Somewhere along the way, a cpu became the cheapest way to build the timer. If I had to build a reliable variable timer these days, I'd choose a PIC and a few l

Somewhere along the way, a cpu became the cheapest way to build the timer. If I had to build a reliable variable timer these days, I'd choose a PIC and a few lines of code instead of a 555 and fiddling with resistor and capacitor values.