Another simple circuit to demonstrate how to make flashing / blinking LED alternately between 2 LEDs. In this circuit 2 x 2N222A transistors are being used to drive the flash and the speed is control by the electrolyte capacitor 47uF. The speed of the flash can be further adjusted by using smaller capacitance value of the capacitor. Schematic diagram is available in the video itself.
2 x 2N222A BJT Transistors
2 x 47 uF Electrolyte Capacitors
2 x 470 Ohm Resistors
2 x 10 KOhm Resistors
2 x Red LEDs
1 x Breadboard and some connector wires