Mosaic
Well-Known Member
Hi All:
I am posting this cuz I wanted a cheap trickle charger. (like $3 -$5) for a new charger, or free as everybody seems to have these laying around.
In this case I am using a Nokia AC 3u travel charger as sold on Ebay /Amazon etc...made in China.
Changing a single resistor from abt 2.7K to 1.7K did the job. The output stage of the charger is limited by a 16V smoothing cap. You can always change to a 25V cap if u need 15V out or so. If you want a variable voltage supply I'd slap in a 1.5K in series with a 1K pot. This should range from around 7V thru 15V.
DIY risk..as this is a 120VAC device...so screwing up the soldering or mis installing the board (hard to do as the case is slotted) can cause poof!
Have a look at the pic for details. BTW the case screws are tripoint..so u need a small flat blade that is a close fit or else you can't open it.
I am posting this cuz I wanted a cheap trickle charger. (like $3 -$5) for a new charger, or free as everybody seems to have these laying around.
In this case I am using a Nokia AC 3u travel charger as sold on Ebay /Amazon etc...made in China.
Changing a single resistor from abt 2.7K to 1.7K did the job. The output stage of the charger is limited by a 16V smoothing cap. You can always change to a 25V cap if u need 15V out or so. If you want a variable voltage supply I'd slap in a 1.5K in series with a 1K pot. This should range from around 7V thru 15V.
DIY risk..as this is a 120VAC device...so screwing up the soldering or mis installing the board (hard to do as the case is slotted) can cause poof!
Have a look at the pic for details. BTW the case screws are tripoint..so u need a small flat blade that is a close fit or else you can't open it.