I have seen a number of comments here that indicate that the ballast
resistor reduces the current. This is not the case. in any given series
circuit, and anything that is across a battery is in general series with the
battery, the current flow is the same in all components. The change you see
is the voltage that is dropped across each individual component. The
ballast resistor is used to drop the voltage that is supplied to the coil.
This is also the reason that those real nice bullet splices get hot, then
dirty, and then the lights quit working. As they age the resistance in the
connection builds forming a resistor (think ballast) which drops the voltage
available the lamp in question, which makes it dimmer. The catch-22 here is
that dropping the voltage generates heat which makes the connection worse,
which causes the resistance to go up........
Steve
tr6@kc4sw.com
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net]On
Behalf Of Mark Anderton
Sent: Monday, June 30, 2003 3:51 PM
To: TR6 Triumph; 6pack@autox.team.net
Subject: Re: Ballast resistor question
The ballast resistor reduces the amount of current flowing through the
points and coil. Advantages include less pitting of the points and cooler
coil operation. If you check the voltage drop across the coil when the
points are closed, you will get a reading of about 6 volts, which means the
other six is being dropped across the ballast resistor. In some cars, the
resistor is a special wire, in others, it's a ceramic rectangle that has
connections on each end for supply (ignition) and coil. You can buy this
type of resistor at most auto parts stores. Most ignition systems with
ballast resistors have a system for bypassing the resistor when the starter
motor is cranking, providing 12 V to the coil to start.
Mark Anderton
72 TR6
Virginia Beach
http://members.cox.net/andertonm/car_stuff.html
----- Original Message -----
From: "TR6 Triumph" <tr6_1969@hotmail.com>
To: <6pack@autox.team.net>
Sent: Monday, June 30, 2003 3:54 PM
Subject: Ballast resistor question
> Hi list!
>
> The posting speaking about the bad points possibly caused by lack of a
> ballast resistor forces me to ask the questions: what is a ballast
resistor
> and what exactly does it do in the ignition circuitry. Further, why do
some
> systems have them and others do not? On the TR6 was it the earlier ones
> that didn't have them but the later ones did? What does the ballast
> resistor look like and where is it? Thank you.
>
> Sincerely,
> Dave Herbert
> 1969 TR6 and nothing else
>
> _________________________________________________________________
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