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Re: SGI Power Supply Tester

Posted: Mon May 22, 2017 3:36 pm
by Y888099
OT, @Elf
I have already reversed the key-matrix of an Apple Powerbook G3, planning to reuse it for a new keyboard design. In my case it will be implemented by CPLD, and meta-key driven on a simple serial bus (like uart, but with a simple protocol on the top). Just to say: I HATE old style ( like PS/2 ) keyboards :D

p.s.
Good projects!

Re: SGI Power Supply Tester

Posted: Sun Jul 23, 2017 3:31 pm
by Elf
So it has been a while, and I have been paying attention to a lot of other projects as well, but I put together a tested, working revision 3 of the load board PCB this weekend. Each board is now produced identically (for both positive and negative rails), and is configured for the voltage afterwards. The schematic and PCB images on the first post have been updated. Now to make more of them, and the "main board" for controlling the whole tester.

Image
(Fuses not populated on that board; only one fuse per board, placed depending on whether it is a negative board or positive board)

The OK / Low / High voltage indicator works well and the crowbar cuts in exactly when you ask, so I think it is functioning quite well.

Still working on the software of the keyboard adapter (sporadically), but the hardware is working quite well.

Y888099 wrote:p.s.
Good projects!

Thank you :)

Re: SGI Power Supply Tester (and other projects)

Posted: Sun Jul 23, 2017 4:37 pm
by Dodoid
Looks great!

PS and minor nitpick: The SGI logo on the load board is upside down. The line between the bottom two thirds goes all the way to the center, while the line between the top two sixths stops at the top thirds bottom line. Here's what it should look like (hasty GIMP work, I know):
sgiboard_fixed.png

Re: SGI Power Supply Tester (and other projects)

Posted: Sun Jul 23, 2017 6:25 pm
by Elf
Ah, good catch. Thank you! I will correct it on future boards (I have to make more).

Re: SGI Power Supply Tester (and other projects)

Posted: Sun Jul 23, 2017 7:40 pm
by Dodoid
Probably would not have caught it if I had not kept seeing (and eventually noticing was wrong) this totally licensedâ„¢ sticker on eBay.

Re: SGI Power Supply Tester (and other projects)

Posted: Thu Aug 10, 2017 10:33 pm
by Elf
I am probably getting ahead of myself since I haven't finalized the bigger keyboard adapter, but here is one to replace the old PS/2 to Indigo functionality as a much smaller, cheaper board (compared to the USB adapter):
Image

Re: SGI Power Supply Tester (and other projects)

Posted: Sun Aug 13, 2017 4:46 am
by dexter1
That looks like a really compact adapter. Does it get its power from the Indigo1 connection cable or does it need a 5 volt supply?

Re: SGI Power Supply Tester (and other projects)

Posted: Sun Aug 13, 2017 11:14 pm
by Elf
1.5 x 2 inches :)

Power is from the Indigo (or Onyx, etc.) connection, via a LTM 8021 single module buck converter. Much less heat and loss vs. the linear regulator in the existing PIC based PS/2 adapter.

The microprocessor is a SiLabs EFM8 Busy Bee, a modern 8051 derivative. It seemed appropriate as a nod to the ubiquity of the 8049 and 8051 as PS/2 controllers in PCs.

Re: SGI Power Supply Tester (and other projects)

Posted: Sat Nov 11, 2017 11:16 am
by Elf
Hi all,
Just wanted to give an update. The big pile of SGIs is still in storage (not on eBay or anything); unfortunately I have not had time to get around to these things... too much else going on!

Had to help do risk analysis and remediation on an acquisition at work, moving to an R&D position away from Operations, had to put in fire suppression at home due to a big fire in the area, regrading my gravel driveway that is getting washed out, redoing the electronics on the septic system, replacing a huge (>2000 linear board-ft of wood) rotting deck, truck needed a quick replacement of the exhaust manifold and turbo ($$$$), etc.

I hope to be able to get back around to these projects in the coming months! However, until then, there is still nothing to show. :(