Jeff said:I received the following suggested work-around for an external power
supply (the two links below) from the place I bought the case from a few
years ago. I might go for it at some point, but for now I have other
machines to use. One was built in a Moneual case. As I was reading up on
this issue, I came across some info on Zalman that elaborates upon what
you've mentioned below. Apparently, Moneual bought Zalman and then the
CEOs engaged in some type of fraud where they were claiming much higher
sales than they actually had. From what was claimed in the article I
read on-line, this was done on purpose in order to default on loans and
use the money for other reasons. So now when I look up Moneual to get
info on my case, the only thing they are currently selling is robotic
vacuum cleaners. Bizarre.
By the way, I did hook up my Zalman machine to another power supply and
it booted just fine. I'll have to learn to use a meter in the future.
Thanks for the help and info.
"Paul" wrote in message
The sad part is, the state of the Zalman business right now.
They were bought by some other corporation, then the
other corporation had financial trouble. It's expected Zalman could
survive, but I don't know in the interim, what it might mean
for customer service. And whether you could still contact them
The specs for that one are on page 3. Note well some of the
"For fanless operation de-rate the output of the 3.3 and 5V
rails by ~35% or ensure PSU surface temperature should not
exceed 65C, whichever comes first.
Input current should not exceed 8A. For current higher loads,
we suggest using a 2x2 mini-FIT JR as an input connector.
It doesn't regulate the 12V onboard. The adapter feeding it
handles the +12V. The 8A rating is a "wires and connectors" rating,
and the warning there is to use good interconnect getting current
into the Pico and out of the Pico. The other rails regulate onboard
and generate heat while doing so.
It generates +3.3V, +5V, +5VSB (standby supply), -12V (for RS232 port).
It's highly efficient, but it also has no surface area, so the
convection cooling is not going to be all that good. And 65C, if
you stick a finger on it, your finger can only stay there for a
second or two. That's a quick way to guestimate what 65C is.
The only time I'd use a Pico, is if space was at a premium.
The difference with supplies like this, is the power-dissipating
components usually have a slightly bigger heatsink.
3,3V 20A, 5V 20A, 12V 33A, -12V 0.5A, 5VSB 2.5A
<---- 100W ---->
<--------------------- 400W ------------------>
If you're in-range for a Pico, maybe that can indeed
run fanless with that tiny loading. If you actually
wanted to run it at "399W", then I would slap a
Vantec Stealth cooling fan to the top of the PSU,
and give it forced air cooling.
When you use convection cooling, conditions matter a lot.
If you put that Seasonic *inside* the Zalman case, it
would likely cook. (It would have thermal protection,
so would shut off as a warning things aren't going well.)
If retrofitting to the Zalman, I would mount it on the
outside. Then look at the heatsinks on the unit, to
optimize the convection process. The hardest part, is
protecting the supply from "spilled beverage syndrome".
One poster here had an issue like that, when a computer
case with holes in the top, a beverage was spilled and
it entered the power supply, to the tune of a lot
of sizzling from the mains electricity. And obviously,
fitting any kind of "lid" over the Zalman, spoils the
The first product I worked on out of university, it
was convection cooled. And a lot of effort went into
designing louvers to shape the available convection airflow,
to do the best we could with absolutely crappy cooling
conditions. Lucky for us, the boards that did the
work in the product used ECL, which loves to run hot.
(Heat was like a "lubricant" for that old bipolar
stuff - if you burned yourself touching a ceramic
chip lid, that was in the right range. It was "warmed
up" ) If only CMOS was so happy-go-lucky.