recommended current through 6 volt coil primary

[Tom Bellfoy]

Can anyone tell me what the recommended current (amps) should be running through a 6 volt ignition coil primary circuit in order to provide long life on ignition points on a model A ford. I can calculate the resistance just need the suggested amps

 

[P.S.]

Should be around 3 amps

 

[Badpuppy]

Long life is mostly provided by a properly functioning capacitor (condenser) to counter the inductance of the coil. Current/voltage varies with generator output @ rpm.

 

[Tom Bellfoy]

ok I willgo with three amps
Thank you
Tom

 

[katy]

Current should be measured w/the engine idling. Current when engine is not running will be a higher.

 

[P.S.]

Current should be measured w/the engine idling. Current when engine is not running will be a higher.

The peak current won't be lower, the RMS (average) will be lower. In that case, it will depend on the cam lobe shapes (which changes dwell time). The simple answer to OP's question was in static amps with the circuit energized. So, I went that route.

 

[Badpuppy]

Primary has dc resistance of 1.5 ohms, minimum battery of 6 volts gives 4 amperes, times dwell of 90%(?) is average 3.6 amps. But only if you believe the math.

 

[JoeCB]

I was waiting for it .... eventually we would get to Mr. Ohm and E=!R (V=IR)
Joe B

 

[old31]

Oh, my head hurts.

 

[JoeCB]

Oh, my head hurts.

Oh, not that bad, could be worse, like E=MC²