dewey-1 wrote:Technician1002 wrote:dewey-1 wrote:
jimmy; my best "edumcated" guess would be the brass colored mounting hole is actually the ground for the HV side, the blue marked tab is the battery +, and the other terminal is battery -. The connection between mounting hole and battery may not be internally connected. These two connections are definitely connected when mounted for it's original application.
I could be wrong, depends on how it was manufactured.
Like you say, I know even less Swedish.

For how to use it, infomation on kettering ignition see,
http://en.wikipedia.org/wiki/Ignition_system
Transformers are not compatible with DC. To use them a pulse is needed. Either a high voltage pulse from a camera flash is used (call Capacitive Discharge Ignition DCI ) or a current of low voltage is allowed to build in the inductive windings and a high voltage pulse is generated when the current is suddenly interrupted. To properly form the pulse a capacitor is needed in addition to the points (Switch).
Even though the low voltage side is fed low voltage DC a high voltage spike is created when the switch is opened. Don't get your finger on it because it is very unpleasant.
Leaving DC connected to the coil will burn it out if a current limiting resistor is not used.
Tech, I realize all your info about ignition system schematics.
I was involved with ignition systems before you were even born.
Now you really know my age!
The capacitor ( condenser back then) across the points was to reduce the arc across the points so they would last longer. Keeps them from being pitted. It would still function without it.
from wiki;
The capacitor is used to absorb the back EMF from the magnetic field in the coil to minimize point contact burning and maximize point life.
Having a full career in electronics, there is something that simplistic explanation is missing. Since the discussion is technical, I'll fill you in.
The condenser is to delay the rise of the voltage on the points so the points can open with little arcing so the EMF of the collapsing field in the coil isn't wasted in an arc at the points. The value of the condensor is selected so the metal transfer at point opening is matched to the metal transfer of the condenser discharge when the points close. Too big causes metal transfer and too small causes metal transfer the other way. The LC time constant determines the rise time of the peak until flash over in the plug. The shorter the rise time the higher the voltage. A small cap is highly likely to have the flash over on the points drawing an arc while a large cap is likely to lower the voltage to the point of misfire. A happy medium is in the middle.
Unless you are a WWII vet, I have my doubts on your age in relation to mine.
Since you are picking on my age, Go back a few more years before plugs when Ignitors were used. They are much like an ignition coil, but without the secondary. Used without a condenser, the points draw an arc when they open. These mechanical points were placed inside the combustion chamber and driven off a cam like the valves.

Yes I have seen them. References gladly
http://en.wikipedia.org/wiki/Low_tension_coil
Igniters can be used on a spud gun if anyone is interested.