how to build a simple timing gun?

[Screech]

Is it possible to build one?

How would you trigger a transitor from a spark plug lead, to flash on an Led or whatever?

 

[Russlk]

Try this circuit, no guarantee.

 

[Roff]

Good idea, Russ, it might work. The lower 1N4148 is upside down. As shown, it limits the base drive to the Darlington to 0.7v, which is not enough to turn the Darlington on. With the resistor values shown (after turning the diode around), the peak voltage at the pick-up must be greater than 400v, which may not be unreasonable.

 

[Screech]

awsome!
thanks Russlk .
I will try it

 

[Russlk]

Thanks again, Ron, I guess I must put more time into my answers.

 

[rockdoctor]

Hi Roff, I don't know if posts are forwarded after such a long time or even if you are still around. I built the device as shown (with the diode turned round) - but sadly it doesn't work. I could only get a TIP122 would this make a difference? How much wrapping around the plug wire should there be and with what? Hope you're out there.

 

[bobledoux]

A neon light might work, driven directly by the spark plug wire.

My dad did it simple: He put a flashlight in his mouth, pointed it at the timing mark. He grabbed the spark plug wire and looked for the timing mark each time he got shocked