TATTLE TAPE DETECTION

[Hyteck]

Hi,

How do tattle tape detection systems work? I need to be able to detect whether one and if more than one tapes/stips are within a small working area ? - any idea's.
The stips are about 140mm long and broken up into 5 sperate sections and are magnetised to de-activate them and - demagnetized to activate? - So I need to be able to detect the strips when in the Unmagnetized state!

any idea's would be most appreciated!

 

[47gandalf]

If the strips can be detected optically, I'd try using both a magnetic detector and an optical detector with their two outputs correlated.

In other words, the optical section would tell you that there is a tape strip present, and the absence of output from the magnetic detector would tell you that the strip (or strip section) is demagnetized.