Ballast resistor ...or not??

hey hotrod...go with the ballast resister- and be safe! the resister cuts the voltage down from 12 to 6 volts. believe me the coil will bring it back up too 200 v. primery to3500 secondery. NUF SAID!!! CALL ME POP.

 

Some do - the coil I am running now has it printed on the side.

 

i hear ya.....

 

Even if you did know these things you still don't have an exact answer. The steady-state DC ****ysis is as good it gets until you do know these things. Doing the best you can with the data you have is the best you can ever do.

A Kettering points igntion system is not an AC circuit by any definition. It is a transisent second order RLC circuit. Phase angles, power factors and all the over things relating to AC ****ysis have no relevence to transient DC circuits.

The potential difference at the +coil terminal will vary between the full 13.5volts from the postive ignition down to the expected value from the steady state DC ****ysis while the car is running. You could never hope to get anything from this measurement.

Interesting toy. They negelected a few factors, and without knowing the ***umptions made in the ****ysis, it is of limited value (condensor capacitance and secondary inductance comes to mind). It does however show the declining energy at higher RPMs.

 

jingles had the best answer to this whole scenerio IMO. I plan on doing the exact same thing in my car.

msd box with a hi energy coil. no load through the points and a backup ignition with no parts to carry around.

 

A coil also has resistance. Some even have an internal ballast, giving them more resistance.

If you put a voltmeter on the positive (+) terminal of the coil, you will normally read about 6 - 8 volts while the engine is idleing, on an external ballast system.

If you used an O-Scope to view this point, it would probably show 6 - 8 VDC, with pulses going to zero, or on-average, less than the voltmeter measurement. The higher the RPM, the more pulses per second, and an even lower average DC voltage.

The question asked, is if the coil in question needs a ballast. The obvious answer is no, because it has an internal resistance (it also has a reactance but who cares except mopar guys I guess--smile).

The coil primary winding rising to a potential of 6 volts produces an X voltage in the secondary winding when it collapses due to the points opening. Would it not seem logical that the primary winding rising to 12 volts would then produce ** volts in the secondary? Just this change from X to ** may be the difference between the engine running or running badly. Consideration of the spark plug heat range and gap, along with the amount of advance on the timing.

If 8 Kv on the coil secondary is good, then 16 Kv sometimes isn't better.

I'm pulling these numbers OMA, so don't go to the bank with them...

I'd do whatever made the engine smooth at idle, and like a ****d ape at 6000 RPM...

That is, try it both ways. See what you get.

 

You don't have to get upset. It's a forum. Of course the gomer could have called the manufacturer. We all could call the manufacturer, and then we wouldn't need to hang around here anymore.

I'm interested in answers right or wrong. Sometimes the wrong answers make you really think about the problem or idea in another way. I love wrong or even half-right answers.

If answers that aren't in "phase" with your answers upset you, then by all means be upset. Just go do it in your sauna.