LED flasher circuit can be built based on 555 IC. Using 555 IC, the flashing rate can be more flexible to adjust. This LED flasher circuit is similar to our transistor flasher circuit, but the flashing period of both LEDs won’t be same.
The flashing frequency is determined by C1, R1, and R2. You can try values around 100k for R1 and R2 to give around 1.4 s flashing period. Variable flashing rate can be implemented by replacing the R1 with 1Mega ohm potentiometer in series with 22k resistor. Lower power consumption can be achieved if we remove LED 2 and R4 and use only LED 1. When the R2 value is much lower than R1, then the LED 1 wil flash only for fast period, gives a strobe efffect. I recommend 9V for this flasher circuit since higher voltage will cause exessive heat on 555 IC.