Reply To: Testing voltage to the points on the Sportfour Imperial

[Buccaneer]

 

Regards to “overkill”, I’m not referring to the price, but
rather that it would seem like using a $1000 gold plated
toilet seat, when the Ohm’s Law should tell me what
size resistor I need.
I just don’t think I have quite the right information in
my calculations perhaps?

With the current volts to the points with the engine running,
V=IxR

I have, between the ignition resistor and primary coil resistance (3 + 1.3)
around 4.3 ohms, and if the voltage to the points is running just under 10 volts,
that calculates to an amperage of 2.3 amps current.

2.3 amps x 4.3 ohms = 9.89 volts, about what I currently have at the points.

When I tried using the 2 ohm ignition resistor, and having a total resistance of
3.3 ohms, the current must have ran at a higher amperage. During that test,
I checked voltage at the coil “Bat” connection, and was running 11 volts,
but in testing at that location, it’s not taking into account the resistance
of the primary coil……. hence, my two test weren’t “apples to apples”.

Then there’s the question, do I calculate the primary resistance of both
coils in the coil tube for my equations, or just the one? I only did
the one.

With all my calculations, I’m stumped why, when using a 3 ohm ignition
resistor, I’m still getting almost 10 volts to the points!

 

 

Prepare to be boarded!