Modern coils for points system?

[Antietam Classic Cycle]

It's amazing that Americans came to the moon so many years ago.  

You live on the moon? Cool!  ;D

[Chuck in Indiana]

To be clear...They're not in parallel cuz they're never in the circuit at the same time.

By the way Chuck, Nice Fluke.

Thanks.  ;D Bought it many years ago (it seems all my tools are antiques)  ??? to tune up the feed back circuits on my cnc mill.
Woo wee, wat a can of worms. Here I was, happily working out in the shop fitting up the wings on the Lario, thinking I had the coil problem under control, and this is almost like an oil thread.  ;D :BEER:

[kckershovel]

Sounds like it's all worked out then. Glad I could muddy the water.

[tusong200]

Thanks.  ;D Bought it many years ago (it seems all my tools are antiques) 

I've got the same one... bought about 30 years ago.

[Rough Edge racing]

With this information I would want to start with 5 ohm coils and wire in a ballast resistor as well. That is probably why Guzziownr got a melted box with the 3 ohm coils not realizing that when wired in parallel they become 1.5 ohm coils.

Two 3 ohm coils wired in parallel remains 3 ohms each, wired in series would be 6 ohms...

[kckershovel]

If they are truly wired in parallel I disagree. It does not apply to the Guzzi though so this would just be for arguments sake. 

[pauldaytona]

Two 3 ohm coils wired in parallel remains 3 ohms each, wired in series would be 6 ohms...

No!

When wired in parralel, the load that the source sees is 1.5 ohms. You will never change the internal resistance of the coils, that stays 3 ohms in any situation.
When wired in series, the load that the source sees is 6 ohms.

[kckershovel]

No!

When wired in parralel, the load that the source sees is 1.5 ohms. You will never change the internal resistance of the coils, that stays 3 ohms in any situation.
When wired in series, the load that the source sees is 6 ohms.

This I agree with

[Kiwi_Roy]

The coils have a common supply, they are not in series or parallel for that matter.
You really can't apply transformer theory, the spark is caused by the magnetic field collapsing, true the
ratio of the Voltage on each winding will be determined by the ratio of turns in the windings but 12 Volts
doesn't come into it, the Voltage on the primary as the field collapses will be many times that, if you were
holding the points terminal you might get a nasty jolt as the points open.

[kckershovel]

Many coils are acutely designed to see 6-9 volts even in a 12 v system while we are adding information. 

[Rough Edge racing]

 When discussing ignitions systems like a Guzzi, two coils ,each feed by a common electrical source are wired in parallel. In this case parallel refers to the power source just like the light bulbs in your home. This does not change the primary resistance of each coil. The voltage at the condenser when the points open can be around 300 volts.

[Kiwi_Roy]

If both coils were operated by the same set of points sparking at the same instant I would agree they are in parallel
They are really 2 separate circuits fed from the same fuse, they operate independently
 
From an electrical point of view two devices with both leads joined together are in parallel

I think we are both saying the same thing really, let's agree to disagree.

300 Volts on the condenser, I suspected it was high, I have had several nasty bites from low Voltage solenoids and seen the guts blow out of electronics not designed to handle it

[kckershovel]

    Right since the Guzzi has dual points the 2 coils are not wired in series or parallel so there is no change in ohms. When I originally asked the question I was not sure how the Dyna S ignition was wired into the Guzzi.

    I have more HD background and most are single points so the series and parallel question does apply to them. With the option of single or dual fire along with single or dual plug heads there are allot of possible combinations.   

[Wayne Orwig]

the Voltage on the primary as the field collapses will be many times that, if you were
holding the points terminal you might get a nasty jolt as the points open.

I did a tachometer design long ago which was attached to the primary. I often saw voltages well over 400 volts on the primary.

[Rough Edge racing]

 Civilized disagreement is a learning process... ;D