We found this circuit in the September 1994 issue of Electronics Now magazine. The circuit uses off-the-shelf components and is powered by mains power.
January 2017 - Mouser Electronics already has the new PMO Sonalert microphone elements from...
This configuration makes use of an LM3900 transconductance operational amplifier. The transistor can...
SST LLE Series Liquid Level Sensor Switches Available through Mouser Electronics, these solid...