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, obtained in a 1983 magazine, can drive loads up to 100 mA if the transistors are...
It is possible to design a monostable multivibrator around a voltage comparator of the four...
This voltage inverter circuit is from a Radio Eklectronics from October 1965. It was used in...