Multi-Mode Timer

No one can call themselves an electronics hobbyist unless they have built a timer. There are several designs using a variety of new and sometimes old circuits. Witness the longest surviving IC of all, the 555, introduced over 20 years ago. Most timers have one characteristic - they only timed one thing; an egg timer, a delayed timer, a timeout timer, a flasher, a photographic timer, etc. As you will see these days are almost over.