This circuit mimics the trill of a bird. We found it in an American documentation from the 90s. It is based on the LM3909 integrated circuits.
This circuit consists of a speed regulator for direct current motors. The integrated circuit used...
When the sensor of this circuit is cut for a moment, the second 555 produces a tone for a time...
This circuit for generating precise reference signals was found in the April 1973 issue of Radio...