This circuit activates a buzzer when the voltage applied to the input falls below a preset value in R1. The circuit is from an 80's American documentation.
Two inverters of a 4069B type CMOS integrated circuit form this oscillator which is characterized by having...
Raytheon's used operational amplifier is rare today, but the configuration can be adapted to use...
Found in a radio amateur magazine of the 1980s, this circuit uses components that can still be...