Ran into a sensor I haven seen before.

[LD240]

A customer asked me to look at some top of (kitchen) cabinet up lighting, the old set I believe the step-down died and the last guy took it a way and never came back.
(Absolute monkey, took the fuse carrier out of a FCU and half taped the hole & worktop height)

The thing is the old set has a sensor to switch them on (which if possible they'd like to keep, replacing is a no-go as the cable is trapped) but it is unlike any I have seen before, it has a single 0.75mm core to it and that's it, my guess is it's piezo sound sensor as I can't imagine how else it's powered or how it sends a signal.

Any guesses or ideas would be a great help, the sensor means some sort of relay is required if it wanders into old tech or great expense, I'll swap the FSU to a Switched type and tell the customer that's how it'll have to be.

(although a FSU with a sensor built in would be quite a thing)

Thanks for reading Klaus.

 

[tazz]

Pictures or a make model would help

 

[LD240]

Indeed they would but the sensor itself had a good few windings of white tape around it (could be scuffed or could be a bodge), and I didn't fancy having a destructive survey while they were cooking dinner, and the control unit (step-down+relay) is of course, missing.

So I really should have posed this query the other way.

What sensors are there that will work with a single core?