Power Adaptors / Famicom Power Supply

[michaelthegreat]

It does clear everything up. Nice explanation. Somewhere someone once said that extra voltage would slowly fry the Famicom. Glad it doesn't. Well, I've got a stepdown anyway, so it makes little difference to me, I guess.

Yeah, if I remember a long time ago somebody said their famicom ran hot and asked if it was ok to use the JP adapter. I said I don't have a famicom but if you think it's the power you might want to get a US adapter with the same power or a step down converter. He did and he said it solved his problem. Then others asked if they needed that and I said I don't know. If should be fine, but if you want to be super cautious, you can. I think that's where it started. So it's partially my fault. We should go back and delete some of those old posts or sticky this info or something.

Start a stickied post with:

In the us you have two good options:
1. Use the original adapter
2. Use a US adapter that puts out the same power

In Europe you have two good options:
1. Use the original adapter and a step down converter
2. Use a 220 adapter that puts out the right power

Never use a NES adapter

Then give the power adapter specs for the famicom, disk system,l etc.

[ancientflounder]

I recently acquired a Famicom and FDS from a friend of mine through a trade.  The Famicom, unfortunately, stopped working but I have since purchased an AV Famicom to replace it.  For the broken Fami, I was given a Hori AC Adapter (HA-7) to power it.  The info shown on the label is:

AC100V 50-60Hz 16VA
DC10V 850mA
+ ----C---- -

It worked fine on the Fami and anything we tested out afterward.  So, after such a long-winded lead-up (XD), my question is if this adapter might work for the FDS, since I did not receive an AC adapter for it?  I know that the Hori AC is not the same as what the official FDS AC provides, power-wise, but is it enough of a difference that could potentially put the FDS in harm's way if I were to use the Hori adapter on it?

[133MHz]

No problems. It will work perfectly with the FDS.

[ancientflounder]

No problems. It will work perfectly with the FDS.

Spiffy.  So, the 9VA difference doesn't really matter?  That was my only real concern, since I know a 1V difference on the DC and the extra 450mA wouldn't really pose much of a threat of blowing out the FDS.

Update:  Indeed, it works dandy.  Tested it out when my AV Fami arrived this morning.  The FDS runs nice and cool. 

[Arctic Feather]

I should have an AV Famicom coming my way soon, but I'll need a power supply for it that can be used here in the UK.  Does the standard Famicom use the same power supply as an AV Famicom?

I was looking at the one listed on here: http://www.robwebb.clara.co.uk/shop/nes/nes.htm, which says it can be used for a Famicom, but was wondering if it would be okay for an AV Famicom too.

Thanks

[133MHz]

I should have an AV Famicom coming my way soon, but I'll need a power supply for it that can be used here in the UK.  Does the standard Famicom use the same power supply as an AV Famicom?

Yes sir.

I was looking at the one listed on here: http://www.robwebb.clara.co.uk/shop/nes/nes.htm, which says it can be used for a Famicom, but was wondering if it would be okay for an AV Famicom too.

Thanks

Mains adaptor/power supply unit      £6
   
    * Brand new item.
    * AC 230V to DC 9V mains adaptor/power supply
    * Output 9V DC, 1.2A, center negative

This is the one you need.

[Arctic Feather]

Thanks a lot 

[JC]

Would I be right that using a UK NES adaptor to power a Famicom in the UK is a VERY bad idea? I'd assume the UK NES outputs DC AC and 220V can cook, no? Someone did this on another forum.

[133MHz]

UK NES AC adapter should have the same output of a US NES AC adapter (9V AC), only the inputs differ to take the line voltage from the country it's being used. So it would do exactly the same as somebody in the US powering his Famicom with a NES AC adapter.

Now if you plug a US/JP AC adapter (100-127V) into a UK socket (240V), then you're cooking with power!
Transformers are linear devices, so if your transformer is 110V in - 9V out, then feeding it 220V in would get you 18V out, with two possible outcomes:

1) The transformer was designed to tolerate twice the input voltage on its primary and will happily churn out 18V at its output.
2) Smoke, sparks and flames since it was not designed to handle twice its input rating.

[JC]

I see...so the only problem then, like with the US NES adaptor is the AC (said DC earlier, I meant AC).

EDIT: For some reason, I never thought of a power adaptor as a voltage regular on it's own; lowering the power from 120V (or whatever) to what the device needs. Seems so obvious. What's the point, then, of the Famicom having an internal regulator?

[133MHz]

A transformer can step a voltage up or down since it's a linear device and it all depends on the turns ratio of the windings and the input voltage (i.e. if you build a transformer with 120 turns on the primary and feed 120V into it, and build a secondary of 20 turns and another with 9000 turns, you'll get 20V from the first one and 9000V from the other one, couldn't be simpler).

Ohm's Law states that voltage is the product of the current by resistance (the famous V=I*R) and also that power is the product of current by voltage (P=I*V). So when voltage goes up, amps go down, and when voltage goes down, amps go up. Everything is nicely related and so you can step the voltage up or down for any given power.

But there's also one more thing: the output voltage from a transformer varies with the load attached to it. If you measure the output voltage from a Famicom plug pack rated for 10V with no Famicom attached you'll get a wildly high reading like 20 volts but if you load it with a Famicom you'll get something closer to 10 volts. This is because the load increases the current (and the power used) and therefore lowers the voltage.

As you may have imagined, the Famicom doesn't always use the same amount of power, it depends on how hard the CPU is working, how many accessories are attached to it, how big is the game, etc. This would mean that the voltage would never be constant, it will be always varying depending on the situation, and that's no good for digital circuits (where 0 and 1 are represented by specific, steady voltage levels) and analog circuits (where i.e. video brightness is represented by a voltage value).

So then, the Famicom's internal voltage regulator is an integrated circuit whose task is to maintain the output voltage at a constant 5 volts no matter how much the input voltage and the output load vary. You can feed any voltage from 7 to 24 volts and load it up to 1 ampere and it will always keep its output at 5.00 V (the excess power is dissipated as heat through its body, that's why it's screwed to a big aluminum heatsink which gets hot during use - for 9V operation it wastes 4V as heat).

And you guessed it: The 05 in 7805 is the output voltage, so a 7810 gives 10V, a 7824 gives 24V, etc.

Hope this clears things up (and I hope I didn't bore you to death )

[SeanOrange]

Hoyl carp, that's actually really fascinating.  I took a bit of this in school for a physics class, but didn't do much beyond that.  It's messed up how the direction of current is backwards because of the assumption of a "positive" flow -- and yet we find that electrons are negatively charged and actually move in the opposite direction.  And yet if you flip your circuitry, it will screw everything up (unless I misunderstood).  Very, VERY weird.

I suppose then that if P=I*V and V=I*R, then actually P=I^2*R?

[133MHz]

Hoyl carp, that's actually really fascinating.  I took a bit of this in school for a physics class, but didn't do much beyond that.  It's messed up how the direction of current is backwards because of the assumption of a "positive" flow -- and yet we find that electrons are negatively charged and actually move in the opposite direction.  And yet if you flip your circuitry, it will screw everything up (unless I misunderstood).  Very, VERY weird.

True dat.

I suppose then that if P=I*V and V=I*R, then actually P=I^2*R?

Also correct .

[turbo D]

Sup dudes. I tested out my crappy famicom today with my turbografx-16 psu and it was a success! So I guess you can add it to the list of compatible psus. heh. Its a little low on the milliamps, but it gets the job done.

Turbografx-16 psu

HES-ACA-01
INPUT: 120VAC 60Hz15W
OUTPUT: 10.5VDC 730mA

[Bobinsky]

I am planning to buy a famicom, but cannot find the ac adapter. i am wondering if a super nintendo's ac adapter will work. it inputs AC 120v 60Hz 17W and outputs DC10v 850mA