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ULTRASONIC GENERATOR FOR RAT RELAXATION
This generator can be used in grain storage and other food storage areas. The generator circuit shown in the figure consists of a low-frequency modulator ( C1, C2, DD1.1, DD1.2, R1, R2 ). ultrasonic oscillator ( SZ, C4, DD1.3, DD1.4, R3, R4 ), a power amplifier with transistors VT1 ... VT3 and a radiator, which is used as a high-frequency loudspeaker 4ГДВ-1 .
When the nominal values shown in the diagram, the generator emits frequency-modulated oscillations in the range 15 ... 40 kHz . The generator frequency is regulated by resistor R4 , the modulation frequency is regulated by resistor R2 within 2 ... 10 Hz . It must be borne in mind that the ultrasonic vibrations emitted by this generator can adversely affect the nervous system of humans and domestic animals. A long stay in a room with a working generator can cause headache, nausea and other discomfort, so it is recommended to turn it on just before leaving the room. If contact S1 is set up in such a way that this contact is closed when an unauthorized entry into the room occurs, the generator can also work as a security alarm siren, since it starts to emit oscillations modulated at the frequency in the range of 1000 ... 2000 Hz . It should be borne in mind that during long-term work in the same frequency range, rats can adapt, therefore it is necessary to change the radiation parameters 2 ... 3 times a week with resistors R2 and R4 . You can also apply this technique: connect capacitor C4 with a piece of wire that creates additional capacitance that changes with changes in temperature, humidity, wind power (if the wire is brought outside), etc. Then the frequency will change at random.
Authors: Victor Boroday
Address: 330000, Zaporizhia, b. Central, 12B-4.
Date of publication: 05/19/05