We found this circuit in an article that describes several alarms that are in the sequence in our section. The article is from the Radio Electronics magazine of May 1971.
Using an operational amplifier, this circuit was found in the March 1996 issue of Electronics Now...
This simple transistor gain test acts as an oscillator for the transistor under test. The circuit is...
Found in a 1980 documentation, this circuit drives a transducer (X1) when the car battery has its...