AC LED

AC LED Circuit

This is a simple AC LED Circuit for 110V or 220V AC power. This can work well using just a few components. This LED circuit is useful for power-on indicator on the panel board such as AC voltage control system installation.

You can use color LED you like, especially the bright colors like red, white, or green. Included in this AC LED schematic is for two different AC power source, i.e. 110V and 220V, in which the design has a different impedance.

AC LED Circuit Diagram

Capacitors are used to drop voltage and resistors to limit inrush current. Because capacitors pass current in both directions, a small diode connected in parallel with the LED to provide a way for the negative half-cycle and to limit the reverse voltage across the LED. Resistor value is selected to limit the current spike, in the worst case, to about 150mA, which would fall to less than 30mA in milliseconds as the capacitor charges.

0.47uF capacitor has impedance of 5600 ohms at 60Hz so the LED current is about 20mA half-wave, or an average of 10mA (for the 220V version of the capacitor impedance is 9600 ohms at 50Hz 0.33uF which gives you also the LED current of about 10mA average)

A larger capacitor will increase the current, and the smaller will reduce it. Capacitors must be a non-polarized type with a voltage rating of 250VDC or more to 110V AC-line, or more to 400VDC or 230V AC-line. Resistors R1 discharges capacitor C1 in a few seconds after the AC-line disconnected. Remember that R1 must be able to withstand the full half-wave peak AC line voltage.

CAUTION: Be Careful High Voltage!!!  Powered from the AC line – The AC LED circuit

See more about DC Power Supply and Mini Bench Power Supply.