No not really. It is a series circuit. So the 12V feed thru ballast to the + of coil and then into the ECU through the power transistor which as the other end of the transistor on chassis ground. If the transistor stays open, you measure 12V on the coil positive and negative with no current flow. Once the transistor conducts to ground you know have series circuit with 12V through .5ohm ballast, 1.9 ohm coil, .7V drop across transistor, any unknown inductor, capacitor, or resistor in the path to ground. That will then determine current flowing in circuit. So raise the ballast resistance, or increase the transistor drop and that reduces current to coil which means longer to charge based on RPM and dwell.
Your description of current flow thru the coil circuit is correct. Your conclusions as to the effect of the ballast resistor are not.
the ballast resistor it a variable resistance that increases it's resistance as it's temperature increases. It's sole function is to prevent the coil from overheating. It has nothing to to do with charge time, that is the function of the points or the ECU.
