Power supply for A1200

[Sim085]

Hello, can anyone suggest a power supply for an A1200 with an accelerator card and from where to buy? Ideally one which would fit in an A500 power supply case.

[Daedalus]

The A500 shipped with a few different power supply types, some bigger than others. However, the Meanwell RPT-50B module (Digi-Key link) should fit in them all with space to spare, and provides 4A on the 5V rail which is enough for most Amiga uses.

[Solderbro]

Here is a ready made product in sale, looks nice.

https://lotharek.pl/productdetail.php?id=145

[Sim085]

Well I am more looking to something like this given I want to put it in an A500 power supply case.



What does "Minimum Load Required" mean? I have a normal ATX power supply but sometimes this does not power up the A1200 with the accelerator card because there isn't enough load on it. Would I still be having this issue?

Originally Posted by Daedalus

The A500 shipped with a few different power supply types, some bigger than others. However, the Meanwell RPT-50B module (Digi-Key link) should fit in them all with space to spare, and provides 4A on the 5V rail which is enough for most Amiga uses.

[mpattonm]

Originally Posted by Solderbro

Here is a ready made product in sale, looks nice.

https://lotharek.pl/productdetail.php?id=145

You can always get MeanWell NET-50 tripple output PSU module alone at Aliexpress for as low as 16USD:
https://www.aliexpress.com/item/Orig...734469871.html

But beware, these are not CE/TUV certified, so they are not meant to be sold in Europe. They are not ROHS compliant either, since its a bit outdated product line.

By the way there are chinese knock-offs of this PSU module available at Aliexpress for even lower price. I would not recommend them either.

[mpattonm]

This is one of them: https://www.aliexpress.com/item/T-50...826856992.html
Visually identical to MeanWell and its just 8 USD!

[Daedalus]

Originally Posted by Sim085

What does "Minimum Load Required" mean? I have a normal ATX power supply but sometimes this does not power up the A1200 with the accelerator card because there isn't enough load on it. Would I still be having this issue?

ATX supplies aren't designed to run without a computer attached, and need a certain amount of power to be drawn for them to properly regulate their output voltages. If you're below that minimum, a good PSU will switch itself off again, while a poor PSU will stay on even if it can't control its output, potentially allowing the voltages to go out of spec enough to cause instability, or even damage your hardware.

Any PC will draw plenty of power to satisfy most ATX minimum load requirements, so you'll rarely see them specified when you buy on. But you can often download datasheets for them that will tell you the minimum requirement. As a general rule, the higher the maximum output, the higher the minimum load. So a 300W PSU is more likely to work well with an Amiga than a 750W unit.

Meanwell units still have a minimum load, but it's quite low (0.5A for the RPT-60B), and so an Amiga will be enough to let the PSU work well, making them a suitable replacement for the guts of the original unit.

Originally Posted by mpattonm

You can always get MeanWell NET-50 tripple output PSU module alone at Aliexpress for as low as 16USD:
https://www.aliexpress.com/item/Orig...734469871.html

Hmmm, that looks like the RT series, in which case it will only fit in the biggest of A500 PSU cases - many I've seen are a little bit too narrow for those units.

But beware, these are not CE/TUV certified, so they are not meant to be sold in Europe. They are not ROHS compliant either, since its a bit outdated product line.

Indeed, and while they're probably still fine (if they are genuine - not everything on Ali is...), for such a small difference in price there seems little point not buying a current, certified unit from a major industrial supplier like RS or Digikey. The RT-50B for example is only £15 from Digikey.

By the way there are chinese knock-offs of this PSU module available at Aliexpress for even lower price. I would not recommend them either.

Yikes! I certainly wouldn't put anything like that anywhere near any of my Amigas.

[Sim085]

I found same model from RS (UK) here:
https://uk.rs-online.com/web/p/embed...50542D36304226

Originally Posted by Daedalus

Indeed, and while they're probably still fine (if they are genuine - not everything on Ali is...), for such a small difference in price there seems little point not buying a current, certified unit from a major industrial supplier like RS or Digikey. The RT-50B for example is only £15 from Digikey.