Noncontact power transmission system to detect presence of a metallic foreign matter
First Claim
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1. A detecting device, comprising:
- a reading coil configured to read a magnetic flux, generated by a detecting coil, to detect a magnetic field of an electromagnetic wave output from an exciting coil;
a Q-value measuring section configured to measure a Q-value of the detecting coil based on a frequency of the electromagnetic wave and a temporal transition of oscillation of a voltage obtained in the reading coil,wherein the voltage is obtained based on the magnetic flux generated by the detecting coil,wherein the Q-value is obtained by a following equation;
Q=π
f(t2−
t1)/ln(V1/V2), andwherein f is a frequency of the electromagnetic wave, V1 is a first voltage value obtained in the reading coil at a first time (t1), and V2 is a second voltage value obtained in the reading coil at a second time (t2);
a determining section configured to;
determine a presence of a circuit between the exciting coil and the detecting coil based on comparison between the Q-value and a reference value,wherein the circuit includes one of a conductor or an arbitrary coil; and
determine a state of electromagnetic coupling between the exciting coil and the detecting coil based on the presence of the circuit; and
a control section configured to control, based on the determined state of electromagnetic coupling between the exciting coil and the detecting coil, a power supply to the exciting coil to minimize eddy currents between the exciting coil and the detecting coil, wherein the eddy currents are generated based on the presence of the circuit between the exciting coil and the detecting coil.
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Abstract
A detecting device includes a reading coil configured to read a magnetic flux generated by a detecting coil for detecting a magnetic field of an electromagnetic wave output from an exciting coil according to the magnetic field. The detecting device further includes a Q-value measuring section configured to measure a Q-value of the detecting coil on a basis of a temporal transition of oscillation of a voltage obtained in the reading coil according to the magnetic flux generated by the detecting coil.
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Citations
14 Claims
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1. A detecting device, comprising:
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a reading coil configured to read a magnetic flux, generated by a detecting coil, to detect a magnetic field of an electromagnetic wave output from an exciting coil; a Q-value measuring section configured to measure a Q-value of the detecting coil based on a frequency of the electromagnetic wave and a temporal transition of oscillation of a voltage obtained in the reading coil, wherein the voltage is obtained based on the magnetic flux generated by the detecting coil, wherein the Q-value is obtained by a following equation;
Q=π
f(t2−
t1)/ln(V1/V2), andwherein f is a frequency of the electromagnetic wave, V1 is a first voltage value obtained in the reading coil at a first time (t1), and V2 is a second voltage value obtained in the reading coil at a second time (t2); a determining section configured to; determine a presence of a circuit between the exciting coil and the detecting coil based on comparison between the Q-value and a reference value, wherein the circuit includes one of a conductor or an arbitrary coil; and determine a state of electromagnetic coupling between the exciting coil and the detecting coil based on the presence of the circuit; and a control section configured to control, based on the determined state of electromagnetic coupling between the exciting coil and the detecting coil, a power supply to the exciting coil to minimize eddy currents between the exciting coil and the detecting coil, wherein the eddy currents are generated based on the presence of the circuit between the exciting coil and the detecting coil. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A detecting system, comprising:
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a detecting coil configured to detect a magnetic field of an electromagnetic wave output from an exciting coil; a reading coil configured to read a magnetic flux generated by the detecting coil based on the magnetic field; a Q-value measuring section configured to measure a Q-value of the detecting coil based on a frequency of the electromagnetic wave and a temporal transition of oscillation of a voltage obtained in the reading coil, wherein the voltage is obtained based on the magnetic flux generated by the detecting coil, wherein the Q-value is obtained by a following equation;
Q=π
f(t2−
t1)/ln(V1/V2), andwherein f is a frequency of the electromagnetic wave, V1 is a first voltage value obtained in the reading coil at a first time (t1), and V2 is a second voltage value obtained in the reading coil at a second time (t2); a determining section configured to; determine a presence of a circuit between the exciting coil and the detecting coil based on a comparison between the Q-value and a reference value, wherein the circuit includes one of a conductor or an arbitrary coil; and determine a state of electromagnetic coupling between the exciting coil and the detecting coil based on the presence of the circuit; and a control section configured to control, based on the determined state of electromagnetic coupling between the exciting coil and the detecting coil, a power supply to the exciting coil to minimize eddy currents between the exciting coil and the detecting coil, wherein the eddy currents are generated based on the presence of the circuit between the exciting coil and the detecting coil. - View Dependent Claims (12, 13)
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14. A detecting method, comprising:
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outputting an electromagnetic wave from an exciting coil; detecting a magnetic field of the electromagnetic wave output from the exciting coil; reading a magnetic flux based on the magnetic field, wherein the magnetic flux is generated by a detecting coil; measuring a Q-value of the detecting coil based on a frequency of the electromagnetic wave and a temporal transition of oscillation of a voltage obtained in a reading coil, wherein the voltage is obtained based on the magnetic flux generated by the detecting coil by a Q-value measuring section, wherein the Q-value is obtained by a following equation;
Q=π
f(t2−
t1)/ln(V1/V2), andwherein f is a frequency of the electromagnetic wave, V1 is a first voltage value obtained in the reading coil at a first time (t1), and V2 is a second voltage value obtained in the reading coil at a second time (t2); determining a presence of a circuit between the exciting coil and the detecting coil based on a comparison between the Q-value and a reference value, wherein the circuit includes one of a conductor or an arbitrary coil; determining a state of electromagnetic coupling between the exciting coil and the detecting coil based on the presence of the circuit; and controlling, based on the determined state of electromagnetic coupling between the exciting coil and the detecting coil, a power supply to the exciting coil to minimize eddy currents between the exciting coil and the detecting coil, wherein the eddy currents are generated based on the presence of the circuit between the exciting coil and the detecting coil.
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Specification