Found in American documentation from 1969, this circuit operates in the frequency range 10 to 150 Hz providing signals as shown in the diagram itself.
Radio Electronics magazine published in a 90's issue this simple alarm that can use any general...
This circuit is from the 2005 Linear Technology Application Manual. The circuit must be powered by 5...
We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the...