Magnetic sensor apparatus and current sensor apparatus

A magnetic sensor apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• an inductance element connected to the sensor coil in series, wherein the inductance element is used for supplying a second current to the sensor coil, the second current including:
• a direct current;
• and
• a current having a frequency different from a resonant frequency of the series resonant circuit.

A magnetic sensor apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• a detection means for detecting the magnetic field by detecting a variation in the resonant current flowing through the sensor coil.

A magnetic sensor apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means for driving the sensor coil by supplying an alternating current thereto;
• an inductance element connected to the sensor coil in series;
• and
• differentiation circuit for differentiating a voltage generated across the inductance element and outputting a signal corresponding to the magnetic field.

A magnetic sensor apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• a current supply means for supplying a second current to the sensor coil, the second current including:
• a direct current;
• and
• a current having a frequency different from a resonant frequency of the series resonant circuit.

A magnetic sensor apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means for driving the sensor coil by supplying an alternating drive current that drives the core into a saturation region to the sensor coil;
• a field detection means for detecting the magnetic field by detecting a variation in inductance of the sensor coil;
• an inductance variation amount detection means for detecting an amount of an inductance variation in the saturation region of the core in an equivalent manner;
• and
• a control means for controlling the drive current, based on the amount of the inductance variation detected by the inductance variation amount detection means.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• an inductance element connected to the sensor coil in series.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• an inductance element connected to the sensor coil in series, wherein the inductance element is used for detecting a variation in the resonant current flowing through the sensor coil.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• an inductance element connected to the sensor coil in series, wherein the inductance element is used for supplying a second current to the sensor coil, the second current including:
• a direct current;
• and
• a current having a frequency different from a resonant frequency of the series resonant circuit.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• a detection means for detecting the magnetic field by detecting a variation in the resonant current flowing through the sensor coil.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means for driving the sensor coil by supplying an alternating current thereto;
• an inductance element connected to the sensor coil in series;
• and
• a differentiation circuit for differentiating a voltage generated across the inductance element and outputting a signal corresponding to the magnetic field.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means having a series resonant circuit part of which is made up of the sensor coil, the drive means driving the sensor coil by supplying a resonant current flowing through the series resonant circuit to the sensor coil;
• and
• a current supply means for supplying a second current to the sensor coil, the second current including:
• a direct current;
• and
• a current having a frequency different from a resonant frequency of the series resonant circuit.

A current sensor apparatus for measuring an electric current by measuring a magnetic field generated by the current to be measured, the apparatus comprising:

• a magnetic core;
• a sensor coil wound around the core and provided for detecting an applied magnetic field to be measured;
• a drive means for driving the sensor coil by supplying an alternating drive current that drives the core into a saturation region to the sensor coil;
• a field detection means for detecting the magnetic field by detecting a variation in inductance of the sensor coil;
• an inductance variation amount detection means for detecting an amount of an inductance variation in the saturation region of the core in an equivalent manner;
• and
• a control means for controlling the drive current, based on the amount of the inductance variation detected by the inductance variation amount detection means.