advice on building a momentary circuit

[crazymofo]

i thank you for the efforts cowboybob. i'll head on down to the electonics shop tomorrow and get what i need and give it a go! happy to try multiple ways to get the results im after. the more ways i do it the more i learn, so if theres a digital way i'm happy to spend a little more and take more time to acheive things.
also,
i note your concern for down changing. im only using the ignition kill on the up changes. and the trigger will be attached to the foot shifter via a contact switch, ive attach an image of the switch below when you pull on the lower part (silver bit) , it creates a contact inside, closing the circuit. it can only be used one way, ie. for upshifts. so when i go to upshift, the first millimeters of shifter travel takes up the slack in the gearbox. its this movement that will pull on the switch to activate the ignition kill.

 

[cowboybob]

i thank you for the efforts cowboybob. i'll head on down to the electonics shop tomorrow and get what i need and give it a go! happy to try multiple ways to get the results im after. the more ways i do it the more i learn, so if theres a digital way i'm happy to spend a little more and take more time to acheive things.
also,
i note your concern for down changing. im only using the ignition kill on the up changes. and the trigger will be attached to the foot shifter via a contact switch, ive attach an image of the switch below when you pull on the lower part (silver bit) , it creates a contact inside, closing the circuit. it can only be used one way, ie. for upshifts. so when i go to upshift, the first millimeters of shifter travel takes up the slack in the gearbox. its this movement that will pull on the switch to activate the ignition kill.

View attachment 82736

OK.

I'd suggest going with a 100k (or higher, for the R3 resistor) PC mount type pot (Radio Shack Model: 271-284, or better yet, a "cermet" type 15 turn). Resistive variability (for pulse width duration) is a plus, and don't forget to take extreme vibration into account (for pulse witdth stability).

There is a slight (11ms) delay in the initiation of the output pulse controlled by R2 and C2. That value can be altered, of course. Coupled with the switch delay that value will increase somewhat. On your prototype, you might want to consider using a pot for R2 as well.

I doubt that it will interfere with the shifting process but only you can test that.

If at all, I'd consider the digital approach only after throughly investigating the current analog method.

Just my take...