Not sure if this is a blogpost or just a cautionary tale, but anyway DON'T BUY THIS SOLDERING EXTRACTOR LAMP! With that said... here is my tale. I wanted a small solder extractor and I saw these extractors built into a angled lamp, running off USB power they peaked my interest and I handed over £40 for one online. On arrival I unpacked it and put it into use, it was OK, not the strongest extractor by any standards but my solder area is under a Velux window and it has enough of a draw to move the solder fumes away from me and out of the window. On the cable to the USB plug it had a controller with 4 momentary press buttons on it, you could switch between 3 "colours" of LED lamp, all shades of white, one a "cool white" one "warm white" and one that was a combination of both. You could ramp up and down the light level in steps, but I always had them on full power. It also had a fan control to set the "power", this was always on full and you could tell that when the fan was on it was starved of current a little as the light would dim. If you turned the lamp off the fan would speed up!
Anyway, the control system lasted about 2 weeks! I came to it one day and it had failed, I couldn't turn the lamp on and although I could run the fan I couldn't adjust it and randomly an LED in the controller was stuck on. I did really like it though, I liked being able to clamp it to my workbench and drag the lamp and extractor really close to work so I decided to try and fix it.
Pulling the controller apart and a bit of probing with a multi meter I realised that basically the control system made or broke the negative power rail and when the microcontroller was operational was probably PWM'ing the power to each circuit. I realised that I could quite simply wire in a switch for the fan and for the two LED light rings. I wasn't bothered about having both the LED lamps on at the same time. So a quick bit of soldering and then a small 3D print and I have a simple but working "controller" back on the lamp. I reattached the USB cable as I have lots of USB outlets and also it's nice that it can run off a battery pack if and when we get back to maker events or rocketry in fields!