# US 5,703,576 A · Embeddable DC power supply for smart structure sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,576 A - Document ID: US5703576A - Status: Granted - Kind: A - Application number: 08/646,705 - Filed: 1996-05-06 - Granted: 1997-12-30 - Earliest claimed: 1993-06-14 - Assignees: Simmonds Precision Products, Inc. - Inventors: William B. Spillman, Jr.; Scott R. Durkee - Web page: https://patentgrep.com/patent/US5703576A ## CPC - G08C 17/04: using magnetically coupled devices - G01D 5/48: using wave or particle radiation means (G01D5/26 takes precedence) - G08C: TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS (fluid pressure transmitting systems F15B; mechanical means for transferring the output of a sensing member into a different variable G01D5/00; mechanical control systems G05G) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract A smart structure comprising a rotatable shaft, and a sensor integrated with the shaft, a resonant detector circuit integrated with the structure for detecting a sensor output, and an external exciter circuit; the detector circuit having first coil means and the exciter circuit having second coil means magnetically coupled to the first coil means when aligned across a gap; and control means exterior the shaft for producing an output that corresponds to the sensor output compensated for the gap. ## Claims ### Claim 1 A smart structure comprising a sensor integrated with the structure, a DC power supply integrated with the structure for providing energy to the sensor, an external exciter circuit, and a resonant detector circuit integrated with the structure for detecting a sensor output and transmitting a corresponding signal to said exciter circuit; said power supply being disposed on a substrate embedded in the structure; said power supply having an inductive coil and ac to dc converter components disposed on the substrate; said inductive coil being disposed in a high frequency magnetic field produced by said exciter circuit. ### Claim 2 (depends on 1) The smart structure according to claim 1 wherein said detector circuit comprises a second inductive coil disposed on said substrate; and said exciter circuit comprises two coils, each of said exciter coils being magnetically coupled to one of said power supply and detector circuit coils respectively. ### Claim 3 (depends on 1) The smart structure according to claim 1 wherein said power supply converter is a resonant circuit including a rectifier for providing DC electrical power to the sensor. ### Claim 4 (depends on 1) The smart structure according to claim 1 wherein the sensor is an optic sensor comprising a light source energized by said DC power supply. ### Claim 5 (depends on 4) The smart structure according to claim 4 wherein the sensor output is a light signal that is incident on a photoresistor connected to said detector circuit. ### Claim 6 (depends on 4) The smart structure according to claim 4 wherein said light source comprises a laser diode disposed on said substrate and electrically energized by said DC power supply. ### Claim 7 (depends on 1) The smart structure according to claim 1 wherein the structure comprises composite laminates and said substrate comprises a thin flexible coupon of insulative material. ### Claim 8 A DC power supply for a sensor embedded in a composite smart structure comprising: a substrate embeddable in the structure, a circuit pattern disposed on said substrate for interconnecting a plurality of components, said components comprising an inductive coil and an ac to dc converter, said coil being disposed on said substrate, said circuit pattern including terminals for disposing said components on said substrate and connection to the sensor, said coil being disposed in a high frequency magnetic field. ### Claim 9 (depends on 8) The power supply of claim 8 wherein said substrate comprises a thin flexible piece of insulator embeddable in the structure. ### Claim 10 (depends on 9) The power supply of claim 9 wherein the structure comprises a non-magnetic composite material forming a laminated structure. ### Claim 11 (depends on 10) The power supply of claim 10 wherein said ac to dc converter comprises surface mounted components on said substrate that are configured as a resonant LC circuit and rectifier. ### Claim 12 (depends on 11) The power supply of claim 11 wherein said resonant circuit exhibits a resonant frequency greater than one megahertz. ### Claim 13 (depends on 12) The power supply of claim 12 wherein said rectifier circuit comprises a full bridge rectifier, and said converter circuit further comprises a low pass filter and a zener diode. ### Claim 14 (depends on 8) The power supply of claim 8 wherein said coil comprises a plurality of circularly spiraled windings disposed on the substrate and that conducts an induced current when exposed to a magnetic field with a portion thereof perpendicular to said substrate surface. ### Claim 15 (depends on 14) The power supply of claim 14 wherein said coil comprises a plurality of laminated windings etched on one surface of said substrate and a plurality of laminated windings etched on another surface of said substrate. ### Claim 16 (depends on 8) The power supply of claim 8 further comprising a second substrate having a second coil disposed thereon that is magnetically coupled with said first coil. ### Claim 17 (depends on 16) The power supply of claim 16 wherein said coils comprise etched copper laminations on said substrates. ### Claim 18 (depends on 17) The power supply of claim 17 wherein said second coil is connectable to a high frequency energy source and overlayed with said first coil.