This circuit uses a 555 (according to the diagram) to generate 50 ms tone bursts at a frequency of 1.5 kHz. The circuit is from an 80's Electronic Design.
This alarm circuit was found in a 1997 publication. It uses two reed-switches to arm and disarm the...
The circuit shown in the figure is suggested by Micrel, based on the MIC2570 boost voltage...
This signal generator found in Japanese documentation of 1973 uses an unusual integrated circuit...