View Full Version : Contactless Dynamo for LED Bicycle wheels

10-27-2011, 10:23 AM

I am planning to make a Contactless Dynamo for my new Bicycle wheels.

Similar to this link:

If my basics are correct, the amount of current you generate is directly proportional to bicycle speed, magnet strength, coil surface area perpendicular to the field and inversely proportional to distance between magnet and coil. Am i right?

I am using high intensity LED, so would need to get max output from this setup. Please post your views, ideas on how this can be done.

Thank you.

10-27-2011, 02:12 PM
Out of curiosity, which bike do you have? I ride a Trek GF Advance.

10-27-2011, 04:10 PM
Out of curiosity, which bike do you have? I ride a Trek GF Advance.

Hi Mohit,

I have a BSA Hercules Atom 18spd. Bit Heavy, but good so far. I would like to build a cycle comp and tail lights once im done with LED bicycle wheels.

10-29-2011, 01:26 PM
High brightness LEDs are 1W upwards. They need around 350mA current at 3.7V. A dynamo wouldn't be so effective in generating this kind of power. My suggestion is either using an array of 20mA white LEDs or if HB LEDs HAVE to be used, getting a good battery pack for them. The other advantage of a battery pack is that you can use it to power your cycle computer, rear lights, GPS etc.

10-31-2011, 04:37 PM
I agree that using a battery pack gives much more power supply, but then there is the problem with contacts and wiring to the wheel. I can put the battery on the wheel, but was thinking it would be good to have the whole system self powered. My intention is to make something like the Revolights: