Introduction: Bike Light 2011

Just another bike light! Generator Light

This one is encapsolated in Epoxy....  I'll update this Instructable on how well it functions... and with Phase 2 following soon.

Dynamo Hub! There are several to choose from. This is a midrange model Shimano DH 3N71. What's great is they're all 6Volt 3Watt.


Step 1: Parts

Need to Bridge the Generator HUB AC power to DC using diodes... this is covered in on my previous light project as well as these geniuses:

https://www.instructables.com/id/Bullnose-LED-Bike-Light-and-Dynamo-USB-Charger/#step1


 There are quite a few circuits and great LED tutorials on Instructables. Just check out some resources to get your bearings.

LED for beginners: www.instructables.com/id/LEDs-for-Beginners/
try out different circuits... blinking, back light, combinations =>
pilom.com/BicycleElectronics/DynamoCircuits.htm
As the front wheel turns it creates alternating current (AC) power. The 'bridge' is a rectifier that converts the AC dynamo power to DC power. The bridge is made up of qty(4) 1N5818 diodes.

Parts:
qty(4) 1N5818 Diodes  
Star Board LED , Warm White 3000K 3.8W 1000mA, $4.73
Lens , $2.25
Epoxy Mold , from TAP plastics, $11.95
Heat transfer paste from Radio Shack ~$6.

Step 2: Weld the Medicine Bottle Mold

So I started with a medicine bottle to create a mold for the light.

I used a propane torch to heat up a bicycle handle bar and form a medicine bottle to the bar.

Then wire the parts, load them into the medicine bottle, and pour in the 2-part epoxy.

Step 3: 2nd Generation RGB

I decided to try something a little different here....

I used a full color RGB LED
Kingbright LED High Power (>0.5 Watts)

So I added switches to get the Blue, RED, and Green to go well Blue, Red or Green and then light up all three to get white....

the only trick was You have to put a resistor in front of the RED when you power all three LEDs so that when you wire everything in parallel, the RED LED does not become the path of least resistant and absorb all the power.  A 20ohm resistor seemed to do the trick.

After throwing my 'switches' so everything is in parallel I got a 1.8 voltage drop across the red LED, 0.8v across the resistor.  So it came out to be 2.7 volts across the two lonely Green and Blue LEDs to make a pretty much White front light.

Comments

author
Akin Yildiz (author)2015-10-25

can this be "hacked" and mounted on the bicycle tire, maybe 2 of them in parallel to get +1A output.? its only $3

http://www.ebay.com/itm/Hand-Crank-Generator-Dynam...

Screenshot 2015-10-25 at 10.14.59 PM.png
author
knihovna123 (author)2014-02-05

hi,

I have few questions:

  1. I have seen this tutorial and it looks quite same. What is the difference between using 1W and 3.8W diode? You have no capacitors in your plan, but it change nothing while talking about W, right?
  2. Is it possible in your first tutorial to not use baterries, but still use it as a device charger? Will it be ok for device to get current which is not still?

Thanks a lot

author
Dr. Pepper (author)2011-02-02

Awesome!

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Bio: just have to figure out how all these things go together....
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