Joke Collection Website - Mood Talk - The self-made LED nightlight uses a light-emitting diode in series with a resistor. Why will the resistor burn out after a long time?

The self-made LED nightlight uses a light-emitting diode in series with a resistor. Why will the resistor burn out after a long time?

Your connection method is wrong. According to your connection mode, the resistance power of 12K at this time is about 220 2/ 12000 = 4W(LED has low reverse withstand voltage), and the rated power of the resistor you use should be less than 4W, so the resistor will burn out as soon as it is energized. It is best to use a capacitor to step down the voltage. The 10 diode is connected in series, and then 1N4007 and other diodes are connected in reverse parallel to the LED.