This repellent operates with frequencies from 30 to 45 kHz, serving for insects and rodents. The circuit is from 80s documentation. The transducer is a piezoelectric type.
The circuit shown in the figure on the right can be used on a data transfer bus with the use of an...
This timer was found in Japanese documentation from the 1960s. The transistor can be replaced by...
We found this circuit in a documentation from the 90's. The circuit can be assembled with 741...