Dynamo powered LED bike lights

Step 3 Part list

- 1W power led (luxeon, SSC P4, Cree or something similar) on star PCB - it must withstand at least 500mA current.
(it looks like [http://commons.wikimedia.org/wiki/Image:2007-07-24_High-power_light_emiting_diodes_(Luxeon,_Lumiled).jpg that])

- Collimator or reflector suited for above power LED with 10 - 30 degrees beam width (10 degrees has visible light-spot in longer range; 30 deg. puts more light to the sides and is more visible for others)

- 3 (or 4 when You don't make the tail light) Shottky diodes (for example 1N5818) for rectifying (faster, lower voltage drop). the normal silicone diodes will also do.

- 13 - 15 red diodes for the tail lamp

- a base for tail light (universal PCB is very good)

- Capacitor C1 - 2200uF 4V

- Capacitors C2 and C3 470uF 63V

- Resistor R1 - 47kOhm

- 1 Longer Bolt and 2 nuts for LED mount/heatsink

- Plastic tubing for the casing

- some casing for tail light (I used some clear plastic rail in which integrated circuits are transported)

- some length of 2 wire cable for connecting dynamo, rectifier, head and tail light

Comments

[kmossman]

(removed by author or community request)

[kptBurek]

Shottky diodes have usually lower voltage drop than german diodes. I suggested using them because of that, not because of their "speed".

[StuNutt]

You mean Germanium diodes (they are made in many countries LOL!), but you are right otherwise.

[kmossman]

(removed by author or community request)

[kptBurek]

Diodes are current driven and for supplied current they keep the voltage according to their characteristic. When the white power led gets its 500mA of current, then the voltage on it is circa 3.5V and that is why the 4V cap is enough. When You disconnect the led then You're right - 4V can be too little...