The LM3909 tone generator integrated circuit of this application is uncommon nowadays. The circuit can operate on a single battery and is very sensitive.
In this 1990s circuit, found in a National Semiconductor manual, the output voltage is the square of...
This mains-synchronized circuit produces a simple 1 pulse per second. The circuit is from a Radio...
August 2017 - Mouser Electronics already has the Connect One Pico WiReach ™ SMTS Pico modules...