H5 with external PSU. Power requirement

Repairs & upgrades.
User avatar
exxos
Site Admin
Site Admin
Posts: 28616
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: H5 with external PSU. Power requirement

Post by exxos »

ijor wrote: Fri Aug 25, 2023 8:08 pm But only the "normal" 6-pin connector is populated in my board. Otherwise I could connect it directly to one of the 4-pin AUX ports. No big deal. I'll use a couple of jumper cables for 5V and GND.
Right, so you need a ST PSU to standard molex 4 pin then ? I can probably just make you one if that's easier.
User avatar
Icky
Site Admin
Site Admin
Posts: 4386
Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Re: H5 with external PSU. Power requirement

Post by Icky »

ijor wrote: Fri Aug 25, 2023 4:56 pm I need to use an external PSU for my H5 motherboard. Of course it is possible to just use a standard ST PSU with some kind of cable extension. But, honestly, I don't feel very comfortable with that kind of setup. If going with an external PSU, it will probably be much safer to use something fully enclosed.
It’s not good having exposed PSUs especially the original ST one where the heat sink is pretty much live to touch :fire:

I have seen in @Badwolf’s videos he has what looks like a 3D printed cover over his PSUs. @Badwolf is there a stl for that cover?
ijor
Posts: 836
Joined: Fri Nov 30, 2018 8:45 pm

Re: H5 with external PSU. Power requirement

Post by ijor »

exxos wrote: Fri Aug 25, 2023 8:10 pm Right, so you need a ST PSU to standard molex 4 pin then ? I can probably just make you one if that's easier.
Thanks a lot for the offer, Exxos. But I tried a couple of "Molex PSU" units I have with jumper cables and it doesn't work. Seems they can't deliver enough power.
http://github.com/ijor/fx68k 68000 cycle exact FPGA core
FX CAST Cycle Accurate Atari ST core
http://pasti.fxatari.com
User avatar
exxos
Site Admin
Site Admin
Posts: 28616
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: H5 with external PSU. Power requirement

Post by exxos »

ijor wrote: Sun Aug 27, 2023 10:57 pm Thanks a lot for the offer, Exxos. But I tried a couple of "Molex PSU" units I have with jumper cables and it doesn't work. Seems they can't deliver enough power.
Thats a shame. 2amps should be enough. Probably not a true specced device as is common these days.

Maybe something like a ITX PSU or simple DC jack PSU would be best ?

https://www.ebay.com/itm/364270000070
User avatar
Icky
Site Admin
Site Admin
Posts: 4386
Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Re: H5 with external PSU. Power requirement

Post by Icky »

So, using a bit of perspex that I had lying about I have created a cover for @ijor's PSU and an extension lead. Yes, I could have created a nice 3D model and printed it but this took about 30 mins to make.

IMG_2786.jpeg
IMG_2786.jpeg (172.09 KiB) Viewed 1370 times
IMG_2785.jpeg
IMG_2785.jpeg (167.32 KiB) Viewed 1370 times
User avatar
Badwolf
Site sponsor
Site sponsor
Posts: 3058
Joined: Tue Nov 19, 2019 12:09 pm

Re: H5 with external PSU. Power requirement

Post by Badwolf »

Icky wrote: Sun Aug 27, 2023 5:08 pm I have seen in @Badwolf’s videos he has what looks like a 3D printed cover over his PSUs. @Badwolf is there a stl for that cover?
Ah, mine are just very flimsy little things that I've guessed at dimensions for and then just gone at with side cutters to make it work. Not sure an STL would be very useful & the result is only there to stop me brushing something I oughtn't.

Your little case looks 10x better.

Although if I were me, I'd probably stick a low-end industrial PSU in an off-the-shelf project box and run a line of 5V-only DC flex to the case with a barrel jack, adapting what I need inside. Use a cheap boost board for the 12V (again, inside the case) if required.

One of these, probably: https://www.xppower.com/portals/0/pdfs/SF_LCW15.pdf.

They're a tenner at Farnell, for example, and will run a lot cooler than an original, I'm sure.

BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon
Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2
FrontBench The Frontier: Elite 2 intro as a benchmark
ijor
Posts: 836
Joined: Fri Nov 30, 2018 8:45 pm

Re: H5 with external PSU. Power requirement

Post by ijor »

Icky wrote: Mon Aug 28, 2023 3:33 pm So, using a bit of perspex that I had lying about I have created a cover for @ijor's PSU and an extension lead. Yes, I could have created a nice 3D model and printed it but this took about 30 mins to make.
...
Wow, this looks fantastic. Amazing job!!!
http://github.com/ijor/fx68k 68000 cycle exact FPGA core
FX CAST Cycle Accurate Atari ST core
http://pasti.fxatari.com
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 15027
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: H5 with external PSU. Power requirement

Post by rubber_jonnie »

Having just pulled a PSU out of the drawer, it is marked 5v @ 3a and 12v @1.6a.

I have seen up to 5v@2.8a on a machine I was testing using a bench PSU while accessing a real floppy drive.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Post Reply

Return to “PSU (power supplies)”