triumphs
[Top] [All Lists]

RE: Alt Conversion Excite Resistor Problems

Subject: RE: Alt Conversion Excite Resistor Problems
From: "Randall" <tr3driver@comcast.net>
Date: Fri, 8 Oct 2004 09:47:05 -0700
Cc: <triumphs@autox.team.net>
> I did a test where I disconnected the white wire from the coil,
> and jumped the
> battery directly to the coil. Started the engine, then switched
> the ignition
> off. The HT circuit is still powered by the jumper from the
> battery so the
> engine is still running.
> Then I measured the voltage at the
> (disconnected)
> white wire and found 10.5 VDC, and the rpm increased.

Did the rpm increase when you turned the switch off, or when you measured
the voltage ?  Was the Pertronix (red wire) also powered by the jumper from
the battery ?

If both the Pertronix and the coil were powered directly from the battery,
the switch should do absolutely nothing unless there was some other load in
operation (brake lights, maybe ?).  And there is no reason for the voltage
to be 10.5 instead of full battery voltage.

> The Pertronix only takes the place of points and, as I
> understood it,
> didn't have any impact to the advance curve.

They don't tell you lots of things ... for example, the gap between the
magnets and the pickup does have an effect on timing.  (not the advance
curve, just the absolute timing)

> I would also suspect
> that there's
> some sort of internal regulator to control the sensing of the Hall Effect
> device thus making the output flat over some input supply range,
> otherwise it
> turns off. If not, that's poor design.

No, it's a cheap design.  I don't know for a fact that a Pertronix doesn't
have an internal regulator, but I'll bet it doesn't.  A little bit of
advance wouldn't hurt while cranking, and once the engine is running, the
supply voltage is fairly well controlled.

Randall

Check out the new British Cars Forum:
http://www.team.net/the-local/tiki-view_forum.php?forumId=8




<Prev in Thread] Current Thread [Next in Thread>