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.
This circuit is interesting for experiments and can be part of the bench in the form of a module. The...
Constant currents from 10 mA to 1 A can supply the load, depending on the selection made by S1. Q1...
In the figure we have the transmitter and the receiver for an optical audio link via infrared. The...