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Topic: Lipo Rider Pro - Bridge Rectifier Generator.. (Read 1 time) previous topic - next topic

troglodisme

I am trying to connect a Lipo Rider Pro (which will power my arduino) to a dynamo/generator. To do this I am using an old wind up torch.. the AC generator goes into a bridge rectifier (http://www.diodes.com/_files/products_inactive_data/ds21211_R5.pdf) which converts the power to DC but it gives a bit too much for what the Lipo can handle. I am measuring around 8 volts at full speed, and the Lipo can only get MAX 6.5..

I know this a nooooob question: what could I use to limit the current to the Lipo's range? 4.5 to 6.5, optimal 5v 500mA

https://digitalmeans.co.uk/shop/seeedstudio-lipo_rider_pro?keyword=no-ajax-mode

http://www.seeedstudio.com/wiki/index.php?title=Lipo_Rider_Pro#Specification

Thanks!

majenko

How about a low drop-out linear 5V voltage regulator?

Something like a 1117 ?

BillO

Or even a good 'ol LM7805.  Very easy to find and cheap.
Facts just don't care if you ignore them.

majenko


Or even a good 'ol LM7805.  Very easy to find and cheap.


Pretty high drop-out voltage on those.  For 5V you'd need a minimum of around 7½V in.  For a 1117 that would drop to just over 6v.  When hand cranking you want to get the 5V with as little effort as possible.

There are better than the 1117 but I don't know their numbers off hand.  The 1117 is as easy (if not easier) to find as the 7805 and is as cheap, if not cheaper.

troglodisme

Could I just use one of these voltage regulator in line with my dynamo and lipo rider, or I would need to build a small circuit?
I am not too sure...

thanks!

majenko

A regulator requires capacitors before and after it, and while you could "dead bug" them, it would be far better to build a small circuit.  A bit of stripboard would suffice.

BillO

Another solution might be to put 3 1N4001 diodes in series between your generator and your charger.  That would drop the voltage about 2 volts.
Facts just don't care if you ignore them.

Zapro

When your objective is to charge the LiPo from your generator, wasting powet to get things working is kind of dumb, and defeats the purpose.

Either modify your generator, or get one that outputs a lower voltage. Making extra mechanical energy just to waste it, is a silly idea.

// Per.

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