This transistorized siren was found in the patent section of Radio Electronics magazine from March 1968. The circuit uses components from the time and has a very elaborate configuration.
This control for 1/15 HP motors with 5,000 rpm for 115 V power grid was suggested by a Motorola...
The circuit below is found in the manuals of several manufacturers in the LM123 series of...
This configuration found in a Motorola documentation consists of an experimental circuit that uses...