This is one of the many possible siren configurations for the 555 integrated circuit. We found it in the October 1992 Radio Electronics magazine. It has a power stage.
This traditional sensor configuration with LDR was found in a 2001 documentation. The integrated circuit...
This circuit is from an 80's Radio Electronics. It triggers a load powered by the power grid from...
This circuit was found in February 1976, Radio Electronics magazine. The circuit is powered by 12 V...