Patent Application
20060198245
The present invention relates to personal devices for repelling insects. Specifically, a sonic wave emitting device is supported on a hat brim to repel mosquitoes.
The conventional way for people to repel mosquitoes is to use a commercially available mosquito repellant spread on vulnerable areas such as the face and arms. However, for some individuals, these repellants may cause irritation and rashes. Consequently, these exposed areas if untreated are prime locations for attack by mosquitoes.
It is known, that female mosquitoes will attack humans and extract blood once they have laid their eggs. At the same time, however, female mosquitoes are no longer interested in associating with male mosquitoes, and will avoid them. If the female mosquitoes detect the sound of a male mosquito, they will fly away and avoid the area where male mosquitoes congregate.
The male mosquitoes generate an ultrasonic signal of approximately 22 KHZ. The present invention generates a sonic signal which substantially emulates the sound of male mosquitoes, and otherwise repels female mosquitoes from the body. Additionally, other insects also appear to be repelled by this sonic signal.
Accordingly, it is an object of the present invention to simulate the sound of male mosquitoes so that female mosquitoes do not attack human flesh.
A personal electronic insect repelling device is provided by the invention. An electronic circuit connected to the underside of a brim of a hat produces a sonic signal directed towards the body of a person wearing the hat. The sonic signal has a frequency which tends to repel insects, particularly mosquitoes. The sonic signal is generated by an electronic battery operated oscillator circuit, which drives an electro acoustic transducer for generating the sonic signal. The acoustic transducer is mounted with respect to the hat brim so that substantially all exposed areas of the person wearing the hat are radiated with sonic energy.
The invention advantageously generates an electrical signal at substantially 22 KHz, and then amplifies it to a level for driving the electro acoustic transducer. By maintaining a frequency of substantially 22 KHz, a sonic signal having essentially the same characteristics as the sound of a male mosquito are emulated. The device may advantageously include an indicator to indicate the status of the battery. In this way, the consequences of frequency drift due to low battery voltage can be readily avoided by replacement of the battery.
The battery operated sonic signal generator 12 is shown more completely in
In accordance with a preferred embodiment of the invention, a battery voltage monitoring circuit is provided. The battery monitoring circuit includes an LED 23 which is viewable through a hole on one side of the sonic generator 12. Diode 25 and resistance 26 limit the current through the LED 23. The frequency of the sonic generator 13 output signal is dependent upon the battery voltage, and its effectiveness in repelling mosquitoes is optimum at 22 KHz. Accordingly, it is advantageous to be certain that the battery voltage does not decrease below a given voltage.
Table 1 illustrates the effect of DC voltage on both power output and the sonic frequency.
When the battery terminal voltage is substantially 3 volts, the LED lights up in a normal way, indicating that the circuit is oscillating at substantially its nominal frequency of 22 KHz. However, when the battery voltage drops to 2.5 volts, the oscillating frequency is shifted down to 20 KHz. At this time, the forward voltage drop across diode 25 plus the drop across resistor 26 will significantly reduce the light output from the LED, indicating to the user that it is time to replace the battery.
The foregoing circuit is useful for providing a battery life expectancy of 50 working hours before it requires replacement. The battery is a conventional CR2016 3 volt DC button cell which is replaceable through an opening in the sonic generator 12.
Thus, there has been described a device for repelling insects which can be worn on a person.
The foregoing description of the invention illustrates and describes the present invention. Additionally, the disclosure shows and describes only the preferred embodiments of the invention in the context of a electronic insect repelling device, but, as mentioned above, it is to be understood that the invention is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the invention. Accordingly, the description is not intended to limit the invention to the form or application disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.
