[TCML] RE: Primary tap lead routing

["S&JY" <youngs@xxxxxxxxx>]

The frustrating aspect of the primary tap lead is that routing it clockwise
to a tap point on the opposite side of the primary yields a different
primary resonant frequency than if the tap lead is routed counterclockwise
to the same tap point.  This is due to additive vs subtractive mutual
coupling of the tap lead to the primary.  This can be minimized by routing
the tap lead perpendicular to the primary through slots in the primary
support structure.

--Steve Y.

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Lau, Gary
Sent: Saturday, April 19, 2008 8:18 PM
To: 'Tesla Coil Mailing List'
Subject: RE: [TCML] First (or maybe 2nd) light on my medium-sized SG coil

I'm all for keeping tap leads and all tank circuit wiring as direct and tidy
as possible, but doing so in the name minimizing inductance to not impede
current peaks doesn't make sense to me.

Any additional inductance in tap wiring would simply be that much more
inductance in the primary circuit, so tapping slightly inward on the primary
inductor would compensate.  Additional inductance in wiring may not couple
strongly to the secondary, so it might be referred to as off-axis
inductance.  But this is not a loss and is not undesirable; it just means
that the secondary may need to be lowered slightly to compensate for a very
marginally lower coupling.  Off-axis inductors are sometimes used for fine
tuning the primary.

Unnecessarily lengthy tank circuit wiring may result in RESISTIVE losses
however, and for THAT reason should be kept as direct as possible.
Resistive losses are truly losses and cannot be compensated for.  I don't
mean to nit-pick, but it's important to keep our reasoning straight.

Regards, Gary Lau
MA, USA


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla