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Old 09-17-2018, 01:48 AM   #12
Dannyx's Avatar
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,642
Talking Re: Modifying laptop adapter for 12v

Here's some more pics of this supply. It's pretty packed in there so I took some close-ups of the output stage as well. That definitely looks like a current sense resistor in that piece of heatshrink tube there, so there is some current sensing going on too.

The one going to VCC is that 24kOhm (2432 resistor). I botched a thru-hole 20k one in its place instead and it works: the voltage dropped to 13,5v, so that's the one....I was lucky to get it just about right from the first time, though I think I'll go slightly higher at around 21-22k, since 13.5 is just slightly too low for charging a lead-acid battery, especially with that diode I'm trying to use which will insert some Vdrop of its own.....
Attached Images
File Type: jpg 20180917_091803.jpg (482.0 KB, 12 views)
File Type: jpg 20180917_091832.jpg (453.5 KB, 6 views)
File Type: jpg 20180917_091851.jpg (439.4 KB, 6 views)
File Type: jpg 20180917_091925.jpg (596.7 KB, 7 views)
File Type: jpg 20180917_092424.jpg (682.1 KB, 7 views)

Last edited by Dannyx; 09-17-2018 at 02:11 AM..
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