Just wanna share circuits using relays to flash LED. I researched and found two different designs which both utilises only one relay and some capacitors .
The capacitance of the capacitors is quite big (around 1,000 uF and higher) to yield a low frequency flashing ( if too high then the LED will not appear flashing since it flashes very fast). I did'nt buy the capacitor, instead I salvaged from an old CRT monitor laying around in my room.
