wiretap wrote on 2021-12-30, 11:47:

Sphere478 wrote on 2021-12-30, 01:01:

That’s brilliant. […]
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wiretap wrote on 2021-05-19, 21:08:

Here's another I just made.. you would just cut the ATX-to-AT adapter and solder this inline. Top is input from the ATX side, bo […]
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Here's another I just made.. you would just cut the ATX-to-AT adapter and solder this inline. Top is input from the ATX side, bottom is output to the AT side. Then just put some heat shrink over the whole thing.

Mouser Cart: https://www.mouser.com/ProjectManager/Project … ssID=72e7534197
Gerbers and KiCAD is attached.

Tested, working design. Assemed on July 23rd, 2021.

That’s brilliant.

Wonder if maybe it could be made to use some sort of alternate attachment method for the wires though like spade terminals. Or little green lugs

I hate having soldered in wires in a application that gets moved often, and lets face it, we are always digging in our retro rigs.

Yes, you could design it to have ferrules on the cable ends with weidmuller blocks on the board. But I wouldn't call it much more reliable. Solder with heatshrink over it is plenty to keep it from bending/breaking. When you remove a connector, you don't pull by the cables, you pull from the connector.

I suppose the big heatshrink probably immobilizes it sufficiently 🤔

ananananas wrote on 2021-02-21, 12:41:

ATX2AT I think was the first solution to address the issue. But it was a very limited run. And I saw one problem with it, beside […]
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ATX2AT I think was the first solution to address the issue. But it was a very limited run. And I saw one problem with it, besides its price: it used a custom-built cable. I saw that as a problem. I didn't like the idea.

So I decided to try and address the issue. And I produced a clone of it. But it was little bit too much to bite so I chose another project which is this one right here. A simple in-line adapter to adapt a 24-pin ATX power connector to AT power connectors. Which lets me use modern ATX power supply with OVP, OCP and short circuit protection, but also adds the missing -5V.

Recently Phil's Computer Lab and Necroware released their own ISA card version, which is very clever and simple. I was impressed. Even envious of such clean design. But some commented they would rather have an in-line solution. One is cheaper, one does not take an ISA slot.

If I can improve this design, what should I add, include or change? Have you seen something else yourself? Please, comment. I have spent enough time on this to not release it. It is of no use if left unreleased. Input is welcomed.

And a final note: I have a bunch of these and I must somehow deal with them. If anyone wants to buy one, post me a message send me an email ananananas@gmx.us. I also have bunch of the ISA card versions assembled but I would like to get a comment from Phil or Necroware before I wish to sell those. I don't feel right selling them. Maybe I can release the Eagle files and if you guys want to take advantage of those and make available an assembled version, perhaps that would be a solution? Because if I could order a bunch of 30 of those since you guys released them, I see there is even more benefit to the community to let these be even more easily available. What do you think?

i saw the adapter being sold on ebay some weeks ago
i think it is now sold out

do you plan on selling more in the future?

wiretap wrote on 2021-07-23, 18:47:

Tested and 100% working. […]
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Tested and 100% working.

Installed in the ATX to AT adapter (wire colors of the chinesium cable aren't right):

do you sell these on ebay=? with cables?

No. They are a diy project.

It’s nice to see so many solutions to this these days.

There is also this

(Which can be used with a wire also)

First pic is the latest version I modified, and the second pic is the previous version by wiretap

Re: AT pico psu.

Hey there,

I don't know if this is the place to post this but eh, why not.

I felt like making a circuit with an inverting buck regulator for some fun, plus to learn something about them and ripple rejection. I took the voltage blaster and replaced the lm7905 with an inverting regulator with a capacitance multiplier to cut out noise hopefully within the range of human hearing.
It should be able to make -5v@100ma well enough and hopefully quiet enough to not be audible on your sound card. Everything in this is a first for me, first time laying out a circuit with a switching regulator and first time using a capacitance multiplier. So if I messed up, point it out nicely please.

I'm not sure if this is really worthwhile over an lm7905 but it was primarily an exercise for me.

In case it's any good to anyone, here is a github with the kicad project files: https://github.com/LimeProgramming/InvertingVoltageBlaster
Just a reminder, that this is obviously untested and may not work.

-Thanks

Ok wow. Very nice! :p can you make a 3.3v pci edge style version? Some mobos required a card for injecting 3.3v into the pci slot to power the cpu. (Weird, I know)

Sphere478 wrote on 2022-10-31, 04:35:

Ok wow. Very nice! :p can you make a 3.3v pci edge style version? Some mobos required a card for injecting 3.3v into the pci slot to power the cpu. (Weird, I know)

How many amps though?

Cpu could be as much as 30w

Board, idk now many. 10-15 tops?

Other cards possibly 0 w or whatever a gpu might pull. 10-20w?

Probably way over estimating here

Typical numbers probably half that or less

Dual cpu might break 30-40w? 🤔 I’d have to look up wattage specs of a bunch of cpus. Looks like dual p mmx would be 34w

Sphere478 wrote on 2022-10-31, 12:43:

Cpu could be as much as 30w […]
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Cpu could be as much as 30w

Board, idk now many. 10-15 tops?

Other cards possibly 0 w or whatever a gpu might pull. 10-20w?

Probably way over estimating here

Typical numbers probably half that or less

Dual cpu might break 30-40w? 🤔 I’d have to look up wattage specs of a bunch of cpus. Looks like dual p mmx would be 34w

At that kind of load, probably a murata module would do?
Or go multiphase with that schematic I sent you in the PDF (reference schematic) Though getting parts might be hard, digikey seem to be the better source and they are expensive.

Well, I may be over estimating. But 1 or 2 muratas seems like a good plan.

Here is a real card used for this. (For a dual cpu mobo)

Re: Dual CPU Socket 5/7 Boards

Suggest we move this convo to:

Adding 3.3v to pci adapter(Released)

ananananas wrote on 2021-02-21, 12:41:

So I decided to try and address the issue. And I produced a clone of it. But it was little bit too much to bite so I chose another project which is this one right One is cheaper, one does not take an ISA slot.

If I can improve this design, what should I add, include or change?

1. So this is for -5v ATX -> AT only, no way to pull it off for just ATX PSUs and mobos?

2. Some recommend LM79XX, then some others say don't do that, and even if I do what happens to -12v rail?

3. Could you design one for ATX only?

wiretap wrote on 2021-07-23, 18:47:

Tested and 100% working. […]
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Tested and 100% working.

Here's my -5V inline adapter assembled:

Installed in the ATX to AT adapter (wire colors of the chinesium cable aren't right):

You may connect the input power to +12 Volt channel, but by replacing + and - polarities!

-12 Volt channel may have limited power inside PSU for both feeding -12 Volt with addition of -5 Volt with heat regulated chips' extra power draw. The 7905 chip gets hot, it must not have to be covered, a little metal sink if attached to the regulator chip would be fine. Finally, this operation might be much better if done inside the PSU....

Not necessary. It barely gets warm.

Also, you don't want to run the 12v line through the board since the traces aren't rated for pass through at the potential amperage draw.

I have power supply repair skills for ages. Samsung (long ago on 200 Watt units) their power supply design was like that, some Astec units, as well as some Chinese no name ones etc. -12 Volt rail is limited. I have removed many 7905CV chips connected to +12 Volt from dead units, reverse connected (with a capacitor and a coil but those are not necessary). So believe me I know. 7905CV chips works with heat build up, if they won't get hot, they can not work well. Thus they need fresh air, optionally a metal heat sink cooler too. Those have also limited 0,5 Ampere design either. If they reach to that limit, you can not touch them. I am a retired computer shop owner seen many many units like that. This way is much better....

Cool story. You're only drawing a dozen or so milliamps for an ISA card requiring -5V, so heat is a non-issue.

You could always use a to-252 package for the 7905 to shrink the PCB a bit.

10uf tant or electrolydic on the in and out plus a 1uf ceramic on the out.

Could be cheap and simple enough.

Here, I'm really sick at the moment and it's hard to do much so I implemented my suggestion of using a TO-252-2(DPAK) package 7905 with CASE-A-3216 package tantalum caps.
This PCB is a good bit smaller than the one using a TO-220 package 7905 but probably requires more soldering experience to assemble.

I done two versions.
this one using simple through hole test points for soldering in the wire and a larger version where I used a a footprint that lets you zip tie wires to the PCB for extra support.

Kicad & gerber files attached.

-Lime

And there's the bigger one.

Very nice 😀