This simple audio generator with the 741 was found in a 90sTexas Instruments. The circuit generates sinusoidal signals from 15 Hz to 150 kHz in 4 bands, as shown in the diagram.
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
This circuit transmits the audio signals from a telephone line to an FM receiver placed nearby. The...
This circuit is from an old manual of operational amplifiers. The setting can be adapted to work...