Voltage/Wiring

[tappan]

My question is based upon this image:

from: http://www.stephanj.com/n64/home.html

Why is the input and ground wired together?
... i.e. The ground has the resistors wired in series(parallel?) attached to the input line. Also... there is no voltage going in.

Is his diagram not right, or am I missing something?

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How should I wire my 3.3v LDO?
Like this?


I'm going to be using 2 8.4v 3Ah batteries wired parallel for 6Ah.
Now, I know that I will running another line off of the 3.3 for LEDs once I mod my screen.

Anybody see anything wrong with the above?

[gannon]

He used an adjustable regulator that requires external resistors to specify the output voltage, not a ldo.

[HK-47]

My question is based upon this image:

from: http://www.stephanj.com/n64/home.html

Why is the input and ground wired together?
... i.e. The ground has the resistors wired in series(parallel?) attached to the input line. Also... there is no voltage going in.

Is his diagram not right, or am I missing something?

-------------------------------------------------------------------------

How should I wire my 3.3v LDO?
Like this?


I'm going to be using 2 8.4v 3Ah batteries wired parallel for 6Ah.
Now, I know that I will running another line off of the 3.3 for LEDs once I mod my screen.

Anybody see anything wrong with the above?

Ahh.. I think I know... I think the 7805 or whatever is ground biased. What I mean is that the regulator takes gnd as 0v then regulates the power 5v above that. So if you put 5v into the 7805 ground, it would start regulating power to 10, instead of 5v. Something like that... Ask sponge hes the electronic-class-taking-guy...
EDIT: Gannons probably right...

[SpongeBuell]

Ask sponge hes the electronic-class-taking-guy...

That was only one term, and there was very little talk of voltage regulators, just how xener (sp) diodes can have a somewhat stable voltage drop.

[HK-47]

Ask sponge hes the electronic-class-taking-guy...

That was only one term, and there was very little talk of voltage regulators, just how xener (sp) diodes can have a somewhat stable voltage drop.

Its zener.

[SpongeBuell]

all the more proof that we didn't talk about voltage regulators much

[tappan]

I'm sorry... I wasn't real clear.
They were two seperate questions.
What's up with his diagram? ( There's no voltage going into his 7805. )
-and-
Does my diagram look correct?

[HK-47]

1. There is voltage going into his 7805
2. Your diagrams fine

[tappan]

Then I guess I'm reading the diagram wrong...
Looking at the 7805 pins.. left to right:
Output Grnd Input

and N64 Power Pinout is:

Code: Select all

3                      1
 (12)(3.3)(3.3)
 (12)(12)(GRD)
6                       4

I guess it's actually reversed.
I always have to make myself remember that when the show voltage in diagrams, they have + and - reversed. I always think of + as ground.

Which I guess means that the power pinout on the N64 is:

Code: Select all

3                      1
 (GRD)(3.3)(3.3)
 (GRD)(GRD)(12)
6                       4

[HK-47]

^Yeah... Some 7805s go IN GND OUT, instead of your OUT GND IN...

[Unidentified Assilant]

That doesn't actually look to hard to wire

[JackFrost22]

Nothing ever does. But when you start it becomes hard

[Gamelver]

well, not always.........that circuit could be wired up real quick, all you'd need are some soldering skils and supplies and stuff..........although more complicated circuits can definitely look easier to wire than they really are....