This diagram was found in the November 1972 issue of Radio Electronics magazine in an article describing benchtop equipment. The transistors are of the time and the frequencies are given by the coils.
This circuit is from 1990 documentation. It can be implemented with BC548 transistors instead of...
When you speak into the microphone of this circuit, the sound produced in the speaker resembles a robot...
This circuit uses an operational amplifier that is no longer on the market but can be implemented with a...