Abstract:
This disclosure is related to marine seismic sources, for example marine seismic sources known in the art as benders. Some embodiments of this disclosure use Lorentz forces to produce seismic energy. For example, magnets and wire coils may be attached to one or more plates of a marine seismic source, and the Lorentz interaction between them may cause deformation of the plates to produce seismic energy. Such marine seismic sources may be components of a marine seismic survey system, and may be used in a method of marine seismic surveying. Methods of making marine seismic sources are also disclosed.
Abstract:
Provided is a broadband and large displacement angular vibrator, comprising an outer housing, a vibration table, a main spindle, a moving coil assembly, a magnetic circuit assembly, a holding brake assembly, a motor and closed loop control assembly thereof, an electric viscoelastic feedback control assembly, an air bearing, and an angular displacement sensor; the moving coil comprises a moving coil substrate and a coil; the moving coil substrate is fixed to the main spindle; the magnetic circuit assembly comprises a magnetic ring, a central magnetic pole, and magnets; the magnetic ring, central magnetic pole, magnets, and air gap form a closed magnetic circuit; the central magnetic pole is located inside the magnetic ring, the magnets are located between the magnetic ring and the central magnetic pole, and the magnets are attached to the central magnetic pole; the outer housing has the holding brake assembly; the holding brake assembly comprises a brake lining, an oil distribution sleeve, and an oil reservoir having a piston; the brake lining and the oil distribution sleeve enclose a hydraulic oil chamber; when the hydraulic oil is pressed into the hydraulic oil chamber from the oil reservoir, the magnetic circuit assembly brakes; when the hydraulic oil flows back to the oil reservoir, the magnetic circuit assembly rotates with the motor rotor. The present angular shaker has the advantage of being able to switch between intermediate-frequency and low-frequency, and has small output waveform distortion.
Abstract:
An adaptive intelligent electronic horn (100) comprises a mechanical soniferous apparatus (112), an electromagnetic coil (106), a driver circuit (104) and an oscillating circuit (102). A sensor (110) is provided between the mechanical soniferous apparatus (112) and the oscillating circuit (102). An on-off ratio adjusting circuit (108) is provided at the input end of the oscillating circuit (102). The sensor (110) measures the oscillation frequency of the mechanical soniferous apparatus (112) and feedbacks the measured oscillation frequency signal to the oscillating circuit (102). The on-off ratio adjusting circuit (108) controls a pulse width of an oscillation signal from the oscillating circuit (102) based on a voltage of power supply and/or an ambient temperature. The oscillating circuit (102) outputs corresponding oscillation signal to the driver circuit (104) based on the oscillation frequency signal received from the sensor (110) and/or the control signal from the on-off ratio adjusting circuit (108).
Abstract:
A circuit for driving an electromagnetic source for generating acoustic waves has a dischargeable high-voltage capacitor with a diode or a diode module connected in parallel therewith.
Abstract:
There is provided a vibration generator that permits to operate by following a mechanical resonance point. The vibration generator 1 has a vibration generation portion 2 having an electromagnetic coil 13 and a magnet 11 float-fixed by a spring member 12. The electromagnetic coil 13 is square-wave driven to obtain vibration force. The vibration generator 1 comprises a driving control portion 10 for detecting a driving voltage of the electromagnetic coil 13 at a predetermined constant interval. By the driving control portion 10, a driving frequency of the electromagnetic coil 13 is made high when an induced voltage waveform of the driving voltage is of rightward increase type, and the driving frequency is made low when the induced voltage waveform is of leftward increase. This permits the driving frequency of the electromagnetic coil to be shifted to a resonance frequency of the vibration generation portion 2. Consequently, driving of the electromagnetic coil 13 can follow a mechanical resonance point so that an sufficiently large vibration can be obtained.
Abstract:
An elliptical vibratory apparatus includes first and second controllers; first and second power amplifiers for amplifying outputs of the first and second controllers; first and second vibratory exciters receiving outputs of the first and second power amplifiers for generating first and second vibrational forces in first and second directions; first and second vibrational systems of an elliptical vibratory machine receiving the first and second vibrational forces; and detectors of first and second vibrational displacements for detecting vibrational displacements of a movable part of the elliptical vibratory machine in the first and second direction. A closed loop is formed by the first and second controllers, the first and second power amplifiers, the first and second vibratory exciters, the first and second vibrational systems, and the detectors of the first and second vibrational displacements. The output of the detector of the second vibrational displacement is negatively fed-back to the first controller in the closed loop. Shift angles of the first and second phase shifters are so predetermined that there is a phase difference of 180 degrees between the output terminal of the detector of the second vibrational displacement and the input terminal of the first controller, when these terminals are cut off from each other, and a predetermined phase difference can be obtained between the vibrational displacements of the first and second vibratory systems for the optimum condition of the elliptical vibratory machine. The first vibratory system is self-excitedly vibrated at its resonant frequency and the second vibratory system is self-excitedly vibrated.
Abstract:
A variable-frequency feeder control using a single oscillator to develop signals for moving materials in either one of two directions. An output signal from the oscillator is applied to a first timing circuit which develops signal pulses for driving a horizontal electromagnetic drive coil. The first timing circuit controls the duration of the signal pulses which determine the amplitude of power to drive the horizontal coil. The output signal from the oscillator is applied to a second timing circuit which developes a phase shifted signal to control the phase between the power applied to the horizontal coil and the power applied to a vertical drive coil. A third timing circuit uses the phase shifted signal to develop signal pulses for driving the vertical coil and controls the duration of the drive pulses.
Abstract:
A vibratory amplitude controller for vibratory mechanisms such as a vibratory feeder having in addition to a parts container, an electromagnetic drive unit operated from an A.C. current source for imparting oscillatory motion to the parts container. The controller includes a sensing means for sampling the electromagnetic drive unit current during a specific predetermined interval each A.C. current cycle to produce a vibratory amplitude representing signal. Means responsive to the vibratory amplitude representing signal controls the amount of power delivered from the A.C. current source to the electromagnetic dive unit to maintain a desired vibratory amplitude under varying load and A.C. line voltage conditions.
Abstract:
A control system is disclosed for use with a device, such as a vibratory bowl feeder, having a bowl or other member mounted for vibratory motion and including an electromagnetic driver for vibratorily driving the part. The control system includes a detector for detecting the vibratory frequency of the part, which tends to vibrate at its resonant frequency, and causes energizing pulses of power to be supplied to the driver supplied at a frequency equal to the detected frequency. Thus, the driving frequency is made equal to the resonant frequency and follows changes in such frequency to obtain maximum performance. The power to the drivers is also switched so that during alternate pulses the current flows through the driver coil in opposite directions to inhibit buildup of residual magnetism in the coil core. The control system uses a phase-locked loop circuit and other parts comprised of components most of which are available as standard integrated circuits. A means for selectively varying the amplitude of member vibration is also included in the control system.
Abstract:
An electronic circuit including a transistor which is biased to conduction is provided to initiate actuation of an electromagnetic transducer. The transducer has first and second coils one of which actuates the sounder. A potential is induced in the other coil and this induced potential is used to cut off the transistor. The next cycle of operation is initiated when the induced potential falls below a predetermined value in response to the reduction of the magnetic flux which, in turn, was the result of the transistor having been cut off.