This circuit was found in a 1966 EEE. The circuit uses transistors from the time but can be made with modern equivalents. The operating frequency ranges from 0.1 to 1 kHz.
This circuit is from Signetics' 80s documentation. The circuit generates 100 kHz signals according...
This circuit was found in a Motorola documentation from the 90s. The transistor used is uncommon...
This two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The...