US3178694A - Shift register - Google Patents

Description

States? Patent Office:

Continuation of application' Ser. Not. 50,695, Aug.. 19",

1960." This applicationiApnlfl, 1964, Ser. No. 360,167 1 Claim". (Cl.'340174) This invention. relates to a magnetic core memory'device, and-more particularly to anirnproved 'andtsir'nplified shift register; This application is a continuation of my earlier filed application, Serial No. 50,695 filed August 19, 1960, and entitled Shift Register, nowabandoned.

An object of, theinvention is to provide: a magnetic core memory" and signalztranslatingdevice havingximproved performance and operation over 'a widestempera lure. range.

, Anotherobject is-to. simplify the'wiringof' a shift register. i v i A-further object is to providea v.wiring'scheme for:a shift register "which lessens the electrical. drive require-- ments of the register.

These and other objects will in part be understood from and in part'iponited out in the following .description'."

In U.S-.i Patent No. 2,995,731 to J. P.Sweeney, there is disclosed an'improved shiftregister wherein a number of. multi-apert-ure magnetic cores are connected .in:' se= quence for the transfer from one "core. *to the :next. of a One core is connected to the,

binary one or""zero. next by a respective -coupling loop.'which is threaded quenceby respective current pulses.

v This shift register circuit is much more.-stable.and. re-' liable inits operation than earlier shift registers. but. even so it has certain limitations. Each coupling windingbe tween two successivecores has-no blocking diode hit and thus would permit an advancedrive pulse applied to. a succeeding core to act adversely on the preceding.

one. To prevent this, the: cores are provided with a holdwinding in'addition to the-drive windings. The hold .windingis inseries with the'advancewindings and serves to apply, to the proper'cores intheregister, when an'advance pulse is applied. toeitheradvance winding'a magnetic field counteracting and .cancelingiout 'thefield induced onithe preceding cores by the coupling windings: This arrangement works quite well but'thenneedi-for the hold windingimposes an important restriction. For'best' operation. of thetregister there shouldbe unity turns-ratio between'the hold. andzadvance windings. hold. windingmust be threaded. through the minor output apertures of the cores and because ihESQQPGHUI'CSIfiIB small (about the size of a pin) only a limited number of turns of the holdwinding can bethreadedthrough. This,

assuminga given turns-ratio of holdto'advance'windings,

drive currents or to permit the use of higher drive core The materials, this previously has not beenpossible. present invention eliminates theneedrfor alholdiwinding and permits'a much larger number of turnsfor the-'ad-.

vance windings.

In accordance with the present invention, in'one specific embodiment thereof, individual multi-aperture cores of a shift register are connected from one core to. the nextby couplingloops uniquely wound on the. cores so that even though no blocking diode is used in the loop, there However, the

is still no tendency'for"one-ofthe'driving pulses to feed backward from one core'to the preceding: one. This eliminates the'need for a hold'windingiand permits'a much larger number ofadvancewindi'rigzturns on each core, these turns beingthreaded.through'themajor aperture and thus being applied easily. Because :the need for the hold'winding is eliminated," there'are' no: residual errow in compensatinggthe unwanted field and this circuit operates reliably overa wider. temperature range than previous 'onesincluding-"the shift" register in. aforesaid patent;

A better 'understanding of the invention "together with a fuller appreciatiomofits many advantages will bestbe gained from the fdllowing description"'giveniii-connection with: the .accompanyingdrawings wherein :r.

FIGURE 'l is a schematic representation. of'a shift register embodyingifeatures of the invention;

FIGURE 2. is a. wiring :diagram of the shift register;

' and.

' FIGURES 3 1,'b, c, d and e are diagramsshowing the conditions of the magnetic lines: of'fliix: inrthevarious cores ofthe register after "each successive drive pulse;

into odd. (0) and even (E) groups;- For simplicity, only two O cores and: one Eicore aress hown"butzitv isto be understood that. in; a complete shift register. .there can be a considerablemumber of cores, with-xanrequal v number of cores in eachzgroup, The-physicallayout. and general. wiring configuration-of this. shift register xcan-be generally thecsame'as for the one'disclosed in'rtheaforesaid patent. Here, the :fiiSti O'core; designatedby numeral 11,.

and havinga relatively large.major iaperturex 12, and a:

small. minor 'aperture113. is provided-xwithsan input winding' 14 which is". threaded I once: througha aperture 13. Wound twice :throughzthis-same. aperture in the relative sense shown is a couplingv1oop-16 whose other end is threaded once through therminor'aperture 17""of.E"core. 18. Similarly,'aperture 17 of core 18 has two turns of the nextv couplingtloopilt) 1 whichconnects this :core to the next core in the register, 0 core 21; through'its' minor' aperture22, successive cores in the register (not shown) being'connected bycoupling loops in: the same. way.

Each of theminor apertures 13,171and 22 of the cores 1 shown; receives threeaturns of a prime windingq24- which after "passing through all of the minor apertures makes a.

single .pass in' reversexdire'ction throughi-allzrof'the major apertures of'the cores. Thisewinding .24; als'ofshowniin FIGURET'Z,v is adapted to be energizedduring operation of the'register :bya relatively long,.sma1l amplitude primingLpulse.

with the advance windings, thoughuof course, they can.

have a common ground: connectioir'as: sh'ownxinzFIG- UREIZ. Furthermore, advance windingrzti'threads only theOIcores and advance windingt28jonly the :E'Tcores.

Assuming that all' of the. cores'iareeinitially' in the clear state; that is, saturatedswith -tiux in theclockwise direction'and that .the first core,iOcore 11,. h'asbeen set by means'ofa suitablecurrent pulseappliedito winding 14,- then thelines offiuxin the-variousrcores will be as indicated. .by the short arrows in: FIGURE-13a. In. this condition, all of thelines of flux in cores-18*and 21 are clockwise, but half 'of thenlinesof fiu'x 'in'core'l l are counter-clockwise. Thereafter, whenr-a prime current is applied to. winding24, certain'lines of'fiux'in the cores, indicated by the. double-headed arrows" in FIGURE 3b will be reversed, the othersingle-headed:arrowsremaim I 5 942} PatenteduApr; 13; 19651 ing the same as they were in FIGURE 31!. Next, applying an advance to E pulse to winding 26 causes the flux to change as indicated by the double-headed arrows in FIGURE 3c. The next prime pulse causes the change shown in FIGURE 3d and finally, an advance E to 0 pulse applied to winding 28 causes the change indicated in FIGURE 3e. This completes a full cycle or shifting sequence for the register and the binary ,one previously stored in core 11 has now been advanced to core 21,

It will be noted in FIGURE 1 that coupling loop 16 encircles the outer leg of the core at minor aperture 13 and the inner leg at minor aperture 17 of core 18 in the relative senses indicated. A one-to-one turns ratio in the coupling loop can be used, but two-to-one ratio as shown, insures that the flux switched about minor aperture 13 will cause the same amount of flux to be switched about aperture 17, and so on. Thus, there will be no loss in the amount of flux transferred from core to core along the register.

This coupling loop configuration prevents an advance pulse applied to a core from feeding flux backward through a coupling loop, whilst still permitting forward fiux transfer. To understand this more readily, consider the flux in E core 18 after the advance 0 to E pulse. The lines of flux about minor aperture 17, as indicated in FIGURE 3c, will be in the set state, that is, the flux in the inner leg will be up or counter-clockwise, and the flux in the outer leg down or clockwise. Priming causes the flux to reverse about minor aperture 17, as indicated in FIGURE 31!, and now the flux in the inner leg is down or clockwise. Thus, when the advance E to 0 pulse is applied, the flux in the inner leg of the core at minor aperture 17 is already clockwise and cannot be changed, only the counter-clockwise flux in the outer leg can be switched. Since no flux in the inner leg switches during this advance E to 0 pulse, no current is induced in coupling loop 16 and hence no flux in the preceding core 11 can be switched. Thus, there is no need of a hold winding in this circuit.

In a circuit, like the one above, which has been built and successfully operated, multi-aperture cores about the size of a small shirt button and made of type 5209 ferrite material manufactured by General Ceramics Company, were used. Six turns of the advance winding on a core permitted good operation of the register with a peak pulse current of less than 3 amperes. This register is simpler to build and has better operating characteristics than previous registers.

The above description is intended in illustration and not in limitation of the invention. Various changes may occur to those skilled in the art and these may be made without departing from the spirit or scope of the invention as set forth.

I claim:

A shift register circuit for transferring binary intelligence in a controlled manner comprising a plurality of multia-perture magnetic cores each having a major aperture and a minor aperture, the said cores being divided into odd and even groups and threaded by a drive circuit capable of applying drive current to said cores to advance intelligence along said register through turns linking said cores and experiencing said drive current, the said circuit including a first advance winding threading the major apertures of the cores of one group in a sense to apply clockwise magnetomotive force with respect to the major aperture thereof, a second advance winding threading the major apertures of the cores of the other group in a sense to apply a clockwise magnetomotive force to the core material with respect to the major aperture thereof, a prime winding threading in series by several turns the minor apertures of the cores of both groups in a sense to apply magnetomotive force in a counterclockwise sense relative to said core major aperture and then in series by a lesser number of turns threading the major apertures of the cores of both groups in a sense to apply a clockwise magnetomotive force relative to the major apertures thereof, the said prime windings including a return path to ground isolating said prime windings from the drive currents supplied by said advance windings, a transfer circuit comprised of coupling loops linking the cores of the groups with each coupling loop encircling the outer leg of magnetic material adjacent the core minor aperture to the inner leg of magnetic material adjacent the minor aperture of a succeeding core, each loop having more turns linking the outer leg of magnetic material than linking the inner leg of magnetic material of the succeeding core, the drive circuit when energized in the advance, prime. sequence to the odd and even cores serving to switch flux in a given core to transmit intelligence to a succeeding core via said coupling loops.

No references cited.

IRVING L. SRAGOW, Primary Examiner.

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