As an experiment, and for my own education into electronics I am trying to light up one LED diode in my 60wLED bulb. I have pulled the bulb apart, I have tested the bulb, and it still illuminates. Now, I am trying to test each of the 8 LED's. I have applied a variable 6-12V power source to the LED, yet it still won't illuminate. Can anyone suggest what I might be doing wrong?
I can confirm that the power source is putting out the correct voltage 7.5V and or 9V, because I checked it with a multimeter.
In reply to Possibly you fired the led. by Sourav Gupta
All LED's are working, I checked them again by attaching the +- of the circuit to power, and they all illuminate.
Just to confirm; I should be able to make each led illuminate by sending a 2V current to the +- of the led diode, correct?
I am not sure why they don't illuminate when I test them one by one like in the image.
This circuit uses a diode bridge. It is a transformerless AC to DC contruction. The LEDs are connected in such a way that the total series voltage is much higher to run on AC outlet voltage. You need to have higher voltage across the LED string to light them up.
Sourav Gupta
Joined February 12, 2018 696Monday at 02:11 PM
Possibly you fired the led. Typically the led start to glow from 1.5v to 2.2v. the voltage will increase the forward current. Going beyon 3 volt is not recommended without current limiting resistor.