How many amps does DS1 and DS2 send to coil?

jamyers

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I've been reading up on spark ignition (uh-oh...), and since the spark energy a function of current over time, and current is volts times amps, and in the equations I've seen: an increase in amperage gives a much more dramatic increase in spark energy than a corresponding increase in voltage...

Looking at a schematic of the Duraspark modules, it sure looks like they don't put out much more amperage to the coil than points, since they use less than 12 volts coil input (except for starting).

Granted, they'll have a much more accurate triggering control, and will be able to generate more dwell (coil saturation) than points, so they will send more current through the coil than points, but I wonder why they still use limited voltage to the coil?

If points can only handle 2 amps or so, the GM HEI modules (full 12 volts to the coil) send up to 5 amps, and some aftermarket HEI modules will send 8 amps through the coil, how many amps does DuraSpark send?

Thinking back to comments made about the benefits from upgrading coils to the TFI coil, makes me wonder if Ford used the coil design to catch up on the amperage.
 
I may be wrong but I think they do that to protect the electronics
 
Jacobs book lists an average of Ford ignitions generate 3.4 amps. Points are listed as 2.5 amps. HEI is listed as 3.9 to 4.1 amps. Computer ignitions are around 16 volts.

and current is volts times amps,

Just a correction, Current is amps. Power or KW is volts times amps. Some of the high performance coils may have more winds and better quality components that result in less current and resistance losses.
 
Whoops, you're right - current = amps, I meant Power. Spark energy = power over a time span, which is often expressed in kilojoules...

What I found interesting was that a small increase in amperage gives a large increase in kilojoules, but not many systems push more than 5 amps max.
 
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