Anyone run ST off 5V only?

[scottinNH]

Has anyone run an ST off a generic 5V power brick, or a USB supply?

 

 

Per Exxos and other pages the ST only requires 5V to operate (although without 12v the serial ports will not work, which is fine for now).

So I am surprised nobody has made such cables to sell.

 

(EDIT: This is an NTSC "520ST", NOT an "STfm". No internal floppy, no SCART. )

 

So why do I want to do this?

• too much clutter...
• I'd like to run the 3-4 systems I have off a common 5V power supply (maybe not all at once, mind you).  For example the XL/XE series already have USB power cables. 
• I'm not interested in rebuilding the original ST PS (which isn't giving problems, but is old)

 

I'm not talking little 5V phone chargers, I know all about how they don't sustain current or may get hot. I have a number of large 5V supplies that are 3A up to 10A.

thanks!

 

 

 

 

 

 

 

Edited December 18, 2022 by scottinNH

[Chri O.]

How about the floppy drive 4-pin power connector.

Edit:

and this

Edited December 18, 2022 by Chri O.

[Sporny Kun]

Hello.

 

Recently, I experimented with a cheap 15W USB Power delivery compatible phone charger to have 5V with up to 3Amps : https://www.atari-forum.com/viewtopic.php?t=42334

 

However, for connecting correctly to a SCART TV, one should still have a 12V power rail, hence the use of a little DC-DC converter 5V->12V.

 

Also, I use a floppy emulator instead of a legacy floppy drive, it should help by lightening the load.

[scottinNH]

13 hours ago, Chri O. said:

How about the floppy drive 4-pin power connector.

 

This is just a 520ST, before the floppies were built in. Edited post for clarity/next reader. Thanks

[scottinNH]

7 hours ago, Sporny Kun said:

Hello.

 

Recently, I experimented with a cheap 15W USB Power delivery compatible phone charger to have 5V with up to 3Amps : https://www.atari-forum.com/viewtopic.php?t=42334

 

However, for connecting correctly to a SCART TV, one should still have a 12V power rail,

Thanks. No SCART here (unfortunately).

 

Nice project, looks exactly what I was looking for. 

 

FYI you can provide 12V using a boost module. ebay has loads of those (some too big), alternatively Linear's boost chips are friendly (don't require a ton of passives to build, some come in PTH form). EDIT: After my comment I see the Exxos link (or rather, that the site's paused until NY... I'll check after)

Edited December 18, 2022 by scottinNH

[snarkdluG]

I don't think I have any 3½" floppy disk drives that run on anything other then 5V. As you pointed out, the connector have 12V but it's not used in the drives. Maybe the older belted disk drives uses 12V for the spindle motor? I don't own any of those so can't confirm that.

[Sporny Kun]

6 hours ago, scottinNH said:

FYI you can provide 12V using a boost module. ebay has loads of those (some too big), alternatively Linear's boost chips are friendly (don't require a ton of passives to build, some come in PTH form). EDIT: After my comment I see the Exxos link (or rather, that the site's paused until NY... I'll check after)

Yes the module sold by Exxos is very tiny, as you can see. English Post Office is in a mess, so yes, he closed the webshop for some weeks.

 

1 hour ago, snarkdluG said:

I don't think I have any 3½" floppy disk drives that run on anything other then 5V. As you pointed out, the connector have 12V but it's not used in the drives. Maybe the older belted disk drives uses 12V for the spindle motor? I don't own any of those so can't confirm that.

Indeed I remember that Exxos states that only old drives use 12V. And I guess that the survival of this 12V rail is due to being "standard connector" (de facto).