[Amps] HV Fuses
Ron Youvan
ka4inm at tampabay.rr.com
Wed Feb 17 06:07:03 PST 2010
> In the old car ignitions there was a capacitor in parallel between the
> points. This was made to avoid an arc between the points when the point
> were switching off 12 Volts into the coil primary.
> What we are trying to avoid in an hV fuse is also an arc when the
> circuit breaks (when the fuse melts).
> So how about using an HV capacitor in parallel with the fuse? would that
> keep an arc from appearing?
> Anyone tried this?
The reason and result are different. In Kettering ignition systems
the capacitor was to resonate the coil at a lower frequency which
produced a lower frequency sine wave spark Voltage, producing a
first half wave that lasts longer than it would have if naturally
tuned. It did prevent arcing at the "points" as a side effect.
A capacitor across a fuse would carry a brief spike of current
which would not be helpful.
--
Ron KA4INM - I'm proud to be Chuck's pop!
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