At 12:27 +1100 7/11/97, Bob Hutton wrote:
>Not being all that electrically minded, I've been following the thread on
>all the AC/DC talk etc. and want to know a bit more about coils.
>
>Are these coils 6 or 12 volt?
>
>In my 2500 Leyland manual it says that the coil is 6 volt and there is a
>separate ballast resistor wire.
>
>Can someone tell me why it is 6 volt when it is a 12 volt system?
>
>Bob Hutton
When the car is running, the coil AND the ballast resistor are connected
across the battery (12V) and each receives about 6V. When the car is being
started, the battery drops to 6V (or thereabouts) under load, but the
ballast is switched out to compensate for the drop and the full 6V goes to
the coil to maintain a good spark.
(If all this did not happen, the spark would be worse when starting the car.)
Therefore the coil is designed to work on 6V and the ballast reduces
(halves) the voltage to the coil under all conditions except starting.
Hope this helps.
Trevor Jordan
74 TR6 CF29281U
What was wrong with magneto ignition? None of these battery problems, but
a bit hard to power the lights!
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