BALLAST RESISTOR........WHAT GIVES?
exactly it will be made from nichrome or similar wound round a glass fiber core and pressed onto the ceramic holder to help disipate the heat
for intersted parties there is loads of ballast here
Everything You Need To Know About Ballast Resistor 2022
ballast is used here to mean "to balance" and it ballances the current flow to a level that is sensible for the circuit it protects.
it has nothing to do with the ceramic poweder often used to pack the ceramic holder of a balast resistor.
balance implies there could be some change that needs to be moderated or steared back to a steady state
Just like a load of lead shot in the hull of a boat keeps it upright, within bounds, it will always return to upright
you igntion will always try to moderate back to about 3 amps
hot ballast takes more volts across it and there are then fewer drving current through the coil
cold ballast takes less volts leaving more across the coil
and all this in the context that the resistance of the coil also varies
hot coil takes more volts to drive current through. less current means less through the ballast as well
ballast is therfore cooler
steals fewer volts
which means more volts across the coil
balanecs things back up
the balast and the coil primary share the avilble voltage in a ratio linked to the individual resistance of each.
that resistance varies with temperature in both cases
as one gets hotter and more restant the other cools and gets less so
all in all you end up with about 3 amps all the time regardless of which is hotter or cooler
hence the term ballast.
my explanation isn't quite right but it illustrates whats going on
i didn't go into the fact that in a series circuit the current is the same everywhere.. but better to get on the right footing than cram high school sicence down to the very last point
Dave