 About The Portland Horn™ |
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INVENTOR OF THE YEAR AWARD & WINNERS AWARD BBC Tomorrow's World International Invention Fair 1999 | |
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The Portland Horn™ - What is it?
The Portland Horn™ evolved from an earlier project, which was to design a communications system that could be used by scuba divers.The Portland Horn™ is an air powered horn that works under water.
It is similar to other horns in that a flow of air causes an elastic diaphragm to vibrate. What is special about it is that the exhaust air is not permitted to escape, rather it is enclosed and exhausted through an escape valve.
This means that the bubbles from the exhaust air do not get in the way of the noise produced by the horn.
When the device is used underwater, it generates a low frequency tone with a high volume. If you vary the tension in the horn's diaphragm it is possible to change the frequency of the tone produced by the horn.
The loudness of the horn depends on the size of the vibrating diaphragm and by how much it is vibrating.