His most popular project is the binary clock. It runs off of mains, uses a bunch of TTL logic chips and a binary counter. He has posted links to the many projects that have been derived from his ...

As you’d expect, it relies on a 32.768 kHz crystal to provide a stable clock. Fed into a 4060 binary ripple counter, that clock is divided down 14 times to deliver a 2Hz square wave. This then ...