The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 1996
Filed:
Apr. 20, 1995
Michael T McCord, Orlando, FL (US);
Larry E Ivey, Orlando, FL (US);
United States of America, Washington, DC (US);
Abstract
The frequency modulated monitor hydrophone system which is used to monitor low frequency sound signals where cross-talk coupling is a problem, consisting of a hydrophone, preamplifier and receiver which includes a control group. The hydrophone comprises an acoustic sensor and low-noise preamplifier utilizing dynamic range compression to condition the electrical acoustic sensor signal before it is frequency modulated (FM) and applied to a coaxial cable. At the remotely located receiver, the FM signal from the hydrophone preamplifier is filtered to remove undesirable signals, such as audio spectrum crosstalk and out of band signals. The partially recovered audio signal is decompressed utilizing dynamic range decompression, amplified, and output for utilization or recordation by an operator. A calibration circuit provides a continuity or partial calibration check for the hydrophone by applying a signal of predetermined frequency and voltage to the hydrophone preamplifier and sensor. A microprocessor in the control group periodically reads the input signal and controls the various receiver and hydrophone preamplifier circuits. Selected controls on the panel of the control group allows the operator to set gains, perform the calibration procedures, and monitor system performance.