A few years ago, we have bought an IKEA Glimt hanging lamp that operates with halogen lamps. It has a "touch dim" functionality, so when a person touches the metal bar of the lamp, it dims (or when touching for a short time, it switches on/off).
After having replaced the halogen lamps with LEDs and replacing the AC/DC converter, I have noticed that my new LED dimmer has an input that when connected to an external button, it does the same.
My goal now is to build a circuit and connect it to the metal bar such that when touched, it closes the input of the dimmer (pulls down one input to ground).
I have tried a plain darlington pair (with no further components) - indeed on a test board, it is able to close the input as expected similar to what can be seen in tutorial videos on youtube (switching an LED via touch). But the problem is that the LED dimmer emits some electric signal during operation such that it triggers the base of the darlington pair itself via cross-talk, so it keeps being "touched". I have also tried a capacitance sensor (using the touch pins of an ESP32), but due to the large metal parts, there is no numeric change while touching it, it cannot be detected.
So I am a bit lost... what I do remember is that the old halogen AC/DC converter (that supported touch via a single "sense" line) only worked reliably when connecting all three lines (phase and neutral as well as ground).
Any advise/hints? Do I need to equip the darlington pair with more components? The aim again is to pull the switch input of the LED dimmer to ground when touching the lamp's metal components.