This can be made to be just a headlight or both a headlight/taillight bike light system.
My NiteRider light was off getting fixed at the factory and I needed something for my daily commute. I have used it in a 45 minute pouring rain commute on the way in to work and it worked like a champ.
Step 1: Parts
18 Leds (white 25000mcd)
Reflector w/ bracket
9v snap connector
Old Bay Tin
PNP Transistor (3906)
NPN Transistor (2222)
2 x molex KK connectors
Step 2: Solder the Lights In
I am using a 8 AA Battery holder, so thats 12v.
So I soldered 3 white Leds in series to drop the voltage to each led to 4v and be plenty bright.
Make 6 rows of these.
I started on the right side of the breadboard so I could use the left to mount to the reflector bracket.
Step 3: Switch
Drill 3 holes, 2 for the mount and 1 for the switch.
Step 4: Done for Now
I secured the battery pack to my rear rack with a piece of velcro.
You are done if you just want to make a headlight.
I'd say its brighter than my niterider light a 10w but not as bright as it at 15w.
And I gotta be honest, this is a good point to stop. For $6 you can buy a nice Red LED VistaLite blinky. Might as well use one of those, and use this light for the headlight..
Step 5: Blinky
If you want a blinky light, make the blinking light circuit from Bill Bowden's web site: http://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm describes. And I made in this instructable : https://www.instructables.com/id/ED42Y0XZ6BEP286Y2B?ALLSTEPS
Step 6: Rear Leds
Solder your rear LEDs in parralel. Its easy if you just bend the leads on top of each other like so. Make two different arrays of LEDs for the blinking...
Step 7: Mark and Drill Holes
mark and drill the holes in the bottom of your Old Bay tin to mount the rear LEDs
Step 8: Switch
put a switch on the lid of the cannister to turn the rear light on and off, Run a 330 Ohm resistor in line with this to drop the voltage down for the blinky light circuit.
Step 9: Strap
Drill a hole in the cannister to attach the velcro strap to. Use this to secure it to your seat or rear rack.
Step 10: Wire It Up, Cram It In
You are really almost done. Hook the power up, wire it in.
I knew I would not be using the blinky light all the time, so I used 9v snap connectors so I would be able to remove the blinky light, and run it just as a headlight..
Step 11: You Are Done
You could coat the inside of the Old Bay tin with paint or tape so none of the wires short out, I just taped up the 555 ic circuit and called it good.