Here we have a really simple and easy to build project for the beginner. It flashes two Light Emitting Diodes (LEDs), a red and a blue one, much like the lights on a police car. The frequency (how fast the LEDs switch on and off) can easily be controlled by the variable resistor (Potentiometer) from anywhere between 0.5Hz to 22Hz.
Semiconductors Resistors (0.5W, 1%) Capacitors Other
1 x 5mm red LED
1 x 5mm blue LED
1 x 555 Timer2 x 150 ohms
1 x 1k
1 x 22k
1 x 1M pot (single turn)1 x 10nF (ceramic)
1 x 1.5uF (electrolytic)
1 x 10uF (electrolytic)1 x 9V Battery
