Found in a 90s Popular Electronics, this circuit is based on a common CMOS component. The circuit triggers a buzzer by approaching objects from an antenna.
Found in an older Radio Electronics, this circuit generates signals that can be used with regular...
The components used in this National Semiconductor circuit are not common today, but the...
June 2016 - It can be purchased from Mouser Electronics the new triacs Z04 for 4 A from...