Bike Forums - View Single Post - LEDs to replace bulbs in a bottle generator system

12-04-07 | 09:58 AM

#6

n4zou

Scott

Joined: Jun 2006

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Quote:

Originally Posted by rhm

Yes, but what about these?
http://superbrightleds.com/other_bulbs.htm

PR2-WHP 1 Watt Flashlight Bulb

Flange base flashlight bulb with 1 Watt High Power White LED
Wide voltage range will operate from 2.8 to 12VDC , 80~550ma
35 lumen, 30 degree beam pattern, bottom contact must be connected to positive

Does anyone know if this will fit in a bicycle headlamp designed for a 6 v halogen bayonet bulb?

OR:

Miniature 10mm screw base bulb with 1 Watt High Power White LED
Wide voltage range will operate from 2.8 to 12VDC , 80~550ma,
35 lumen, 30 degree beam pattern, bottom contact must be connected to positive

Is this (10 mm) the same socket size as dynamo lamps use? If so, couldn't you wire it so the positive current alternates between the head light and the tail light? If so, you wouldn't even need a bridge rectifier....

For comparison's sake, does anyone know how much light (in lumens) a typical bottle dynamo light emits?

These will work but you will need a bridge rectifier circuit between the dynamo and that light. A bicycle dynamo produces AC current and these LED replacement lights need DC current. Maximum current for a typical dynamo is 500mA and as these are rated for a maximum of 550mA you should be ok. These lights are only rated at 35 Lumens. New LED's from Cree and Luxeon are rated at 80 Lumens in the 350mA current range and can be driven with 500mA with only a slight decrease in life.

Not all dynamo lights produce the same light output. There are cheap dynamo lights that are not bright at all and burn for only a few hours like flashlight bulbs. There are also expensive halogen dynamo bulbs that last many hours with exceptional beam patterns producing lots of usable light.

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