Ground mineralisation rejecting metal detector (power saving)
AssigneeBHC Consulting Pty., Ltd.
InventorBruce Halcro Candy
Life of this patent
Estimating the term…
Abstract
A metal detector apparatus including a transmit coil which transmits a magnetic field, transmit timing control circuitry which also includes timing for a semiconductor switch, and receive signal circuitry and receive signal processing circuitry, with a transmit coil damping network including at least one resistor connected in series with the semiconductor switch across the transmit coil, and timing control circuitry which generates a timing sequence which is selected so that for at least some of the time no transmit field is generated and at least during part of the transmit signal, the first semiconductor switch is controlled to be off and is turned on before the cessation of the transmit field.
Claims5
A metal detector apparatus including a transmit coil adapted to transmit a magnetic field when operating with electrical current flowing through the said transmit coil, transmit timing control circuitry which also includes timing for a first semiconductor switch, and receive signal circuitry and receive signal processing circuitry;
- wherein a transmit coil damping network including at least one resistor is connected in series with the said first semiconductor switch across the transmit coil,
- and the timing control circuitry generates a timing sequence which is selected so that for at least some of the time no transmit field is generated and at least during part of the transmit signal, the first semiconductor switch is controlled to be off and is turned on before the cessation of the transmit field.
A metal detector apparatus including a transmit coil adapted to transmit a magnetic field when operating with electrical current flowing through The said transmit coil, a least one power supply, a first power supply, and transmit timing control circuitry which also includes timing circuitry for a switch mode power supply, and receive signal circuitry and receive signal processing circuitry;
- wherein there are means to control the transmit coil so that a back e.m.f. following the transmit coil current energising period derived from energy from the said first power supply, causes current to flow to a capacitor, a first capacitor,
- and the said switch mode power supply is adapted to transfer energy from the first capacitor to the said third power supply.
A metal detector apparatus including a transmit coil adapted to transmit a magnetic field when operating with electrical current flowing through the said transmit coil, at least one power supply, a first power supply, and transmit timing control circuitry which also includes timing circuitry for a switch mode power supply, and receive signal circuitry and receive signal processing circuitry;
- wherein a transmit coil damping network including at least one resistor is connected in series with the said first semiconductor switch across the transmit coil, and the timing control circuitry generates a timing sequence which is selected so that for at least some of the time no transmit field is generated and at least during part of the transmit signal, the first semiconductor switch is controlled to be off and is turned on before the cessation of the transmit field,
- whereby the transmit coil is controlled so that a back e.m.f. following the transmit coil current energising period derived from energy from the said first power supply, causes current to flow to a capacitor, a first capacitor,
- and the said switch mode power is adapted to tranfer energy from the first capacitor to the said third power supply.
Dependencies are inferred from the claim text.