N64 Power - DO I need 12V and 3V?

chodges84 · Post by **chodges84** » Fri May 13, 2005 3:47 pm

Hi Guys,

N00b here with a few questions (I've had a look through all six pages adn If anything I'm more confused than when I was when I began).

Anyway, I'm about to start building an N64p, with a psone screen. Here's where I'm stuck though. I thought I'd use High Capacity AA's with one of these boxes to hold them in;

http://www.maplin.co.uk/Module.aspx?Mod ... &doy=13m5D

Now, how many AA's am I going to need. From what I can gather, I will need 12V on the N64, 3V on the N64, adn 7.2 (?) on the screen.

I thought if I use 8 x AA, that will get me approx. 12V (although do rechargeable AA's have only 1.2V?) don't they?). So no probs with the 12V, as I can wire that staright in (I think). If I then wire in a car DC-DC convertor, I can knock it down to 3V (I assume it is wired in parallel), so that's the 3V.

Now the 7.2. I found this wiring diagram;

http://saoghal.cywh.com/N64m_Pictures/Wiring.JPG

And the person used an extra battery pack with 5 AA's for the screen. If I replace this with another DC-DC convertor, would it work, or is there a more graceful way of doing this?

Thanks in advance.

Craig.

*o* · Post by ***o*** » Fri May 13, 2005 3:58 pm

to make it with a psone do the same as him excet in place of the extra battery pack you need a 7808 regulator to drop the voltage to 8v (suitable for tthe psone screen

nos_slived · Post by **nos_slived** » Fri May 13, 2005 4:35 pm

PS1 screen has 7805 already.

*o* · Post by ***o*** » Fri May 13, 2005 4:51 pm

to go to the 8v required

Post by **gannon** » Fri May 13, 2005 7:02 pm

Why do you guys keep on saying 7808? It's a 7805 in the n64 and psone lcd

Warrior_Rocker · Post by **Warrior_Rocker** » Fri May 13, 2005 7:06 pm

in answer to your power question, it is not wise to run independant power for each voltage, this only increases circuit complexity, charge time, and the amount of batteries?, goto ebay find a 12v to 3v walkman adapter and use that, so that you can have a central 12v power system, and then be able to have a single power input for recharging, as for the ps1 screen, i dunno about inputting anything not around 7~8v so to achive that go buy the 5 dollar converter off ebay for the ps1, you, a) save space in your portable b) cut down on cost c) cut down on charge time d) cut down on batteries and weight

*o* · Post by ***o*** » Fri May 13, 2005 7:20 pm

could i run the whole thing of 8v the n64 and screen?

Warrior_Rocker · Post by **Warrior_Rocker** » Fri May 13, 2005 7:51 pm

only if you found a way to run the 3.3v rail off 8v? im not sure if they make a such converter as a 7803, or how you would find a regulator to convert 8v to 3.3v?, however the rest should work fine

chodges84 · Post by **chodges84** » Sat May 14, 2005 6:41 am

Ok, thanks guys.

So i need to replace the 5 AA battery pack in the wiring diagram (see first post) with a 7805 regulator? Is this going to be enough power though, because the PSone Screen needs 7.2V rather than 5V.. (does the PSone screen have a 7805 built in then? those 4 posts up there confused me a bit).

The diagram in this picture would lead me to think so.

http://benheck.com/ipw-web/bulletin/bb/ ... .php?t=469

If it's already got one built in, could I just put a 12V staright into it (Slot 1, Pin 12 on the diagram), and it would work, or do I need a 7808 and plug it in the Slot 1, Pin 1 7.2V?

I've just re read that and it really doen't make much sense. I guess what I'm trying to ask is: Do i need a 7805 or 7808?, could I just put 12V into the LCD screen's 5V input (a 7805 presumably) and it would work? or do i need a 7808 into the 7.2V input?

Thanks,

Warrior_Rocker · Post by **Warrior_Rocker** » Sat May 14, 2005 11:54 am

i dont really understand the '+5v' on the 12th pin of the ps1 screen, im thinking that isnt a input????, someone correct me, i think its only an output, and yes if u had a 7808 regulator you could wire that so you can input 12v into the regulator and then have it inputted to the screen, i dont think you can input 12v directly becuase the last time i did that i think i almost cooked my screen

chodges84 · Post by **chodges84** » Sat May 14, 2005 12:21 pm

cool,

so 7808 it is then. 8 AA's are going to be enough though aren't they. I looked at some rechargeables today at work, and they reckon 1.2V, but I guess they work in everything else under voltage (samera's walkman etc.) so they should do the job.

Warrior_Rocker · Post by **Warrior_Rocker** » Sat May 14, 2005 1:00 pm

yea..., actually the funny part about rechargeables is they never really are what they say, like 1.2's generally charge up to like 1.4 or even 1.5, and yess a 7808 regulator should work fine, since they normally take appx 3v hihgher then what they are rated to output, so since ur batts are 1.2 that will put u at like 10 ~12v i mean, maybe having 10 of them wouldnt be the worst idea, there is nothing that is going to get cooked that way, and the 78XX family regulators will work till like 30is Volts???, and since the n64 uses one on its 12v in, and since u should use a 3v walkman adaptor for your 3.3v input to your n64, you should be great, so basically id reccomend using 10 of those buggers, just cuase also 12v power adaptors are a dime a dozen, and ehh, its only 2 more batteries...., but certianly you should be able to get by with 8, i just think you would get more gameplay time off 10 cells

Post by **Triton** » Sat May 14, 2005 2:48 pm

why would you get more gameplay off of 10 cells? it would only give you more voltage, not amperage.

Warrior_Rocker · Post by **Warrior_Rocker** » Sat May 14, 2005 3:13 pm

as ive explained before, a voltage converter has to work harder as the voltage drops, therefor the more voltage you start out with the less the voltage converter has to work, and the less energy the regulator has to consume the more effient it is, and then the more time you get to play on the same amount of energy....

thats how you would get more gameplay, at least from my experience
however with portables its all just how you engeneer it...

chodges84 · Post by **chodges84** » Sat May 14, 2005 3:40 pm

Ok, thanks warrior_rocker, I'll go with 10 batteries.

Triton, you say it won't produce any more amperage, what I would like to know is how amperage is worked out. If i had 10 x 2000mAh AA's, Would I have 20000mAh (2 AH) in total, and If I went with 8 AA's, would it be 16000mAh? That seems like a good enough reason alone to have the extra 2 batteries, or doen't it work like that. (I'm sure I can work that one out myself, but it's getting late over here in the UK and i'm tired)

Thanks.