This circuit reproduces the dial noise in a small speaker. The transistor can be a general-purpose type. We found it in an 80's Electronic Design.
To obtain triangular signals, we have the circuit in the figure that uses two amplifiers. One of...
This circuit was found in an old Electronic Design. It makes use of sidacs and operational not very...
This circuit was found in an American publication from 1969. Transistors are from the time and can be...