Author Topic: Making a mobile device charger to work with your hub dynamo, part 2  (Read 8802 times)

Andre Jute

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    • Andre Jute
Re: Making a mobile device charger to work with your hub dynamo, part 2
« Reply #30 on: April 02, 2015, 10:04:28 PM »
I hope you get well soon.

Here are some notes for the rest of the lurkers on this thread:

Generally speaking, Chinese boards, where they have heatsinks at all, come on heatsinks vary carefully calculated to absolutely the minimum spec, with all calculations rounded down. The minimum spec is for free air out to all horizons. If you put the board in a bottle like Mickeg does, you will need more heat sinking.

A really good heatsink can be made from a piece of aluminium angle or U profile which then also provides weather protection for boards mounted under it, and a mounting for instruments above it.

A good current draw for a longrange tourer who depends on his equipment for his security is half or even 40% of a Chinese rating...

Caps you add should be rated at 35V to catch spikes produced by the hub dynamo and have a ramping margin.

mickeg

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Re: Making a mobile device charger to work with your hub dynamo, part 2
« Reply #31 on: June 23, 2015, 12:14:59 AM »
UPDATE:

After spending too many hours soldering and designing and ordering parts and testing different options to make a low cost USB charging circuit, I have given up tryign to make one that is reliable and works the way I want it to.  I will be buying an off the shelf USB charger or a combination USB charger and headlamp.

See:
http://www.thorncycles.co.uk/forums/index.php?topic=11153.0