| MINELAB ELECTRONICS PTY LTD. Patent applications |
| Patent application number | Title | Published |
|---|
| 20120025815 | REAL-TIME RECTANGULAR-WAVE TRANSMITTING METAL DETECTOR PLATFORM WITH USER SELECTABLE TRANSMISSION AND RECEPTION PROPERTIES - 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. | 02-02-2012 |
| 20110210740 | METAL DETECTOR HAVING CONSTANT REACTIVE TRANSMIT VOLTAGE APPLIED TO A TRANSMIT COIL - 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 reactive transmit coil voltage to be approximately constant and approximately equal to zero whilst the transmit coil current is non-zero and approximately constant for at least part of the first period; and receive electronics which are adapted and arranged to receive and process a receive magnetic field during at least some of the first period to produce an indicator output. | 09-01-2011 |
| 20100026485 | METAL DETECTOR WITH IMPROVED MAGNETIC SOIL RESPONSE CANCELLATION - A metal detector with improved magnetic soil response cancellation is disclosed. The metal detector including, in one aspect, at least one or more inductors arranged and adapted to transmit and receive an alternating magnetic field, transmit electronics arranged and adapted to generate a transmit signal applied to at least one inductor to produce a transmitted magnetic field, at least one inductor, a first inductor, arranged and adapted to receive a magnetic field to produce a receive emf signal, the said first inductor being connected to receive electronics arranged and adapted to amplify and may filter the receive emf signal to produce a receive signal, the transmit signal is arranged and adapted to contain at least three different frequency components, a relatively high frequency component, a relatively low frequency component and a relatively medium frequency component, the receive electronics is arranged and adapted to contain signal processing which may process the receive signal to produce and output indicator signal, such that at least part of the signal processing includes at least one linear combination of in effect adding receive signal components containing at least relatively high frequency resistive components to receive signal components containing at least relatively low frequency resistive components and the resultant sum is subtracted from receive signal components containing at least relatively medium frequency resistive components to give a linear combination output, coefficients of the linear combination being selected so that a further processed linear combination output which may include filtering is approximately independent of signals from magnetic soils including at least some higher order effects of different soils under the influence of the transmitted magnetic field which may include small variations in a ratio of received relatively high frequency resistive components compared to medium frequency resistive components, and also may include small variations in a ratio of received relatively medium frequency resistive components compared to lower frequency resistive components, the said linear combination arranged and adapted such that the further processed linear combination output is responsive to at least some metal targets, and the further linear combination output is arranged and adapted to produce the said output indicator signal. | 02-04-2010 |
| 20100019769 | METAL DETECTOR HAVING CONSTANT REACTIVE TRANSMIT VOLTAGE APPLIED TO A TRANSMIT COIL - 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 reactive transmit coil voltage to be approximately constant and approximately equal to zero whilst the transmit coil current is non-zero and approximately constant for at least part of the first period; and receive electronics which are adapted and arranged to receive and process a receive magnetic field during at least some of the first period to produce an indicator output. | 01-28-2010 |
