Re: [tlug] EE question (was: VPN?)

[Kalin KOZHUHAROV <me.kalin@example.com>]

On Sat, Jul 7, 2018 at 7:14 AM, David J Iannucci
<jlinux@example.com> wrote:
> I've recently acquired a sweet little "tiny form-factor" PC that I'm
> looking forward to throwing some distro on and playing with. I got it
> really cheap at a thrift shop and it didn't come with a PS. It
> apparently takes a laptop-style PS, and the specs are 19V @3.42A. As it
> turns out, I have one in my junk box that seems to fit the bill but the
> specs are 18.5V @<something >= 3.42A, can't recall now>.
>
> Should I worry about this thing being rated 0.5V below the machine? It's
> only 2.6% off, which (based on what I can see from googling) is probably
> within the expected tolerance for such equipment. What's the worst that
> could happen from undervoltage?
>
19V x 3.42A = 65 W (well VA actually). If you use a 65W or beefier PSU
with around 19V, you should be fine.

Do a triple check that polarity is matched! If you reverse the + and
-, oftentimes you will let the magic smoke off (some regulator on the
board) and that is the end.

In the case of say 18.5V@3.25A (=60W), you might be running at/over
the specs of the PSU, so it may shut down or burst into flames ;-D

I think it is safe (for me at least, LoL) for you to try. Check the
temperature (by hand) on the PSU, load the machine (cpuburn, build a
kernel with -j8, `john --test`, etc.) for an hour and check the
temperature every few minutes initially.

Cheers,
Kalin.

P.S. Did I say to check polarity _FIRST_?
P.P.S. And... make sure you use a DC PSU, one with labeled + and - :-)
Once I pulled an AC unit (for some old modem) from the "PSU box" and
had a superb bang from a filter condenser :-D