Abstract: This invention relates to a distance measuring device, in particular for motor vehicles, in which a converter is utilized for transmission of an ultrasonic signal and also for reception of the echo signal. Thereby the echo signal received by the converter is compared at a comparator with a threshold value after having been appropriately amplified. This threshold value is at a particular changeover time changed over from a first high value, which is independent of time, to a smaller, time-dependent value. Thereby the changeover time is computed from a measured time depending on the dying-out behavior of the converter.

Abstract: An energy generator of a Sonobuoy is overlapped by a sleeve or chimney guiding gas bubbles given off by the generator to a sufficient distance from an electro-acoustic transducer of the Sonobuoy, to prevent such bubbles from coming into contact with the transducer under heaving effects. The result is suppression of unwanted noise produced by the contact between the bubbles and the transducer.

Abstract: A marine cable system including one or more elongated cable sections whose buoyancy may be independently controlled. Each section is associated with a pump and a variable volume, elongated bladder. In one embodiment, one reservoir containing buoyant fluid is included, and fluid from the reservoir is pumped between adjacent sections to inflate or deflate the associated bladders. In another embodiment, a rigid reservoir containing compressed gas is included in each section. The associated pump releases gas from the reservoir to inflate the bladder, or pumps gas from the bladder into the reservoir when desired. The pumps are operated in response to control signals from a remote control unit, such as one aboard a vessel towing the cable. One or more depth sensors may be attached in or near each section. Depth information from the sensors may be supplied to the control unit for use in generating the pump control signals. The buoyant fluid is entirely contained within the cable.

Abstract: A bucket brigade filter is disclosed having a feedback loop resulting in a tight comb structure filter response whereby a periodic noise and all its harmonics may be removed from a signal. Scalers featuring selectively variable scaler parameters permit prompt adaptation to changes in the noise period, rapid initialization of the filter to an operating condition and adjustable stopband widths of the filter frequency response. Sampling of the input data signal may be synchronized to the periodic variations of the noise to be eliminated from the signal.

Abstract: Apparatus is provided for adapting an analog depth sounder for the calling out of the depth at regular time intervals. In one embodiment, a self-contained adapter module is mounted to the face of the depth sounder so as to cover the depth sounder display, with the module including a transparent plate carrying a detector array and with electronics and speaker carried at the center of the array. In this embodiment, the detectors are arranged in thin radially extending lines to permit accommodation to displays of different diameter. Alternatively, small detectors are arranged along a circle having a diameter which overlies at least a portion of the orbiting radiating element which radiates along a considerable length. This alternative array configuration also accommodates a range of display diameters. As a further alternative, to accommodate different diameter displays, the thin line detectors may be replaced with radially extending light pipes with detectors at their ends.