This circuit is from a 1968 documentation using one of the first integrated circuits available at the time, the TAA370. The circuit is powered by 1.3 V using a 200 ohm handset.
Twin-T oscillator are designed to produce sine low frequency signals. These oscillator are...
This circuit keeps an LED on briefly when S1 is pressed. The time depends on C1. The circuit is...
This stage was used in old audio ampliiers and radios from the 1950s and 1960s. It uses one of the...