This circuit controls two LEDs that fash in an alternated mode. The circuit ws simulated in the Multisim and frequency depend on R4, R5 and C1. The circuit can be powered from 5 to 12 V supply. When powering from a 5 or 6 V supply R1 and R2 can be reduced to 470 ohm.
Dual Flasher Using the 555 IC