Intro: LED Bulb for Dewalt 18v Light
The goal here was to create a led bulb alternative for my 18v battery powered light that would draw less power and last longer for my nightly fishing trips. My first time I made a few mistakes and I'll share those at the end. Not including time and the supplies I had, this project costed about 5 dollars.
Step 1: Gather Supplies
- Hemostats (makes the job so easy)
- Soldering Iron
- Perf Board
- Appropriate Resistor
- 2-Wires about 3 inches long
Step 2: Set It Up.
Arrange the LEDs on the Perf Board in a way that they create a good light pattern. LEDs work best in evenly spaced clusters at the center. Lights that are spread too thin will not be very powerful and LEDs too close to the edge will be blocked by the shroud.
Step 3: Configure the Rows to Get Power.
The "D" in LED stands for diode. And since diodes only allow current to flow in one direction, be sure you place all the positives and negatives in separate rows. If you mess up this part, some LEDs won't work and the remaining will have too much juice flowing through them.
Step 4: Solder Them in Place.
Using the hemostats, hold the bent leads in place and solder them. I made it a point to keep all the positive leads on the outside to make it easier.
Add the resistor and wires.
Note: I'm not an expert on electronics. There are some Math equations involved here that I did reference. Other that "Google Academy", I've had no formal training on circuits. In this scenario, I tried a 220k Ohm resistor and it started to smoke. I then used a 1M Ohm resistor and achieved the light output I wanted and placed my finger on the resistor to see if it would get hot. It didn't and so there you go.
Step 5: Connect to Power.
The first time it's connected to power, it should be momentary to make sure all the connections are correct. If the lights do not come on disconnect the power immediately.
Step 6: Mount Inside Flashlight.
There are many different flashlights out there and they are fairly different except for the bulb configuration.
Find positive and negative leads and connect the wires accordingly.
I hope you've enjoyed the instructable!!! The next step will show some of my mistakes doing this the first time around.
If you noticed that I forgot something or left out a crucial detail, leave it in the comments below and I'll add it.
Note: Hobby stores sell two part resins that can be used to waterproof Perf Board lights like this one. Hot glue is a great alternative.
Step 7: Mistakes.
The first time, I made a few mistakes. I've included some pictures.
- Lights spread out too much (made the light weaker)
- LEDs too close to the edge of the light shroud (ineffecient)
- The use of super cheap LEDs (some of them didn't get very bright)