I saw on here somewhere a short while ago a single chip that could be used for a touch switch application. All it required extra was a capacitor and the chip cost around $2. Anyone have any idea what it is? I can't find it on here for the life of me!
I've used them for display activation switches. The schematic is for a display control to allow either "touch on/touch off" or "touch on/timed off" (selected by jumper J1). T1 is wired to a foil-backed sign on the inside of a glass display case. T2-T3 go to the LED input of an SSR. Hand proximity to the sign starts the display.
Thanks for the tip, if I had those components kicking around I'd build it...but since I'd have to order it...I just ended up ordering the qprox unit from Digikey.
You could always make your own capacitive touch switches using a microcontroller? Not as stable as the q-touch ones, but linear sliders, and buttons are possible. You can even use LED's in this way..far better than using their 'light sensitive' qualities.