The circuit was designed to create a low cost frequency meter that will cover the range of 1 Hz to 1 MHz with a digital indication using three 7-segment displays. 7805 – a 3-terminal 1A positive ...

You think of digital displays as modern, but the idea isn’t that new. We had clocks, for example, with wheels and flip digits for years. The Racal frequency counter that [Thomas Scherrer] is playing ...