Interference cancelling metal detector
AssigneeBHC Consulting Pty., Ltd.
InventorBruce Halcro Candy
Life of this patent
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Abstract
Metal detection apparatus containing at least two inductive coils one of which acts as a transmit coil and all of which act as receive coils and processing circuitry wherein a proportion of the first receive electronic signal and a proportion of the second receive electronic signal may be selected to produce various first resultant linear combination signals for the purpose of improved interference cancelling.
Claims8
A method for effecting metal detection using a metal detector including transmit and receive electronic timing control circuitry, power supplies, and receive and transmit signal electronic circuitry, and at least two inductive coils, a first and second coil, wherein at least the first coil when connected to the transmit signal electronic circuitry when operating is adapted to transmit magnetic pulses, and also to act as a receiver to receive magnetic field signals which when connected to the receive signal electronic circuitry produces at least one receive electronic signal, being a first electronic receive signal, and at least the second coil is adapted to receive magnetic field signals which when connected to the receive signal electronic circuitry produces at least one receive electronic signal, being a second receive electronic signal, and processing circuitry adapted to accumulate at least the first and second receive electronic signals, characterized in that at least a proportion of the first receive electronic signals is linearly combined with a proportion of the second receive electronic signal, to produce a first resultant linear combination signal which is further processed to produce an output signal for indicator means.
A metal detector apparatus including at transmit and receive electronic timing control circuitry, power supplies, and receive and transmit signal electronic circuitry, and least two inductive coils, a first and second coil;
- wherein at least the first coil when connected to the transmit signal electronic circuitry when operating is adapted to transmit magnetic pulses, and also act as a receiver to receive magnetic field signals which when connected to the receive signal electronic circuitry produces at least one receive electronic signal, a first electronic receive signal,
- and at least the second coil is adapted to receive magnetic field signals which when connected to the receive signal electronic circuitry produces at least one receive electronic signal, a second receive electronic signal,
- and processing circuitry accumulates at least the first and second receive electronic signals, characterized in that at least a proportion of the first receive electronic signals is linearly combined with a proportion of the second receive electronic signal, to produce a first resultant linear combination signal which is further processed to produce an output signal for indicator means.
Dependencies are inferred from the claim text.