Chuck,
Good job. It's been tough to sit back and read some of these theories
and not want to jump in. Too bad some of these folks never heard of di/dt.
Thanks.
Bud Krueger, OFEE
52TD
Chuck Schaefer wrote:
>
<BIG SNIP>
> Its not unlike a flyback switchmode power supply.
>
>
> <SNIP>
>
> Also please understand that the purpose of the coil is to store
> energy, not the capacitor.
<SNIP>
> Therefore it is not used as an
> auto-transformer, even though it may look like one.
> <SNIP>
>
> When the points open, with no more potential applied to the primary,
> the field begins to collapse. This collapsing field induces a voltage in
> BOTH the primary and the secondary windings.
> <SNIP>
>
> The purpose of the capacitor is limit the rate of rise and fall of the
> voltages on the coil and consequently the points, NOT to provide the
> energy to fire the plug.
> <SNIP>
>
> This will be my one and only discussion on this subject. Next lets talk
> about why the points in the fuel pump burn out and why the capacitor
> fixed it somewhat but the anti-parallel diode fixes it better. And how
> about adding a transistor switch as a final solution.
>
> Of course, this is just my opinion. yours may be different.
>
> Chuck Scahefer
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