The circuit has been designed for a person who loves to jog or walk while measuring the distance that have been covered during the activity. 4093 – a quad 2-input NAND with Schmitt trigger inputs ...

[Scott] built this frequency counter using less than $10 in parts. It’s set up to meter frequencies in megahertz which is fitting since he’s planning to use it with his radio hardware experimentation.

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 ...