How to Make an IR Pen Light
- 1). Disassemble an existing marker or a felt tip pen to remove its core. Do this above a working surface covered with used newspapers or paper towels. If needed, use pliers to remove the marker’s tip. This is likely to cause a spurt of ink so be prepared by wearing disposable thin latex gloves.
- 2). Clean out the inside of the marker to remove any remaining ink.
- 3). Make a hole for the switch button at the bottom of the marker. Choose a spot where you will be holding your thumb since this push button will switch the infrared LED on and off. Use a power drill to make a 1/4 inch hole for the button switch.
- 4). Place the push-button switch into the hole to make a tight and secure fit. Note that a push-button switch, along with other elements needed for this project, can be bought in specialized stores such as Radio Shack.
- 5). Prepare the LED light for installing into the marker. First use fine sandpaper to lightly treat the surface of the IR LED. Then remove the bolt and its seal from the LED and then pull the stem through the holder and secure it with a rubber plug.
- 6). Use a soldering iron to solder the 8-inch length or black wire to the negative lead and the 8-inch red wire to the positive lead.
- 7). Pull both the positive and the negative wire through the marker and then screw the LED holder to the marker’s tip. Use a pair of pliers to make the holder tight and secure.
- 8). Use the soldering iron again, this time to connect the end of the black wire to the push-button. First trim an inch from the black wire, then pull it through the hole for the switch and then solder it to the switch terminal.
- 9). Place a battery into the marker’s body, trimming any excess wiring if needed. Solder the red battery wires of the battery to the red pen wires, repeating the same with the black wires.
- 10
Finish your IR pen light by closing the top with a pen cap.
Source...