TAM - Aux PSU for Expansion Card(s) in Development . . .

[Trash80toG4]

. . . hopefully!

Start of this project was info about the anemic TAM PSU issue from many sources, here, MLA, WWW and ThinkClassic back in that day.
Was working on putting together a better Initial Post, but what the heck . . . just chuck it out to the pack of wolves!

First notion was a PicoPSU inside years ago, but recently been thinkin' about USB-C.




Looks to me like only 12V & -12V would be handled nicely? Those are for disk drives, no? What else?

Whatcha' think? Is is even possible to take the pressure off the TAM's pathetic 5V and 3.3V rails with an AuxPSU Hack on a new riser design?
Next evolution of the project will be TwinSlot/TAM in the upper right corner. 6360 version PCBs are in, look good and on the way to me for function testing . . . very soon now!


edit: typo in files, the 6" Pigtail is USB-3 running in Mac supported USB-1 role.

 

[luRaichu]

Hi,
USB PD 3.1 supports up to 240W, should be plenty for a TAM.
It can only output one voltage at a time, you would need a power supply that converts its 20-48 VDC into your +5V, +12V, -12V rails.
And it would have to work with the soft-power switch...

 

[Trash80toG4]

USB PD 3.1 supports up to 240W, should be plenty for a TAM.
It can only output one voltage at a time, you would need a power supply that converts its 20-48 VDC into your +5V, +12V, -12V rails.

So USB-C is the rough equivalent of a Switching Power Supply? Might a couple of BIG MOHONKING CAPACITORS even out those switching effects?

And it would have to work with the soft-power switch...

The power from USB-C AuxPSU to the cards would be continuous and unrelated to soft-power silliness in the rest of the TAM. It won't be replacing the TAM's PSU, just feeding the Riser's power line cutouts.

As in the IP: is 12V and -12V even used by PCI Cards in the TAM? Should be able to leave those voltages to the anemic TAM PSU's rails to feed those voltages to the TwinSlot/TAM Riser, I'd think?

 

[Trash80toG4]

My thinking on trying this madness IRL would be a jumper cutout on every power line of the TwinSlot/TAM riser:
- fit headers on all lines for baseline testing of the TAM Riser.
- match sockets on the AuxPSU protoboard to the risers power cuttouts.
- AuxPSU experimental circuits could be done via Wire Wrap to the TAM Riser, perf board works fine for such things.

Could experiment with powered and unpowered riser that way. However TAM's pathetic PSU reportedly can't handle a single PCI Card, CSII Card and G3/L2 Accelerator all at the same time.

TwinSlot/TAM riser would be useful for getting around a Single PCI Card power dilemma for the TAM.