Quote:
Originally Posted by aeberbach
I have seen a video where Jens talks about power supplies. Several are tested. True, the Mean Well units have higher ripple than the Amiga originally specified (but so do pretty much all of the supplies tested). How do we know that the low ripple specified by Commodore engineers was actually required? What incredibly sensitive component is on an Amiga that requires such low ripple?
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Yes, this is all very valid stuff. I should point out that there are a huge number of Meanwell models, and many of them do meet the 50mV ripple requirements of the original Commodore specification, just not the cheapest or smallest modules (which are also likely to be the ones used in the PSUs tested). It should be noted, of course, that the original Amiga PSUs generally don't meet that spec either. They probably did 20-30 years ago, but none that I have here now do. And all of them work fine, including with expanded Amigas, such as an A1200 with a Blizzard 1230, mechanical hard drive and CD-ROM drive, despite having ripple voltages well beyond the Commodore specification, the ATX specification and even the looser Meanwell specification. It's something I must sort out, but anyway...
It should be noted too that ripple specifications are generally stated for maximum load, and that the ripple is lower when the PSU isn't operating at its peak. Given that most Amiga setups don't even max out the original PSUs' specified capacities, let alone a modern Meanwell, it can be assumed that the normal-use ripple from a Meanwell-based PSU will be lower than the specification given in the datasheets, because a typical Amiga setup is likely much lower than the PSU's rating. My tests on a very small sample of PSUs would indicate that this is the case anyway. Of course, heavy consumers like 040+ or PPC cards are a different story...