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RE: OT: Electronics advice needed to make a combined emergency charger
/ USB supply lead for my PDA
- Subject: RE: OT: Electronics advice needed to make a combined
emergency charger / USB supply lead for my PDA
- From: "Mark A Wright" <mawright@xxxxxxxxxxxx>
- Date: Wed, 14 Jul 2004 18:12:34 +0100
>1) Double check the continuous current your USB port can supply. In
days
>gone by it was only 300ma.
Good point, my powered hub can provide 500ma
>2) The LED needs connecting direct from the positive rail to the
negative
>rail with an appropriate resistor (all upstream of the diode). 1k will
>give a nice low current draw.
Noted thanks
>3) Battery charging circuits are usually more complex than you have to
>stop over charging etc.
I'm beginning to realise that, it all seamed so simple :-)
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