This is a very simple LED flasher circuit diagram that is powered from  AC 230V mains. This Flasher can be used as a power indicator for the AC  230V mains supply. This circuit is made with few numbers of parts  namely, a LED, two Resistors, one Capacitor, one Diode and one DIAC.   The DIAC act the main role to flashing the LED. DIAC is a bidirectional  device. It conducts current only after its breakover voltage has been  reached its threshold. Most DIACs breakover voltage is around 30 V.
230V Mains Power Indicator LED Flasher Circuit Diagram
When mains is connect to the circuit, the Capacitor(C1) starts charging  through Diode(D1)&Registor(R1). When the voltage on the capacitor  reached the DIAC’s threshold voltage, the DIAC get turn on. And LED gets  Lights(flash). At the same time Capacitor(C1) goes discharges and  breakover voltage of DIAC also decrease and LED turns OFF. The on off  time of the LED depends on the value of Capacitor(C1)  and Resistor(R1).
Note that the flashing time of the LED shown in the animating figure is not the exact timing of ON/OFF.
 


 
 
 
