If the battery provides 4.5 volts and the led I want to use takes in 3 volts will that work? Like will the other components (speaker) not have enough power from the led taking in more than usual power?
if battery voltage is higher than led forward voltage a resistor is required.
the resistor value will set the power the led will use. try a value that is bright enough, not too bright.
>>948775
this is something that you shouldn't worry about
for a standard jellybean LED just throw in 1k unless you are working with unusually high power. otherwise just get a 10k pot, and test it.
Use a resistor to drop the extra 1.5V (and limit current).
Resistor_Value = 1.5Volts / LEDamps
So an LED rated 20mA would need a R of:
R = 1.5/0.02 = 75ohms
>>948814
it's hard to get a 75 ohm resistor
just throw in a 500 ohm
or hell, even 1k would probably work
>>948822
500 ohm would reduce the current to 3mA.
68 & 82 are both common values.
Even 100 would be fine. (15mA)
