Claims
- 1. A low frequency, high powered underwater sound source comprising:
- a housing; and,
- disposed in said housing:
- a loudspeaker;
- containing means for containing a pressurized non-liquid sound transmission medium adjacent said loudspeaker;
- fill means for filling said sound transmission medium containing means with a sound transmission medium in response to a fill signal;
- vent means for venting said sound transmission medium containing means of a sound transmission medium in response to a vent signal;
- sensing means for generating a pressure
- differential signal representing a comparison of the pressure in said sound transmission medium containing means with an ambient underwater pressure;
- signal generating means for generating an acoustic signal at said loudspeaker in response to an acoustic drive signal; and
- programmed control means connected to said fill means, said vent means, and said sensing means, for generating said fill signal or said vent signal in response to said pressure differential signal and connected to said signal generating means for producing said acoustic drive signal.
- 2. The low frequency, high powered underwater sound source of claim 1 wherein said acoustic drive signal includes a square wave of a predetermined frequency.
- 3. The low frequency, high powered underwater sound source wherein said signal generating means include means for converting a square wave of a predetermined frequency to an analog signal, low pass filter means for filtering said analog signal and power amplifier means for generating an acoustic signal at said loudspeaker in response to said filtering of said analog signal.
- 4. The low frequency, high powered underwater sound source of claim 1 wherein said signal generating means includes a power amplifier, a relay connected to said power amplifier and to said control means, said relay being activated by said control means to connect said acoustic drive signal to said power amplifier following a predetermined time delay and determination by said programmed control means that said sound transmission containing means have reached a predetermined differential pressure.
- 5. The low frequency, high powered underwater sound source of claim 1 wherein said acoustic drive signal includes a CW frequency.
- 6. The low frequency, high powered underwater sound source of claim 1 wherein said acoustic drive signal includes a set of signals with preset frequencies.
- 7. The low frequency, high powered underwater sound source of claim 2 wherein said acoustic drive signal includes a frequency sweep.
- 8. The low frequency, high powered underwater sound source of claim 7 wherein said programmed control means varies a signal on-time and a signal off-time of said acoustic drive signal and linearly sweeps the frequency of said acoustic drive signal in a plurality of linear sweeps, each of said linear sweeps including respective frequency increments.
- 9. The low frequency, high powered underwater sound source of claim 1 wherein said programmed control means include means for maintaining a selected pressure differential between said pressurized sound transmission medium and the ambient underwater pressure by selectively generating said fill signal or said vent signal.
- 10. The low frequency, high powered underwater sound source of claim 9 wherein said programmed control means further include means for selecting a range of pressure differential between said pressurized sound transmission medium and the ambient underwater pressure.
- 11. The low frequency, high powered underwater sound source of claim 1 wherein said programmed control means include a digital processor.
- 12. The low frequency, high powered underwater sound source of claim 11 wherein said programmed control means include paged Eproms containing control programs and routines to boot and start said digital processor.
- 13. The low frequency, high powered underwater sound source of claim 11 wherein said pressure differential sensing means include a differential pressure sensor and an analog/digital convertor connected to said differential pressure sensor.
- 14. The low frequency, high powered underwater sound source of claim 11 wherein said signal generating means include a digital-to-analog converter, a low pass filter connected to said digital-to-analog converter, and a power amplifier connected to said low pass filter.
- 15. The low frequency, high powered underwater sound source of claim 11 wherein said fill and vent means each includes a solenoid, and a relay connected to said solenoid and to said programmed control means.
- 16. The low frequency, high powered underwater sound source of claim 1 further including a tilt switch means for providing electrical power in said underwater sound source in response to a predetermined orientation of said underwater sound source.
- 17. The low frequency, high powered underwater sound source of claim 1 wherein said housing includes a first end, a second end and a central body portion disposed between said first and second ends.
- 18. The low frequency, high powered underwater sound source of claim 17 wherein said loudspeaker is mounted over an aperture formed at one end of said housing, and said containing means are mounted on and extend from said housing end.
- 19. The low frequency, high powered underwater sound source of claim 18 wherein said containing means include a resilient inflatable diaphragm covered by a net.
- 20. The low frequency, high powered underwater sound source of claim 1 further including a flotation device attached to said housing.
- 21. A low frequency, high powered underwater sound source comprising:
- a housing having a first end, a second end and a central body portion disposed between said first and second ends, said first end having a loudspeaker mounting portion disposed thereon and said second end having a flotation device attachment portion;
- a loudspeaker mounted within said housing at said loudspeaker mounting portion, said loudspeaker mounting portion of said housing having a loudspeaker aperture therein through which sound to be generated by said loudspeaker may be directed out of said housing;
- a resilient expandable diaphragm disposed at said first housing end, over said loudspeaker aperture;
- a source of pressurized gas disposed in said housing;
- a fill valve operatively connected to said pressurized gas source to provide pressurized gas to said diaphragm;
- a vent valve to vent pressurized gas from said diaphragm;
- a differential pressure sensor for producing a pressure differential signal indicative of a comparison of the gas pressure on said diaphragm with the ambient underwater pressure;
- a signal generator for generating an acoustic signal at said loudspeaker and;
- a programmed controller to selectively control said fill and vent valves in response to said pressure differential signal from said differential pressure sensor, and to control the output of said signal generator.
- 22. The low frequency, high powered underwater sound source of claim 21 further including a differential pressure regulator, and wherein pressurized gas is provided from said pressurized gas source to said fill valve through said differential pressure regulator.
- 23. The low frequency, high powered underwater sound source of claim 21 wherein said housing includes at least one electrical storage device for powering said controller, said signal generator and said fill and vent valves.
- 24. The low frequency, high powered underwater sound source of claim 21 further including a flotation device attached to said second housing end.
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereupon or therefor.
US Referenced Citations (15)