US1997208A - Electrical counting system - Google Patents

Description

Patented Apr. 9, 1935 a ELaoTRidaLQCoum-rivq SYSTEM ThornasBoontong-N. J; assignor to Bell TelephoneLaboratories, Incorporated, New a I York,vN. Y., a corporation of New York Application January 30,1934. Serial No. 707,474-

r aolaims. (or. 179- 1 6 This invention relates to electrical pulse storing systems and its=object is tosecure improvements in storingand repeating electrical impulses. I j

In'the applicants copending application, Serial No. 707,471. filed Jan. 1934, a system has been. provided for counting and denoting the number of operations of contacts, the arrangement being such that a neon lamp or similarj discharge device is included in a circuit in which a firstcondenser' is charged from a source of energy under controlof contacts and a second condenser is charged fromthe first condenser under control of said contacts. These operations are repeated until the-second condenserhas accumulated a charge equal to the breakdown potential of the discharge device in series withthe second condensen'the breakdownof the deviceindicating that the contacts have operated a certain number of times.

It is a feature of the present invention to store impulses and count them out or repeat said impulses through circuit arrangements making use of condensers and'contact' arrangements as disclosed in the above-mentioned copending application. The arrangement in the present case comprises'a discharge 'devicefof the three-element type, an input circuit including the grid, two condensers and contacts, one con-' denser being charged from the other through the operation of the contacts and anoutput.

circuit including the filament, two'condensers and contacts in which one; condenser is charged from the other due tothe' operation of these latter contacts. The circuit connections are such that the grid normally has a negative bias with respect to the filament dueto. a slight drop through resistance in the filament circuit. This bias is suflicient to prevent breakdown through 'the vfiow of plate current in the tube; 'When the contacts in the input circuitare operated byincoming impulses to be stored, a first condenser in the input circuit is charged in incrementsi-roma second condenser to a: pointt.de

The rise in voltage across this first condenser does not causethe tube to breakdown since the grid becomes more negative with respect to the filament. The impulses thus stored on the first the condenser 2 from condenser 5 which re- P nding on the number of impulses received 7 V 'as was stored'on the first condenser in the input circuit. In the meantime or prior to the repeating of the impulses the bias between the filament and grid is slightly decreased by the operation of a key to short circuit a resistance in the filament circuit. -Thi's will not haveany immediate effect on the tube to cause it to break down as the bias was materially increased by the charge on the first condenser in the input circuit. When, however, the first condenserin 10 the output circuit has reached practioallyithe same potential as'on the first condenser in the input circuit thetube will break down to cause .a'curren't toflow through the plate circuit to operate a relay therein to indicate that the 16 stored impulses have 'been repeated by the out-' put circuit; A modified form' of this invention is an arrangement of circuits similar to those outlined above, wherebythe potential on the to accomplish the same result.

Another feature of this invention is that this. circuit arrangement'includes a common source" I of current and therefore operates independently filament, is varied instead of the-grid potential 20 of the value of the applied voltage used in operating the devicewithin reasonable limits sin'ce the voltages to which the condensers in both the input and output circuits are charged for any particular number of impulses are'each proportional to the applied voltage. i

The invention has been illustrated in the accompanying drawing in which: a V Fig. 1 shows the invention applied'to a three element tube of the thyratron type; I

Fig.2 shows asirnilar arrangement Withthe input and" outputcircui'ts reversed? while Fig. 3 shows-a modification of Fig. 1.

Referring tOFig. 1 the tube 1 comprises a plate, a filament and a grid. The input circuit in this case includes the grid anda condenser? While a charging meansfor the condenserj in increments comprises an input relay 3 or other suitable device for operating contacts t to charge throughcontacts I5 and battery l4. A key [5 is provided to short-icircuitf a" resistance I 6 controlling the operation of the deviceas will here-4' matter, be described. r

The operation of the system disclosed in Figfl is as followsz' 'I'he input relay .3 may receive im.

pulses of di'nerent digits to be stored. Each digit will charge the condenser 2 correspondimpulses have" been. stored as represented by in-- crementsoi charges'on-condenserZ. As the-condensers2 and it are normally completely'd is;

charged and due to the presence of the resistances IS, IT and I8 in the filament circuibtlregpgi'q i -g tial on the grid will be the'same as that of the drop through resistances I6 and I1. This grid bias is just suflicient to prevent the breakdbwn eficit 1 .currenttmtouebthe uber The DO E -T.

tie n c mmute-applied by. h m ul e as.

escribe "w le h r encte us he. tube t break downsince the grid'has merely become. l rgne e i e with. espee c he lament.

The digitrepresented by the. charge on the. condenser- 211133 be repeated or countedout. by. the operation of the output relay l2, Toflac. ccmplish this the contacts it; must; first be. 0136!:

ated to short-circuit resistance I6 in order vto. slightly reduce t e. positivebias onthe filament. The tubewill, of course, not break down atthis.

time due to the grid having been-madehighly. negative with. respect to the filament by thc charge on condenser 2'. .The. alternate'operation and releaseof, the. output relay. !2,.-w.illj now. charge the condenser H! in. steps from. condenser H in thesame manner ,as condenser2 was:

charged from condenser 5 'Asthe ratio between the capacities of" condensers I I and [this ,the'. same as that between the capacities of condensers. 5 and 2,- the voltage across condenser. illjwill'be .egual to that across condenserZ whentheoutput relay; I2 has operated thesame number of timesras-theinput relay,3;. Since these; voltages arev opposing in the circuit'from-the negative side of battery M-tothe grid-the grid is now at exactlythe; same potential as. the negative side of battery I4 or, in other words, it is at the same;

T potential it was before any pulseswerestored. However, since the grid bias Was changed Joythe operation of contacts [5; the .tube will nowgbreak down and cause the control relay. IS in the plate circuit to operate." The control. relay 1.9.maybe.

employed toprevent further impulses from being transmittedby-the output relay and cause it to discontinue to function in any suitable; manner in'the circuit and it may also be used toindicate that a certain number; of impulses has been stored-and repeated.- It is evident that this'sys tem may be used for storing-and repeating SllQ' ceeding series of impulses. Theonlyactions re;-

quired between the storing of the digits are to open theplate circuit to release. l whichmay be done by theopening of contacts and-tolre- 7 store key I5 to normal-and. to discharge. the

condensers 2 and In.

J In Fig. 2' the same typeyof thyratron tubal is; employed and the circuits are similar except, that; the filament is included in the input circuit and the grid in the output cir'cuit'.j The input relaye'el in this case will operate to lalt'ernatelyfcharge condenser 22 from condenser 23 by' thg a. ..tion of its contacts, and the outputrelay124'iw'i1l respect to the'grid and resistances 28, 29 and 30 maybe-suchthat-the tube will be blocked or prevented from breaking down; After the charge negative side of the batteryir;;since therejisnoi Yon condenser has increased by the nvoltage drop across .eitherthe aae er'fi 'orj it), while the filament will have a positive bias with respect to the grid on-..ac&=o\mt 'oiwtheeIR';

eration f-"relay Zilfito store a desired number of "impulses; contact 31'' will beoperated to shunt refiififiili 3.9. 1 9. make. the filament slightly less positive inrespect to the grid. The output relay ance 29. Since thisbiasjs not sufiicient tobloek;

the tube will pass plate current. throughbat; tery 34, the. control relay 3.5.;andtheplate circ it The controlrelay 35- may; be used; for the same, purposeJas control relay; l9}- for example tapre vent further operation .ofoutput relay24 to transmit-further. impulses. The function of the tentiometer arrangement of; resistances 36 and 3'1 to. ground in-the circuit for thecondenser 26 1s to provide the same charging voltage for con denserlfi asfo'r condenser-23 V Both of thecircuitsshown in Figs. 1 and-2 are practically independent of; applied: voltageswitlnn reasonablelimi ts since the voltages towhich both;- the charged condensers- 2 and min Fig. 1 and 22 and .25 in Fig.2 for a certain number ofimpulses; are eacheproportional to-the applied voltage.

It is" evident that this invention may be ap;-

pliedto othermodified circuit arrangements ,such; as,- for example, where several succeeding dig-itsmay be stored in succeeding} condensers. corre-- sponding to. condensers- 2 For 2.2 and coupled to theLinput circuit and'thenoounted out at wilt. In such eases, the condensers vused tor storing the pulses need not be directly connected in; the; putir i nt ev i itsas oredzmama-same are to be counted out, Consequently,-. thesama tubemay. be used with severalstoring condensers"; corresponding to condensers v 2': andv 22; each or which may be independentlychargedby aeircuitl similar to the input circuits and later connected inproper sequence to:thetubeand associated 'out-=- put circuit. I Such a circuit has been shown in Fig. 3' which is-in all other-respects similar to Fig. l. In tliis=-' figure two storing condensers-M and 41 have been-shown. These cOndensersmaybeconnected individually throughcontact' 42. for condenser and contact 4& forj condenser-4'1 to thej-contacts of'the input: relay 3" and-charged independently b s any. des edi s r of mpl l fifi. as ntro ed; by relay 3 and condenserbi' Later the condensers! Aland, maybe. connected individually in sement, means inlthe output .circuittior. making .quence'through contact 44 for condenser 40 and contact 4 5;for condenser 4| to the input circuit of the tube 1 for repeating of the succeeding series of impulses to the output circuit. It should be notedythat the contact, l,; 5 used in Fig. 1 to shortcircuit resistance It is not required in this case as when condenser 39 or ii is connected to the input circuit it is always chargedsufiiciently to block the tube from breaking down. A similar arrangement may be provided for the input circuit of the arrangement shown in Fig. 2.

What is claimed is: i

1. In combination, a conduction device having a filament, grid and plate, means for normally maintaining a difference between the potentials on the filament and on the grid sufiicient to prevent the breakdown of the device, means for changing the potential on a first one of said two elements in steps to increase the potential difference between said elements, means for slightly decreasing said established potential difierence between'said two elements, and means for changing the potential on said first element in the same number or" steps to decrease said established potential difference to a point where said device breaks down.

2. In combination, a conduction device having a filament, a grid and a plate, means for nor-' mally maintaining a negative bias on the grid with respect to the filament sufiicient to prevent the breakdown of the device, means for increasing said bias by changing the potential in vary-' ing numbers of steps on the grid, means for decreasing said bias by changing the potential on the filament, and means for eliminating said bias by changing the potential on the grid in the same number of steps to cause the device to break down at various potentials corresponding to the number of steps at which the potentials were lowed by the change of potential on the first mentioned of said elements in the same number of steps as the potential on said first mentioned element was originally changed.

4. In combination, a conduction device having a filament, a grid and a plate, means for normally maintaining a negative bias on the grid with respect to the filament sufiicient to prevent the breakdown of the device, means for increasing the negative bias on the grid, means for decreasing the positive bias on the filament, and a separate means for thereafter decreasing the mega tive bias on the grid to the point where the device breaks down.

5. In combination, a conduction device having a filament, a grid and a plate, an input circuit including a condenser and the grid, an output circuit including a condenser and the filament, means in said circuits for establishing a positive bias on the filament with respect to the grid, means for charging the condenser in the input circuit in small increments at intervals to establish corresponding potentials on the grid to make the grid more negative with respect to the filathe filamentslightly less positive withrespect .to

the festablished gridpotential, and means for charging with the same small increments the condenser, in the outputcircuit in the same, manner .asthe chargingof, the condenser in the input circuit to establish a potential on the grid of the same valueas that established on the filament to cause the breakdown of said device at said potentials and a plate circuit for the passage or" plate current When said device breaks down.

6. In combination, a conduction device having a filament, a grid and a plate, an input circuit including a-condenser and a grid, an output circuit including a condenser and a filament, a common source of current for said circuits, means in said circuits and including said'source for normally maintaining a potential diiference between the grid and filament to prevent the breakdown of the device, means for charging the'condenser in the input circuit in varying numbers of steps to establish corresponding potentials on the grid making the gridpotential more negative with respect to thelfilamentpotential, a key in the output circuit, means controlled by the operation of said key for making the filament potential slightly less positive with respect to. the established grid potential, means for charging the condenser in the output-circuit in corresponding numbers of steps to establish a potential on the grid of the same value as the potential established on the filament tocause the breakdown of said device at said corresponding potentials.

'7. In combination, a conduction device having means in said circuits for establishing a potential difference between said grid and filamentlwith a positive bias on the filament with respect to the grid, means including a third condenser for charging the condenser in the input circuit in small increments from said third condenser at intervals to establish corresponding potentials on the grid making the grid more negative with respect to the filament, means in the output circuit for making the filament potential slightly less positive with respect to the established grid potential, and means including a fourth condenser for charging the condenser in the output circuit in the same small increments from said fourth condenser at intervals an equal number of times as the condenser was charged'in the input circuit to establish a potential on the grid to cause the breakdown of said device.

'8. In combination, a conduction device having a filament, a grid and a plate, means for normally maintaining a negative bias on the gridwith respect to the filament, means for changing the potential on the filament in steps to increase the positive bias on the filament with respect to the ference between said grid and filament with'a 7 negative bias on the grid with respectto the filament, means for charging the condenser in the input circuit in steps to establish corresponding potentials on the filament to make thepositive bias greater on the filament with respect to the grid, means for'decreasing said'positive' bias on 5 the filament to a small degree, and means for charging the condenser in the output circuit in em crease the positive bias'ofthe filament to cause the-breakdown of the device.

THOMAS L. DIMOND.

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