In article ,
Vaughn Simon wrote:

"Ted Edwards" wrote in message
...
Vaughn wrote:

I don't think that those "electronic ignitions" for lawnmower
engines are
anything more than a hefty zener diode.

Now, why would a Zenner diode create the KV necessary for a spark?

It can act just like a set of points. It allows the voltage to rise to
a certain point, where it suddenly conducts, which collapses the magnetic
field. The collapsing field cuts the turns in the coil creating a spark. (I
think)

I seem to remember something else for that purpose. Like a
zener, it does not turn on until it reaches a threshold voltage, but
unlike a zener, it does not remain at that voltage drop -- instead it
switches to an extremely low voltage drop. (Consider it to be like a
Zener diode connected between the gate an anode of an SCR, so when
things reach the right voltage, the SCR is turned on, and all the
current is dumped into the coil.

Enjoy,
DoN.

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