US 6,650,113 B2Granted

Detector and method thereof for determining magnetic flux based on electromotive force induced by an excitation current

AssigneeHonda Giken Kogyo Kabushiki Kaisha

InventorShigenobu Sekiya

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Abstract

A magnetic flux detector has a core member and an armature member. The core member generates a magnetic flux by an exciting coil receiving an excitation current controlled by an excitation current controller. The magnetic flux detector also has a search coil provided in a magnetic path for the magnetic flux, and a magnetic flux calculator, which determines the magnitude of the magnetic flux by measuring an electromotive force induced in the search coil by a change in the magnetic flux. The excitation current controller controls the excitation current to increase from zero to a predetermined value during a first predetermined time period and then to decrease to zero during a second predetermined time period. The magnetic flux calculator determines the magnitude of the magnetic flux based on the integrated electromotive forces during the first and second time periods.

Claims6

Dependent claims

A magnetic flux detector comprising:

a magnetic flux generator, which includes an exciting coil and generates a magnetic flux when an excitation current is supplied to said excitation coil;
an excitation current controller, which controls said excitation current being supplied to said exciting coil;
a search coil, which is placed in a magnetic path where the magnetic flux generated by said magnetic flux generator passes, such that an electromotive force is induced in said search coil in response to a change in the magnetic flux;
and
a magnetic flux calculator, which determines the magnitude of the magnetic flux generated by said magnetic flux generator by measuring the electromotive force induced in said search coil;
wherein:
said excitation current controller controls said excitation current to increase from zero to a predetermined current value during a first predetermined time period and then to decrease from the predetermined current value to zero during a second predetermined time period;
and
said magnetic flux calculator determines the magnitude of the magnetic flux generated by said magnetic flux generator based on a difference between an increasing electromotive force integral value which is calculated by integrating the electromotive force induced in said search coil during said first predetermined time period and a decreasing electromotive force integral value which is calculated by integrating the electromotive force induced in said search coil during said second predetermined time period.

6 more elements

A magnetic flux detection method for determining a magnetic flux that is generated in a magnetic path by an exciting coil being supplied with an excitation current, by measuring an electromotive force induced in a search coil which is placed in said magnetic path;

wherein:
an increasing electromotive force integral value is calculated by integrating the electromotive force induced in said search coil while said exciting coil is being supplied with said excitation current which increases from zero to a predetermined current value during a first predetermined time period;
after said first predetermined time period, a decreasing electromotive force integral value is calculated by integrating the electromotive force induced in said search coil while said exciting coil is being supplied with said excitation current which decreases from said predetermined current value to zero during a second predetermined time period;
and
the magnitude of the magnetic flux generated in said magnetic path is determined based on a difference calculated by subtracting said decreasing electromotive force integral value from said increasing electromotive force integral value.

2 more elements

Dependencies are inferred from the claim text.