......and more importantly the fragile transistor in the chrysler electronic ignition box.
As a slight addendum.....the Mopar ECU switching circuit keeps the switching transistor always ON. The reluctor / pick up coil assembly in the distributor produces a pulse, when the reluctor tooth and pick up coil pole piece aligns, this pulse turns OFF the switching transistor, collapsing the magnetic field in the coil, which generates the ignition spark. The switching transistor is a IGBT device (Insulated Gate Bi-polar Transistor) with transient supressor around the current junction (to absorbe the coil's collapsing voltage spike, similar to the condenser in a points distributor). The balance of the ECU's circuit senses the coil's voltage decay and turns ON the switching transistor to recharge the coil for the next cylinder (equate to dwell time).....its a closely choreographed system.....coil, ECU, distributor, ballast resistor (to LIMIT coil current)....everyone changes the coil....in search of more HP....because it's the easiest to change.....which usually results in ECU failure ......I've dissected the ECU to determine how it works......
agreed. The hardest worked part of the whole ignition system is the ground to trip the coil.
Any idea what resistance value that ballast has?
An inductive system works by turning the coil's primary current on and off, thereby INDUCING the high spark voltage in the coil's secondary windings (the process is called inductive reactance). An MSD system uses a CAPACITOR DISCHARGE principle, where the capacitor in the MSD box, furnishes a high voltage pulse to the coil's primary winding, which in turn, raises this high voltage pulse, thru the same inductive reactance principle as previously described. The capacitor discharge system DOES NOT CREATE THE HIGH VOLTAGE SPARK VOLTAGE DIRECTLY BUT THRU THE EXISTING COIL WINDINGS.....BUT IT PROVIDES MORE ENERGY TO THE COIL'S PRIMARY (in terms of watt/seconds or Coulombs per Coulomb's Laws) FASTER, ALLOWING THE COIL TO PRODUCE MORE ENERGY IN THE SPARK VOLTAGE. The system still uses the distributor to control the on/off - when the spark occurs function. Instead of the coil's primary winding voltage of 12 volts, with a conventional ignition system, a CAPACITOR DISCHARGE IGNITION SYSTEM provides the coil's primary winding voltage approximately 400 + DC volts to yield more spark ENERGY. The term CD IGNITION SYSTEM is a misnomer but a combination of s conventional coil ignition system with a CAPACITOR furnishing the coil's energy source. Thus endith the lesson......class dismissed.......
System overload! All this time I thought you just throw a coil in there and away ya go. Education has taken place, thank you.
Mallory Ignition 700
I do not particularly care what you think you know or when you learned it....btw...are you a degreed Electrical Engineer?...or just a "shirt sleeve mechanic? Just curious..
Is it possible for me to use my DVOM and check the coils resistance value and then determine the appropriate RB to intall, or is there more that needs to be added to the equation? I'm trying to upgrade the ignition in the car from a 1966 to a 1970 system. I have the correct alt, that isn't grounded to itself (the case), as well as the volt reg (2 pin), and the ign control is a 4 pin unit. Or am I not even in the ball park with this yet?
