Power Supply for LED (Q026E)



“I have a purple LED, and whenever I plug it directly into the 3V transformer it will dim your lighting intensity even completely erasing over time, what am I doing wrong? Thank you in advance ...”


The LEDs should not be powered by alternating current and even more connected directly to a transformer. LEDs need direct current or DC. For AC power supply there are special circuits (See article ART288E - How to Use LEDs on 110 V). In addition, we always need to put a resistor in series with the LED to limit its current. For 5 and 6 V with high-brightness LEDs the resistor normally has 47 to 100 ohm. For other LEDs of 220 to 470 ohm and for 12 V we usually use between 47-ohm and 1 k depending on the current. In DC power supply the polarity must be observed. The fact that the LED is decreasing in brightness means heating the insert and that damage may be occurring ... I hope I have helped you before your LED has burned ...



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