Device, system and method for a sensing electrical circuit

• US 7,622,907 B2
• Filed: 09/27/2006
• Issued: 11/24/2009
• Est. Priority Date: 09/27/2006
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Vranish, John M.
• Primary Examiner(s): Dole; Timothy J
• Application Number:
  US11/535,872
• Publication Number:
  US 20080074098A1
• Time in Patent Office: 1,154 Days
• Field of Search: 324/76.11, 324/661
• US Class Current: 324/76.11
• CPC Class Codes: G01D 5/24 by varying capacitance

Abstract

The invention relates to a driven ground electrical circuit. A driven ground is a current-measuring ground termination to an electrical circuit with the current measured as a vector with amplification. The driven ground module may include an electric potential source V_S driving an electric current through an impedance (load Z) to a driven ground. Voltage from the source V_S excites the minus terminal of an operational amplifier inside the driven ground which, in turn, may react by generating an equal and opposite voltage to drive the net potential to approximately zero (effectively ground). A driven ground may also be a means of passing information via the current passing through one grounded circuit to another electronic circuit as input. It may ground one circuit, amplify the information carried in its current and pass this information on as input to the next circuit.

Claims

1. A sensing electrical circuit system embodied in a deformation camera sensor, said system comprising:

an electric potential source;

an impedance load; and

a driven ground comprising a resistor and an operational amplifier, said electric potential source driving a current through said impedance load to said driven ground, and a voltage source exciting a minus terminal of the operational amplifier reactively generating an equal and opposite voltage driving a net potential to approximately zero;

wherein

said sensing electrical circuit system is embedded in a flexible skin, wherein deformation of said flexible skin changes said current through said impedance load to said driven ground.

2. The system of claim 1, further comprising:

a driven source interposed between an electric potential source and said impedance load;

said driven source comprising a resistor and an operational amplifier; and

said driven source generating a voltage vector source which enables measuring amplitude, phase, and frequency.

3. A sensing electrical circuit system embodied in a tool, said system comprising:

an electric potential source;

an impedance load; and

a driven ground comprising a resistor and an operational amplifier, said electric potential source driving a current through said impedance load to said driven ground, and a voltage source exciting a minus terminal of the operational amplifier reactively generating an equal and opposite voltage driving a net potential to approximately zero wherein said tool is a deformation camera sensor, said deformation camera sensor comprising a compressed flexible multi-layer sheet including layers of;

a first natural ground layer;

a driven shield layer;

a plurality of driven source columns;

a separation layer;

a plurality of driven ground rows;

a thin insulation layer; and

a second natural ground layer;

wherein deformation of said first natural ground layer correspondingly deforms the separation layer and increases a corresponding proximity of the plurality of driven source columns to the plurality of driven ground rows, thereby increasing displacement current between the plurality of driven source columns and the plurality of driven ground rows, and thereby generating a displacement current identifying a location of three dimensional displacement.

4. The system of claim 3, wherein the separation layer is an elastic insulator layer.

5. The system of claim 3, wherein displacement current is measured for each row and for each column and then related to measure their mutually simultaneous values.

6. The system of claim 3, wherein displacement current passing between columns and rows is apportioned on a pixel by pixel basis.