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 15 V regulator uses the integrated 100 mA L series. The circuit was suggested by Motorola's Linear...
This 1992 circuit operates in the range of cordless phones used at the time. The circuit is based...
We find this circuit in the manual of the used integrated circuits. The manual is from Linear...