5v-os telefontöltőről használt led, ellenállással az 5 voltot elfogyassza?

Látom az angol már megy...resistor. Nekem nem annyire megy az angol de a kedvedért megpróbálom...

First of all, voltage is not the right unit for electrical energy consumption, the amper is the right one.

The LED's type determines how many ampers are needed for the led drive. An average RED LED gives light around 10 mA. Let's say if you have a device with with RED LED + series resistor the total consumption of the circuit will be 10 mA. It does not depending on the supply voltage, it can be 10 - 20 ..30V - the circuit will "use" 10 mA.

Other hands the serial resistor's value depending on the power supply's voltage and the LED's opening voltage:

1. You have to subtract the LED's opening voltage from the Supply voltage. Let's say this is U1.

2. Depening on this the result you have to divide the U1 with the LED's current, this is typically 10 mA in case of RED LED's.

3. If the serial resistor value too big, then there won't be enough current for the emitting effect. If the serial resistor value too small, then the LED will be damaged due to over current.

Remélem hasznos volt, bocs, de nem vagyok jó angolos.