We found this circuit in the Radio Electronics magazine of February 1993. The main integrated circuit is from that time and the power supply is made with voltages of 6 to 15 V.
This simple humidity alarm circuit includes a timed warning oscillator whose time is set to R4....
Tone controls for audio applications can also be considered filters that must attenuate certain...
Found in an American documentation, this circuit shows how an interface should be made for...