Sensor having free fall self-test capability and method therefor
First Claim
1. A device comprising:
- a transducer, the transducer comprising;
a movable element;
a self-test actuator disposed proximate said movable element for providing an electrostatic force to move said movable element from a negative gravitational position to a neutral gravitational position, said neutral gravitational position simulating free fall; and
a sensing element disposed beneath said movable element, said sensing element being adapted to detect movement of said movable element from said negative gravitational position to said neutral gravitational position along an axis perpendicular to a plane of said sensing element.
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Accused Products
Abstract
A transducer (20) includes a movable element (24), a self-test actuator (22), and a sensing element (56, 58). The sensing element (56, 58) detects movement of the movable element (24) from a first position (96) to a second position (102) along an axis perpendicular to a plane of the sensing element (56, 58). The second position (102) results in an output signal (82) that simulates a free fall condition. A method (92) for testing a protection feature of a device (70) having the transducer (20) entails moving the movable element (24) to the first position (102) to produce a negative gravitational force detectable at the sensing element (56, 68), applying a signal (88) to the actuator (22) to move the movable element (24) to the second position (102) by the electrostatic force (100) , and ascertaining an enablement of the protection feature in response to the simulated free fall.
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Citations
14 Claims
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1. A device comprising:
a transducer, the transducer comprising; a movable element; a self-test actuator disposed proximate said movable element for providing an electrostatic force to move said movable element from a negative gravitational position to a neutral gravitational position, said neutral gravitational position simulating free fall; and a sensing element disposed beneath said movable element, said sensing element being adapted to detect movement of said movable element from said negative gravitational position to said neutral gravitational position along an axis perpendicular to a plane of said sensing element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for testing a protection feature of a device having a transducer adapted to sense free fall, said transducer including a movable element, a self-test actuator disposed proximate said movable element, and a sensing element disposed beneath said movable element, said method comprising:
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moving said movable element to a first position, said first position producing a negative gravitational force detectable at said sensing element; applying a self-test signal to said self-test actuator to move said movable element to a second position by electrostatic force, said second position simulating said free fall; and ascertaining an enablement of said protection feature in response to said simulated free fall. - View Dependent Claims (12, 13, 14)
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Specification