US3413631A

US3413631A - Indicator apparatus

Info

Publication number: US3413631A
Application number: US481992A
Authority: US
Inventors: William M Carey; Jr Thomas E Baker
Original assignee: Navy Usa
Current assignee: US Department of Navy
Priority date: 1965-08-23
Filing date: 1965-08-23
Publication date: 1968-11-26
Anticipated expiration: 1985-11-26

Description

Nov. 26, 1968 Fig. 1 :3

Filed Aug. 23, 1965 W. M. CAREY ETAL.

INDICATOR APPARATUS CODING sw1'rc11 a a 7 e 5 4 a 2 1 o 1 1 I 1 1 1 1 l l l I 18\--' '9 12 11 11 11 11 11 11 11 I 1 V 1 1 1 1 1' 1- rl J1 1| I [I 1' Al ll II III 10 C) (T (9 Al F 5g 2 INVENTORS AC 433%? 215F511 M K JR. SUPPLY BY ATTORNEY United States Patent 3,413,631 INDICATOR APPARATUS William M. Carey, Sonth Lincoln, and Thomas E. Baker,

Jr., Framingham, Mass., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Aug. 23, 1965, Ser. No. 481,992 6 Claims. (Cl. 340-336) ABSTRACT OF THE DISCLOSURE An alphanumeric indicator comprising a plurality of multiaperture devices (or transfluxors) which selectively energize an array of lamps in accordance with a digital input signal. A coding switch pulses one of a plurality of conductors each forming serially connected windings at selected major aperture of its respective transfluxor. The conductors are then connected in common to one end of another conductor which forms serially connected windings at the minor aperture of each transfiuxor, and which is connected to ground at the other end. The number of turns in the major aperture winding is greater than the number of turns in the minor aperture windings. An output winding at the minor aperture of each transfiuxor is connected to a respective lamp and to a common power supply.

The present invention relates to apparatus for the display or indication of alphabetical or numerical symbols, and more particularly to a high speed decoding and memory apparatus for selectively operating lamps in an array suitable for displaying alphabetical or numerical symbols.

Presenting digital information in directly readable form to an operator is usually an expensive and, in terms of computer timing, a slow process. Commercially available devices such as electromagnetic elements, gas storage tubes, or a complete array of electronic equipment are either slow, unreliable or expensive. Some of these devices are also heavy power drains on the computers associated therewith.

Briefly, the present invention contemplates a plurality of multi-aperture devices (MAD), also known as transfiuxors, which selectively energize an array of lamps in accordance with a digital input signal. Each MAD acts as a variable impedance in series with a lamp, and by applying a pulse of current through selected MADs, the respective lamps illuminate. The result is an apparatus which decodes, memorizes, and indicates in alphabetical or numerical symbols the digital input signal in a response time of less than 20 microseconds. The memory and high speed features, in particular, greatly simplify the design and reduce the hardware requirements of the associated computers.

Accordingly, it is an object of the present invention to provide a novel and improved apparatus for the indication of alphabetical or numerical symbols, in which digital input signals representing the symbols are decoded and memorized, and which is especially suitable for displaying digital information from computers.

Another object of the invention is to provide a novel circuit means for operating a plurality of multiple aperture devices capable of decoding and memorizing digital information.

Still another object of the invention is to provide an improved alpha or numeric indicator apparatus which is relatively inexpensive to manufacture and maintain, which is reliable and has relatively fast response, and which is not subjected to the operational limitations of the prior art devices.

Various other objects and advantages will appear from the following description of one embodiment of the invention, and the most novel features will be particularly pointed out hereinafter in connection with the appended claims.

In the drawing:

FIG. 1 pictorially represents a typical array of elongated lamps suitable for indicating alphabetical or numerical symbols;

FIG. 2 is a schematic wiring diagram of one embodiment of the present invention as applied to the array of FIG. 1; and

FIG. 3 is a more detailed schematic diagram of one multi-aperture device as applied to the embodiment of FIG. 2.

Referring now to the illustrated embodiment of the invention, FIG. 1 shows a numerical indicator 10 which includes seven elongated electrical lamps identified by the letters A through G, and which are arranged to display any of the digits 0 through 9 depending on which combination of lamps are illuminating. For example, the number 1 requires illumination of lamps B and E; number 2, lamps A, B, C, G and F; and number 3, A, B, C, E and F. As will become apparent, it is contemplated that the number of lamps can be changed or their arrangement modified for displaying many other symbols without departing from the inventive concepts.

The manner in which the indicator 10 is operated is best described by reference to FIGURE 2 in which the lamps A through G are conveniently shown as a row of filaments. Each lamp is associated in a circuit to be described, with a MAD (multi-apertured device) 11 of the type having one major and one minor aperture, 12 and 13, respectively. There being seven lamps in the illustrated embodiment of the invention, there are therefore seven MADs. A more detailed disclosure of the two-aperture MAD (a transfiuxor) appears in the article The Transfluxor by J. A. Rajchman et al., Proceedings of the I.R.E., vol. 44, March 1956, pp. 321332.

Each MAD 11 is connected to its respective lamp A. B, C, etc. by a wire 14 threaded once through the minor aperture of the MAD and connected at one end to one terminal of the lamp filament. The other end of each wire 14 is connected in common to one output terminal of an AC. supply 15, and the other terminal of each lamp filament is connected in common to another output terminal of the supply 15. The supply 15 may be of any conventional design capable of generating an alternating current; for example, a free-running blocking oscillator.

The major aperture of each MAD 11 receives up to ten parallel-connected wires from a coding switch 16, each wire representing a discrete symbol of 0 through 9. The total number of wires from the switch 16, of course, will be equal to the number of symbols subject to indication by the indicator 10. The coding switch 16 may be of any conventional type which generates a short (e.g. 1O microseconds) pulse of current at one of a plurality of output terminals in accordance with a command input signal (not shown). Each output terminal is assigned to represent a discrete symbol (alphabetical, numerical, etc.) indicative of the input signal.

For convenience of illustration, only three

wires

17, 18 and 19 have been drawn which connect to the 0, 7 and 8 terminals of the switch 16. These wires serially pass through only selected major apertures of the. MADs 11 depending on which of the lamps A through G must be illuminated to indicate the corresponding number. For example, a current pulse at the output terminal 0 of the switch 16 must energize all but lamp C. Accordingly, the wire 17 must serially pass through all of the major apertures except the one associated with lamp C. Similarly, wire 18 passes through only the major apertures associated with lamps A, B and E; and wire 19 passes through all of the major apertures. The wires from the switch 16 are connected in common to one end of a wire 21 beyond where all of the selected major apertures have been threaded. The wire 21 passes through all of the minor apertures and is connected to ground at its other end. Thus, whenever a current pulse appears on any wire passing through the selected major apertures, the same pulse appears at all the minor apertures. The resulting operation is that whenever a pulse from the switch 16 appears at both the major and minor apertures, the impedance in wire 14 becomes low, and the associated lamp illuminates. If the pulse only appears at the minor aperture, the impendance in wire 14 becomes high, and the associated lamp extinguishes.

The theory of this operation is best explained in connection with the MAD 11 associated with lamp D as shown in more detail in FIG. 3. Where the

wires

17, 14 and 21 pass through the MAD apertures, they will now called windings W W and W respectively, as in fact they are. A current passing through any winding will impart a magnetomotive force in its adjacent aperture. Thus, when a heavy current pulse from coding switch 16 is sent through the winding W sufiicient to switch the field flux about the major aperture and in a direction to produce counterclockwise saturating fluxes (p and the MAD becomes blocked. In this condition, an alternating current through the winding W in the minor aperture is insufiicient to switch the flux qfl or about the minor aperture. The magnetmotive .force of winding W will encounter no opposition and manifest itself as a low impedance in winding W This low impedance in winding W orwire 14 impresses a high voltage across the lamp D which causes it to illuminate.

Now, if another heavy current pulse is sent through the winding W sufiicient to switch the saturated flux qb about the minor aperture and in a direction to produce clockwise flux, the MAD 11 becomes unblocked. No amount of current of either polarity through the winding W or W can drive the MAD back to the blocked condition. Only another heavy current pulse in the winding W can do this. It is this property which provides the memory feature.

In the unblocked condition, a relatively low amplitude alternating current applied to winding W will produce a changing flux offering thereby a high impendance in the winding W A low voltage therefore appears across the lamp D and causes it to become extinguished.

The winding W has two turns through the major aperture as compared to one in winding W to insure blocking of the MAD 11 even though the same current pulse passes through both windings. Where a MAD has no winding W the winding W will unblock.

It should now be apparent that the utilization of multiaperture devices as variable impedances in an electrical circuit responsive to digital input signals may be used to selectively energize any plurality of lamps or other electrical components. Except for the power required to energize the lamps, the only other power required is for initiating and maintaining selection, and this requirement is extremely low. This is due to the inherent memory characteristics of the MAD inasmuch as no power is required after the initial pulse to maintain the selection. The system is automatically reseting when another pulse is impressed at the input; and the inherent high speed response characteristics makes it ideally suited for high speed computer applications.

It will be understood, of course, that various changes in the details, materials, steps and arrangement of parts, which have been herein described and ilustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

What is claimed is:

1. Apparatus for decoding and memorizing information comprising:

a decoding switch having a plurality of output terminals for selectively producing a digital output signal, each of said terminals representing a discrete symbol;

a plurality of multi-apertured devices, each having a major and a minor aperture,

a plurality of first conductor means, each connected at one end to respective output terminals of said switch, and forming serially connected windings through predetermined major apertures of said devices, and connected in common at the other end to each other; and

second conductor means connected at one end to said common connection, and forming serially connected windings through all of said minor apertures, and connected at the other end to ground, the number of turns in the windings of said first conductor means being greater than the windings of said second conductor means.

2. Apparatus as comprising:

a plurality of electrical loads;

a plurality of third conductor means each connected at one end to one terminal of respective loads, passing through the minor aperture of a respective device, and connected in common at the other end to each other; and

alternating current supply means having two output terminals connected respectively to the common connection of said third conductors and the other terminals of said loads.

3. Apparatus as set forth in claim 2 wherein said device produces high impedance in said third conductor means when a pulse of current passes through said first conductor means of said major apertures.

4. Apparatus as set forth in claim 3 wherein said device produces a low impedance in said third conductor means when a pulse of current passes through said second conductor means.

5. Apparatus as set forth in claim 4 wherein said plurality of electrical loads comprise electric lamps arranged in an array for indicating the discrete symbols in accordance with which of the terminals of said switch is energized.

6. Apparatus as set forth in claim 1 wherein the number of turns in the windings of said first conductor means are at least twice the number of turns in the windings of said second conductor means.

set forth in claim 1 further References Cited UNITED STATES PATENTS 3,329,829 7/1967 Grimm et al 340-174 3,357,010 12/1967 Sweeney 340-324 OTHER REFERENCES Rajchman et al.: The Transfiuxor IRE Proceedings, pp. 321-332, March 1956.

Rajchman et al.: Transfiuxor Controlled E-L Display Panels, IRE Proceedings, pp. 1808-1824, November 1958.

JOHN W. CALDWELL, Primary Examiner.

A. J. KASPER, Assistant Examiner.