I'd like to change the blue status LEDs on the Deck Legend Fire from blue to orange. The one's I have are here
. They're 1.7V/20mA.
Can anyone tell me if these will work as a drop-in replacement for the blue LEDs? If not, which resistors on the board would need to be changed, and by how much? Different colors should be possible since the blue Legend has red status LEDs, but I'm just not sure how to go about it.
Any info would be appreciated. Thanks!
You'd be better off converting a yellow or red keyboard to those LEDs.
Rule of thumb for LED forward voltages:
With 20mA current should give you ~85% of max brightness.
Remember some LEDs can go up to 5A! and I've seen LEDs with 10mA max current but those are rare. You should always know the specs of your LEDs before you use them, one of the biggest killers of LEDs is the reverse bias voltage is SO much lower than normal diodes it is easy to blow them.
For the LEDs you said above use ohms law to calculate the voltage to them.
(5V – 1.7V)/5mA = 660Ω
Closest common resistor value is 680Ω which will give you
3.3V/680Ω = 4.8mA
That should give you close to 50% of the mcd value of the LEDs you posted.
edit: you could also run the LEDs 2 per resistor like Deck does
(5V - 1.7V - 1.7V)/5mA = 320Ω
common closest value = 330Ω which gives you ~4.8mA current.
You could also use a 390Ω for ~4.1mA current... Deponds on the LED test them on a breadboard with diffrent resistance values to see which one you like (remember lower current = better yet dimmer)