I bought some LED sticks (similar to this one) awhile back with the intention to make them into desk lamps or reading lamps, since LED lighting was still very expensive back then, but the project never really took off. I did wire up two of the LED sticks cruelly and secured them with screws for the kids. They kind of worked but looked ugly and eventually I took them off. For myself, I needed a small, portable work lamp for doing my projects, so I re-used one of the sticks, and made it into something even more ugly looking than before, but at least it is more functional.
The Frankenstein LED work lamp marries parts from three of my favourite things: Bicycles, Power Tools, and Photography gear.
The base of the lamp is the lens barrel from either a Vivitar or Soligor 200mm f3.5 lens with M42 mount. This base (lens barrel) is mounted on an M42 to E-Mount adapter, which is screwed onto the base plate, made of 1/8″ thick aluminium. The aluminium plate is screwed onto the base of another part, that I took from a broken DeWalt jigsaw. A suspension spring from a kiddie bike is attached to the DeWalt part, and is used to secure the LED stick. A picture below should make it more clear.
Originally, I had some fancy ideas that I want to use on the LED lamp. For one thing, I wanted to put an Arduino nano inside with a variable power supply to control the brightness of the LEDs, and a tiny, 1 inch OLED to show the voltage/current/power usage. But I just don’t have the time for that, and it’s kind of useless anyway so it’s what it looks now. I might still try it later though. I think it will be cool, in a useless way 🙂
I don’t remember what the power rating of the LED stick is, but it runs on 12 volts, so the LEDs are most likely divided into groups with 4 LEDs in each group that’s wired in series, since most LEDs have typical forward voltage supply of about 3 volts . The LED strip has 30 LEDs and I figure each one draws about 15mA, and that would be about 450 mA for the entire stick. I used an old style 500 mA transformer and it worked for a little while, but the maximum current draw from the LED stick made it work at full capacity and pretty soon destroyed it. Right now I used a switched type power adapter that provides 1.5 Amp of current so that it won’t have to work at maximum load. I think the LED stick has built-in current limiters, otherwise the LEDs would have been burnt out by now.
One nice feature of the work lamp, is that it’s height is adjustable through the focusing ring. Not a big range, but hey, it’s a bonus :). Another good thing about it is that it’s 18 inches long, which provides illumination for a very wide area.
In case you are going to say this post is not lens related, but look at that lens barrel, eh?