ok so im upgrading a junk button box i purchased and i use it for my sim racing and flight sim. I ordered the Arduino mega 2560 so i can attach 12mm pushbuttons and 3 rotary encoders. I want to change the 12mm pushbutton to LED lit 12mm pushbuttons that say maximum voltage 3V. I know the Arduino says 5V output so being a newbie im curious if i can do what i want and if so how can i accomplish it.
That is probably a blue led an no extra electronics.
The 3V might be the forward voltage of the led. Don't apply a voltage. Every led needs a current.
Let's assume that it is a standard 20mA led, then you can use an Arduino output pin and a resistor of 150 ohm to the led.
(5V - 3V) / 20mA = 100 ohm, let's make that 150 ohm for safety.
This is just a guess, you need to know the normal current for the led.
Model : sometimes QN12-C1
Or is there a small light bulb inside with a blue filter ?
Could you open it ?
Of course you can use them, it's just a question of what value resistor to use....
Most likely it's a normal blue LED, probably 10-20mA, put like a ~200 ohm resistor in series, maybe lower if you're not happy with the brightness with 200 ohm resistor.