there's a pretty easy way to deal with this, though some folks might prefer
other solutions. Connect the alternator directly to the battery through a
double-throw ignition switch. Then the alternator is on the battery side of
the power kill switch. If the alternator is a one-wire it's regulator will
prevent the output voltage from rising.
Another alternative is a second oil pressure switch that cuts off the
alternator charging. A third is nothing at all--connect the alternator
output directly to the battery. The wire will always be hot, with full
battery current available to it, but it won't really discharge the battery
unless it sits forever.
-----Original Message-----
From: owner-fot@autox.team.net
Cc: fot@autox.team.net
Sent: 4/25/2005 9:50 AM
Subject: RE: Kill Switches
> I may be confused on this thread. My alternator's output is wired to
> the positive battery terminal. When I flip the kill switch, the
battery
> and alternator are still connected, but they're isolated from the rest
> of the system. If the alternator is still spinning, then it will
still
> be happily charging the battery.
That should work fine, with the exception that the wire to the
alternator is
always hot. If you've been in a wreck that shorted that wire, opening
the
kill switch won't let the fire go out.
> Even if they weren't connected,
> wouldn't the voltage regulator handle it?
There's been lots of debate on this topic ... the answer is that it
probably
should. But it takes time for the regulator to respond, and time for
the
magnetic field in the rotor to decay ... you can potentially get quite a
nasty spike in the intervening nanoseconds. If the spike is enough to
short
the regulator ...
Anyone remember those old kits to get 110vdc from an alternator ? All
they
did was switch to a 110v regulator, the rest of the alternator was
unchanged.
Randall
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