Re: auto ignition coil: why autotransformer?

George wrote:

I want to use an old automotive ignition coil to generate a spark. I'm
puzzled that the (HV) secondary is connected to the primary. (I guess I
knew this, but I never gave it much thought before.) So, the spark
return current has to go through the battery and the harness:

________+12__________________
| | |
| | |
Batt PRI SEC
| | |
| | | (HV lead to distributor)
| | |
| POINTS SP PLUGS
| | |
|_____Gnd_____|_____________|
*** ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^--- *NOT* part of harness, all of this is the auto chassis and enginr block.



It seems it would make more sense to have an isolated secondary, with
one side connected to the coil's case. Then, the spark return current
could just go through the block back to the coil:

________+12____ _______
| | | |
| | | |
Batt PRI | SEC
| | | |
| | | | (HV lead to distributor)
| | | |
| POINTS | SP PLUGS
| | | |
|_____Gnd_____|_______|_____|
(block)

I must be missing something?

Thanks,
George

.

Relevant Pages

  • Re: auto ignition coil: why autotransformer?
    ... George wrote: ... Then, the spark return current ... I must be missing something? ... Phil Hobbs ...
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  • Re: 1971 Engine Wont Start
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  • Re: 1971 Engine Wont Start
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    (rec.autos.makers.vw.aircooled)
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