METHOD AND APPARATUS FOR FORMING RODENT REPELLING SUPERSONIC FIELD Russian patent published in 1999 - IPC

FIELD: agriculture, in particular, protection of objects from rodents by supersonic acoustic field effect and investigation of animal, bird and insect behavior. SUBSTANCE: method involves varying electric signal frequency within the range of 20-70 kHz in continuous, smooth mode at rate commensurable with piezoelectric emitter time constant; optimizing radiation power of supersonic acoustic field by mechanical adjustment of sizes of supporting construction and spatial mutual position of constructional members of casing. Apparatus has generator and continuously adjusted DC voltage source connected to generator and adapted for modulating frequency of generator within the frequency range of 45 plus and minus 25 Hz at rate commensurable with piezoelectric emitter time constant. Apparatus casing is formed as parallelepiped constructed from two U-shaped metal members mechanically connected one with another so that relative position and linear sizes of metal members may be adjusted. Method allows level of supersonic acoustic pressure to be increased by 10 dB without increasing level of power taken from power source by improved circuit technique and rodent repelling area to be increased by 1.5-2 times by improved circuit technique and efficiency to be increased by 25-30% by providing correction of geometrical sizes and mutual position of constructional members. EFFECT: increased efficiency and reduced power consumption. 3 cl, 6 dwg