Servosystem operating about noise component error signal

• US 4,348,632 A
• Filed: 09/15/1980
• Issued: 09/07/1982
• Est. Priority Date: 09/15/1980
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kanazawa, Kay K., Galwey, Ronald K.
• Primary Examiner(s): Rubinson, Gene Z.
• Assistant Examiner(s): Indyk, Eugene S.
• Application Number:
  US06/187,120
• Time in Patent Office: 722 Days
• Field of Search: 318/632, 318/650, 204/195 F, 204/228, 204/231, 323/280
• US Class Current: 323/280
• CPC Class Codes: G01N 27/48 using polarography, i.e. measuring changes in current under a slowly-varying voltage

Abstract

The control of the operation of an electric circuit element, such as an electrochemical cell, is performed by positive feedback servocircuitry developing an error signal or inherent noise component, and having algebraic computing capability for developing the compensating control. Current follower circuitry is arranged for developing a potential proportional to the current drawn by the electric circuit element to be controlled. A portion of this potential is algebraically combined with the externally applied operating electric wave. The inherent noise component of the control circuitry is sensed by a high pass filter and an ac-dc converting circuit and thereafter integrated for generating a slowly varying potential for determining the portion of the potential derived by sensing the current. The two potentials are applied to a conventional multiplying circuit and the product potential combined with the operating wave.

Claims

1. A closed loop servocircuit arrangement for controlling the operation of an electric circuit element having at least two terminals, comprising

circuitry for controlling and applying operating energy across said electric circuit element for passing electric current therethrough, which electric current includes an inherent electric noise current component which also manifests an electric noise potential,

servocircuitry having input terminals coupled to points on said circuitry at which said noise current component and said noise potential components are manifested and having an output terminal at which a processed error signal is presented and combined with said operating energy for controlling the flow of electric current through said electric circuit element,

said servocircuitry comprising

an inverting summing circuit having balanced input terminals and having an output terminal,

a control amplifying circuit having an input terminal connected to said output terminal of said summing circuit, and having an output terminal connected to one terminal of said electric circuit element,

a current following circuit having an input terminal connected to the other terminal of said electric circuit element and having an output terminal,

a converting circuit having an input circuit connected to said output terminal of said control amplifying circuit and having an output terminal,

an integrating circuit having an input terminal connected to said converting circuit and having an output terminal, and

a multiplying circuit having input terminals individually connected to said output terminals of said current following circuit and said integrating circuit and having a product output terminal connected to one of said input terminals of said summing circuit.

2. A closed loop servocircuit arrangement for controlling the operation of an electrochemical cell having a working electrode, a counter electrode and a reference electrode, comprising

circuitry for controlling and applying operating energy across said electrochemical cell for passing electric current therethrough, which electric current includes an inherent electric noise current component which also manifests an electric noise potential,

servocircuitry having input terminals coupled to points on said circuitry at which said noise current component and said noise potential components are manifested and having an output terminal at which a processed error signal is presented and combined with said operating energy for controlling the flow of electric current through said electrochemical cell,

said servocircuitry comprising

an inverting summing circuit having balanced input terminals and having an output terminal,

a control amplifying circuit having one input terminal connected to said output terminal of said summing circuit, having another input terminal connected to said reference electrode, and having an output terminal connected to said counter electrode of said electrochemical cell,

a current following circuit having an input terminal connected to said working electrode of said electrochemical cell and having an output terminal,

a converting circuit having an input circuit connected to said output terminal of said control amplifying circuit and having an output terminal,

an integrating circuit having an input terminal connected to said converting circuit and having an output terminal, and

a multiplying circuit having input terminals individually connected to said output terminals of said current following circuit and said integrating circuit and having a product output terminal connected to one of said input terminals of said summing circuit.

3. A closed loop servocircuit arrangement for controlling the operation of an electric circuit element having at least two terminals, comprising

a summing circuit having balanced input terminals and having an output terminal connected to one terminal of said electric circuit element,

a current following circuit having an input terminal connected to the other terminal of said electric circuit element and having an output terminal,

a converting circuit having an input terminal connected to said output terminal of said summing circuit and having an output terminal,

an integrating circuit having an input terminal connected to said converting circuit and having an output terminal,

a multiplying circuit having input terminals individually connected to said output terminals of said following circuit and said integrating circuit and having a product output terminal connected to one of said input terminals of said summing circuit for correcting for varying resistance between said terminals of said circuit in operation, and

input terminals connected across said balanced input terminals of said summing circuit for operating said electric circuit element.

4. A closed loop servocircuit arrangement as defined in claim 3, and incorporating

a circuit component interposed in circuit between said output terminal of said summing circuit and said input terminal of said converting circuit for blocking direct current flow.

5. A closed loop servocircuit arrangement as defined in claim 4, and wherein

said circuit component is a capacitor.

6. a closed loop servocircuit arrangement as defined in claim 4, and wherein

said circuit component is a highpass filter.

7. A closed loop servocircuit arrangement as defined in claim 6, and wherein

said filter circuit comprises a series capacitor coacting with a high impedance input circuit of said converting circuit.

8. A closed loop servocircuit arrangement as defined in claim 3, and wherein

said summing circuit comprises

potential adding circuit component and

an operational amplifying circuit.

9. A closed loop servocircuit arrangement for controlling the operation of an electric circuit element having at least two terminals, comprising

an inverting summing circuit having balanced input terminals and having an output terminal,

a control amplifying circuit having an input terminal connected to said output terminal of said summing circuit, and having an output terminal connected to one terminal of said electric circuit element,

a current following circuit having an input terminal connected to the other terminal of said electric circuit element and having an output terminal,

a converting circuit having an input circuit connected to said output terminal of said control amplifying circuit and having an output terminal,

an integrating circuit having an input terminal connected to said converting circuit and having an output terminal,

a multiplying circuit having input terminals individually connected to said output terminals of said following circuit and said integrating circuit and having a product output terminal connected to one of said input terminals of said summing circuit for correcting for varying resistance between said terminals of said circuit in operation, and

input terminals connected across said balanced input terminals of said summing circuit for operating said electric circuit element.

10. A closed loop servocircuit arrangement for controlling the operation of an electrochemical cell having a working electrode, a counter electrode and a reference electrode, comprising

an inverting summing circuit having balanced input terminals and having an output terminal,

a control amplifying circuit having one input terminal connected to said output terminal of said summing circuit, having another input terminal connected to said reference electrode of said cell and having an output terminal connected to said counter electrode of said cell,

a current following circuit having an input terminal connected to said working electrode of said cell and having an output terminal,

a converting circuit having an input circuit connected to said output terminal of said control amplifying circuit and having an output terminal,

an integrating circuit having an input terminal connected to said converting circuit and having an output terminal,

a multiplying circuit having input terminals individually connected to said output terminals of said following circuit and said integrating circuit and having a product output terminal connected to one of said input terminals of said summing circuit for correcting for varying cell resistance in operation, and

input terminals connected across said balanced input terminals of said summing circuit for operating said electrochemical cell.