6 volt generator 12 volt system

[52 Ford]

I am using my 6 volt generator in a 12 volt system. Would I be better off with a 12 volt coil with external resistor or internal resistor?

[JSeery]

There is some confusion here. There really isn't a 12v or 6v coil, but I know they are often referred to that way. The coil doesn't care about the voltage, it is the current flow that is the issue (but the voltage, current and resistance are all related). What is commonly referred to as a 6v coil is in the 1.5 ohm range of resistance. So with a 6v system and a 1.5 ohm coil the current is in the 3 to 4 amp range, and that is what you want. If you switch to a 12v system, then you need to add a 1.5 ohm ballast resistor. So now you have 1.5 ohms in the coil and 1.5 ohms in the ballast resistor for a total of 3.0 ohms and you are back to the 3 to 4 amps. The white ceramic things you might have seen on the firewalls of some older vehicles is a ballast resistor.

OR you could switch out the coil for a 3.0 ohm one and not use a ballast resistor. The internal resistance of a coil is determined by the winding during manufacturing. The whole idea here is to control the current flow in the ignition system to something in the 3 to 4 amp range.

So to answer your question, you don't need to change the coil unless you want to (this is assuming it currently has a modern "can" style coil and not an original Ford style coil). You can add a ballast resistor OR switch to a 3.0 ohm (what you are calling a 12v) coil. There are advantages to each.

If you are switching to a "12v" coil, the Bosh Blue coil is a popular one.

Note: All of the numbers used a just examples, the actual values can be off some, but there are round numbers that are in the ball park. As an example, I think the Bosh coil is a 4 ohm coil.

[52 Ford]

Sponsored Links (Register now to hide all advertisements)

Thank you