Apparatus and method for repelling rats and mice from an area by means of generation of a modulated ultrasonic sound level. The sound level is frequency modulated within a range of ultrasonic frequencies to which rats and mice respond. In addition, it is amplitude modulated in a random manner. The modulations of the signal prevent rats and mice from adapting to the sound, and thereby renders the sound particularly unpleasant to them.
A method of and system for sonifying a portion of a given area to rid the area of unwanted pests comprising providing at least one ultrasonic point source each producing a set of pulsed signals having a randomly varying frequency in the range of about 18-30 KHz and having an intensity of at least 90 dB at the periphery of a cone shaped area extending outwardly therefrom and having a predetermined maximum length and a predetermined maximum width. The point sources are spaced in the given area to maintain the minimum sound intensity level at any point in the sonified portion at not less than 90 dB by disposing point sources opposite one another when the distance therebetween is greater the maximum length, disposing point sources adjacent one another to effect a longitudinal overlapping of adjacent cones when the room width is greater than the maximum width and disposing point sources perpendicular to the adjacent point sources to sonify any dead space therebetween.
The apparatus according to the present invention is provided with two or more output systems to which transducers are connected, a source output on/off control unit that turns on/off the output from a source based upon the output from a random signal generating unit and a frequency varying unit that causes changes in the frequency of an electrical signal provided to the transducers over time at a specific rate. Every time the source output is turned off, the output of the electrical signal is stopped and the output systems are switched over, whereas when the source output is on, the electrical signal provided to the transducers on the output system to which the signal is to be provided. Since the output systems are switched over to be selected for use, it becomes possible to connect a greater number of transducers while using the same source capacity as in the prior art and noise generated from the transducers, when switching over the output systems, is eliminated.
A pest control apparatus and method for dispersing pests, e.g., rodents, from a designated area by the transmission into the area of high intensity ultrasonic sound waves having a primary frequency varying as a function of time and frequency modulating the sound waves with a secondary vibrato. The apparatus additionally provides periodic bursts of such ultrasonic power affording transducer rest periods maximizing the power handling capability of the transducer during "on" periods.
An integrated system which provides an extension of the effective operational area of a single unit ultrasonic pest repeller is disclosed. A master unit produces selectable acoustic waveforms from a speaker and also produces selectable electronic output signals for delivery to a first satellite unit. The first satellite unit produces a similar acoustic repelling waveform and also replicates the master unit electronic output signal for delivery to an identical second satellite unit. Each subsequent satellite unit in a serial chain of satellite units is powered by its own wall plug-in transformer so that the chain may be as long as necessary to accomplish deterrence of roaches, insects including bees, and rodents from the entire area to be protected.
Ultrasonic pest control apparatus comprising a pair of transducers, one in the form of a ring and the other in the form of a disc positioned within the ring, carried by a housing, a pair of oscillators operatively connected to the transducers, a timer controlling the oscillators, and a reflector extending from the housing. The oscillators apply to the transducers electrical signals having frequencies different from the natural frequencies of the transducers, and the timer controls the oscillator duty cycle. The generated sound waves are a composite output in the form of a random pattern of harmonics in the ultrasonic frequency range noramlly inaudible to humans and intolerable by pests such as rodents. A system includes a pair of units in opposed alignment whereby sound waves of one unit work against sound waves of the other. A gas-tight sealing arrangement associated with transducer and housing permits safe operation in explosive atmospheres. The transducers, oscillators and timer are removable as a unit from the housing which is frusto-conical in shape permitting a plurality of units to be nested during storage and shipment.
