On Mon, 19 Feb 2007 12:43:05 -0600, > wrote:

>
>"Mike Romain" > wrote in message
ng.com...
>> The points 'do' arc out and burn in those regulators or you wouldn't
>> need new ones.... I was always under the impression you needed the
>> condenser to slow this down.
>
>You're right, Mike. The condensor is there to stop RFI but it does it by
>stopping the sparking, which is an interrupted DC. Just like the condensor
>used to do on points, it provides a low impedance path for high frequency
>AC or interrupted DC.
>
>While an electromechanical regulator might not be a critical to spark damage
>as ignition points were, the principle is similar.
>
To the OP.. you do NOT need this cap.....
It is NOT a functional part of the charging system in any way...
It is only a high frequency bypass to ground for radio noise
suppression.

Its purpose and connection into the circuit in this application does
not affect nor control the arcing at the voltage control contacts...

Having this cap in the circuit (or not) will not damage the regulator
or affect the charging system in any way.

The capacitor on the GM Delco voltage regulator is ONLY for RFI
suppression.. it is not in the "Field" circuit where the altenator
field (rotor) contacts are located.

In the days of generator (as opposed to "alternator" charging systems,
mis-connecting the RFI capacitor to the field terminal of the
generator (an easy mistake to make in the day) would CAUSE a failure
of the voltage control contacts in the regulator!!
The cap in this particular application was mounted on the generator
case, and designed to be connected to the generator "Armature"
terminal which was in fact the current output terminal.

GM DELCO used to put a big round red cardboard warning tag on the
"field" terminal of the generators telling you NOT to connect the
capacitor wire to this (field) terminal!
In this instance, the capacitor was being used to suppress the RFI
from the arcing at the generator brushes which would be heard as a
"whine" on an AM radio..

Of course these two connection terminals were located side by side on
the generator case, and only a few of us could read the big red tag.
So when this mistake was made the voltage regulator failure would
occur within a couple hundred miles. <BG>

These uses are NOT related to the use of a capacitor in "Point +
Condenser ignition system, where the cap serves an entirely
different function in the creation of the High Voltage spark and
in fact does absorb the arc at the contacts that is created
by the collapse of the field in the primary of the ignition coil on
the "break" of the contacts.

Again, I repeat, this capacitor on the Delco Altenator regulator base
is NOT involved in the charging circuit in any way, and only exists to
suppress the RFI generated by the arcing at the vr contacts...
If you look at the back of the regulator base, you will see that the
capacitor terminal is merely an extension of the "B" or Battery
terminal lug. The capacitor from there to ground suppresses any
HF RFI that might be generated from reaching the rest of the car's
electrical system and thence being heard as a "popping" type of
static on an AM radio..

Feel free to ask for more technical explanation an any time.
School is out fo now .. there will be a quiz later <G>



Bob F.