Battery to Wall Charger Wiring Diagram

[XFactor]

Here is a diagram i made for my system's power supply:
<a href="http://img318.imageshack.us/my.php?image=diagram6mx.png" target="_blank"><img src="http://img318.imageshack.us/img318/2644 ... 6mx.th.png" border="0" alt="Free Image Hosting at www.ImageShack.us" /></a>

I'll try to describe this since it looks confusing, but i made this off of an idea that i believe someone told me on another thread:

1. Once Schottky diodes recieve a voltage on their opposing end (and therefore prevent the flow of electricity in that direction), the diode will close itself off to both the connection being allowed by the diode and the one being prohibited to pass. Is this correct?

So, anyways, this is how the system will work if the above is true: The battery will always have a connection to the N64 through the diode. When i plug in the wall adapter, the schottky diode will cut the connection from the battery. I will then be able to totally run on wall power. When i remove the wall adapter, the schottsky will reconnect the connection between the battery and the N64. The line you see out to the side of the battery is the charging line. It charges independently from the system when the master power switch is off. This allows me to only charge the battery.

Any suggestions or improvements to this method would be appreciated...

[usbcd36]

I see two problems you might want to fix…

1. I don't know if you anticipated this, but the portable will turn on when you plug it in, regardless of whether the switch is on or off. If you want to fix this, move the switch to beyond the point where the AC adapter wire connects to the positive line. Don't change this yet though, since there's something else coming up that you probably want to do instead.

2. If you plug in a charger when the portable is on, it might cause damage to the battery, or even the AC adapter (if you happen to be using it). If you want to prevent this from happening, there is a different way to wire it that would work better. First, take the switch out of the diagram entirely. You will need to use a DPDT switch instead, so get one of those. It should NOT have a center off position. Connect the battery to the middle two terminals, then switch the switch to the position where you want the portable to be on. Connect the portable guts to the side that is hot, keeping the positives on one side and the negatives on the other. Connect the charging terminals to the other side, again keeping the negatives and positives on the same sides. This way, the portable will charge only when the switch is off, avoiding any possibility of accidentally killing something.

You probably won't do something to damage the portable, but that doesn't guarantee someone else won't. Moms, dads, siblings, little cousins, etc…all try to use electronic devices sometimes, and when they are custom built (and therefore not as robustly designed), things can happen. Just read Ben's book; his hand-built SNES portable uses the same circuit as I described.

[codeman]

2. If you plug in a charger when the portable is on, it might cause damage to the battery, or even the AC adapter (if you happen to be using it). If you want to prevent this from happening, there is a different way to wire it that would work better. First, take the switch out of the diagram entirely. You will need to use a DPDT switch instead, so get one of those.

I agree that the power switch should be on the other side of the diode, but I don't agree that the battery could ever be damaged. When the wall charger is plugged in, the battery will not even be in the circuit anymore, the diode will see to that. As long as the charging voltage is lower than the voltage of the wall charger it will be fine.