In my youth I was always intrigued by electric coil relays and the control capabilities that they presented. As many people who have been involved in the systems industry for at least 20 years, the electric coil relay can be your best friend as well as your worst nightmare. Because of the many different types of relays, such as timer relays, I have always found them fun to work with. The flexibility that they offered made it possible to do some amazing things.
However, if a relay network design was implemented and not documented very well, it could become my worst nightmare. There was nothing worse than attempting to troubleshoot a relay network without proper documentation. Well, as technology advanced, relays and their little brother, the transistor, became incorporated onto the circuit boards of integrated circuits. The advancement allowed firmware and/or software to control the integrated circuits and subsequent electronics.