SNES lowest voltage?

[blackevilweredragon]

what's the lowest voltage an SNES (original US model) will run on?

I don't have a SNES powersupply, and I modded it with a standard DC jack, but noticed something, the lowest power brick I have right now, is a 7v 500mA, and it's working fine, no screen glitches, it's perfect...  the power brick isn't even getting all that hot either, so it's not working it hard..

so if this is the case here, why did Nintendo chose a 10v?

[Guest]

My guess is because of the voltage regulator.  There's a certain voltage input (and factors like temperature) that's different for each regulator, that gives the most effecient and balanced output.  ie With the minimum voltage input the output current might not be strong enough to puwer the system, but the max voltage might damage the regulator.  The graph would look like an arc and somewhere in the middle is the best input (probably 10v in this case).  That's always been my take on it.

[viletim!]

It's all about looking at the worst case scenario. The 7805 voltage regulator is only guarenteed to work with minimum of 7 volts input...it may work with a lower input, it may not. So input must be > 7V. The output of a typical ac adaptor has about 20% of voltage ripple couple of volts of AC ripple on the output under full load (so the output of a 10v supply will lie somewhere be between 9 and 11v at any given instant). Considering this the input must be > 8v. But what about the power line regulation? it's something like +- 10% so now the input must be > 9v in case the mains voltage is low one day. And we'll add another volt to cover all the other minor variables like transformer tolerance, tolerance of components changing due to high temperatures, aging of components (capacitor gets old, and now there's more ripple voltage on the output), etc, etc

So, to summarise, the SNES power supply is 10v so your SNES (that has a borderline spec voltage regulator) will work with a old, heavily used power supply, on a really hot day, when the mains line voltage is low (cause everyone's got their aircons runnig on max probably).