How I build my lightbars

I measure the inside of the steel bar (1 inch) and cut the perfboard to fit.

-Use the box cutter and cut along the closest perf line that will fit.

At this point, I would normally paint the perf board and bar to get a base coat, but my garage is about 14 degrees (F) right now and I wont use the paint near my pregnant wife, so it stays blonde for now :)

Now you figure out how they will fit on the perfboard. A 3X3 grid is just under 1" square. Leave about 1/4" between the grids for the resistor and 1/4" on the end of the perf board for mounting. For this demo, I am just going to do 2 3x3 grids to show how they tie together.

http://www.otherpower.com/otherpower_lighting_leds.html

I don’t use the voltage regulator, but feel free!

LEDs have to be wired for the right polarity. They will not function if you wire them backwards. So, the positive end of LED has to have the positive current and the negative side of the LED needs to be connected to negative. Create your 3x3 grid of LEDs so the positive all face one direction and the negatives face the other. As you add the LEDs, bend the posts down so that the negatives from the first row bend over the positives of the next. Since I am using the 4 post LEDs, I bend them into an X with the other LEDs next to them. It makes it easier to solder. Now, just solder the connections.

http://www.aaroncake.net/electronics/solder.htm

Now attach the resistor after the grid and solder it to the end of the last LED on the grid. Since the LEDS are all wired together the way they are, they will only need one resistor for the grid. If you think of the way the power flows through the circuit, it makes sense. Power comes in on connection and powers the entire grid. It connects to ground the same way.

Now you have to wire leads to hook the grid to the power supply. I use 20g wires (repurposed from cat 5e cable). The positive wire (pick your color and stick with it) connects to the positive side of the first row. The negative wire connects to the free end of the resistor. You have just wired up your first light!

Hook it up to a power source and test it. All the LEDs should light up. If you have an LED that does not light up, double check your soldering on that LED. Chances are it needs a touch up. If you checked all of the pins and it still doesn’t work, pull out that LED and replace it. Make sure it is not turned in the wrong direction when replacing it.

Now that you have the first grid of your light done, just add additional grids to the perfboard. Instead of putting leads to each individual grid, connect all the positives with one wire and all the negatives with another one. That way, when you hook up the leads, all the grids will light up with only the two wires.

Once you have all the LEDs soldered and connected, test the entire module. Leave it on the power source for a minute or two to ensure all the LEDs are working correctly and you do not have any dim LEDs.

Now seal the unit with silicone. Ensure you don’t have any bare wires or posts poking through the sealant.

Drill holes through the ends of the perf board and sandwich between two spare pieces of ABS. Use bolts to secure the modules to the bar.

Wire some heavier gauge (I use 18g) wires to run out of the steel bar and to connect to the power source.