All mains powered LED circuits work with 240 volt AC current.
Mains powered LED – Single LED
The power diode in the first diagram is designed to discharge the 220n during one half of the cycle so that the capacitor will charge during the other half-cycle and deliver energy to the LED. The 1k resistor limits the peak in-rush current when the circuit is first turned on and the main happens to be at a peak. A single LED can be illuminated by using a 100n or 220n capacitor with a rating of 400v.
- Two LEDs can be driven from the same circuit as one LED will be illuminated during the first half cycle and the other LED will be driven during the second half of the cycle.
Mains Powered LED – Multiple LED’s
When 50 to 80 white LEDs are connected in series, a resistor can be used. For 50 white LEDs, use a 4k7 2watt resistor to provide 10mA average current.For 100 white LEDs, use a 2k2 1watt resistor to provide 10mA average current.
The above circuit can be modified with a bridge rectifier to provide DC input to LED. This will prevent from flickering or strobing.
Mains light with 10 LED
The following circuit illuminates a column of 10 white LEDs. The 10u and 100 R prevents flicker.
*Caution: All the circuits involve high current. There is a significant risk of death through electrocution if mains voltage electricity is allowed to pass through the body. There can also be a risk of fire and explosion if electricity is not cabled and fused correctly. Therefore precautions must be taken when using mains electricity
R3 in fig 1 should be 1K instead of 100 ohms. I will update the image shortly.
Can I drive 70 smd leds 5730 with this? One 5730 is 150mA 0,5W 3.2-3.4V. If I can’t, can you give me some other scheme?
Just one more question. Does 5730 require heat sink?