Low Battery Indication LED for GBC

[N00BModdr]

Does anyone know a circuit for use on a GBC that would use 2 LEDs, one blue, and one red, that would switch the power LED, (which would be blue), to red when the batteries get low? Say, below 20%.

 

[Bibin]

There are circuits to do this, but if I remember correctly Radioshack sells a dual color LED that switches colors based on what voltage is going through. It is really just two different diodes in one package with different operating voltages, but it works all the same.

 

[N00BModdr]

So all I would need to do is desolder the current power LED and solder in the dual color LED of the voltage I want?

 

[Bibin]

So all I would need to do is desolder the current power LED and solder in the dual color LED of the voltage I want?

It's been a while since I saw one, so you should really go look at it at the store. I believe it has some basic diagrams on the back, but I last saw it 3 years ago, so they may have become worse in how helpful they are.

 

[N00BModdr]

I looked on RadioShack's website, and all I can find is bicolor LEDs that have three prongs, and change color depeding on what is hooked up where. Nothing on voltage. I'm going to RadioShack tomorrow anyways, so I'll ask...

but I last saw it 3 years ago, so they may have become worse in how helpful they are.

They have.

 

[jleemero]

Maybe you mean these:
http://www.radioshack.com/product/index.jsp?productId=2062549&tab=summary

Unfortunately, it's not voltage dependent or anything like that.
Just a simple bicolor LED.

Run current through one way, it's Red.
The other way, Green.

 

[Bibin]

Maybe you mean these:
http://www.radioshack.com/product/index.jsp?productId=2062549&tab=summary

Unfortunately, it's not voltage dependent or anything like that.
Just a simple bicolor LED.

Run current through one way, it's Red.
The other way, Green.

No, it was a different one, made to work in the fashion described. I only saw it a few times a year ago, though, so I'd not be surprised if Rat Shack stopped carrying them (or anything else useful)

 

[N00BModdr]

Maybe you mean these:http://www.radioshack.com/product/index.jsp?productId=2062549&tab=summary

Yeah, that's what I meant.

Unfortunately, it's not voltage dependent or anything like that. Just a simple bicolor LED. Run current through one way, it's Red. The other way, Green.

[/quote]
That's basically what I said. I do want it to be blue and red, though.

 

[jleemero]

Maybe you mean these:
http://www.radioshack.com/product/index.jsp?productId=2062549&tab=summary

Unfortunately, it's not voltage dependent or anything like that.
Just a simple bicolor LED.

Run current through one way, it's Red.
The other way, Green.

No, it was a different one, made to work in the fashion described. I only saw it a few times a year ago, though, so I'd not be surprised if Rat Shack stopped carrying them (or anything else useful)

Interesting.

 

[N00BModdr]

Just so I don't look like an idiot:

I looked on RadioShack's website, and all I can find is bicolor LEDs that have three prongs, and change color depeding on what is hooked up where. Nothing on voltage. I'm going to RadioShack tomorrow anyways, so I'll ask...

Maybe you mean these:http://www.radioshack.com/product/index.jsp?productId=2062549&tab=summary

Yeah, that's what I meant.

Unfortunately, it's not voltage dependent or anything like that. Just a simple bicolor LED. Run current through one way, it's Red. The other way, Green.

That's basically what I said.

I was refering to that post.

 

[Basement_Modder]

This is the simplest solution. The circuit will need to be modified a little, working on that.

EDIT-
Battery-6v (approx. 6.3v on full charge. LED goes to red at 6.1v)
R1-5600 ohm
R2-4700 ohm
R3-470 ohm

Just apply that to daftmike's circuit and you're all set.

 

[Bibin]

This is the simplest solution. The circuit will need to be modified a little, working on that.

EDIT-
Battery-6v (approx. 6.3v on full charge. LED goes to red at 6.1v)
R1-5600 ohm
R2-4700 ohm
R3-470 ohm

Just apply that to daftmike's circuit and you're all set.

Close, but the GBC runs on 3V.

 

[XCVG]

This is the simplest solution. The circuit will need to be modified a little, working on that.

EDIT-
Battery-6v (approx. 6.3v on full charge. LED goes to red at 6.1v)
R1-5600 ohm
R2-4700 ohm
R3-470 ohm

Just apply that to daftmike's circuit and you're all set.

Close, but the GBC runs on 3V.

That's what voltage regulators are for.

 

[jleemero]

Close, but the GBC runs on 3V.

That's what voltage regulators are for.

 

[Basement_Modder]

Yes, you would need a reg, I just forgot to draw it in.

 

[Basement_Modder]

Here- I made a diagram for the reg:

 

[jleemero]

Find a place to shove those 2 extra batteries in a Gameboy Color.

 

[Basement_Modder]

That's what LI-PO batteries are for. :wink3:
If you used 2 of these in parallel, you could fit them in, and use the originally designed 7.4v circuit. Win-win.

 

[Bibin]

Why not just do it right the first time with 3V? A voltage regulator will waste a bit of power anyway, and take up more space.

 

[eurddrue]

Why not just do it right the first time with 3V? A voltage regulator will waste a bit of power anyway, and take up more space.

Then his precious circuit wouldn't work.