View Single Post
Old 12-01-2010, 12:51 PM   #19
denson1932
Senior Member
 
denson1932's Avatar
 
Join Date: May 2010
Posts: 260
Default Re: Mallory tech answer to coil/ballast ?

Just a few comments....total watts dissapated is divided between ballast resistor, coil, and point resistance....without a ballast resistor on an ignition system that originally had a ballast; the coil now has to dissapate 4X as much energy because it now has twice the current thru it AND twice the voltage across it! Probally its life is ending soon!
Also the current flo is somewhat less that DC resistance calculations because the coil has DC resistance but also has AC impedance which means a coil will oppose any change in current. So a coil opposes the initial current flo which is why we need 'dwell' to get the coil nearly saturated with current and then the coil opposes an end to current flow which is why, when the points open we have a inductive kick to produce spark....
denson1932 is offline   Reply With Quote