored into the circuitry on some applications. In reality the hall effect sensor is simply a switch and = not the conductor that all current must pass to charge the coil and = this leaves you many possibilities.

To understand this best it is best to realize that dwell exists even in distributorless ignitions, though it is often ignored, it = is a percentage of time in a given engine revolution. That = doesn't matter but that it is important to realize that without = contact points you do still have a dwell angle.