Recently I got a used dell laptop but the original power adapter is missing. Since the interface and power ratings seem to be pretty much same as my current dell, I thought I could be able to share the power adapter for both laptops, but I was wrong…
With the power adapter plugged, the laptop can be turned on, but I immediately noticed there are something on the BIOS screen saying that the adapter can not be identified, and the battery will not charge (the picture is from internet but it has almost identical information):
So, that means there is something other than just power being transferred to the laptop. What is that? This really brings up my curiosity. Before cutting the cord and counting wires, I did a search, and internet will never fail you. This is what I got:
http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed
The post was created 5 years ago and I’m not sure if things have changed, but it worth a shot. So, a chip with OneWire protocol! Funny thing is, I’m currently working on a small wireless sensor network project which requires communicate with a temperature sensor called DS18B20:
And it’s using exactly the same OneWire protocol!
By simply tapping a digital analyzer I should be able to see what’s communicating between two sides, but I don’t have one. So, it’s time to write some code and hook up a uC to see what I can read out from the power adapter.
To be continued…
My Not-So-Boring Life 
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Apple was doing this and now Dell … whos next .. if i cant use a non genuine charger to help me, rescue me … Its not worth buying from them anymore
Recently I got a used dell laptop but the original power adapter is missing. Since the interface and power ratings seem to be pretty much same … dlaptopsd.wordpress.com
Tons of them are available at ebay for a cheap price
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Got my Latitude D 520 from UAS surplus. Tried five PSU’s. Only two of them did charge the battery. Now one year later one PSU sometimes working ok, sometimes not. Never buy Dell
Awesome!
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Ok you rocket scientist how about this idea? Since you are emulating the Maxim Chip using a
MP why not use your laptop to emulate the chip output then pipe it into the AC Adapter
Jack that plugs into your laptop? Recursion always puzzled me? So, when you first plug the Non-Dell AC Adapter into the laptop it will boot but at low performance levels and no battery charging.
Then, you plug in the USB cable into your computer and to the Gizmo you made using an old
Dell 7.4mm Barrel Connector Power Jack wired to a 7.4mm Dell Plug and the Device Driver
loads the program that send the information from the laptop to the Gizmo and then through the
center signal pin__back to where? Back to the laptop where the stupid machine doesn’t know
that it is generating the signal that will fool the computer into charging the battery and not slowing down the CPU. With that said I was wondering if this makes any sense?
Was this. Ever continued?
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Yes : https://hclxing.wordpress.com/2014/02/09/hacking-the-dell-laptop-power-adapter-part-ii-2/