I have been trying to make an AC LED lamp consisting of 44 LEDs. The LEDs are rectangular and give out a bright white light. I am not sure of the current of the LEDs and so have been trying different driver circuits to drive the LEDs. I tried the following circuit but the LEDs were dim. Can someone tell me what's wrong with the circuit? :???:
It seems your current is too low. Replace the 220nF capacitor and place a 1uF one. You may require to add another capacitor in parallel if the light intensity is not desirable.
The bright whites that I'm familiar with are rated 3.6V at 20 mA.
It's a good idea to include a resistor to limit inrush current on power-up. 330 ohms should be sufficient. 1W rating.
I've made a simulation showing how you could drive these from 230V mains AC.
The smoothing capacitor will acquire upwards of 180 V and must be rated higher than that. Its value is not critical.
A 470 nF dropping cap appears sufficient to obtain 18 mA through the led's.
If you are certain they can tolerate 25 mA, then try a 680 nF.
Or a 1 uF if they are they kind that can tolerate 36 mA. Then the inrush resistor is carrying 3W peak.