N64 portable power supply question?

Kadok · Post by **Kadok** » Tue Apr 22, 2008 4:01 pm

Since the normal electrical outlet output is 120V that means that the N64 power supply converts it to 3.3V and 12V before sending it through to the MOBO, so what I was wondering is could I just plug the power supply into the N64 then wire my battery to the N64's power supply and have it convert the voltage for me. I made a diagram cause its easy to understand when you see it. look below.

see what I mean?

evilteddy · Post by **evilteddy** » Tue Apr 22, 2008 4:06 pm

I don't know if its possible or not but even if it is that power brick is huge. Its way bigger than you want for a portable. What you need is a switching regulator. The TI card is the most common. You could probably get one from someone on the forums.

Kadok · Post by **Kadok** » Tue Apr 22, 2008 4:08 pm

I dont really care about size, its not a concern. I can work out the issue of heat I just want to know if It will work

evilteddy · Post by **evilteddy** » Tue Apr 22, 2008 4:18 pm

According to the third topic on the second page it has been done. You will probably have to break out a multimetre and find out how much voltage is coming out of the transformer (the DC side that is). Thats assuming that the transformer is converting AC to DC but it also might be regulating the 3.3V line. I would tend to assume that it is doing the former. After investigating with the multimeter and finding that a Dc supply of x volts is coming out one side of the transformer and that afterwards it runs to the regulator part of the circuit then all you have to do is desolder the transformer and solder in a battery on the old +- dc leads with x voltage mentioned above.

Remember this is all assuming that the transformer is used to turn AC into DC and that the circuitry before that has no connections to the other side. But it is what I have said above is probably correct just trust what your multimeter tells you.

Oh I nearly forgot. If the two halves on the circuit aren't interconnected then you will be able to cut down the AC side so that the board is much smaller.

HBN · Post by **HBN** » Tue Apr 22, 2008 5:30 pm

Theres a way to do this properly, but it'll cost ya about $50. An automotive voltage converter. I suggest ACAnyware, by Belkin.

It converts the 12VDC coming from the battery, to 120VAC. Then plug your power supply into that. Most also have a indicator lamp that tells you when the battery is getting low.

Kadok · Post by **Kadok** » Tue Apr 22, 2008 5:33 pm

why do I need 120VAC goin in to get 3.3V and 12V out? does it matter how much goes in?

HBN · Post by **HBN** » Tue Apr 22, 2008 5:56 pm

Yes. It can effect a lot of things. Like power fluctuations. Which will kill a lot of electronics. And seeing as how sensitive the 3.3v line is, I'd be worried about frying it.

Not to mention; if the power drops to low, the system will shut off.

bacteria · Post by **bacteria** » Wed Apr 23, 2008 2:34 am

This doesn't make sense - the power supply that comes with your N64 takes mains electricity and converts it into two DC power lines, 3v and 11v lines, to feed the N64. That is why we can portablize the system, the N64 needs DC power, and a 7.2v battery runs the larger power line and a TI step-down regulator (the size of a large thumbnail) also gives you 3.2v; thus you can run an N64p. If you don't have a step-down regulator you can run the system off two sets of batteries to get the two voltages but this is daft as they will run out at different times; the 11v line barely uses any draw but the 3v line uses quite a lot.

HBN · Post by **HBN** » Wed Apr 23, 2008 9:16 am

bacteria wrote:This doesn't make sense - the power supply that comes with your N64 takes mains electricity and converts it into two DC power lines, 3v and 11v lines, to feed the N64. That is why we can portablize the system, the N64 needs DC power, and a 7.2v battery runs the larger power line and a TI step-down regulator (the size of a large thumbnail) also gives you 3.2v; thus you can run an N64p. If you don't have a step-down regulator you can run the system off two sets of batteries to get the two voltages but this is daft as they will run out at different times; the 11v line barely uses any draw but the 3v line uses quite a lot.

As near as I can figure, thats because the RAM in on the 3.3. I dont know if that helps, but RAM is one of the most energy-sucking things you can find in a computer. And lets face it. Thats what all these systems are. Just some are way better than others.

Thats another reason that 12VD/120VAC converter is needed. I can't believe I missed this: The power supply runs on AC current. It wont do anything if you just plug that into a battery.

vskid · Post by **vskid** » Wed Apr 23, 2008 3:11 pm

I'm assuming the N64 PSU converts the 120v AC to 12v DC, which then goes to the 12v line and a converter down to 3.3v. So you could probably just find the 3.3v converter portion. I'd try it myself, but I think I threw out chopped up PSU.

evilteddy · Post by **evilteddy** » Wed Apr 23, 2008 3:17 pm

So instead of finding what voltage to input at the transformer find where the voltage is regulated to twelve and then is sent off to the 3.3V regulator? Thats a good idea considering he has 7.2V batterys and the resulting hacked up board could be quite small.

bacteria · Post by **bacteria** » Wed Apr 23, 2008 8:24 pm

No, the 12v and 3v lines are converted in the thick and bulky N64 power pack not on the N64 mobo. Get a TI card if you want to make a portable!