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Date: Wed, 14 Dec 1994 19:49:33 -0600 (CST)
From: Lewis Dunbar Dove <mfldd@uxa.ecn.bgu.edu>
Subject: diode conversions
Lew talks about putting the diode in parallel with the points: This is NOT
correct, the diode is in parallel with the coil of the pump and permits the
energy stored in the coil inductance to discharge in the coil resistance when
the points open. Some EE's would say that the diode is a "Free Wheeling"
diode. With out the diode, the stored energy is dissipated in the arc that
appears at the points. This is what causes the points to wear and pit. One
point will pit or crater and the other will build a little mound that mirrors
the pit. Which does which depends on the polarity. This phenom gave rise to
the
Capacitor across the points. The capacitor give an alternate path for the
stored energy to dissipate in the coil resistance instead of an arc at the
points.
Just to make sure no one ends up frying their wiring harness, once again:
Diode in parallel with the coil, capacitor in parallel with the points.
Cheers
Terry
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