ATX PSU in PEB mod

[+Vorticon]

All good points for sure. As a matter of fact, from what I have read on this, using an AT/ATX PSU replacement is actually a very bad idea to start with given the increased stresses it puts on the cards 5V regulators, and it would be far better to rejuvenate the original PSU. The heat path is what concerns me the most with my setup, but there seems to be good outflow of air from the fan grille and quite a bit of clearance inside the PS enclosure. Also the PEB is not a tight enclosure at all with lots of open slots and holes, and it would be hard to build up excessive amounts of heat in it. I will continue to monitor that closely and as I stated I may add a fan to the side as well if needed.

Regarding the use of epoxy, it's only to secure the intact metal casing of the PS to the PEB. That should be fairly harmless, even it does break down at some point since all all the components are safely enclosed and there is nothing to short.

With all that said, my work on this is the very definition of an amateurish kludge at best. Welcome to the hobby

[Sinphaltimus]

Yeah, I'm an amateur. I know about shrink wraps but never used them before. Working in my peb atx psu mod was a multi stage thing. The next stage is too cut all the wires going to the front displays and connect them to a pluggable interface so I can easily remove the front cover.

 

When I have the peb open for that project, I'll replace the tape with heat shrink wrap or whatever it's really called.

 

And, I have a broken connection to fix on the psu.

 

As for temp probes. I installed one in each card, right above and almost touching the the front end voltage regulators.

 

So far, they stay under 100 degrees Fahrenheit. Typically in the 80s.

 

I'm very grateful for the expertise here. I may walk away better informed and skilled. I've been lucky, my inexperience has somehow worked out to this point, but with old components, I should really focus on the longevity and safety of my modifications.

Edited December 11, 2016 by Sinphaltimus

[+OLD CS1]

After reading that excellent bit of information, my take is as follows:

1. Load up the PEB with heat generating cards
2. install fan to circulate air rather than exhaust
3. Make room for a brownie tray
4. Instant EasyBake Oven reborn (profit!)

Oh, and please please please never look closely at anything I solder. It will look something like using a mallet to drive a brad.

[Sinphaltimus]

We're all mad here....

[+Vorticon]

There is a reason why I did not post pictures... I'm surprised I haven't burned the house down yet!

[+InsaneMultitasker]

After reading that excellent bit of information, my take is as follows:

1. Load up the PEB with heat generating cards
2. install fan to circulate air rather than exhaust
3. Make room for a brownie tray
4. Instant EasyBake Oven reborn (profit!)

Add a surface mount soldering tray above the brownie tray, and watch your geek profits explode.

[Sinphaltimus]

There is a reason why I did not post pictures... I'm surprised I haven't burned the house down yet!

Yeah but posting pictures (a lot like I do) can provide others with a good laugh (never a bad thing) and to serve as a warning to others (again, never a bad thing) or an encouragement to some who have never done it before (wow, if he can do that I can do better!).

 

Etc...etc...

 

Edited December 11, 2016 by Sinphaltimus

[+Vorticon]

One observation: It will probably be best to replace the original 5V regulators on the legacy cards with 1A rated ones along with a heat sink if one does the ATX modification. Had to do that with both my RS232 and my pcode card in order to keep the system stable. I think I'm going to have to do the same to the PEB interface as well.

[+OLD CS1]

One observation: It will probably be best to replace the original 5V regulators on the legacy cards with 1A rated ones along with a heat sink if one does the ATX modification. Had to do that with both my RS232 and my pcode card in order to keep the system stable. I think I'm going to have to do the same to the PEB interface as well.

 

My thinking is age alone makes this a good idea.

[Sinphaltimus]

One observation: It will probably be best to replace the original 5V regulators on the legacy cards with 1A rated ones along with a heat sink if one does the ATX modification. Had to do that with both my RS232 and my pcode card in order to keep the system stable. I think I'm going to have to do the same to the PEB interface as well.

Do you have a source? (link)

[+OLD CS1]

Do you have a source? (link)

 

Mouser

Jameco

Digi-Key and Digi-Key

 

I suspect any of these should work, and there are others. Essentially, you are looking for 7805 power management ICs (voltage regulator) with 1A output.

[Sinphaltimus]

 

Mouser

Jameco

Digi-Key and Digi-Key

 

I suspect any of these should work, and there are others. Essentially, you are looking for 7805 power management ICs (voltage regulator) with 1A output.

Awesome thank you. I currently don't have any issue with my PEB related to this and I'm monitoring temperatures inside the peb (my basement is always cold). However, I like to be prepared and if I'm going to be joining the peb to do dine more modifications and adjustments (Like removing all electrical tape) then I might as well do the voltage regulators too. At least the ones that get the warmest for now.

[+arcadeshopper]

and this for the 12v?

https://www.jameco.com/z/7812T-Major-Brands-Standard-Regulator-12-Volt-1-Amp-3-Pin-3-Tab-TO-220_51334.html

 

I'm going to buy a few and make kits to sell on the website for the less knowledgable to just solder in also what type heat sync compound for these? http://www.ebay.com/itm/NTE-303-Silicone-Thermal-Heat-Sink-Compound-1g-Tube-5-Pcs-/221732713730?hash=item33a04cb502:g:6ZUAAOSwstxVHX9umaybe?

 

Greg

 

 

Mouser

Jameco

Digi-Key and Digi-Key

 

I suspect any of these should work, and there are others. Essentially, you are looking for 7805 power management ICs (voltage regulator) with 1A output.

[Shift838]

and this for the 12v?

https://www.jameco.com/z/7812T-Major-Brands-Standard-Regulator-12-Volt-1-Amp-3-Pin-3-Tab-TO-220_51334.html

 

I'm going to buy a few and make kits to sell on the website for the less knowledgable to just solder in also what type heat sync compound for these? http://www.ebay.com/itm/NTE-303-Silicone-Thermal-Heat-Sink-Compound-1g-Tube-5-Pcs-/221732713730?hash=item33a04cb502:g:6ZUAAOSwstxVHX9umaybe?

 

Greg

 

 

i probably need to stock up on these voltage regulators too and compound since I am performing moving it all to an ATX power supply!

[Shift838]

and to further disperse the heat we can also use something like this with the new voltage regulators:

 

HERE

[+arcadeshopper]

and to further disperse the heat we can also use something like this with the new voltage regulators:

 

HERE

 

i have these:

https://www.arcadeshopper.com/wp/?page_id=11#!/19*15*10mm-Aluminum-Heatsink-pack-of-2/p/67985772/category=16275021

[AMenard]

Hi,

 

Does anybody knows how many amp does the PEB PSU is rated at on the 16v and 8v line?

 

Also, why not use a 24v PSU with a couple of step down converter to output the 16v and 8v?

 

Something like this: https://www.trcelectronics.com/View/Mean-Well/EPP-300-24.shtml

 

And a couple of this: http://www.minikits.com.au/MP1584-PSU-01

[digdugnate]

this may or may not help you with your questions:

 

http://www.nouspikel.com/ti99/titechpages.htm

 

http://www.harmlesslion.com/text/atx_peb.htm

 

http://www.mainbyte.com/ti99/peb_pow/peb_pow.html

 

those are quick links i found while on lunch

Edited December 21, 2017 by digdugnate

[AMenard]

this may or may not help you with your questions:

 

http://www.nouspikel.com/ti99/titechpages.htm

 

http://www.harmlesslion.com/text/atx_peb.htm

 

http://www.mainbyte.com/ti99/peb_pow/peb_pow.html

 

those are quick links i found while on lunch

 

The last link helped a bit since it included a mod to boost the psu on the 12v (really 16v at that stage since the individual card are the one who drop it down to 12v and/or 5v) from 1a to 2a...

 

Of course, another solution is just to rebuild the existing PSU by replacing the caps, diode and the voltage regulator specified in that mod. The transfo is probably still good as those tend to last for a very long time if they never were overloaded.

 

This link is also nice: https://www.disavowed.jp/index.php?/archives/45-Refurbishing-a-TI-PEB-power-supply.html

[Omega-TI]

Don't forget << THIS GREAT THREAD >> by Wyerd.

[AMenard]

Don't forget << THIS GREAT THREAD >> by Wyerd.

 

Yep, I already read it. Thanks.

[GDMike]

Any tips before I start to replace my peb PS?

I'll be using this PS.

I found this was mentioned by Mike:

Instead of bypassing the regulators, simply wire the ATX +12v to *both* the TI +16v and +8v lines. The card regulators will take the 12v down the 5v quite well, and the drop on the 12v lines is still good enough to run the card. (Also wire the -12v to the PEB's -16v line). (He tested on RS232 and HDFC, I'm testing on the TI 32k and Disk, and Corcomp RS232). This does in fact work and is a much! better solution.

ok, which are the TI +12, -12, -16, +8 lines

 

Edited July 23, 2020 by GDMike

[+Vorticon]

I actually changed all the regulators on my cards to higher current load versions. Fairly easy to do.

[GDMike]

I've got a bunch of 7805s. But not sure there needed. 

 

[GDMike]

Will start disassembling Peb soon.

Edited July 24, 2020 by GDMike