This is a how-to for a set of lights for a recumbent trike. The system consists of 3 headlights and 3 taillights, all running off a central power block. It is capable of being run off a variety of batteries (as long as there are at least 7.2 volts) as well as bike generators (12 volt 6 watt type). I decided to build this system because it is much more powerful than typical bike lights and much cheaper than the high-end systems.
Check out the web site:
Step 1: Parts List
Here is the grand list of parts!
-Clear bullet lights
-Red bullet lights
-Large red bullet light with fins
-Large white bullet-style bike light
-Red LEDs - Digikey part 67-2061-ND
-White LED Resistors
-Red LED Resistors - Digikey part TWW3J8R2-ND
-Two battery holders - Digikey part BH24AAW-ND
-Waterproof project box - Digikey part HM954-ND
-Power switch - Digikey part CKN1019-ND
-Five volt regulator - Digikey part 296-8157-5-ND
-Bridge rectifier - Digikey part VS-KBPC108-ND
-Circuit board - Digikey part 3405K-ND
-Epoxy; caulk or hot glue would probably work fine as well
Note: Not all parts are pictured.
Step 2: Disassemble and Remove Innards From Lamps
First disassemble all the lamps and remove the existing light bulbs and wires.
Step 3: Solder Wires to LEDs
You'll want to solder some wires the the LEDs. The white LEDs have solder pads built into the heatsink, but the red LEDs just have straight wires coming out of the acrylic. You may want to test the LEDs after soldering to make sure they're not heat-damaged. There is a photo of me testing a recently soldered LED.
Step 4: Mount Lights in Lamp Enclosures
This step really isn't that difficult. You thread the wire through the hole in the back of the lamp, put a dab of epoxy/hot glue/caulk on there, and let it dry. The wires holding the LEDs are plenty enough to keep them in place, and the epoxy waterproofs the entry point of the wires. Let the glue dry with the lamps held in place by a clamp so the glue doesn't drip down the metal casing. After the glue has fully dried, you can fiddle with bending the wires a bit to make the lights point in the direction you want.
Step 5: Build Power Electronics
Assemble the power electronics as shown in the schematic diagram. You'll need to get everything to fit onto a 2" by 2" board or it won't fit in the project box (even then it's a little tight). Pictured is the almost-completed circuit. It lacks the white LED resistors. The heatsink for the voltage regulator is probably optional, but I had some sitting around and thought I'd play it safe.
Step 6: Add Insulators
Now you'll need to add insulators so that the circuit board and battery casings don't contact the metal project box. This step is not necessary if you use a plastic box.
Step 7: Add Power Switch
You'll need to add the power switch to the project box. A 1/4" drill bit is the perfect size.
Step 8: Put It Together
Finally, solder on some wires to carry the power out of the box, drill a couple more 1/4" holes for the wires, solder the battery holders to the circuit, and cram it all into the box! The wires coming out of the box carry the correct voltage for the LEDs. I color coded the wires: red wire for red LEDs, green wire for white LEDs (pictured coiled inside the box, not coming out of the box, I had not yet completed the white lamps), and black wire for ground.
Step 9: Carrying Case
You'll need a bag on the trike (or bike) to carry the electronics box. You'll also need to run wire to all the locations where you want lamps. I used 20 guage lamp wire held in place with black zip ties to match the color of the trike frame.
Step 10: Mount the Lamps
You'll need to mount the lamps. This will vary for different trikes, but I included some pictures to give the general idea. I used crimp connectors to connect the lights to the wires. Eventually I am going to cover the crimps in heat-shrink plastic.
Step 11: The End
That is it. Now all that remains is to ride! These lights are extremely bright, so bright that you may want to disconnect some of them when riding on a trail, as they could annoy other trail users. The project as described here will accept any battery or combination of batteries as long as they are at least 7.2 volts, and it will also accept bike generators of the 12 volt 6 watt variety. The parts all fit in the project box, but it is a tight fit; this keeps the parts from rattling around while riding. Enjoy!