spridgets
[Top] [All Lists]

Re: calling electrical engineers

To: spridgets@autox.team.net
Subject: Re: calling electrical engineers
From: Chris M West <chris_west@juno.com>
Date: Sun, 9 Jul 2006 22:13:24 -0400
Geoff Branch asked:
What will happen if I use a 6V ignition coil in a 12V system?

Well, you'll get a very hot spark for a very short time.  The 6V coil
will draw more current and at the very least the points will burn
prematurely, at best.  Worst case the coil will overheat and fail,
possibly spewing the cooling oil contained within it all over the engine
compartment.  BTW you could use the 6V coil with a "ballast" resistor in
the circuit, but why not use the correct voltage coil?  Ballasted coils
were very common on US cars with points, as well as some Jap stuff (sorry
Frank!)  A relay bypassed the resistor when cranking, sending 12V to the
(nominal) 9V coil and producing a hotter spark for start up.  In "run"
mode the resistor dropped the system 12V to 9V to avoid the
aforementioned burned points etc.

Chris

AN5L35578




<Prev in Thread] Current Thread [Next in Thread>
  • Re: calling electrical engineers, Chris M West <=