kaspar389 said:
Im so ****** confused its not even funny. Can you explain all this MAH and crap. What does this mean? I dont get this. All Im doing is hooking up a 9v battery, to a 5v resistor, then I have the 120ohms resistor to the LED.
Yes it can be confusing, do you want to learn all this stuff or do you soally just want to make a charger???
mA(milli Amps) is what your application (LED,or any other load) will draw from the battery, the resistor, "resists" the amount of current(mA) passing though the LED.
if you use a resistor that does not "resist" inuf current(mA) then the LED will be really bright and burn out.
LED's have a milli Amp rating
and a voltage
eg: if your LED is rated at 3Volts and 25mA of current.
then you will need to find a resistor to suit 25 mA of current
and this is how you find the correct resistor
say your power supply is 5V
and your LED is 3V
and the mA (milli Amps) needed to light the LED is 25mA
so you do the followong:
5V - 3V (LED) = 2V
so now
2V / 0.025A(25millAmps) = 80
so you would need a 80ohms resistor to get 25mA supplied to the LED
i hope this makes sense, iv tried to explain it as noob friendly as possible