The 555 timer IC, originally introduced by the Signetics Corporation around 1971, is sure to rank high among the most popular analog integrated circuits ever produced. Originally called the IC Time Machine, this chip has been used in many timer-related projects by countless people over decades. This book is all about designing projects based on the 555 timer IC. Over 45 fully tested and documented projects are presented. All projects have been fully tested by the author by constructing them individually on a breadboard. You are not expected to have any programming experiences for constructing or using the projects given in the book. However, it’s definitely useful to have some knowledge of basic electronics and the use of a breadboard for constructing and testing electronic circuits. Some of the projects in the book are: Alternately Flashing Two LEDs Changing LED Flashing Rate Touch Sensor On/Off Switch Switch On/Off Delay Light-Dependent Sound Dark/Light Switch Tone Burst Generator Long Duration Timer Chasing LEDs LED Roulette Game Traffic Lights Continuity Tester Electronic Lock Switch Contact Debouncing Toy Electronic Organ Multiple Sensor Alarm System Metronome Voltage Multipliers Electronic Dice 7-Segment Display Counter Motor Control 7-Segment Display Dice Electronic Siren Various Other Projects The projects given in the book can be modified or expanded by you for your very own applications. Electronic engineering students, people engaged in designing small electronic circuits, and electronic hobbyists should find the projects in the book instructive, fun, interesting, and useful.