Ignition Kill box.

[jimr1]

Hi guys, I need to build an ignition kill box for a friends drag bike.
I have an OK understanding of electronics, i.e. what I need to be able to achieve my goal, but I don't understand the nuances.
On the ECU of the bike is a +B pin/lead that goes to the coils, basically a signal pin, now what I plan to do is make a monostable 555 with a p-channel mosfet to interrupt this signal from between 50-100ms.
Eventually, in the future, when he gets an air solenoid for the gear shift, I will be modding this to cut the ignition for 15-20ms, then activate the solenoid (5-10ms for it to shift) then leave it another 10-20ms before putting the ignition back on, I'll want all these latencies to be adjustable.
Now the rather embarrassing question I have is what values of components to I need to enable this 50-100ms signal from the monostable. I would LOVE to have a led readout of the time, but this can come in the future when I'm a bit more familiar with what I am doing.
I never was any good at figuring out freq/pulse times on 555's, mental block I guess.
So, what I need to know is what cap/potentiometer do I need?
Regards
Jim.

 

[gramo]

You could do all that and more with a micro-controller, but it seems a little out of your scope atm.

Have you searched the web (google) for info on the 555, there are tons of projects and examples of setting up different signals

 

[jimr1]

I never was any good at figuring out freq/pulse times on 555's, mental block I guess.
So, what I need to know is what cap/potentiometer do I need?
Regards
Jim.

That's why...

 

[gramo]

Just googled "555 timer example" 497,000 hits

 

[jimr1]

Ahhh, I see, this is one of those "J00 must google" sites, not one of those "sure, we'll help you out and explain things to you so you can understand" sites.
Cheers for all your help.

 

[gramo]

This one looked rather interesting

http://www.williamson-labs.com/555-tutorial.htm

 

[gramo]

Ahhh, I see, this is one of those "J00 must google" sites, not one of those "sure, we'll help you out and explain things to you so you can understand" sites.
Cheers for all your help.

I'm not going to build the application for you, perhaps someone else would? I dunno.

You have posted less than 10 times on the forum, and have not really contributed toward anything, except how easily you do not apply your self to researching basic fundamentals

So, put simply, don’t come here too be spoon fed. At least have a go first

 

[Roff]

Gramo, some people can't do simple arithmetic.
Jim, use a 100k pot in series with a 100k resistor, and a 0.47uF capacitor.
This will give you a range of approximately 50 to 100ms.

 

[gramo]

Gramo, some people can't do simple arithmetic.

That old chestnut, well if thats you, then I'm sorry

 

[jimr1]

Sorry if I caused any strife, I'm not expecting it to get built for me, but just an explanation on how to figure out what I need to achieve my desired needs.
I am not an electronics engineer.
Once again, I apologise.

 

[icedeocampo]

the easiest kill switch would be to put a switch on one of the wires from the CDI, if one of the wires from the CDI is not connected, the bike won't start.