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Guest765 Guest765 is offline
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Join Date: Apr 2011
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According to the Wikipedia posted above, unless they used the wrong terms, a parallel circuit is used ;
Quote:
A parallel circuit supplies the "charge" warning indicator and is earthed via the regulator.(which is why the indicator is on when the ignition is on but the engine is not running).
According to that, if a series circuit was used, then the exciter would not be powered with a burned out bulb. A circuit in parallel supllies voltage regardless of the bulb.

From wiki;
Quote:
In a series circuit, every device must function for the circuit to be complete. One bulb burning out in a series circuit breaks the circuit. In parallel circuits, each light has its own circuit, so all but one light could be burned out, and the last one will still function.
That doesn't mean porsche didn't wire it in series, but why would you when the bulb is powered off the rectifier according to wiki? I believe the wiki is meant to say
Quote:
The drawback of this arrangement is that if the warning lamp burns out and the "exciter" wire is disconnected, no current...
Which would be logical when the (again, wiki)
Quote:
The field windings are supplied power from the battery via the ignition switch and regulator. A parallel circuit supplies the "charge" warning indicator and is earthed via the regulator.
there is no reason the bulb would prevent the alternator energizing, again parallel vs series circuits. The bulb only prevents charging if it is in series with the enegizer. Q.E.D.

Last edited by fwayfarer; 03-25-2013 at 08:42 PM..
Old 03-25-2013, 08:40 PM
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