Question about wiring and batteries

[Chapel]

Ok, so I have read quite a bit on this forum and player around with some electronics. Now, I have come to this really basic understanding about how this all works. If someone could please tell me, more or less, how close I am to the real thing it would be appreciated.

There are, in simplistic terms, 4 items inside a portable: battery, console, screen, controller. The screen and controller should both be connected to the console for data exchange. Then wire up the screen and console to battery in parallel (don't forget the ground, apparently that is an easy mistake to make). So basically, if that is all correct it is like those old elementary school circuits with complex electronic parts instead of 3W light bulbs, right?

Anyway, as for battery selection. There are two major ratings that I should be concerned with: Voltage and Milliamp-hours (right?). Now, if my console and my screen are rated for different voltages, do I need to create a step down for the lower voltage or will it simply be turned into heat somewhere along the line and not ruin any parts? For example: A Gamecube is rated at 12V - 3.5Ah, but a 5" LCD screen is rated at 7.5V - 1.5Ah. Would a 12V battery with 5Ah be sufficient to run both components or would I have to worry about the 12V ruining the 7.5V screen? (As a secondary question, I noticed that batteryspace.com sells 7.2V batteries, will the .3V difference mean that the screen won't run?)

I'm very sorry for the basic questions, I just want to make sure I have all of this stuff correctly organized in my head before I go out and ruin some mildly expensive consumer electronics. Thank you in advance to everyone who responds.

[marbs]

I can answer two of your questions:
1) Putting 12v through the PSone screen will most likely break it;
2) The PSone screen can run off a voltage slightly lower than the stated 7.5v, so 7.2v should be fine (but I am not certain of this);

And so yes, if the gamecube needs 12v and the screen 7.5v you'll need to get some sort of thing to drop down the voltage. As far as I am aware there are two main ways of doing this, one with a device like a 7805 regulator which converts the extra voltage into heat, or by using a more efficient regulator circuit such as I am using in my N64p project.

Hope that helps

[Valium]

I can answer two of your questions:
1) Putting 12v through the PSone screen will most likely break it;
2) The PSone screen can run off a voltage slightly lower than the stated 7.5v, so 7.2v should be fine (but I am not certain of this);

And so yes, if the gamecube needs 12v and the screen 7.5v you'll need to get some sort of thing to drop down the voltage. As far as I am aware there are two main ways of doing this, one with a device like a 7805 regulator which converts the extra voltage into heat, or by using a more efficient regulator circuit such as I am using in my N64p project.

Hope that helps

2; It will work with 7.2v.
A 7805 would bring the voltage down to 5v, a 7808 is likely what you'd want

But, as I recall, the Gamecube only needs 12v for the sound amplifier, so it'd be better off to use a 7.2v battery and a step up converter to bump it up to 12v.

[Neildo_64]

You can make a 7808 from a 7805. Here is a link to bic's page. and here is a more in depth version

[Chapel]

Thanks a lot folks, you have probably saved me many headaches with these few posts.

Does everything else check out more or less? For instance, in this example would my choice of battery (5 Ah) be under doing it, over doing it or about right. No one would really need a battery that lasts for days on end, especially if I was sacrificing so much size for it.

[Valium]

Thanks a lot folks, you have probably saved me many headaches with these few posts.

Does everything else check out more or less? For instance, in this example would my choice of battery (5 Ah) be under doing it, over doing it or about right. No one would really need a battery that lasts for days on end, especially if I was sacrificing so much size for it.

I don't exactly remember the draw of the Gamecube, but I do remember it being fairly high. 5Ah will probably get at least 3-4 hours of game play.

[Chapel]

Thanks a lot folks, you have probably saved me many headaches with these few posts.

Does everything else check out more or less? For instance, in this example would my choice of battery (5 Ah) be under doing it, over doing it or about right. No one would really need a battery that lasts for days on end, especially if I was sacrificing so much size for it.

I don't exactly remember the draw of the Gamecube, but I do remember it being fairly high. 5Ah will probably get at least 3-4 hours of game play.

Is there an equation to approximate battery life or is it just familiarity with the materials?

[Valium]

Thanks a lot folks, you have probably saved me many headaches with these few posts.

Does everything else check out more or less? For instance, in this example would my choice of battery (5 Ah) be under doing it, over doing it or about right. No one would really need a battery that lasts for days on end, especially if I was sacrificing so much size for it.

I don't exactly remember the draw of the Gamecube, but I do remember it being fairly high. 5Ah will probably get at least 3-4 hours of game play.

Is there an equation to approximate battery life or is it just familiarity with the materials?

MAh of battery divided by mAh used by the system.

5000mAh battery / (est) 1500mAh draw from gamecube + screen = 3 hours and 20 minutes of play time

[Chapel]

Thanks a lot folks, you have probably saved me many headaches with these few posts.

Does everything else check out more or less? For instance, in this example would my choice of battery (5 Ah) be under doing it, over doing it or about right. No one would really need a battery that lasts for days on end, especially if I was sacrificing so much size for it.

I don't exactly remember the draw of the Gamecube, but I do remember it being fairly high. 5Ah will probably get at least 3-4 hours of game play.

Is there an equation to approximate battery life or is it just familiarity with the materials?

MAh of battery divided by mAh used by the system.

5000mAh battery / (est) 1500mAh draw from gamecube + screen = 3 hours and 20 minutes of play time

Beautiful... it is so simple I feel I should have known that. Thanks.

[timmeh87]

Seig heil! its the unit nazi.

mA vs mAh. They are different things. One is instantaneous while the other is a summation over time. Kind of like speed vs distance.

You consoles are all rated in mA
Your batteries are all rated in mAh

play time in hours = mAh/mA

you can do an analysis on the units, and see that the mA/mA part cancels out and we are left with hours.

You guys throw mAh around like its a toy.

[Chapel]

Seig heil! its the unit nazi.

mA vs mAh. They are different things. One is instantaneous while the other is a summation over time. Kind of like speed vs distance.

You consoles are all rated in mA
Your batteries are all rated in mAh

play time in hours = mAh/mA

you can do an analysis on the units, and see that the mA/mA part cancels out and we are left with hours.

You guys throw mAh around like its a toy.

Yeah... I kinda realized my mistake when he gave the equation. Sorry about that. Units are important.

Although, I guess one could say that a 1500mA item draws 1500mAh per hours, but that would just be overly wordy.

[grossaffe]

Seig heil! its the unit nazi.

mA vs mAh. They are different things. One is instantaneous while the other is a summation over time. Kind of like speed vs distance.

You consoles are all rated in mA
Your batteries are all rated in mAh

play time in hours = mAh/mA

you can do an analysis on the units, and see that the mA/mA part cancels out and we are left with hours.

You guys throw mAh around like its a toy.

I was gonna ask about the units as it seemed a little odd to be left with a measurement with no units. glad I didn't have to ask.

... i guess i didn't even have to post this, did i? moving along...

[Chapel]

Ok, last thing here before I go experiment and ruin some cheap equipment before working with real equipment.

If I am working with something with only a single audio out, is it sufficient to simply solder that to both the L-audio and R-audio to make sound is coming out of both speakers (even if it isn't true stereo, I would rather use both speakers)?