Anyone here a pro on these?  Specifically...

I usually see regular diodes across the inductive load itself, but I=20
notice the LM1949 fuel injector driver puts a zener across the switching=20
transistor.  Makes sense to protect the transistor, but wondering if=20
this was just for the ease of putting it internally to the controller,=20
or if there's something other better about this arrangement.

Secondarily, how does one calculate the value for these?  I can=20
calculate an estimate of the energy held in coil once energized, but=20
with the field collapses, what determines the voltage and current=20
produced?  It should be the resistance of the load, but that would be a=20
diode in this case.

My end goal here is to determine how to calculate the correct size=20
protection diode.

Cheers,
-Neil.

--=20
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