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US 11,539,279 B2Granted
Gap-closing actuator having a double-wound driving coil
AssigneeApple Inc.
InventorsRiccardo Tarelli, Yumeng Liu
Life of this patent
Estimating the term…
Abstract
A haptic engine includes a gap-closing actuator having a double-wound driving coil in which the two windings can be activated with two driving sources, respectively. Or, the two windings double-wound driving coil can be activated with a single driving source when the two windings are connected with each other either in series or in parallel. By using the double-wound driving coil in the gap-closing actuator as described, an instant inductance of either of the two windings can be determined without having to measure in real time a resistance of the corresponding winding.
Claims45
A haptic engine comprising:
- a frame;
- a first coil and a second coil wound together around a common core, the first coil and the second coil being thermally coupled with each other and mechanically coupled with the frame, the first coil having first terminals and the second coil having second terminals;
- first driver circuitry electrically coupled with the first coil at the first terminals to drive a first driving current through the first coil;
- first voltage- and current-sensing circuitry electrically coupled with the first coil at the first terminals to sense a first driving voltage across, and the first driving current through, the first coil;
- second driver circuitry electrically coupled with the second coil at the second terminals to drive a second driving current through the second coil, wherein
- the first driving current and the second driving current have different values, and
- an increase of the first current is different from a decrease of the second current;
- second voltage- and current-sensing circuitry electrically coupled with the second coil at the second terminals to sense a second driving voltage across, and the second driving current through, the second coil;
- an attraction plate spaced apart from the first and the second coils through a gap, the attraction plate arranged to be driven relative to the frame along a driving direction to cause variation of the gap when the first driving current is driven through the first coil, and the second driving current is driven through the second coil;
- and
- computing circuitry configured to determine values of the gap between the attraction plate and the first and the second coils, the gap values determined
- independently of resistances of either the first coil or the second coil, and
- dependently of the first driving current through, and the first driving voltage across, the first coil, and the second driving current through, and the second driving voltage across, the second coil, and rates of change of the first and second driving currents.
10 more elements
A method for determining inductance of each winding of a coil with two windings wound together around a common core, the method comprising:
- driving a first current through a first of the two windings;
- driving a second current through a second of the two windings, wherein
- the second current is different than the first current, and
- an increase of the first current is different from a decrease of the second current;
- sensing a first voltage across, and the first current through, the first winding;
- sensing a second voltage across, and the second current through, the second winding;
- and
- computing a first inductance the first winding or a second inductance of the second winding, wherein each of the first inductance and the second inductance is computed
- independently of resistances of either the first winding or the second winding, and
- dependently of the first current through, and the first voltage over, the first winding, and the second current through, and the second voltage over, the second winding, and rates of change of the first and second currents.
7 more elements
A haptic engine comprising:
- a frame;
- a double-wound driving coil that is mechanically coupled with the frame and comprises a first coil and a second coil wound together around a common core and thermally coupled with each other, the first coil and the second coil being connected in series and having a common terminal, wherein a first ratio
- N
- =
- R
- 1
- R
- 2
- of the resistances of the first coil and the second coil is different from the square root of a second ratio
- M
- =
- L
- 1
- L
- 2
- of the inductances of the first coil and the second coil;
- driver circuitry electrically coupled with the first coil at a first terminal different from the common terminal, and the second coil at a second terminal different from the common terminal to drive a driving current through the first coil and the second coil, such that its rate of change is non-zero;
- first voltage sensing circuitry to sense a first driving voltage across the first coil when electrically coupled with the first coil at the first terminal and the common terminal;
- second voltage sensing circuitry to sense a second driving voltage across the second coil when electrically coupled with the second coil at the second terminal and the common terminal;
- an attraction plate spaced apart from the first and the second coils through a gap, the attraction plate arranged to be driven relative to the frame along a driving direction to cause variation of the gap when the driving current is driven through the first coil and the second coil;
- and
- computing circuitry configured to determine values of the gap between the attraction plate and the first and the second coils, the gap values determined
- independently of resistances of either the first coil or the second coil, and
- dependently of the first driving voltage over the first coil and the second driving voltage over the second coil, the rate of change of the driving current through the first and second coils, and the first and second ratios.
21 more elements
A method for determining inductance of each winding of a coil with two windings wound together around a common core, the two windings connected in series, wherein a first ratio
- N
- =
- R
- 1
- R
- 2
- of the resistances of a first of the two windings and second of the two windings is different from the square root of a second ratio
- M
- =
- L
- 1
- L
- 2
- of the inductances of the two windings, the method comprising:
- driving a current through the two windings, such that its rate of change is non-zero;
- sensing the current through the two windings;
- sensing a first voltage across the first winding;
- sensing a second voltage across the second winding;
- and
- computing a first inductance of the first winding or a second inductance of the second winding, wherein each of the first inductance and the second inductance is computed
- independently of resistances of either the first winding or the second winding, and
- dependently of the first driving voltage over the first winding and the second driving voltage over the second winding, the rate of change of the driving current through the two windings, and the first and second ratios.
19 more elements
A haptic engine comprising:
- a frame;
- a double-wound driving coil that is mechanically coupled with the frame and comprises a first coil and a second coil wound together around a common core and thermally coupled with each other, the first coil and the second coil being connected in parallel at common terminals;
- voltage-driver circuitry electrically coupled with the parallel-connected first coil and second coil to drive a driving voltage across the parallel-connected first coil and second coil, wherein the voltage driver circuitry comprises a voltage sensor electrically coupled with the parallel-connected first coil and second coil to sense the driving voltage across the parallel- connected first coil and second coil;
- first current sensing circuitry electrically coupled with the first coil to sense a first driving current caused through the first coil by the driving voltage;
- second current sensing circuitry electrically coupled with the second coil to sense a second driving current caused through the second coil by the driving voltage, wherein
- a first ratio
- I
- 1
- I
- 2
- of the first and second driving currents is different from a ratio of square root of a second ratio
- M
- =
- L
- 1
- L
- 2
- of the inductances of the first winding and the second winding and a third ratio
- N
- =
- R
- 1
- R
- 2
- of the resistances ot tne nrst winding and the second winding, and
- an increase of the first current scaled by the square root of the first ratio is different from a decrease of the second current;
- an attraction plate spaced apart from the first and the second coils through a gap, the attraction plate arranged to be driven relative to the frame along a driving direction to cause variation of the gap when the driving voltage is supplied across the parallel-coupled first coil and the second coil;
- and
- computing circuitry configured to determine a velocity of the mass along the driving direction, the velocity determined
- independently of resistances of either the first coil or the second coil, and
- dependently of the values of the driving voltage, rates of change of the first and second driving currents, and the first, second, and third ratios.
28 more elements
A method for determining inductance of each winding of a coil with two windings wound together around a common core, the two windings being connected in parallel, the method comprising:
- supplying a driving voltage across the two parallel-connected windings;
- sensing the driving voltage;
- sensing a first current through the first winding;
- sensing a second current through the second winding, wherein
- a first ratio
- I
- 1
- I
- 2
- of the first and second driving currents is different from a ratio of square root of a second ratio
- M
- =
- L
- 1
- L
- 2
- of the inductances of the first winding and the second winding and a third ratio
- N
- =
- R
- 1
- R
- 2
- of the resistances of the first winding and the second winding, and
- an increase of the first current scaled by the square root of the first ratio is different from a decrease of the second current;
- and
- computing a first inductance of the first winding or a second inductance of the second winding, wherein each of the first inductance and the second inductance is computed
- independently of resistances of either the first winding or the second winding, and
- dependently of the values of the driving voltage, rates of change of the first and second driving currents, and the first, second, and third ratios.
26 more elements
Dependencies are inferred from the claim text.