ABXY Buttons

[Blazinkaos]

Hey guys im trying to do the ABXY mod with the Led lights. Im trying to a series with it but not finding the right info for it im using a site to try to calculate what resistance i need and so on but come up with error and im doing soemthing wrong. This is the site http://ledcalc.com/#calc.
Im using i believe 3mm leds for this.
-blue
-green
-yellow
-red
I belive the voltage for them are 3.0v-3.3v i believe but yea im trying to figure out how to make thos into a series circuit. Some help on this would be nice.

[Hazer]

For starters:

Blue is 3.0V
Red, Green, and Yellow are ~2.2V

Since the controller voltage is 3.0V, you will keep getting an error using the calculator since your supply voltage needs to be greater than the LED voltage. You cannot connect any of these in series, there is not enough voltage.

For the RGY LEDs, you will want a 47 Ohm resistor for each LED connected in parralel. For the Blue ones, use a 10 to 22 Ohm resistor for each LED. It will slightly underpower the LED (you probably wont see the difference) but helps ensure you do not burn it out prematurely (which really blows if you hotglue it into a button).

This is all assuming a 3V supply. Not the 2V switched point on the Matrix. Not the 5V from the wired.

[Blazinkaos]

Ok but im using  wired controller witch gives out 5v though so then the whole process would change.
I had a feeling the series wouldnt work but the parallel would be the best option. But i dnt have to connect a resistor to each led do i can i wire like all the ones that require the 10 to 22 ohm resistor just wire them and connect them all to that.

[Hazer]

You can, but not to a 22 Ohm resistor.

If you plan to use a single resistor:

you take the number of LEDs you plan to wire in parallel and multipy it by 0.02 Amps. (You can only wire red, green, and yellow together. Blue will have its own resistor.) If you have 5V supply, then the resistor will drop 5-2.2V=2.8V.

So, if you will have 3 LEDs, then your amps will be 60mA or 0.06A. Divide 2.8V/0.06A= 47 Ohms. It will have to be a 1/4Watt resistor though. The blue one will drop 2V, so 2/0.02= 100 Ohm resistor for that one.

I would suggest having a single resistor per LED though. They do not come perfectly matched for forward voltage and tying them together and calculating the current limiting resistance is not accurate. If one LED burns out, then the current going through the resistor will be split between the remaining LEDs and probably burn them out too.

I generally calculate for 15mA per LED and keep them all seperated. But thats just me. I have also only had one burnt LED ever happen after being installed over a year. And since I keep them isolated, it did not burn out everything. The people who do not take those precautions end up with alot of stuff burning out and generally dont link the failure back to the LED wiring.

[Blazinkaos]

Yea that gonn be a lot of wiring but if that the case to make them last for a log time then ill do that.
So i would need a 22 ohm resistor for red, green and yellow. Then a 100 ohm for the blue and just wire them all and yea.

[Hazer]

The blue will need 100 Ohm resistor.

If you tie the red green and yellow together, you will need a single 47 Ohm resistor.

If you give each of the red green and yellow LEDs get thier resistors, then they will be 150 Ohm each.

[Blazinkaos]

yea ok then