I constructed a 12V LED ring light with the right dimensions to mount it on the lower side of the drill stand. This instructable will show you the details.
- 12 white 3mm LEDs
- 4 SMD 100ohm resistors
- circuit board
- some wires
- 12V power supply
Step 1: Laying Out the Circuit
Using 3mm white LEDs running at around 20mA each with a voltage drop of about 3.2V per LED gives you the value for the current limiting resistor as R=(12V-3*3.2V)/20mA or approximately 100ohm. I had to use SMD resistors because of the limited space on the circuit board, while I chose standard 3mm through-the-hole LEDs because I happen to have a large stock of these.
Step 2: Etching and Soldering
After cutting out the circular part of the circuit board using a fretsaw I first tin-plated all copper traces. Then I mounted the four SMD resistors and finally the twelve 3mm LEDs.
Step 3: Mounting the LED Light
Finally I could attach the lights to the drill stand and enjoy the comfort of an illuminated drill spot.