Modern PSU for the SE/30

[Trash80toHP_Mini]

The ATX -> Mac Gazette AKA: ATX LinksProject™  is one of my threads which has gone missing in the most recent forums upgrade, IIRC. I'd posted links from all over the Mac forums. There's a lot of good info over on 'fritter if it has surviverd their recent upgrade.

Mods: is there any way we could host a backup of the forums from before this past upgrade like the Snitz archive? You guys did a GREAT job getting things up and running, restoring the lost attachments from the previous upgrade, but it seems we've lost more than pictures, we're missing real content this time around.

 

[superjer2000]

I plan to follow this thread closely. I'm not seeing a downside in using the FSP mini ITX supply noted above.  

I found another related thread in case it helps anyone. 

 

[omidimo]

@joethezombie Here is a clearer shot of the wires, i tried to unplug it from the Mean Well unit, but it's not coming off, so it might have been glued on. 

 

[Trash80toHP_Mini]

I'm not a fan of dumping any old PSU into an Apple Power Supply Can without airflow/cooling analysis. Heck, I'm not sure Apple did all that wonderful a job of specifying what went in their own cans from the get go. I just took a look at the PPT-125B Datasheet:



Seems like it calls for 18CFM of active cooling in something more like the open spaces of a piece of stereo equipment. Methinks it's not intended to be haphazardly stuffed into a metal crate with holes on top and bottom for half-assed convection cooling that's aided by just a small fan mounted above and at the back that's expected to cool not just PSU, but CRT, A/B, logic board and all the crap whith which we're packing the SE/30 to the gills.

Could someone post pics of the insides of the real deal? I'm hoping the heat sinks are pretty much aligned vertically to pull air from bottom to top inside the OEM PSU. They were set up in a vertical orientation on the 128-Plus A/B to direct airflow up and out the top vents Jobs didn't think were needed. :

Take a look at the horizontal positioning of the Mean Well PSU in the illustration. The heat sinks are three sided sheds with slots/holes in the roof for convection cooling. Turn that assembly on its side to fit within the SE/30 sheet metal as Artmix did and the passive cooling designed into the Mean Well PSU is negated.

I like the idea of putting an actively cooled, temperature controlled fan equipped Mini-ITX PSU in its stock sheet metal into Apple's can. Position air dams directing all the air entering from the bottom of the stock can so that it passes into the PSU in all the right places from the correct directions and then it all exits via the PSU's temperature controlled fan and out the upper side of the air dam setup, exiting the perforations on top, preferably aimed a bit at the system exhaust fan above and behind.

Tired, hope this makes some sense in words.

edit: when I posted I noticed the mass of connectors/wires blocking up the open side of the front heatsink shed. NOT the spot to do wire mismanagement with a zip-tie.

 

[joethezombie]

@omidimo, thats perfect!  It shows the small board takes 5V from the MeanWell, boosts it to 12V, and powers the SWEEP.

jt, in the datasheet, we see it is rated for 125W with a fan, and 100W with convection cooling.  Even with Ethernet, 50MHz 68030, and grayscale, I doubt we'd be using 100W.  I think the convection cooling would be adequate.

EDIT:  Forgot to add, it is not a trivial task to use the mini ITX power supply.  There is a BOAT LOAD of wires that I had to desolder, cut, and/or insulate to get a usable bundle:



Everything hanging out the left side in the bread-tie had to be painstakingly desoldered or snipped and insulated with heatshrink.

 

[Trash80toHP_Mini]

I imagine that would be convection cooling with the supply positioned horizontally. I didn't see any specs about enclosures or applications?

edit: copy paste doesn't work: It needs to be in a bigger box.

View attachment 23057

 

[joethezombie]

Yeah, me neither.  The casing of the old power supply has holes all around the perimeter, and with the existing fan pulling air in from the bottom and exhaust out the top, we should be golden.  The nice thing about the MeanWell is that there is not so many wires like there is with the mini ITX.  Makes it easy and clean to make.

 

[omidimo]

The board is also slightly off the casing.

 

[joethezombie]

Thanks again omidimo, you really nailed it pulling your build apart just to confirm our suspicions.  You're a scholar and a gentleman!  Much appreciated.

 

[Trash80toHP_Mini]

Again, it's spec'd to be mounted horizontally to a 14" x 14" x 1mm metal plate in a much bigger box.



Not sure it'll be happy living on its side in Apple's tin, but I'll shut up now. []

 

[Bolle]

No Ethernet on the Grayscale SE/30 though since I don't know how to make it fit.  Do you?

I'll just leave this here:

View attachment 20855

I am running all my SE/30s on the stock power supply still. Even with the big card stack and a real spinning SCSI hard drive.

They are all Sony PSUs and only one is recapped I think. No issues so far.

 

[joethezombie]

jt, that's only if we wish to keep the same EMI rating MeanWell tested for EMC.  I don't think I care too much about that.

 

[Trash80toHP_Mini]

Not worried about specific ratings, that's a hint as to how they expect it to be employed. I'm just sayin' it's not really meant for the purpose or orientation in which we're planning to place it. But that doesn't mean it really matters, there's a whole lotta slop in the parts/spec.

You up already, Bolle, what time is it around there?

 

[joethezombie]

Bolle, every time I see that, it brings a tear to my eye!

Bolle and jt, WE DID IT!  

 

[Trash80toHP_Mini]

[]

 

[omidimo]

Bolle, every time I see that, it brings a tear to my eye!

Bolle and jt, WE DID IT!  

Now if I can only get two of them!?! I am dying to get ethernet working on my SE/30s. 

 

[Bolle]

You up already, Bolle, what time is it around there?

Got up at 5:30am and first thing I did was checking in here while still in bed

Now if I can only get two of them!?!

You're on the list, as said I will get another batch and also have some of the IIsi adapters done.

Time to work on those things is sparse at this time of the year due to outdoor activities being #1 priority right now but I will get back at the adapters. Promised

 

[JDW]

What a wonderful discussion has been taking place during the time I was away from my computer!

A thousand thanks for the photos.

So...

Is the consensus that the Mini ITX FSP220-60LE power supply is best to use inside a stock metal PSU enclosure convection cooled, or are you gentlemen saying the ARTMIX dual board setup is preferred?  Or is it a draw?

If a draw, the cheaper solution is the FSP220-60LE.

 

[superjer2000]

On the ITX topic, I found this which seems like an interesting approach:

http://bylenga.ddns.net/index.php?page=SE_ATX.php

Recognizing the large number of wires on the ITX supply, I might try:

1) Cut out some of the extra wire on the ATX connector wiring harness (just cut, splice & solder and shrinkwrap)

2) Build an ATX to SE/30 wire harness like the gentleman did on the website above

3) Rewire the ITX power plug to the plug on the back of the SE/30

4) Lop off any unused wires.

I'm not sure if the SE/30 Power switch can or should be directly wired to the power plug and keep the PS_ON# grounded or if the power switch on the Mac should just ground the PS_ON# wire.

Using an off the shelf power supply should be easier than recapping the existing power supply.  

 

[Trash80toHP_Mini]

This is the setup described above:

Here's the FlexATX PSU I've been working with for fitment into the stock IIsi sheet metal that I'm thinking might be also be a good fit for this project:



Mo' betta pics from many angles in this post and a later one in my thread about the minitower spinoff of the U2BG3 Rackmount project. The solid "top" of the PSU in this position being the majority of the hot/cool zone air dam setup. Pics there show the air intake perforations three of the six sides of the PSU which are engineered to provide optimal cooling of the heatsinks and components within the retained PSU enclosure. They're all within the "cool zone. Using only 100W/300W for the SE/30, the temperature controlled fan might silent within the baffles of the muffler enclosure.



Angle of PSU is only an approximation for the pic. The HDD mounting sled bolted up to the side of the PSU is in the way, but the pic'll do for a quick illustration. With minimal, simple sheet metal work, the fan can be angled straight up. Voltage converter would be mounted with PCB solder side up, components down in the front near the wire grommet.

What's the voltage converter doing anyway, why is it necessary? If it supplies a value between 5V and 12V a Buck Step-down converter ought to be more efficient than a step-up converter. As trag said, we're heavy on the 12V rail and light on the 5V rail to begin with.

edit: now that I think of it, the larger volume hot/coo zone setup might cause a bit of Venturi effect where the airflow is pinched as it passes through the PSU enclosure. Even a tiny bit of increased of cooling air velocity from that effect would be a welcome reduction in fan activity.