Patents by Inventor Bruce Halcro Candy
Bruce Halcro Candy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20170299753Abstract: This invention relates to metal detectors used to detect metal targets in soils wherein the detector is insensitive to signals induced by a received magnetic field due to perpendicular components of a uniform conducting half-space, including metal detectors simultaneously capable of suppressing signals due to components of substantially log-uniform viscous superparamagnetic soil, and including metal detectors using repeating transmit signal cycles resembling a pulse induction-like waveforms. It discloses signal processing, in particular synchronous demodulation functions which may simultaneously substantially suppress signals due to perpendicular components of a uniform conducting half-space in a received magnetic field, signals due to components of substantially log-uniform viscous superparamagnetic soil, and signals due to a movement of the receive coil with respect to a static magnetic field.Type: ApplicationFiled: April 6, 2017Publication date: October 19, 2017Inventor: Bruce Halcro Candy
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Patent number: 9547065Abstract: A method for reducing a delay, between a transition of a transmission of a metal detector and a process of a receive signal received by a receive coil of the metal detector, due to a critically damped time constant of the receive coil, including: introducing a negative capacitance into the receive coil to reduce the critically damped time constant.Type: GrantFiled: March 6, 2013Date of Patent: January 17, 2017Assignee: Minelab Electronics Pty LimitedInventor: Bruce Halcro Candy
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Patent number: 9348053Abstract: The present invention relates to a method for detecting an electrically conducting target in soil, including the steps of generating a repeating transmit signal cycle of a fundamental period using transmit electronics, the repeating transmit signal cycle including a first period and a second period within each fundamental period; generating a transmit magnetic field using a magnetic field transmitter, based on the repeating transmit signal cycle, for transmission into the soil; receiving a receive magnetic field using a magnetic field receiver; producing a receive signal induced by the receive magnetic field; arranging for a current flowing through the magnetic field transmitter to flow to a first potential through a damping resistor during the second period for providing a damping effect on the current flowing through the magnetic field transmitter; arranging for the current flowing through the magnetic field transmitter to flow to a second potential, predominantly through an alternative path with a lower reType: GrantFiled: December 14, 2011Date of Patent: May 24, 2016Assignee: Minelab Electronics Pty LimitedInventor: Bruce Halcro Candy
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Patent number: 9250348Abstract: A metal detector has one or more feedback loops to control its repeating transmit signal cycle so that there is no reactive voltage drop across the transmit coil of the metal detector during at least one receive period of the metal detector.Type: GrantFiled: December 19, 2012Date of Patent: February 2, 2016Assignee: Minelab Electronics Pty LimitedInventor: Bruce Halcro Candy
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Publication number: 20150168584Abstract: A method for reducing unwanted signals, due to a back emf decay, within a receive signal received by a receive coil of a metal detector during a demodulation of the receive signal after a transmission by a transmit coil of the metal detector, including controlling a T/R switch to control a characteristic of the back emf decay to reduce a duration of the period of the back emf decay.Type: ApplicationFiled: December 11, 2014Publication date: June 18, 2015Inventor: Bruce Halcro Candy
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Publication number: 20150145517Abstract: A method for detecting an electrically conductive target in soil using a metal detector, including the steps of: processing a receive signal using at least two different functions for producing at least two processed signals, each of the processed signals is at least partly insensitive to at least one unwanted signal due to the soil or an electromagnetic interference noise; determining a noise level of each of the at least two processed signals for producing at least two noise signals; and producing, from at least one of the at least two processed signals, an indicator output signal indicative of the presence of the electrically conductive target when the electrically conducting target is within the influence of a transmit magnetic field transmitted by the metal detector; wherein the step of producing an indicator output signal is dependent upon characteristics of the at least two noise signals.Type: ApplicationFiled: November 25, 2014Publication date: May 28, 2015Inventor: Bruce Halcro Candy
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Publication number: 20150035543Abstract: A method for reducing a delay, between a transition of a transmission of a metal detector and a process of a receive signal received by a receive coil of the metal detector, due to a critically damped time constant of the receive coil, including: introducing a negative capacitance into the receive coil to reduce the critically damped time constant.Type: ApplicationFiled: March 6, 2013Publication date: February 5, 2015Inventor: Bruce Halcro Candy
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Patent number: 8854043Abstract: A method for detecting an electrically conductive target in a soil using a metal detector, including: generating a transmit magnetic field for transmission into the soil based on a transmit signal; receiving a receive magnetic field; providing a receive signal induced by the receive magnetic field; processing the receive signal to produce a processed signal; processing a duration of the receive signal, the duration begins after a time the processed signal exceeds a threshold value and ends after a time the processed signal no longer exceeds the threshold value, to produce more than one estimations indicative of a presence of the electrically conductive target when the target is within an influence of the transmit magnetic field; and presenting graphically the more than one estimations.Type: GrantFiled: March 5, 2013Date of Patent: October 7, 2014Assignee: Minelab Electronics Pty LimitedInventors: Bruce Halcro Candy, Gregory Peter Harmer, Laurentiu Stamatescu, Pavel Valentine Kursa
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Publication number: 20140232408Abstract: A metal detector transmitting, through a transmit coil, a repeating transmit signal cycle, which includes at least one receive period and at least one non-zero transmit coil reactive voltage period; and sensing a current in the transmit coil during at least one receive period to control a magnitude and/or duration of the at least one non-zero transmit coil reactive voltage period such that the average value of the current during at least one receive period of every repeating transmit signal cycle is substantially constant from cycle to cycle, and the current during at least one receive period is substantially independent of the inductance of the transmit coil.Type: ApplicationFiled: March 26, 2014Publication date: August 21, 2014Inventor: Bruce Halcro Candy
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Patent number: 8614576Abstract: An electronic metal detector having, a transmit coil arranged and adapted to transmit an alternating magnetic field associated with a reactive transmit coil voltage, the transmit coil being connected to transmit electronics arranged and adapted to generate a transmit signal, the transmit electronics having at least two power sources, a first power source and a second power source, wherein the first power source is adapted and arranged to connect to the transmit coil for at least a first period, and the second power source is adapted and arranged to connect to tie transmit coil for at least a second period, the said transmit electronics including at least one servo control negative feedback loop, a first servo control negative feedback loop, which is adapted and arranged to monitor a transmit coil current for at least part of the said first period, and to control at least part of the said transmit signal, the transmit electronics being adapted and arranged to control the transmit signal to produce the reactiveType: GrantFiled: March 16, 2011Date of Patent: December 24, 2013Assignee: Minelab Electronics Pty LtdInventor: Bruce Halcro Candy
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Publication number: 20130234716Abstract: A method for detecting an electrically conductive target in a soil using a metal detector, including: generating a transmit magnetic field for transmission into the soil based on a transmit signal; receiving a receive magnetic field; providing a receive signal induced by the receive magnetic field; processing the receive signal to produce a processed signal; processing a duration of the receive signal, the duration begins after a time the processed signal exceeds a threshold value and ends after a time the processed signal no longer exceeds the threshold value, to produce more than one estimations indicative of a presence of the electrically conductive target when the target is within an influence of the transmit magnetic field; and presenting graphically the more than one estimations.Type: ApplicationFiled: March 5, 2013Publication date: September 12, 2013Applicant: Minelab Electronics Pty LimitedInventors: Bruce Halcro CANDY, Gregory Peter HARMER, Laurentiu STAMATESCU, Pavel Valentine KURSA
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Publication number: 20120212227Abstract: This invention relates to receive electronics of a metal detector for processing a received signal from a target in a soil, the receive electronics including: processing electronics for synchronous demodulating or sampling the received signal to produce at least two substantially ground balanced signals; processing electronics for processing the at least two substantially ground balanced signals to produce at least two substantially ground balanced processed signals, a first substantially ground balanced processed signal being more indicative of a spread of a time constant density spectrum of the received signal than a second substantially ground balanced processed signal, and the second substantially ground balanced processed signal being more indicative of an average time constant of the received signal than the first substantially ground balanced processed signal; and processing electronics for processing the at least two substantially ground balanced processed signals to produce an output signal indicativType: ApplicationFiled: July 28, 2010Publication date: August 23, 2012Inventor: Bruce Halcro Candy
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Patent number: 8237560Abstract: A highly flexible real-time metal detector platform which has a detection capability for different targets and applications, where the operator is able to alter synchronous demodulation multiplication functions to select different types or mixtures of different types to be applied to different synchronous demodulators, and also different waveforms of the said synchronous demodulation multiplication functions; examples of the different types being time-domain, square-wave, sine-wave or receive signal weighted synchronous demodulation multiplication functions. The operator can alter the fundamental frequency of the repeating switched rectangular-wave voltage sequence, and an operator may alter the waveform of the repeating switched rectangular-wave voltage sequence and corresponding synchronous demodulation multiplication functions.Type: GrantFiled: October 11, 2011Date of Patent: August 7, 2012Assignee: Minelab Electronics Pty LimitedInventor: Bruce Halcro Candy
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Publication number: 20120146647Abstract: The present invention relates to a method for detecting an electrically conducting target in soil, including the steps of generating a repeating transmit signal cycle of a fundamental period using transmit electronics, the repeating transmit signal cycle including a first period and a second period within each fundamental period; generating a transmit magnetic field using a magnetic field transmitter, based on the repeating transmit signal cycle, for transmission into the soil; receiving a receive magnetic field using a magnetic field receiver; producing a receive signal induced by the receive magnetic field; arranging for a current flowing through the magnetic field transmitter to flow to a first potential through a damping resistor during the second period for providing a damping effect on the current flowing through the magnetic field transmitter; arranging for the current flowing through the magnetic field transmitter to flow to a second potential, predominantly through an alternative path with a lower reType: ApplicationFiled: December 14, 2011Publication date: June 14, 2012Applicant: MINELAB ELECTRONICS PTY LIMITEDInventor: Bruce Halcro CANDY
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Publication number: 20120025815Abstract: A highly flexible real-time metal detector platform which has a detection capability for different targets and applications, where the operator is able to alter synchronous demodulation multiplication functions to select different types or mixtures of different types to be applied to different synchronous demodulators, and also different waveforms of the said synchronous demodulation multiplication functions; examples of the different types being time-domain, square-wave, sine-wave or receive signal weighted synchronous demodulation multiplication functions. The operator can alter the fundamental frequency of the repeating switched rectangular-wave voltage sequence, and an operator may alter the waveform of the repeating switched rectangular-wave voltage sequence and corresponding synchronous demodulation multiplication functions.Type: ApplicationFiled: October 11, 2011Publication date: February 2, 2012Applicant: MINELAB ELECTRONICS PTY LTDInventor: Bruce Halcro Candy
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Patent number: 8106770Abstract: A method for detecting a target in a soil, including the step of generating a transmit signal, the transmit signal including at least three different frequency components, a relatively high frequency component, a relatively medium frequency component and a relatively low frequency component; and processing a receive signal, the processing including selecting coefficients for, in effect, linearly combining the relatively high frequency components, the relatively low frequency components and the relatively medium frequency components of the receive signal to produce an indicator output signal, the indicator output signal including a signal indicative of the presence of the target in the soil, and wherein the coefficients are selected such that the indicator output signal is approximately independent of log-linear frequency-dependent resistive signal components and log-uniform resistive signal components from the soil.Type: GrantFiled: October 5, 2007Date of Patent: January 31, 2012Assignee: Minelab Electronics Pty LtdInventor: Bruce Halcro Candy
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Patent number: 8063777Abstract: A highly flexible real-time metal detector platform which has a detection capability for different targets and applications, where the operator is able to alter synchronous demodulation multiplication functions to select different types or mixtures of different types to be applied to different synchronous demodulators, and also different waveforms of the said synchronous demodulation multiplication functions; examples of the different types being time-domain, square-wave, sine-wave or receive signal weighted synchronous demodulation multiplication functions. The operator can alter the fundamental frequency of the repeating switched rectangular-wave voltage sequence, and an operator may alter the waveform of the repeating switched rectangular-wave voltage sequence and corresponding synchronous demodulation multiplication functions.Type: GrantFiled: December 14, 2006Date of Patent: November 22, 2011Assignee: Minelab Electronics Pty Ltd.Inventor: Bruce Halcro Candy
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Publication number: 20110210740Abstract: An electronic metal detector having, a transmit coil arranged and adapted to transmit an alternating magnetic field associated with a reactive transmit coil voltage, the transmit coil being connected to transmit electronics arranged and adapted to generate a transmit signal, the transmit electronics having at least two power sources, a first power source and a second power source, wherein the first power source is adapted and arranged to connect to the transmit coil for at least a first period, and the second power source is adapted and arranged to connect to tie transmit coil for at least a second period, the said transmit electronics including at least one servo control negative feedback loop, a first servo control negative feedback loop, which is adapted and arranged to monitor a transmit coil current for at least part of the said first period, and to control at least part of the said transmit signal, the transmit electronics being adapted and arranged to control the transmit signal to produce the reactiveType: ApplicationFiled: March 16, 2011Publication date: September 1, 2011Applicant: MINELAB ELECTRONICS PTY LTDInventor: Bruce Halcro CANDY
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Patent number: 7924012Abstract: An electronic metal detector having, a transmit coil arranged and adapted to transmit an alternating magnetic field associated with a reactive transmit coil voltage, the transmit coil being connected to transmit electronics arranged and adapted to generate a transmit signal, the transmit electronics having at least two power sources, a first power source and a second power source, wherein the first power source is adapted and arranged to connect to the transmit coil for at least a first period, and the second power source is adapted and arranged to connect to tie transmit coil for at least a second period, the said transmit electronics including at least one servo control negative feedback loop, a first servo control negative feedback loop, which is adapted and arranged to monitor a transmit coil current for at least part of the said first period, and to control at least part of the said transmit signal, the transmit electronics being adapted and arranged to control the transmit signal to produce the reactiveType: GrantFiled: July 12, 2007Date of Patent: April 12, 2011Assignee: Minelab Electronics Pty Ltd.Inventor: Bruce Halcro Candy
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Publication number: 20100283467Abstract: This invention discloses a low cost metal detector which suppresses signals arising from signals induced in a receive inductor from a rate of change of environmental static fields. The metal detector processes a signal due to a rate of change of environmental static fields to produce a first signal, and processes a signal due to the transmitted magnetic field to produce a second signal, the second signal includes a proportion of the first signal. Signal processing includes the subtraction of an estimation of the proportion of the first signal from the second signal to produce a third signal, such that the third signal is substantially independent of the first signal; and the receive electronics further processes the third signal to produce an indicator output signal, the indicator output signal includes a signal indicative of the presence of a metallic target and is substantially unaffected by the signal due to a rate of change of environmental static fields.Type: ApplicationFiled: November 11, 2008Publication date: November 11, 2010Applicant: MINELAB ELECTRONICS PTY LIMITEDInventor: Bruce Halcro Candy