Leds Have Resistors at marcusdmoraleso blog

Leds Have Resistors. to drop 6v at 20 ma the resistor needed is r = v/i = 6 / 0.02 = 300 ohms. Resistors behave linearly according to ohm's law:

2 LEDs in series with resistor at 3.3V won't light up, one LED works
from electronics.stackexchange.com

Let's explore how to calculate. an led behaves very differently to a resistor in circuit. to drop 6v at 20 ma the resistor needed is r = v/i = 6 / 0.02 = 300 ohms.

2 LEDs in series with resistor at 3.3V won't light up, one LED works

Leds Have Resistors Let's explore how to calculate. leds have a characteristic called “forward voltage” which is often shown on the datasheets as vf.the answer is to place a resistor in series with the led, and allow the resistor to drop down the voltage to the led by 0.3 v. an led behaves very differently to a resistor in circuit.