Question about using ATX PSU for DC Power

As of now I still haven't purchased the actual PSU I'm going to use.

To provide context, this is what I'm getting for my Amiga 1200:

Case: https://www.checkmate1500plus.com/Products.aspx?id=342

The Power for the Amiga's motherboard is being provided by this:

https://www.checkmate1500plus.com/Products.aspx?id=357

In terms of the actual PSU, it has to be in the SFX format factor (basically a smaller ATX PSU). I've yet to decide on which one to buy, although this one has been bought up:

https://www.amazon.co.uk/gp/product/B06X6HFR2K/

I have a spare (female) 3.5" molex connector lying around from a fan similar to this:

https://image.made-in-china.com/43f34j00YjOTKVSyLEke/8cm-PC-Case-Cooler-Fan-4-Pin-Molex-KCF-1000-.jpg

With which I'm going to use to connect to the Scan Doubler in some way using the supplied cable by soldering where necessary (see the lower right of this image for the cable):

https://images.yaoota.com/SVYk42TFlf2nEzUi_TrRqz_nbHE=/trim/yaootaweb-production-ng/media/crawledproductimages/7dffa0747…

I never liked having the Scan Doubler being exposed on the side of my 1200, so one of my goals is to put the Scan Doubler inside the above case (obviously isolating it from the case) and powering it from the PSU as I'm hoping this will become a better setup (e.g. not needing a second external adapter and powering it on when I power on the Amiga).

I hope this helps.

BTW, the Amiga community is still quite surprisingly active, if niche, just recently they released Workbench 3.1.4 which I also plan on installing.

Does anyone have any experience/opinions of converters such as this for my type of usage:

https://www.amazon.co.uk/Lorjoy-CPT-UL-1-Converter-Regulator-Vehicular/dp/B07FXR6TNF

Bearing in mind the information I posted before (i.e. this will only power the Scan Doubler and nothing else), is something like this ok?

I would test any such device before installation.

A decent industrial quality 15W DC-DC converter will cost about £28 (cheapest 5V 3A Traco converter stocked by Farnell).

if you pay £2.06 for one it may work, it may even work quite well. I wouldn't connect it to anything I cared about not blowing up.

There is no way of telling how reliable it will be and how it may fail. It might also be noisy (electrically) and almost certainly won't comply with EMC standards.

If you test it, run it at the working load for at least 48 hours and it still looks OK then you may well get away with it.

How much is the scan doubler worth ?

MK

Around £20, but the risk of high EM is off putting so thanks for the info.

Ok so I've done some digging around.

So would a 3A fast blow fuse be suitable for my needs? If I go with the fuse I would buy a set to be able to test different Amps.

I've also looked into Polyfuses/PTCs but my main concern with those is the heat output and whether leakage may be a problem.

Unfortunately I have neither spare lying around to be able to test in advance of buying anything.