Nice comparison. There's quite a few different A500 PSU models though. I have both a switching and a transformer model. Looking at the board, I think even the transformer model doesn't do simple linear regulation for 5V. Also, I wonder how much the ripple varies with the current. Because I suspect that different A500 revisions have huge differences in power consumption. I think Rev 5 and below have 16 NMOS DRAM chips, while Rev 6 and higher use 4 CMOS chips. Same applies to the different 512k trapdoor expansions. From my experience, older NMOS chips get much warmer during operation. So I would expect that a Rev 5 draws significantly more current on 5V than a Rev 6. I don't think anyone made a vid on that topic yet ;-)
Interesting findings. Thanks for taking the time to do such a careful test.
Surprised to see that the original Amiga 500 power supply is so light - the C64 one I have by contrast is a real heavy brick.
That's because the C64 one is basically a linear supply. A huge transformer coupled with a small linear voltage regulator.
There are heavier versions of these as well, which also have a huge transformer in them. Not sure how these compare to the lighter ones though.
Which also explains the size of the case. Mine is mostly empty space…
Nice comparison. There's quite a few different A500 PSU models though. I have both a switching and a transformer model. Looking at the board, I think even the transformer model doesn't do simple linear regulation for 5V. Also, I wonder how much the ripple varies with the current. Because I suspect that different A500 revisions have huge differences in power consumption. I think Rev 5 and below have 16 NMOS DRAM chips, while Rev 6 and higher use 4 CMOS chips. Same applies to the different 512k trapdoor expansions. From my experience, older NMOS chips get much warmer during operation. So I would expect that a Rev 5 draws significantly more current on 5V than a Rev 6. I don't think anyone made a vid on that topic yet ;-)
If you start to go down the PSU rabbit hole: it is VERY deep. I think I barely scratched the surface!