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Electrically Alterable Resistive Element

IP.com Disclosure Number: IPCOM000082087D
Original Publication Date: 1974-Oct-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Kennedy, PJ: AUTHOR

Abstract

A dynamically selectable resistance element is provided by encapsulating three electrodes in a container which holds a plating solution. The resistance is changed by selectably actuating appropriate electrodes with or without measurement of the resistance change at other electrodes.

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Electrically Alterable Resistive Element

A dynamically selectable resistance element is provided by encapsulating three electrodes in a container which holds a plating solution. The resistance is changed by selectably actuating appropriate electrodes with or without measurement of the resistance change at other electrodes.

Insulating container 10 is filled with an appropriate plating solution 11 such as copper sulfate. Terminal 12 is attached to an electrode 13 within container 10 which is made of a plating material such as copper. Terminals 14 and 15 are connected across a resistive element 16 such as carbon. As an EMF is applied between the electrodes 12 and 14 or 15, a transfer of metallic ions occurs between electrode 13 and element 16. The direction of the ionic transfer depends upon the polarity of the EMF.

After ions have been transferred to element 16 the ohmic resistance as measured between terminals 14 and 15 will reduce, although this process is reversible. Thus, the resistive value of carbon element 16 can be trimmed or dynamically adjusted in place. The apparatus is well suited for automated techniques for precision selection of discrete resistances, and can be easily extended into construction of resistive ladder networks.

The device is useful as an analog memory device, a sample and hold circuit element, a precision resistance manufacturing process, a precision ladder resistance network manufacturing process, in-place resistance matching requiremen...