NES power supply question

[Fudoh]

Is it right that all european 50Hz models use power supplies with 9V AC output, while the NTSC US NES units use a power supply with 9V DC output ? Or did the original US NES psu supply AC as well and the US NES simply can be used with a DC power supply as well ?

[ApolloBoy]

The American NES uses AC as well, but you can use a DC power supply without problems.

[leonk]

All modern circuit boards use DC power to drive the logic. The first thing the NES does on the power input is use a bridge rectifier to convert AC to DC. That's why you can use DC without harm.

[Fudoh]

Ok, and if I were to use a DC power supply, would the polarity matter ?

[RGB]

No, the polarity doesn't matter in this case.

[PC Engine Fan X!]

On a whim, I used one of those variable 120v AC to DC convertor adapters with DC voltages ranging from 3v, 4.5v, 6v, 7.5v, 9v, & 12v. If the selection power switch was placed on 7.5v or even 6v with an USA region NES console, you'd get some strange looking & funky graphics on the TV monitor just for kicks. There was a switch for reversing the polarity "on the fly" as well.

PC Engine Fan X! ^_~