This circuit generates the busy tone of ordinary telephones. The transistors can be the BC548 and the components of the T filter and the multivibrator can be changed to obtain the exact tone.
This simple monophonic electronic organ of several octaves was found in a 1987 publication....
This circuit improves the performance of semi-automatic or six-pack machines, allowing the...
Although it is not convenient to directly associate triacs in parallel without a resistor that...