E-Gads. I guess I get to jump in.
Low level thingummy bits just mentioned.
Most Racing Switches have extra terminals, other than the big gnarly
ones that are obvious. Racing organizations require a KILL switch. This is
to kill the engine of a crashed/burning car that may have cockpit access
problems. To kill an engine the battery AND generating system must be
isolated from the ignition circuit. This is done by (1) disconnecting the
hot feed from the electrical system. (big gnarly terminals) (2)
disconnecting the ignition circuit from the coil and grounding the coil feed
(3) shunting the generating circuit to ground through a resistive load.
For street use, all this fun stuff is not really necessary. Most of
us want a disable switch, not a kill switch. So long as you do not cut the
battery out of circuit with the engine running!!!!!!!! Disconnecting the
battery with the engine running tends to make the alternator very unhappy.
Think of the battery as a damper in a spring/mass/damper system.
The battery cut off switch can be on either the hot, or ground lead.
Since this is something that is getting stuck into the car, the ground side
would be safer, as the exposed terminals will not be a shorting hazard. A
suggestion for those with radio presets, is to wire a low current fuse
around the switch. That way if someone tries to steal the car when the
switch is off, the fuse will blow.
Sits down and shuts up again.
Kelvin.
> -----Original Message-----
> From: Ajhsys@aol.com [mailto:Ajhsys@aol.com]
> Sent: Wednesday, February 09, 2000 11:31 AM
> To: kwaringa@dynsys.com; mgs@autox.team.net
> Subject: Re: Battery cut-of switch
>
>
> In a message dated 2/9/00 1:44:01 PM Eastern Standard Time,
> kwaringa@dynsys.com writes:
>
> << If you have a radio
> with presets, you will loose them when you turn the switch
> off, just like
> disconnecting the battery. The way to avoid this is to wire
> your radio
> directly to the battery (with an in-line fuse of course). >>
>
> - - - - - - - - - - - - - - - - -
>
> I have seen a batt. cutoff switch with a low level shunt that
> allows a small
> current to get thru when it is switched off. This keeps
> clocks running and
> radio presets...um...set. I can't remember where I saw it.
> Maybe Summit
> racing or even Moss. Or Whitney, or maybe Harbor
> Freight...no...Grainger?
>
> You are right Larry. I have to get back to work. BTW, the
> Russion submarine
> is still for sale on e-Bay, Your Personal Trading Community. (Only
> $1,050,000.00)
>
> Allen Hefner
> SCCA Philly Region Rally Steward
> '77 Midget
> '92 Mitsubishi Expo LRV Sport
>
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