re: hornet wire wanted

[<mail@xxxxxxxxxxxx>]

DUH!!! Joe, Pete, I accidentally typed the EXACT OPPOSITE of what I
meant!! Both are correct. The ballast resistor doesn't usually have a
bypass wire, it IS the bypass, working as Joe explains -- it passes 12V
when cold, increases resistance to the stated value and only passing 6V
as it heats up, which usually just takes a few seconds (I'd guess 15-30?
Never saw any specs or tested one.). Outside temperature affects
heating, so on colder days the ignition will get more voltage for a
slightly longer period. I'm pretty sure the resistance wire works the
same way. Otherwise a relay and timer would be needed. This heat/cool
cycle is what causes them (resistor or wire) to eventually fail. That's
why I like a ballast resistor better -- easier to check and replace. The
resistance wire usually lasts 20 or so years and is easier for the
manufacturer to install. One less thing on the firewall also. 

Joe Fulton wrote:----------------

Uh, I may be all wet here, but I seem to remember from general physics
class and electricity and magnetism classes that resistance (like in a
wire) increases almost linearly with temperature). Therefore a
resistance wire (or ballast resistor) will pass a decreasing amount of
current as it heats up, ie. voltage will drop.

Joe Fulton
Salinas, CA

Pete Savage wrote:----------------
Frank,

I hate to disagree with you, but placing a resistor in-line any
electrical circuit will always reduce voltage, whether the resistor is
hot or cold!

The reason you need a voltage reduction to the coil in historical.  When
cars had 6 volt systems coils were designed for 6 volts.  With the
advent of 12 volt car electrical systems there was a need to reduce the
voltage to the coil from 12 to 6 volts and as such ballast resistors and
resistor wires were invented.

When a car is cold and starts the ballast resistor is bypassed and a
full 12 volts are made available to the coil to aid in a hotter initial
spark for starting.

later
Peter


----- Original Message ----- From: <mail@xxxxxxxxxxxx>
To: <mail@xxxxxxxxxxxx>
Sent: Tuesday, November 08, 2005 4:49 AM
Subject: re: hornet wire wanted


Eddie, www.amcgremlin.com blanks out the e-mail address in messages, so
please forward this to Hornetracr!


The wire he needs is the resistance wire. It's pretty generic -- it can
be found on the electrical isle of any auto parts store. It will be
marked "resistance wire" and may or may not have the ohms, and may not
be pink. An alternative is to use a ballast resistor. They range from
1.1K-1.5K ohms. Value shouldn't make much difference as long as it's in
that range. All resistance wires/ballast resistors are designed to cut
voltage to 6V until they warm up, then they will pass 12V. The actual
resistance just means it will warm a little faster or slower (1.1K will
warm a little faster than 1.5K). We're only talking seconds difference,
so it shouldn't make a difference in the exact value, but I bet 1.35K is
a common value.

Frank Swygert

MSgt Frank Swygert
436 CES/CECM (MilCon)
302-677-6436, Cell 302-363-0530