Electronics, how hard can it be? Not very hard it seems.
First I will try to describe the project with words: The idea is that when I open the drawer, the lights will go on. A switch – simple. Well, no. I don’t have the luxury of switches, because of 2 reasons. I don’t have a switch that fits and I don’t know exactly where the drawer is going to end up when I close it. This is beacuse the drawer is not solid but rather made of fabric with a plastic core
The solution I wanted to build was based on a MOSFET and a phototransistor. the photo transistor will then be used to turn the MOSFET on and off.
I start by building a simple IR LED. The Ledberg lamp is running on 12V so that’s what I’m having available. I want to have 20mA through the IR LED so that gives me a resistor value of 600. the E12 has a value of 560 – close enough. a little less current, but that is OK for this purpose.
This is the LED circuit. Plain and simple.