This circuit can generate signals up to 100 kHz. Found in documentation from the 1980s, it makes use of operatives of the time.
We found this 4 W amplifier in an old Argentine publication of the 70's. The circuit can be made...
This traditional configuration was found in a 1988 publication. Its gain depends on the base...
When a small air current reaches the piezoelectric sensor, a small audio signal is generated and...