|
John T
05-29-2000 20:12:47
|
|
Re: arcing or no arcing points??????? in reply to jeff ruth, 05-28-2000 21:25:27
|
|
|
Jeff, yeah Ol Doug and zane there already hit it right on the head for you and I agree with both. As far as theory, one purpose of the condensor (capacitor) is to absorb some of the energy energy in the coils primary, since when the points open, the energy stored in the magnetic field (produced by current flow in its wire), wants to dissipate, and it causes current to arc at the point gap producing heat tending to deteriorate the silver point coating and burn them up. But, the condensor (sort of like a big electron storage bank just hungry to accept current flow and store electrons) is setting there all discharged (throught the parallell closed points) and when the coils primary magnetic field collapses when the points open, some of the initial surge current flows into the condensor, as opposed to all arcing at the points. So, if the condensor was way way bigger than it is, the points would never burn up BUT if the condensor is that big, you would not get a good high voltage spark (too slow a di/dt) in the secondary either. Conversely, if there were NO condensor at all, you would still get a spark
(but a weaker one), and the points would burn up quickly having to absorb that current arc every time the points open. The proper size of a condensor to match a particular coil, is therefore, important and why Dave Wickman is always telling guys to get the right condensor. Yes you should see that arcing at cranking speeds, and if you dont, theres a good chance your not getting a high voltage spark either. Ol John T Engineer in Indiana
|
|
|
