Inductive load control
AssigneeYazaki North America, Inc.
InventorRichard P Cuplin
Life of this patent
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Abstract
A method is provide for controlling an inductive load device (ILD). The method includes providing a voltage potential across ILD and disabling a flow of current through the ILD resulting from the voltage potential across the ILD when a voltage across a sensing device rises to substantially equal an upper threshold value. The rate at which the voltage across the sensing device rises is a function of resistive and inductive characteristics of the ILD. The method additionally includes enabling the flow of current through the ILD resulting from the voltage potential across the ILD when the voltage across the sensing device decays to substantially equal a lower threshold value. The rate at which the voltage across the sensing device decays is a function of the resistive and inductive characteristics of the ILD.
Claims10
A current control circuit for an inductive load device (ILD), said current control circuit comprising:
- a measuring sub-circuit for measuring current flowing through the ILD, wherein an amount of current flowing through the ILD is based on a resistive characteristic and an inductive characteristic of the ILD;
- and
- a switching sub-circuit for responding to an output of the measuring sub-circuit to thereby control a duration of current flow through the ILD as a function of the resistive and inductive characteristics of the ILD, the switching sub-circuit comprising:
- a voltage on/off switching device for controlling application of a voltage across the ILD;
- a shorting switching device responsive to the voltage on/off switching device for shorting a recirculating current dissipation device;
- and
- a current flow switching device for regulating a flow of current from a power source through the ILD and the shorting switching device.
A method for regulating current through an inductive load device, said method comprising:
- providing a voltage across the inductive load device (ILD) causing current to flow through the ILD that is a function of resistive and inductive characteristics of the ILD;
- measuring a voltage across a sensing device of a control circuit connected to the ILD, the voltage induced by the current flowing through the ILD;
- disabling a flow of current through the ILD resulting from the voltage across the ILD when the voltage across the sensing device rises to substantially equal an upper threshold value, wherein the time for the voltage across the sensing device to rise to the upper threshold is a function of the resistive and inductive characteristics of the ILD;
- measuring a voltage across the sensing device induced by a recirculating current generated by the ILD when the current through the ILD resulting from the voltage across the ILD is disabled;
- and
- enabling the flow of current through the ILD resulting from the voltage across the ILD when the voltage across the sensing device decays to substantially equal a lower threshold value, wherein the time for the voltage across the sensing device to decay to the lower threshold is a function of the resistive and inductive characteristics of the ILD.
- wherein providing a voltage across the ILD comprises enabling a voltage on/off switching device and a current flow switching device, whereby enabling the voltage on/off switching device enables a shorting switching device thereby allowing the current to flow through the ILD resulting from the voltage across the ILD.
Dependencies are inferred from the claim text.