The 220V electronic candle circuit can be divided into three parts:
The first part consists of IC1 (555), IC2 (74LS164), IC3 (74LS86), IC4 (74LS00) and the associated pars. These generate a randomly changing train of pulses.
The second part of the circuit comprises SCR1 (C106), an electric bulb connected between anode of SCR1 and mains live wire, and gate trigger circuit components. It is basically half-wave AC power being supplied to the electric bulb.
The third part is the power supply adapter circuit to produce regulated 5V DC from 230V AC for random signal generator. It comprises a stepdown transformer (X1), full-wave rectifier (diodes D3 and D4), filter capacitor (C9), followed by a regulator (IC5).