Police Style Strobe Light Circuit.

This circuit shows the familiar lights which are used on police cars. It uses a 555 timer as a clock for the 4017B decade counter, two transistors and twelve LEDs

Electronic Doorbell Circuit using a 555 timer and a CD4017 decade counter

This electronic doorbell circuit gives us all the possibility to change the tone of each of the 10 musical notes that the circuit can have. This means we can create our own sound sequence.

LED Sequencer using 4017.

This circuit has 10 LEDs connected to the 4017 decade counter outputs. The LEDs light up in sequence. (only one is ON at a time)

Music box Circuit using a CD4017 Decade Counter and two 555 Timer

This circuit attempts to emulate the operation of a music box. The maximum number of notes is 10, allowing us to make a simple melody.

This Electronic two-way traffic light circuit achieves the functionality of a typical two-way traffic light using a 555 timer and a CD4017 decade counter.