US3434120A - Capacitive memory storage device employing magnetizable material as a dielectric - Google Patents

Description

Mam}! 1969 E. o. OLSEN 3,434,120

CAPACITIVE MEMORY STORAGE DEVICE EMPLOYING MAGNETIZABLE MATERIAL AS A DIELECTRIC Filed Oct. 14, 1965' INVENTQR. EVERETT O. OLSEN BYDWMECH'WL ATTORNEY 1 United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE A capactive memory storage device employs a magnetizable material as a dielectric sandwiched between two electrically conducting members; the combination has a capacitance dependent upon the magnetization of the dielectric; a quantity is stored in the device by magnetizing the dielectric to a degree related to the quantity, which stored amount may be read at any time in terms of the device capacitance until such time as the magnetic state is again altered.

This invention relates to storage devices and more particularly to a capacitive memory employing a dielectric that may be varied by magnetization means.

An object of this invention is to provide a memory device controlled by magnetizing means having a variable capacitive readout.

Another object of this invention is to provide a memory device whose capacity is related to the condition of its magnetization.

Another object of this invention is to provide a memory device having a non-destructive readout.

Another object of this invention is to provide a means for storing a digit according to magnetic switching of a core and employing a non-destructive capacitive readout means therewith.

Another object of this invention is to provide a memory device employing a magnetically-controlled core having a dielectric property influencing the capacity of readout means associated therewith.

Another object of this invention is to provide a magnetically-controlled memory device having a non-destructive resistive read-out.

Other objects and advantages of this invention will he in part apparent from the specifications and in part from the figure, which is:

A view of the memory device of the invention showing a dielectric core between capacitive elements and including magnetizing means and read-out terminals therewith.

Referring now to the figure, core is composed of a magnetizable material whose dielectric constant varies with the degree of magnetization. Ferrites, for example, have medium to high dielectric constants with some in the order of 500,000. It is also convenient to employ in this embodiment a core having a high resistance thereby enhancing the storage characteristic of the invention. Sandwiching core 10 are two conducting plates 11 and 12 composed of any material having good electrical conductivity. Winding 13 loops about the core sandwich comprised of magnetizable material 10 and conducting plates 11 and .12 thereby providing a means of magnetizing core 10. Winding 13 has input terminals 14 and 15 to which may be applied a pulse of positive or negative polarity, or to which may be applied an analog signal having a variable degree of magnitude.

The state of magnetization of core 10 determines its dielectric constant at any instant, and conducting plates 11 and 12 comprise the plates of a capacitive element whose capacity is influenced and determined by the dielectric constant of core 10 therebetween. Terminal 18 connected to plate 1.1 and terminal 19 connected to plate 12 form the read-out terminals of the capacitor comprised of plates 11-12. Terminals 18 and 19 may be connected to any capacity-determiningmeans such as the tuned circuit of an oscillator, the variable leg of a capacitor bridge, or to a momentary switching means in which charging current will be determined by the combination of capacity and degree of previous charge.

It may be seen that the applications of such a device are many, as it is simple in construction and offers the combination of non-destructive read-out from its capacitive element and further ofiers a number of possibilities of applications utilizing advantages related to the integrating characteristics derived from its chargeable feature.

As an alternative embodiment of the invention of the figure, terminals 18 and 19 are employed to read the resistance of core 10. The resistance of core 10 will change with its degree of magnetization, and terminals 18 and 19 will therefore offer a means of sampling the magnetization status and degree of core 10. In this embodiment a relatively low resistance core may be convenient for more easily detecting changes in its resistance by an output sensing device resulting from magnetization change in the core. High resistance core materials may also be used having sufiicient resistive change therein related to the extent of core magnetization.

Core 10 may be rectangular or round, or any shape Which may be conveniently affected by magnetizing means and adaptable for use in conjunction with any number of capacitance elements 11-12 serving as capacitive areas or plates. It is to be understood that the plates herein may be of any size and may consist only in the electrical terminal 20 itself employed to connect the core to an output. Multiple capacitance elements may be used, or duplicate pairs associated with each core, to facilitate multiple substantially non-interacting outputs for purposes such as setting up a matrix logic for reading out on an x-y or x-yz matrix designation.

It has been found that configurations of members 11 and 12 are practicable which are not adjacent winding 13 so that winding 13 does not influence the electrical constant, capacitance or resistance, to be detected between the members 11 and 12. That is to say, winding 13 may be only wound about core 10 itself.

Applications requiring either a variable capacitive element or a variable resistive element which are varied by control means and which are to retain their analog value until recontrolled may be appropriate, such as in selftuning means for an R-F stage, or in means for the tuning of a process controller. It is apparent that the invention is adaptable to the entire range of digital applications in which each unit may represent a discrete number of states, usually two.

While there has been shown what is considered to be a preferred embodiment of the invention, it Will be manifest that many changes and modifications may be made therein without departing from the essential spirit of the invention.

What is claimed is:

1. A memory device having a variable capacitive condition dependent upon changes in state of magnetization comprising:

3 a core including magnetizable material capable of retaining a magnetized condition, at least two electrically conducting members disposed adjacent said core to include said core in the dielectric path between said members, means responsive to an analog signal having a variable degree of magnitude associated with said core for changing the state of magnetization of said core in accordance with said magnitude, and means interconnected with said conducting members for sampling the value of the electrical capacity between said members resulting from the state of magnetiz-ation of said core and which value is related to changes in the state of magnetization of said core and which value represents a quantity stored by said means for changing the magnetization of said core. 2. The memory device of claim 1 Wherein said means for sampling is adapted to distinguish said electrical capacity over a continuously variable range of values related to the state of magnetization of said core.

December 1959, p. 33.

References Cited UNITED STATES PATENTS OTHER REFERENCES W. K. French: Chopper, IBM TDB vol. 2, N0. 4,

15 BERNARD KONICK, Primary Examiner.

JOSEPH F. BREIMAYER, AS- siS/(Int Examiner.

US. Cl. X.R.

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