Described in an article in the March 1979 issue of Radio Electronics magazine, this generator was used in an audio test station. The frequencies are given by the capacitors.
This circuit reinforces signals in a frequency range between 1500 and 2000 Hz for use in...
When a small air current reaches the piezoelectric sensor, a small audio signal is generated and...
This circuit is from a Poptronics, American magazine from August 2000. The circuit can be...