NES power adaptor spec?

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Zepper
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NES power adaptor spec?

Post by Zepper »

I need another power adaptor, but I need to know the voltage and ampères.
tepples
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Re: NES power adaptor spec?

Post by tepples »

The NES Control Deck needs 9 to 10 V, at least 850 mA. Polarity is not important because it uses a diode bridge rectifier. Center negative, center positive, and 9 V AC will all work. Thus the AC adapter for Famicom, Master System, Mega Drive/Genesis model 1, or Sega CD (all 9-10 V DC center negative) will safely power an NES. For example, a Sega MK-1602 (for Genesis) will provide 9 or 10 V DC depending on revision, center negative, at up to 1200 mA. A Sega 3025 (for Master System) provides 9 V DC, center negative, at up to 1000 mA. (See specs and photos at Sega Retro.) It's OK to use an adapter that provides more current (mA) than you need; that's called "headroom".

But don't try using the official NES-002 adapter on a Famicom or Sega system. It'll fry it because these systems can handle only center negative, not the AC that the NES-002 produces.
lidnariq
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Re: NES power adaptor spec?

Post by lidnariq »

Official NES-001 power source is a 9VAC 1.3A supply. (AC, therefore nonpolarized)

It doesn't use the AC anywhere, it just converts it to unregulated DC, goes through the power switch, and then goes two places:
1- presents it on the expansion port for the never-released FDS.
2- goes through a standard 7805 to produce 5V for everything else.

This only counts if you're using an actual NES-001.

The actual NES seems to consume approximately 400-600mA at 5V. I have been using mine with a switching 9VDC 0.5A supply. Anything above 8.2VDC should be fine.
Pokun
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Re: NES power adaptor spec?

Post by Pokun »

So the NES expansion port gets 9V.

I use a Sega model 1 adapter with my Famicom. It's 1 A so it's probably enough even with a flashcart and lots of accessories.

Here's a sticky that should cover most models of the Famicom and NES:
https://www.famicomworld.com/forum/inde ... pic=6933.0
lidnariq
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Re: NES power adaptor spec?

Post by lidnariq »

Pokun wrote:So the NES expansion port gets 9V.
Ehhh....
It's an unregulated power supply. It gets something somewhere between 20VDC and 9VDC depending on load.

The 9VAC 1.3A means that when 1.3A are being drawn the voltage will be 9VAC, but when less current is drawn the voltage will be higher. In addition converting from AC to DC using a full-wave rectifier increases the received voltage by √2. (9VRMSAC ≈ 13VppAC)
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