ajw62428

I really want to try this kill switch setup does anyone have the actual part numbers and/or list of parts? Where can I find these parts? I tried online but there are too many switches/relays to choose from. Thanks

mt_goat

You can find 30A relays at Radio Shack, don't know about magnetic reed switches though.

midiwall

Try DigiKey.

http://www.digikey.com/scripts/DkSea...S&Cat=34931610

http://www.digikey.com/scripts/DkSea...141302&Site=US

I'm not sure of the specific circuit you're looking at, but my guess would be a relay in the starter circuit activated by a hidden reed switch? if so, then you'll need a _latching_ relay (one that will stick "on" when pulsed by 12v). That would be something like this:

http://www.digikey.com/scripts/DkSea...693488&Site=US

Note that the current rating is only 1A (it's all that Digikey stocks for 12v latching), so you'll have to use that to drive something larger than you can pass an ignition wire through.

mt_goat

Hey Mark, on those latching relays what makes them turn off after they get latched on?

mt_goat

Never mind Mark, I found the answer here: http://zone.ni.com/devzone/conceptd....256F1C006B7124

midiwall

yeup. cool huh?

The circuit that ajw62428 is looking to do is "classic", but it can be a bit tricky to wrap your head around.

Also... there's a failure point here with the reed switch and the latcher. It's one thing to do something like this in a street machine, but bouncing around off-road can be hard on something like a latching relay. If you pop off of a steep drop and hit hard, the latcher can pop open, and poof... there's goes your ignition. If the latcher happened to _break_, then you're really sunk until you bypass the whole thing.

The _right_ way to do something like this would be to go solid-state and use something like a TRIAC or SCR to switch the ignition load. It would elminate the mechanics of the latching relay and the layered relay aspect required to handle the load.

On THAT point... I know I've seen high current latchers, but they're gonna be expensive. ajw62428, you may want to look into the surplus market - know any ham radio operators? Those guys always have keen sources for stuff like this.

Here're a few to get you thinking.

mt_goat

Yep, I have something I want to do if I can find a 2-coil latching relay.