Hacker News new | ask | show | jobs
by neilv 888 days ago
I've stockpiled a few W520 units, in case I ever need that upgrade step. The huge 170W power brick is the reason not to just move to it now, since I have a fleet of 90W AC adapters I've been using for everything since the T60.

I've also wanted to get X220, for more portable, but still matching keyboard. (I currently have some X200 units, with better displays than X220 usually has, but different keyboard layouts. They'll be a bit of work to sell, for the upgrade, since I'll have to replace the custom Coreboot that's on them.)
1 comments
csdvrx 888 days ago
> The huge 170W power brick is the reason not to just move to it now, since I have a fleet of 90W AC adapters I've been using for everything since the T60.

Can't you get a barrel connector on top of a modern GaN adapter? It should be much smaller!

link
neilv 887 days ago
Good question. The W520 wants 20V (at up to 170W). Looks like the newish USB PD standard can supply 20V in addition to 5V. So maybe it could be done with a current/forthcoming consumer USB PD wallwart, without needing to add additional power circuitry?
link
csdvrx 886 days ago
> So maybe it could be done with a current/forthcoming consumer USB PD wallwart, without needing to add additional power circuitry?

You may need a circuit to negotiate the USB-PD, then to ouput 20V from that, but it should be possible.

It could even be a very interesting project: expose an artificial resistance on the barrel plug to simulate the Lenovo AC wattage resistor by matching what the USB-PD can deliver.

link