Overkill, especially OLED display. Could be interesting for testing purposes though.

That is pretty awesome.

I wouldn't mid getting at least one... depending on how low the price can go if a lot of people want one or more.

Bare boards and kits would also be an option for quite a few people along with a parts list for those who only need the bare board.

The way I see it, this little board would only really be good for testing purposes. In a build, you would really want a switch on the case.

I currently use the passive ATX to AT adapters with 5v added with the "bulky" power switch which is great for AT cases as you can just swap in that switch on the case in place of the original one.

Absolutely, it's designed as a testing tool to check motherboards in unknown condition (or expansion cards) and not intended for a "fixed" rig (as soon as everything is running correctly).

PS: the added cost for the OLED display is ~$3. Not really expensive but of course, the adapter can work without one.

I also think it's awesome!

One thing that may or may not be important, but I have seen that some of those passive ATX2AT adapters have a dummy load for the ATX 3.3V line since 3.3V is not used in AT units and the unbalanced load could cause problems with some PSUs. Now, I don't know if that is really necessary, but have you considered including it in your design?

In any case, great work, it should be a great tool for a test bench.

I would totally use one of those for testing.

Seems like a great idea, especially if it's inexpensive. Its also simple enough that I would attempt to build my own if I could purchase a PCB and the parts. 😀

TheMobRules wrote:

I also think it's awesome!

One thing that may or may not be important, but I have seen that some of those passive ATX2AT adapters have a dummy load for the ATX 3.3V line since 3.3V is not used in AT units and the unbalanced load could cause problems with some PSUs. Now, I don't know if that is really necessary, but have you considered including it in your design?

In any case, great work, it should be a great tool for a test bench.

Thanks!

The potential crossloads issues are interesting. On very low-end (< $35) or old PSU, you can see some voltage drop or overvoltage when the current consumption between 3.3/5V rails and 12V rail is unbalanced. So you have to place a resistor on the "idle" rail to add some current consumption. On old AT motherboards, almost all the power is drawn on +5V, so if a resistors is placed, it should be placed on the +12V rail. But even on Old or bad quality PSUs, that issue is unlikely to happen with 50W of power drawn. Modern PSU (especially DC-DC ones) are totaly immune to crossload at such low current. Anyway, it will be easy to add a feature on the firmware to check (and shut down) everything if a severe crossload condition is detected (& the PSU is unable to handle it correctly). I can also see if I can add an optional slot for a 5W resistor.

Ozzuneoj wrote:

I would totally use one of those for testing.

Seems like a great idea, especially if it's inexpensive. Its also simple enough that I would attempt to build my own if I could purchase a PCB and the parts. 😀

If you can solder them by yourself, I'll be glad to provide a bare PCB. They're not as cheap as "standard" PCBs because I use 2 oz copper, but it will not cost more than $5. The most expensive parts are the current sensors and the SMT fuses w/ holders ($3 ea).

xsecret wrote:

Ozzuneoj wrote:

I would totally use one of those for testing.

Seems like a great idea, especially if it's inexpensive. Its also simple enough that I would attempt to build my own if I could purchase a PCB and the parts. 😀

If you can solder them by yourself, I'll be glad to provide a bare PCB. They're not as cheap as "standard" PCBs because I use 2 oz copper, but it will not cost more than $5. The most expensive parts are the current sensors and the SMT fuses w/ holders ($3 ea).

Usually the thing that gets me is the shipping cost of the individual parts, but I'd try it if the total price was still significantly lower than a pre-built.

One thing I just realized though is that there are several surface mount components. I can do some by hand with an iron (I replace those SMD electrolytics all the time on Voodoo cards), but anything that requires proper SMT soldering equipment wouldn't be doable for me.

That adapter is a great idea

It is pretty nice, but it is like killing a mosquito with a flamethrower.
with that being said, i really liked, the only thing that i would add is a header for an external power button.

.legaCy wrote:

It is pretty nice, but it is like killing a mosquito with a flamethrower.
with that being said, i really liked, the only thing that i would add is a header for an external power button.

That's planned for the final revision 😀

I understand that it may look like overkill, but many decent 486 boards are now selling for more than $100 and some rare motherboards (Nexgen, etc.) can be even more costly. It's time to protect the investment 😎

First thought: Great idea. Second thought: Overengineered.

Great project. However a 'lite' version would be nice with minimized PCB size and component count. PCB manufacturers like Aisler charge per square centimeter, so the lite version without display could be made much cheaper.

I like it. Kudos for making this xsecret - and I also like that LCD screen for some visual feedback.
Is there a BOM for the needed parts? I want to build one 😀

keropi wrote:

I like it. Kudos for making this xsecret - and I also like that LCD screen for some visual feedback.
Is there a BOM for the needed parts? I want to build one 😀

Kicad plus BOM would indeed be nice to make our own board.

appiah4 wrote:

First thought: Great idea. Second thought: Overengineered.

Can you tell me what looks overengineered to you? The $3 OLED screen is optional and doesn't take any PCB space, perhaps the fuses ?

I think this kind of tool is almost useless if you can't trust it 100% to protect your board. It's clearly a luxury tool, only for the 10% of retro-addict who deal with high-value boards (the 90% remaining will be happy with a $3 passive adapter). I only collect Engineering Sample CPUs (check my sig! 😎 ), some worth more than $1000, so It doesn't seem crazy to me to spend $50 to make sure a disaster will not happen easily 😊. In addition, beyond protecting the investment, I also want to protect some invaluable pieces of hardware.

xsecret wrote:

appiah4 wrote:

First thought: Great idea. Second thought: Overengineered.

Can you tell me what looks overengineered to you? The $3 OLED screen is optional and doesn't take any PCB space, perhaps the fuses ?

I think this kind of tool is almost useless if you can't trust it 100% to protect your board. It's clearly a luxury tool, only for the 10% of retro-addict who deal with high-value boards (the 90% remaining will be happy with a $3 passive adapter). I only collect Engineering Sample CPUs (check my sig! 😎 ), some worth more than $1000, so It doesn't seem crazy to me to spend $50 to make sure a disaster will not happen easily 😊. In addition, beyond protecting the investment, I also want to protect some invaluable pieces of hardware.

Not sure how it is "overengineered".

For effective protection I don't see how it could be made any simpler.

I lack the technical expertise to carry valid oppinion about the "overkill factor" but this is a beautiful little tool which serves a valid purpose - very well done.

Any news on the progress of manufacturing here? I want to put my 286 in a case now, and would love to have this converter in there as well. 😀