well i have a very small batch of p621 opticouplers that exhibit unusual characteristics perhaps it normal for these couples perhaps not. Is anyone else using couplers and do they exhibit the same characteristics for them …???
i was building a simple arduino circuit to drive some LED solar lighting project, that suppose to light up a local monument. and to save on power slowly dim the lights as time progressed . but anyways these opticouples are working as a simple touch sensitivity circuit - if what ever metal you have the single sensor wire connected to is under 1 square foot in surface area it will not drive the circuit . and also curiously it is also light sensitive. but it seams only to natural light . if I place in under strong led light nothing happen place it in a window the circuit closes and light comes on.
if these opticoplers work normally like this then it is fairly easy to build touch sensitive switches and alarms, plus other environmental switches if any one is curious…