Need help with switch and high current


I'm modifying my R6 to make a dedicated track bike, so I'm getting rid of all electric accessories. I also went completely keyless, so I removed the ignition module and replaced it with a simple switch.

I'm all good with the wiring on the bike, but I want to make a nice push-button switch for it rather than a simple flip switch.

I found this schematic on the web: http:///kyhemdy and tested it on a breadboard with 9V. It works like a charm. However, I'm not sure how it will behave on the motorcycle when that starter motor will draw much current. I fear all my components will just burn up...

So I kind of added a MOSFET to the circuit, trying to separate high current from the rest of the circuit. Considering I have a MOSFET with high enough tolerances (voltage and amps), would it work the way I put it in the schematic? Or do I still risk frying the rest of my circuit?

Here's my schema:

Battery is 12V, and main fuse the the positive is 50 A!! That's huge, so that's why I have some concern.

I have basics understanding of electronics, but I'm just a beginner...

Any help would be greatly appreciated.


by frzburn
September 16, 2013

You might like to have a careful look at this, a modification to your circuit:

Be careful with this idea.

I'm not sure having a momentary-push to turn on and a push-and-hold-for-several-seconds to turn off button scheme is the best idea ...

There's a lot to be said for old fashioned clunky key switches and a wrist strap pulled kill switch.


by signality
September 17, 2013

That's very helpful, thanks!

Just for clarification... The stock kill switch is still there and functional. I omitted it in my schematic since I don't have to worry about it for this application. It doesn't turn off the circuit, but cut power to the fuel pump and starter motor.

Thank you for your time working on this, it's really appreciated!

by frzburn
September 17, 2013

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