Ignition lead sensor


An option to make trigger simpler - if you really need it.
This was suggested by a chap called Phil Pilgrim.

Or use 555 or just about any monostable with appropriate adjustments.



Senior Member

Yup, that's what I would (and have) used as well.

But note (for the uninitiated) that the "curly thing on the cable" is NOT an inductor (because no current can flow through its open end) but (one plate of) a low value (pF, but high voltage) capacitor (the other "plate" being the HT cable core).

IMHO, the triggering is the easy part, "slow" optical sensors probably not a major issue (it's called integrating the signal), but I'm not sure where I'd even start with the "colourimetry" (and a significant part of my career was spent designing colour TVs).

Cheers, Alan.