When we use the soldering iron we should avoid breathing the smoke that is created by heating the material, especially if we do it daily or if we use a lead-based solder.
And so, in defense of his lungs, Jeremy S Cook added a fume extraction fan to his welding station. However, without proper power controls, the fan could easily drain the battery while you are not using the soldering iron. To address this, he recently upgraded his system with a passive infrared sensor (PIR) .
The PIR sensor detects movement, enabling the fan only when it sees the hands in its area, so it is no longer necessary to use manual controls.