Cheapo led bulb circuit

This is the circuit from a cdrking stark led bulb it only use a capacitive dropper to lower the voltage for the leds . A capacitive dropper ia quite efficient becuase a capacitor does not waste power .it uses its reactance to somewhat resist the flow of AC current. But however, it has a resistor in series it still disspate a small power. I use this lamp for about 2 years and it still works but . The brightness slowly decreases. And the problem is the metal film capacitor, because its equivalent series resistance increases and it now dissipates power. we should use an SMPS because its more reliable.

published 8 years ago