N64p guide!!!!!!!!

*o* · Post by ***o*** » Sat Jul 23, 2005 5:14 pm

i have read the data sheet and the resistors dont carry any current. so buy 1 or 2w i geuss

Godzilla · Post by **Godzilla** » Sat Jul 23, 2005 7:18 pm

So, I should go with 2 ohms instead of 3 just to be safe? Since my N64 is a NUS-001, I should probably error on the side of too many volts instead of too few.

*o* · Post by ***o*** » Sat Jul 23, 2005 10:24 pm

nos_slived · Post by **nos_slived** » Sun Jul 24, 2005 2:13 am

I still say stick with the LM317, and wire some resistors in parallel. If you wired them in parallel, you could use lower wattage resistors, and you could get closer to the proper resistance(a 680 ohm would be about 3.05V). At 3.3V, with a draw of 1.5A, you would be under 5W, so if you used 3 2W resistors in parallel, you would be safe. The 7805 and 3 ohm resistor circuit works, but it is unefficient.

BTW, you will probably need to use 2 regulators, regardless of whether you use the 7805 or LM317, because both can only handle 1.5A max draw(make sure you get the right ones).

EDIT: I just looked at the layout again, and the current flowing through those resistors should be low, so you probably don't need high wattage resistors.

*o* · Post by ***o*** » Sun Jul 24, 2005 2:32 am

1 lm317 works fine

nos_slived · Post by **nos_slived** » Sun Jul 24, 2005 2:49 am

You're fine aslong as the draw doesn't go over 1.5A. Did you try playing any games with it.

*o* · Post by ***o*** » Sun Jul 24, 2005 2:55 am

yes it worked fine! i used zelda majora mask!

Godzilla · Post by **Godzilla** » Sun Jul 24, 2005 9:22 am

Any chance I could get a diagram of the LM317 and the resistors in parallel?

nos_slived · Post by **nos_slived** » Sun Jul 24, 2005 10:02 am

I'll make a new diagram later. *o*, did you happen to test the cu8rrent going through those resistors?

Post by **Gamelver** » Sun Jul 24, 2005 10:56 am

the maximum current that the 3.3V line draws is 1.5A, so 1 Lm317 should be fine

....the reason I'm trying to get this to work with simple resistors is because I don't feel like ordering resitors online and I'm not even sure of the specs of the Lm137......anyone feel like posting them

?

btw, I'm pretty sure that using my previous wiring diagram (a 7805 wired to a 1ohm resistor) should theoretically work fine, because from the range of currents that the N64 usually draws on the 3.3V line (1.2-1.5), the voltage would end up being around 3.5 to 3.8V....hmmm....actually, 3.8V might be too high....I'll have to do some testing

.....hmm...a 1.2 ohm resistor would work fine, actually

...

to get a 1.2 ohm resistor, just get 6 1ohm resistors (at least 5W), wire 5 in parallel, and then wire those in series with the other 1 ohm resitor. Wire those between the 5V leg of a 7805 and the 3.3V line and there's a simple circuit to power the N64

!!!...that should theoretically work

Godzilla · Post by **Godzilla** » Sun Jul 24, 2005 12:35 pm

Wouldn't it be easier, if you go with the 7805, to just put two of those 1 ohm resistors in series? Shouldn't that get you comfortably in the range for the 3.3 line?

Post by **Gamelver** » Sun Jul 24, 2005 12:49 pm

nope, because then at 1.2A, the voltage would be 2.6V and at 1.5A the voltage would be 2V...with a 1.2 ohm resitor, the voltage would be 3.56V at 1.2A and 3.2V at 1.5A

Godzilla · Post by **Godzilla** » Sun Jul 24, 2005 1:41 pm

What would it be with just a 1.0 ohm resistor?

Edit:
Nevermind, it's already been answered. But wouldn't 3.5 to 3.8 work because I have a NUS-001?

nos_slived · Post by **nos_slived** » Sun Jul 24, 2005 2:18 pm

Gamelver wrote:the maximum current that the 3.3V line draws is 1.5A, so 1 Lm317 should be fine ....the reason I'm trying to get this to work with simple resistors is because I don't feel like ordering resitors online and I'm not even sure of the specs of the Lm137......anyone feel like posting them ?

btw, I'm pretty sure that using my previous wiring diagram (a 7805 wired to a 1ohm resistor) should theoretically work fine, because from the range of currents that the N64 usually draws on the 3.3V line (1.2-1.5), the voltage would end up being around 3.5 to 3.8V....hmmm....actually, 3.8V might be too high....I'll have to do some testing .....hmm...a 1.2 ohm resistor would work fine, actually ...

to get a 1.2 ohm resistor, just get 6 1ohm resistors (at least 5W), wire 5 in parallel, and then wire those in series with the other 1 ohm resitor. Wire those between the 5V leg of a 7805 and the 3.3V line and there's a simple circuit to power the N64 !!!...that should theoretically work

LM317 PDF Datasheet. They show the formula: Vout = 1.25 [1 + (R2/R1)] + lAdj(R2). I don't know what lADJ is, so I stick with: Vout = 1.25 + R2(1.25/R1). I think *o* used my formula and it worked.

If you're sure that the max draw is 1.5A, then a TO-220 will be fine. The 7805 setup would probably be fine for NUS-001s, but 3.8V might be high for the later models.

Are you sure that 5 parallel and one in series is 1.2ohms? If one was in series with all of them, they would all be, brought up by 1 ohm. I think it should be a 2ohm series in parallel with the other 4 resistors. Am I crazy, or is that right?

Here is the new LM317 diagram:

Post by **Gamelver** » Sun Jul 24, 2005 5:42 pm

yeah, I'm sure it's 5 1ohm resistors to get .2....
here's the equation: (1*1*1*1*1)/(1+1+1+1+1)...in other words, 1/5, which is .2 ohms

...add that to 1 ohm and I THINK you get 1.2

.....also, the max voltage using a 1.2 ohm resistor is 3.56V, not 3.8, so hopefully it'll work

. along with the fact that the current doesn't go down to 1.2A very much, I think the 7805 setup should work fine

oh, and Iadj is simply the current coming out of the "adjustable" pin..I think