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 circuit shows how to use an LED as a photodiode controlling a signaling LED. As the LEDs can...
This circuit was obtained in an Argentine publication from 1973. The original version uses...
This tiny photocell-powered audio oscillator was found in a book on transistors from the 1960s. The...