US2696572A - Pulse generating circuit - Google Patents

Description

Fild Oct. 3l, 1952 2 Sheets-Sheet l mh C w D N @www TH .T NC g., s A WR@ 5 Vp B Dec. 7, 1954 E. R. scHMlD PULSE GENERATING CIRCUIT 2 Sheets-Sheet 2 www I .VLYAY /v/VVENTOR E. SCHM/D Filed Oct. 3l, 1 952 ATTQRNEV United States Patent() f PULSE GENERATING CIRCUIT Erwin R. Schmid, Bernardsvlle, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application October 31, 1952, Serial No. 317,859

14 Claims. (Cl. 315-163) This invention relates to a timing sequence system, and more specifically to such system using a plurality of multiple cold cathode glow discharge tubes arranged in a counting circuit for controlling the time sequence. In a specific aspect, the invention is concerned with a generator of electric current pulses whose time duration and time rate of repetition Iare variable.

A specific aspect of the invention has been found to be useful as an accurate timing control in aging certain cold cathode gaseous discharge tubes during their manufacture. ln the manufacture and prior to the testing, the cold cathode tubes are aged at the factory by applying t=o them a series -of high current pulses having a preselected duration and recurring at predetermined intervals. Ls the characteristics of the manufactured cold cathode tubes depend to a great extent on the proper aging of them, it is evident that the production of the aging current pulses with a high degree of accuracy as to their length and repetitive rate is important and desirable in the manufacture of those tubes.

it is the main object of the present invention to produce a series of current pulses whose duration and rate of repetition are controllable with a high order of accuracy.

It is another object to provide a series of current pulses whose length and rate of repetition are substantially constant.

It is a further object to provide a series of electric pulses f vention employed with a group of glow discharge step- =1 ping tubes arranged in a counting circuit comprises a source of alternating current connected to the input of a first tube in the counting circuit, a source of direct current, a work circuit, and a group of interconnected gaseous discharge devices controlled in regard to conduct tion `and non-conduction therein by the -counting circuit for the purpose of connecting the direct current source to the work circuit and disconnecting it therefrom in a predetermined timing sequence. Multi-contact switches interconnect the stepping tubes of the counting circuit and the group of gaseous devices in such manner that the direct current source can be connected to the work circuit for a time interval equal to a preselected number of the alternating current cycles counted by the stepping tube counting circuit; and further in such manner that the time interval can be caused to recur at a time rate of repetition equal to -a predetermined number of the alternating current cycles counted by the same counting circuit, the predetermined number of counted cycles being in excess of the preselected number of counted cycles.

p `As one example of a specific timing control according to the present invention, the direct current source is con- 'fnected to the work circuit, i. e., to the cold cathode tubes to be aged, for a time interval equal to two cycles of the alternating current cycles counted by the stepping tube counting circuit, and such two-cycle connection is caused to recur at a time rate of repetition equal to each 80 cycles of the alternating current cycles -counted by the stepping tube counting circuit. Thus, in eiect, a series ,of current pulses, each having a constant time duration 2,696,572 Patented Dec. 7, 1954 and a constant time spacing between successive pulses, isv produced and applied to the work circuit.

A feature of the invention involves an arrangement whereby the time duration of the respective current pulses and/ or the rate of repeating them to constitute a series of current pulses can be changed at will.

Another feature resides in a voltage coincidence circuit insuring that a group of gaseous discharge devices in a timing circuit are changed from conducting condition to non-conducting condition, and vice versa, in a time sequence controlled by a stepping tube counting circuit whereby a voltage of preselected magnitude can be connected to a work circuit and disconnected therefrom for preselected time intervals.

The invention will be read-ily understood from the following description taken together with the accompanying drawing, in which:

Figs. l and 2 constitute a schematic circuit illustrating a specific embodiment of the invention, and

Fig. 3 is a curve illustrating action obtainable in Figs. 1 and 2.

Referring to Figs. 'l and 2, there is shown a plurality of multicathode gaseous discharge stepping tubes T1, T2 and T3, each c-omprising a common anode 10, ten rest cathodes A1 through A10, ten transfer cathodes B1 through B10, an auxiliary anode AA, and a normal cathode N. The transfer cathodes B1 through B10 are connected together internally of a sealed bulb 11 to a bus 12 which projects therethrough. The normal cathode N mounted in proximity of transfer cathode B1 for initiating a main discharge between the latter cathode and the common anode is connected to a lead 13 which projects through the bulb 11. The auxiliary anode AA positioned adjacent rest cathode A10 is connected to a lead 14 which also extends through the bulb 11.

A preference mechanism disposed in proximity -of the normal section and the adjacent transfer cathode assures stepping of the main discharge from the normal section into the stepping row of cathodes in one direction following the application of the initiating or normalizing voltage pulse to the normal cathode. This preference mechanism may comprise a second portion of low discharge efficiency secured to the transfer cathode and facing the normal cathode.

Bias of -a high positive voltage for Iauxiliary anode AA of units tube T1 is obtained from a bias and output circuit comprising ground terminal 15a, resistor 15, capacitor 16, resistor 17 and terminal 18, to which is connected a source of positive voltage, not shown, such for example as a +55 volt battery. The bias for auxiliary anode AA is obtained via lead 14 connected to a junction point between resistor 15 and capacitor 16; and output connection 19 for auxiliary anode AA is constituted by a junction point between resistor 16 and capacitor 17.

As discharge is stepped from rest cathode A9 through transfer cathode B10 and then to rest cathode A10, an auxiliary gap defined by auxiliary anode AA and rest cathode A10 breaks down. As a consequence, capacitor 16 discharges through resistor 15 to provide a negative voltage pulse of relatively large amplitude. Now, a voltage applied to transfer cathode B1 in a manner to be mentioned later herein will cause discharge to transfer from rest cathode A10 to transfer cathode B1 and in due time to rest cathode A1, as will be pointed out hereinafter. During this time, capacitor 16 will be discharged to such extent that 4the auxiliary gap will no longer sustain discharge, and will be extinguished.

The voltage across resistor 17 which is included in the output of auxiliary anode AA constitutes the negative output voltage pulse previously mentioned. Such output voltage pulse eected by stepping tube T1 can be used to step the discharge in tens stepping tube T2; and when effected by the latter tube, the voltage pulse can be used to step the discharge in hundreds stepping tube T3. Thus, the stepping tubes T1, T2 and T3 can be connected in sequence in a circuit for the decade counting of alternating current cycles from l through 1000 in such manner that the auxiliary anode AA in each tube in the sequence, except the last one, serves to step the discharge to the next succeeding tube. In such decade counting circuit, units tube T1 will step discharge between its rea conventional manner unless hereinafter noted otherwise.

In the operation of the ele :tronic pulse generating circuit shown in Figs. l and 2, it will be initially assumed for the purpose of this explanation that direct current source 144, normally disconnected from work 145, is to be connected to work 145, that is, to the cold cathodes of the gas tubes which are to be aged, for a time interval equal to 2 cycles out of a total time interval equal to 80 cycles of the 60-cycle current available at terminal 25 in the input of units tube T1; and the operation of the circuit on this basis will be repeated indefinitely. According to this operation, each such 2-cycle time interval will comprise the first 2 cycles out of each 80-cycle period and will be referred to subsequently as on-time interval, whereas each 80-cycle period will be referred to as total time interval. Thus, for the assumed operation, work 145 will receive a current pulse of suitable magnitude for an on-time time interval equal to the time of 2 cycles repeated at recurrent total time intervals, each of which is equal to the time of 80 cycles.

Also, it will be initially assumed for the purpose of the explanation that in the units, tens and hundreds tubes T1, T2, and T3, respectively, discharge is taking place simultaneously in the auxiliary gap comprising rest cathode Ato and auxiliary anode AA and in the main gap comprising rest cathode A and anode 10. The tubes T1, T2, and T3 are thus initially conditioned for the cycle counting action which will be presently explained. Movable arms 90, 132 and 115 of 3-stage switch 72 are initially adjusted to rest on corresponding contacts 74, 126 and 117, respectively, of switch stages 72, 72b and 72e. At this point, it should be noted that tubes T4, T5, and T6 are in the non-conducting condition; and relay 140 is in the non-operated condition. As hundreds tube T3 is effectively disconnected from the circuit shown in Figs. l and 2 for the purpose of this explanation of the assumed operating condition, this tube will not be mentioned in the subsequent explanation of the circuit operation.

Further, let it be assumed that as a consequence of the next previous operating cycle of the circuit, a positive voltage from RC network 45 connected to rest anode As of tens tube T2 has been applied simultaneously to the starter anodes 97 and 95 of the output and reset tubes T5 and T6, respectively, in a circuit including contact 74 and movable arm 90 of switch stage 72a, lead 91, capacitor 92, junction point 93 and resistors 94 and 96. Since starter anode 95 of reset tube T6 was provided initially with a predetermined fixed amount of positive bias via a voltage divider including resistor 106 and re- 'v sistor 107, and the -j-B voltage source, the additional positive voltage supplied by tens tube T2 in the manner just mentioned serves to trigger the starter gap in reset tube T6 whereby the main gap including anode 105 and cathode 108 of the same tube is also fired. As the starter anode 97 in output tube T5 was also provided with a predetermined fixed amount of positive bias effective via a voltage divider including resistor 100, resistor 101 and resistor 88, and the -l-B voltage source, the additional positive voltage produced by the tens tube T2 in the respect just explained also serves to trigger the starter gap in output tube T5 from which the main gap between cathode 87 and anode 98 in the same tube is also fired. Hence both tubes T5 and T6 are caused to conduct at the same time. The effect of cathode resistor 88 in the associated voltage divider circuit is negligible due to the low resistance value of resistor 88 compared to the combined resistance value of resistors 100 and 101.

As the anode voltage of reset tube T6 in the conducting condition drops to a sustaining magnitude, a large negative voltage pulse is developed across capacitor 109 and RC network 110, both of which are included in the anode-cathode circuit of reset tube T6 which is now functioning effectively as a relaxation oscillator. This large negative voltage is supplied via junction point 112, movable arm 115 of switch stage 72C, contact 117, lead 118 and lead 13 to normal cathode N of tens tube T2. This conditions the tens tube T2 to commence the cycle counting action in a manner which will be presently explained. Here, it will be evident that since tens tube T2 is connected in circuit to count a maximum of 80 alternating current cycles during each complete cycle of the counting action of the circuit, the hundreds tube T3 is effectively disconnected from the counting action of the circuit as above mentioned. Units tube T1 was also conditioned for the next-mentioned cycle counting' action by th'e operation of the bias circuitry including resistor 15, capacitor 16 and resistor 17 in response to the receipt of the tenth sharp negative pulse applied to input terminal 25 during the next preceding cycle counting action which was assumed for the purpose of this explanation as above mentioned. At this point, it will be understood that turnoif tube T4 rests in the non-conducting state. Since reset tube T6 is functioning effectively as a relaxation oscillator as previously mentioned, this tube will automatically return to the non-conducting condition to await the next activating positive voltage supplied to its starter anode from tens tube T2.

The action of the cycle counting operation of the circuit will now commence due to the fact that output tube T5 was changed to the conducting state simultaneously with reset tube T6 in the manner just explained. The conducting condition in output tube T5 establishes a current ow in the operating winding b of relay 140 whereby the latter is operated. This actuates armature 143 into engagement with the two contacts associated therewith whereby direct current source 144 is connected to work 145. In the specific example of a timing circuit according to this invention as previously mentioned, source 144 supplies a current pulse of proper magnitude to work 145 which comprises the cathode of one or more cold cathode gas tubes which are to be aged. This marks the beginning of the time interval during which the current pulse is to be applied to the work, i. e., the beginning of the time interval during which output tube T5 commences to discharge.

At the same time, the first cycle of the sinusoidal 60- cycle current applied to input terminal 25 connected in the input of units tube T1 is translated by clipping and shaping network 29 into positive and negative sharp pulses having an average d.c. level which is above that of the output voltage due to the discharge of the respective rest cathodes A1 through A10 in a manner to be hereinafter mentioned. The shaping network 29 prevents the tied-together B-cathodes ot units tube T1 from receiving such amount of positive voltage as to become effectively an anode. The negative pulse serves to transfer the discharge from a particular A-cathode to a particular B-cathode because the latter B-cathode is more negative than the preceding particular A-cathode. The positive pulse ensures a quenching of the discharge at the gap involving the particular B-cathode by driving the effective positive voltage on the latter cathode well above that on the next succeeding A-cathode.

The first sharp negative pulse developed by the clipping and shaping network 29 in response to the first cycle ot the alternating current input at terminal 25 is applied through capacitor 27 to bus 12 of the B-transfer cathodes in units tube T1. This causes the discharge in the auxiliary gap and in the main gap in units tube T1, both of which have been identified hereinbefore, to transfer from rest cathode A10 to transfer cathode B1 and thence to rest cathode A1 at the cessation of the pulse as explained in the Townsend copending application and patent, supra. Since the rest cathode A1 and RC network 35 are connected to open contact 66 of switch 65, no further action in the cycle counting circuit is effected by the first sharp negative pulse applied to the input of units tube T1.

The second sharp negative pulse developed by the clipping and shaping network 29 in response to a second cycle of alternating current input at terminal 25 is applied through capacitor 27 to bus 12 whereupon transfer cathode B2 is caused to discharge, and in due course this extinguishes the discharge of rest cathode A1 and institutes discharge at rest cathode A2, at the cessation of the pulse. As rest cathode A2 and RC network 36 associated therewith are connected to Contact 67 upon which movable arm 80 of switch 65 is resting, a positive voltage from RC network 36 is supplied over a circuit including switch contact 67, movable arm 80, lead 81, capacitor 82 and resistor 83 to starter anode 84 of turn-off tube T4.

Coincident with this voltage, another voltage developed across cathode resistor 88 of output tube T5, which is in the conducting state as above mentioned, is also applied over a circuit including lead 86 and resistors 85 and 83 to the starter anode 84 of turn-off tube T4 whereby discharge is instituted in the starter gap thereof. In due course, discharge is effected in the main gap in- .apodera cluding anode 98a and associa-ted .cathode 98.1? in .-turn.- off tube T4.v Resistors 83 and :85 tend to limrt :peak currents ,in :the .starter .gap .of turn-oil .tube TA, As. .a consequence, la .negative evoltage is .deyeloped 1n series network LCR which is slow acting, and applied through capacitor .1.0.2 to .anode v-98 Yof .output :tube 15. As .turnol tube TA functions .effectively .as a relaxation .oscillator, ,it .automatically .returns -itself .to the non-.conducting condition. yIn ythe LCR network, incluctance L causes the xoltage .appearing .across Vthe .LCR network ,to fall below .the normal sustaining A.voltage .of the turn-olit tube T4.. Because of :the long .time lconstant .of ,the LCR network, the voltage on the anode kof ,turnofiE tube T4 is .preyented from .returning :to the 13.-!- yalue .while the positive .voltage due to RC network .3.;6 of units .tube Tl and .the .coincidence -yoltage .on .cathode resistor 8.8 `of output tube T are .still .-iointly .ehective onthe .starter anode .of turn-off t-t-ube Td. As a consequence. turn-off tube EFH tis prevented from discharging .a second time in response .to .the .set .of starterzanode voltages. Thus, .the LCR network serves to hold turn-oil tube Tl in the non-.conducting condition -until .the voltage at RC network 3.6 of units .tube Tl has .disappeared The negatiye yoltage .appearing across .the LCR network drives the positive yoltage .eiectiye on .anode 9.8 down to a velue which ,is .less than that Vrequired .to sustain discharge .in output itube T5. Accordingly, this tube is caused .to .return .to :the non-.conducting .condition and thereby .to .rernove tl.) the .current from .the .operating winding .litlb .of relay litl :and .(2) Ithe coincident voltage from starter anode 84 of turn-off tube TA. This causes .relay .1.4.0 to return .to the .unoperated state to disconnect direct .currcntsource 1.44 .from .work 145- 1.11 View of this, .it will he apparent that turn-od ,tube I4 .have .conduction instituted and maintained therein only v.when .conduction .is effective in .output tube T5. Zfhis .marks .the .termination of .the time interyal during which the eurrentpuls to .be .applied to its work..

The third sharp negative pulse developed by network 29 in .response tothe .third cycle Vof alternating current applied .to input terminal .25 .is supplied .through capacitor .27 to bus .-1.2 connected ,to .the .B transfer .cathodes in units .tube .Td whereupon .the .discharge is stepped to transfer cathode .Bs .and .in Side course .the discharge -is transferred .to :rest cathode Ae .at .the .cessation of the negative pulse As rest cathode As and the RC network .38' associated .therewith are grounded, no .further .action is -eiiected in the operation of vthe .cycle counting .circuit- Similarlyl the Yfourth sharp negative pulseiprcduced in ,network 2.9 in response .to the Afourth I.cycle of .alternating current .at input .terminal .2S causes .the .dischargev to v.step to transfer ...cathode .Br and :rest cathode .Afr .in sequence but as the latter zcathode and its associated RC network .39 are grounded, .no further .action is Iproduced in the operation of vthe cycle scouting circuit.

The fifth .sharp negative pulse 4developed hy network `2.9 in response 'to the fth cycle of .alternating .current present at input terminal ..25 .effects `.discharge at cathode Bs- At thc cessation ofthe pulse. .discharge will transfer to rest cathode A5 but since Vthe Alatter cathode and its associated network ,3.7 are connected to open .contact 6s of switch tiri., no .further :action :taires .place in the opcrationof `.thecycle.countingcircuit .In .like Inertner,"the 6th, 7th, 8th, 9th and 10th Anegative pulses developed by network .29 in response .to .the .6th, 7th, Sth. 9th and -lQth cycles of alternating current present at 'input terminal 25 serve to .cause discharge at transfer athodes Bs, B7, Bg, he and Bio and thence atrestcathodes A6A'LAV8, A9 and Aro in succession'at the cessation .of the .respective .negative pulses. until discharge is effected in units tube T1l at the auxiliary gap including restcathode Ain and auxiliary auodeAA and in the main gapcornprising rest cathode Ain-and anode lll. As .no rhial cathode N connected to lead '1,3 of units tube T1 is open-circuited, this cathode exerts no influence on the action of the cycle counting circuit. kThis 4is:explaincd in ythe .copending Townsend application and Athe Towns send patent, supra.

Prior to the discharge in the auxiliary gap of units tube T1, Vit .will be .understood `that the high positive voltage for-auxiliary anode AA had a certain value which comprises the .voltage on one side of capacitor V16 and the voltages at the output-terminal V18 for auxiilary anode AA .'had another .value which comprises 4the voltage op vthe oppositeside of capacitor :16. When discharge-took plane 4in tthe auxiliary gapJ the biasing .and .output yoltages effective on the opposite sides of capacitor 16 lle.- creased .in magnitude .to .an egual amount.; and capacitor 16 .disharged .and together with resistor ..1.5 sorted .to produce the .large negative output Asigna-l .at output terminal 1.8, as explained in the Townsend .copending .applicationfsupra- This sharp .negative pulse applied yia output terminal -119 and lead ,dll to Bfcathode bus 1.2 in tens .tube TZcllects discharge :between .cathode B1 .and .anode .lll in this tube, and upon the .cessation .of the pulse .the discharge .is transferred to rest cathode Ai and anode lili. As the latter cathode and associated RC network .41 yare connected to open ternrinal 69 Yof switch o5, no further action in .the .operation .of the cycle counting .circuit .takes place .in response to .the :first negative pulse generated by units tube rT1 Vand ,transmitted to tens `tube T27. Thus, the-first ten cycles of `the vahorita-ting current .applied to .input .terminal 2.5 .at .units tube T1 are .effectively counted in tens tube T2..

On the eleventh cycle .of the sinusoidal current applied to .the .input terminal 25 `and the eleventh sharp negative pulse derived therefrom `and Vapplied to bus 12 `of .the B cathodes of units tube T1., the auxiliary discharge and the main discharge are vtransferred from rest cathode A10 .to transfer .cathode B1 and the main 4,discharge to rest cathode A1,l as hereinbefore explained. In response -to the twelfth through twentieth .cycles of .the sinusoidal current applied .to input .terminal 25, .the discharge in units tube ."i`l is stepped :from transfer cathodes B2 through Bro andrestcathodes A2 through A10 in sequence .as hereinbeiore explained until discharge is effected again in the auxiliary gap including rest cathode A10 and auxiliary anode AA and in the main gap comprising rest cathode A10 and lanode lil. in response to such discharge, the bias and .output circuitry including resistor 15, capacitor i6, resistor 17 and output terminal 19 produce and apply a second llarge negative .output voltage pulse at the output terminal 1S and thereby a't 'bus 12. of the B .cathodes in tens tube T2.

Referring for the moment to the operation of the circuit involved in the counting of the second .group of ten cycles of sinusoidal current at input terminal 25, it will be recalled that turn-.olf tube Td, output tube T5, and

reset .tube T6 are now resting in the non-.conducting vcondition. AsV a consequence, the positive voltage produced by rest cathode A2 in the discharge state and associated RC network 36 in .units tube Tl and applied via .contact 67 and arm Sil of switch 65, lead 8l, capacitor .82 and resistor 83 .to the starter anode Sdof turn-oif tube T4 -will be 4ineffective totinstitute .discharge therein. This is occasioned .by the .fact that the coincidence ypl-tage required for the starter anode 8.4 and effected by .cathode resistor 8S in .the cathode circuit .of output tube T5 is not present since the latter tube is resting in the ynon-conducting state.

In regard to .the second nega-tive volta-ge pulse applied to bus 12 of the B cathodes in the tens tube T2 in response Vto -the vcount-ing of the second group of ten cycles of sinusoidal current by units tube T1, the discharge .in

Vtens tube T2 will be stepped by such negative voltage 4from -the A1 cathode to the B2 cathode and upon the cessation of the pulse the discharge will be transferred to the Ag. cathode. As the latter Vcathode and its -ass'o ciated RC network .42 are connected to open terminal 70 of switch 65, no further lact-ion in the operation of the cycle counting circuit takes place.

ln response to the counting of the -th-ird group of -ten cycles of sinusoidal current present at input terminal 25 by the uni-ts tube T1 and the application of the third large negative voltage pulse to the input of the tens tube T2, the discharge in tens tube T2 is stepped from the A2 cathode to the B3 cathode, and upon the cessation of the pulse is transferred to the ,A3 cathode. As the latter cathode and its associated RC network 47 are merely grounded no fur-ther action in the operation of the .Cycle counting circuit is effected. ln response to the counting of the fourth group of ten cycles of sinusoidal current at input terminal 25 vb-y units tube Tl and the transmittal of the fourth large negative -voltage pulse to tens tube T2, the discharge in the latter `tube is stepped from the A3 cathode to the B4 cathode, and upon the cessation `of the pulse is transferred -tro the A4 cathode. Since this cathode and its associated RC network 48 are merely grounded, no further action in the operation of the'cycle counting circuit'is-achieved.

When the fifth group of ten cycles of sinusoidal current present at input terminal 25 is counted in units tube T1 and the fifth negative voltage 'nulse is sent thereby to tens tube T2, the discharge in the latter tube is stepped from the A4 cathode to the B5 cathode, and upon the cessation of the pulse is transferred to the A5 cathode. This cathde and its associated RC network 43 produce and supply a positive voltage to open contact 71 of switch 65. This voltage therefore fails to institute further action in the operation of the cycle counting circuit.

In response to the counting of the sixth group of ten cycles of sinusoidal current at input terminal 25 by units tube T1 and the transmittal thereby of the sixth large negative voltage pulse to the tens tube T2, the discharge in the latter tube is stepped from the A cathode to the Bs cathode, and upon cessation of the pulse the discharge is transferred to the A cathode. As this cathode and its associated RC network 44 are connected to open contact 73 of stage 72a of switch 72, the action of the operation of the cycle counting circuit is arrested at that switch contact. When the seventh group of ten cycles of the sinusoidal current at input terminal 25 is counted by units tube T1 and the seventh negative voltage pulse is sent thereby to tens tube T2, the discharge in the latter tube is stepped from the As cathode to the B7 cathode, and upon the cessation of the pulse is transferred to the Av cathode. Since this cathode and its associated RC network 48 are merely grounded, no additional action in the operation of the cycle counting circuit is achieved.

In response to the counting of the eighth group of ten cycles of sinusoidal current present at input terminal 25 by units tube T1 and the transmittal thereby of the eighth negative pulse to the tens tube T2, the discharge in the latter tube is stepped from the A7 cathode to the B8 cathode, and upon the cessation of the pulse is transferred to the As cathode. This cathode and its associated RC network 45 supply the positive voltage pulse to starter anodes 97 and 95 of the output and reset tubes T5 and T6, respectively, in the circuit previously traced. As a consequence, conduction is simultaneously established in the starter gaps of output tube T5 and reset tube T6, and thence in the main gap including the main anode and the cathode of the respective tubes.

As a result of the establishment of conduction in the main gap including anode 105 and cathode 108 of reset tube T6, this tube and its associated capacitor 109 and RC network 110 serve to supply the large negative voltage pulse to the normal cathode N of tens tube T2 over the circuit previously traced in order to condition tens tube T2 for the next succeeding cycle in the counting operation of the circuit. This also determines the total time of the operating cycle of the pulse counting action of the circuit. Thereafter, reset tube T6 still in the conducting condition and functioning as a relaxation oscillator as above mentional automatically returns itself to the non-conducting condition. The institution of conduction in output tube T5 commences the cycle of the pulse counting action, and the operation of the circuit including turn-off tube T4, output tube T5 and reset tube T6 have been explained in detail hereinbefore.

Thus, the conditioning of the tens tube T2 under control of reset tube T6 at the count of 80 cycles of the sinusoidal voltage applied to input terminal 25 establishes the total time of one complete cycle of operating of the counting circuit. From the such complete cycle, it will be seen that the current source 144 was connected to the work 145 during the time equal to the first 2 cycles of the total time of 80 cycles, and further was disconnected from the work 145 for the time equal to the final 78 cycles of the total time of 80 cycles. This can be readily comprehended from an inspection of the curve in Fig. 3 which illustrates graphically, for each complete operating cycle of the circuit, the on-time interval, i. e., the time interval during which the output tube T5 is in the conduction condition and relay 140 is operated; the time interval during which the output tube T5 is in the non-conducting condition and the relay 140 is in the non-operated condition; and the total-time interval during which the output tube T5 is in both the conducting and non-conducting conditions and the relay 140 is in both the operated and non-operated conditions. As the above operation recurs on an automatic basis, it will be evident that the cathodes of the gas tubes to be aged can have applied thereto a spurt of current lasting a pre- 1Q Lt.. determined time interval out of each recurrent preselected total time interval.

The total time of each complete operating cycle involving the tubes T1 through T6 can be varied by (l) appropriately connecting the rest cathodes A1 throughV A10 and associated RC networks of the tens tube T2 and hundreds tube T3 to the respective contacts of switch stage 72a and/or (a) by selectively positioning the movable arm thereof to engage the proper contacts of the latter switch stage. In the circuit shown herein for the purpose of the instant explanation, it would appear to be obvious that the total time can be extended to embrace a time interval equal to 1000 cycles of the sinusoidal alternating current supplied to input terminal 25. For the latter purpose, the negative voltage pulses to step discharge in hundreds tube T3 are supplied thereto frorn tens tube T2 in a manner identical with the supplying of the negative voltage pulses from units tube T1 to tens tube T2 to step the discharge therein. The total time interval can be expeditiously extended to count beyond 1000 cycles by including further stages in sequence with the hundreds tube T3 whereby the total time can be increased by a factor of 10. In regard to the total time, this is achieved'in the circuit shown in the drawing by appropriate connections from the respective contacts and movable arm of switch stage 72e to reset tube T6 and to the normal cathode N of the proper counting tube connected effectively in the counting circuit. The switch stage 72b disconnects the source of -I-B voltage from the hundreds tube T3 when such voltage is not required for a particular circuit adjustment. As shown in the drawing, the -l-B source is disconnected from the hundreds tube T3y for total time intervals equal to less than that of 100 cycles of sinusoidal current supplied to input terminal 25.

The institution of conduction in turn-olf tube T4 under control of output tube T5 terminates the ontime interval for one complete cycle of the circuit. Such on-time interval comprises the time during which output tube T5 is conducting to connect current source 144 to work 145. As previously indicated, the ontime interval for the circuit adjustment shown in the drawing includes the time interval equal to the first 2 cycles out of each recurrent total time interval of 80 cycles. That is to say, a current pulse equivalent in time to 2 cycles of the alternating current voltage applied to input terminal 25 is available to energize suitable Work out of each recurrent total time interval equivalent to 80 cycles of the same voltage. The ontime interval can be changed by (l) appropriately connecting the rest cathodes A1 through A10 and associated RC networks of the units and tens tubes T1 and T2, respectively, to the several contacts of the switch 65, and (2) by selectively positioning movable arm 80 thereof to engage the proper switch contacts. In the circuit shown in the drawing, it is apparent that the on-time interval can be extended to comprise a time interval equal to 50 cycles of the sinusoidal current applied to input terminal 25.

In accordance with the circuit shown in the drawing, one of six different on-time intervals is available by actuating movable arm 80 of switch 65 to one of the respective contacts 66 through 71; and one of six dify ferent total time intervals is possible by adjusting movable arm 90 of switch stage 72a to one of contacts 73 through 78; and the respective time intervals are determined by a timing sequence controlled by the stepping tubes T1, T2 and T3 connected in circuit to count the cycles of the sinusoidal alternating current present at input terminal 25 in steps of 1, l0 and 100, respectively. In regard to the determination of the on-time interval and the total time interval, it is possible to obtain l-cycle steps from l to 1000 cycles in each of the steps via suitable coincidence triggering circuits, not shown.

It is to be understood that instead of utilizing output tube T5 to operate the mercury relay 140 as illustrated in the drawing of the disclosed embodiment of the invention, it would be readily evident to those skilled in the art that the embodiment may be expeditiously adapted to perform other timing sequences. For example, a different load could be substituted in the anode cathode circuit of output tube T5 for the 0perating winding b of the mercury relay 140; or a voltage signal could be taken off cathode resistor 88 :in the anode-cathode-circuit of output tube T5.

in. the art that other cycleV counting or pulse' steppingy devices could' be utilized equally' as Well.. For example, an electromechanical stepping switch ofa type used in. automatic telephone switchin'gf systems' is. contemplated t`or use as a pulse stepping. device.r Inview of the. foregoing, numerous additional" specic' applications of! the invention will occur to those. skilledy in the art. A

Whatis claimed is:

l'.. In. a circuit for timingl therate ofl repetitionl of' a. series. of.` voltagel pulses. andthe. duration ofi each pulse;4 in. the series, a source ofl alternatingV current, a plurality ofi stepping devices for counting the cycles of said source current, each of` said devices' including aplurality of'outputterminals ateachr of which a voltage isproduced to represent the numberofAV cycles of the source current" countedi thereat;V means connected to one terminal of said devices and' responsive to the voltage produced thereat to commence thev production of one of said voltagepulses; said' meanssir'nultaneous= ly. producing a second voltage',v and` means connected to. another terminal of" said devices and responsive to the voltage producedthereat and to saidi secondlvol'tage for. causing said. first-mentioned means.V to terminate the production' of said one. voltage' pulse, the time. interval occurring between the voltage produced' at one said terminal. and' the next? succeeding, voltage; produced* at said other terminal being. equivalent to` that represented by'tlie numerical?valueotthe cycles of' said" source current counted between the voltages produced' at said lst=mentioned one and otherk terminals, said time intervall constituting the' durationv of each voltage. pulse produced; byA said' first-mentioned means, the: timeinterval occurring between' tvvo` successive voltages pro'- duced att said one terminalA being equivalent to that representedEA by the numerical value ofthe cycles ot` said source current counted betweenA saidr two successive voltages produced'I at said last-mentioned one. terminal; said last-mentioned time interval` constituting the rate of repetition of' the voltage' pulses'- produced' by said first-mentioned means. p

2.' In a circuit for timing the rate` olL repetitionV of a series ofvolt'age pulses and the duration of each pulsein thev series,v a source of alternating, current, a plurality of' stepping tubes arranged to count' the cycles 0E said source current, each' of' said tubes including ati least' one input'termina'l a'twhich a voltage is produced to represent the number of cycles of said' source current counted thereat, meansl connectedlt'ofsaid terminalof one of said tubes and responsiveto. the voltage produced thereat to commence; the production of" one of said'. voltage pulses, saidl means simultaneously' producing another voltage, and means connected.` to said terminalof another ot. said tubes and' responsive. to. the voltage. produced thereat. and to said other. voltage for causing saidfirstfmentioned means to terminate the production of said one voltage pulse, the time interval occurring between the voltage produced at. said' terminal of'said one tube, andthe next succeeding voltageproducedf at said:terminal' of said other tubebeing equivalent to thatrepresented by the numerical valueofthe cyclesofsaid sourcecurrent counted between the voltages produced. at saidV last-mentioned tube. ter.- minal`s said time. interval constituting the duration of each voltage pulse. produced by said? first-mentioned means, the time interval occurring between two successive voltagesproduced atsaid terminal. on. said one tube being equivalentto that. represented. by the. numericalvalue of the cycles of. said source current counted between two successive. voltages produced? at. said last-mentioned ter.- minals, said last-mentioned time interval constituting the rate of. repetition of the. voltage pulses. produced by said. first-.mentioned means.

3.. A timing'circuit. inaccordance with claim 2V` inwhich each of s aid tubesincludes aplurality of outputterminals at eacliioi which; the produced.voltagesrepresent dilerent numerical values of.` the cycles. of.` said. source. current counted circuit, andj said" first-mentioned means' includes meansfor'varying the rate of repetition of.` said voltage pulses, saidlvarying means comprising meansl for selectingone'ofsaidplurality of output terminals of said one tube for varying the time interval occurring between the two' successive voltagesA produced at saidl last-mentionedA selected terminal'4 inaccordance with the varying numbers of' cycles of( said source current counted between the last-mentioned' two' voltages.

4 A timingl circuit'v in accordancel withV claim 2 in which ea'ch-` oih said tubes includes aplurality of output terminals representingr differentiV numerical values of'they cycles of'V saidl sourcecurrentl counted by said counting circuit, andl said second-mentioned meansiincludes means for varyinlr the duration: of! each, of said voltagev pulses, said varying means comprisingv meansA for selectingVv one of! said plurality' of output`v terminals of said' other4 tube for varying' the timex interval: between the voltage. pro duced. at: saidV one. terminal? of: said; one tube and the next succeedingY voltage producedv at said selected' ter-V minal' of'said other; tubesin accordance=with the varying number.' of. cycles z of' said; source current'. counted between: said lastfmentioned; two; voltages.

5". Au. timing circuit. ina accordance with;v clairn 2; in whichV eachv of; said tubes includes." a plurality of i output terminals; representing different,r numerical.- values: of' the cycles. of said source. current. counted: by said counting circuit, said: tirstfmentionedt means includes. means'. ion varying: the rate-:of repetitiony of. said=voltage pulses, said varyingxmeanscomprisingmeans for selectingfone of said plurality-of output terminals of said onetube` for varying the: timel interval. occurring between' the. two successive voltages; produced at the selected terminal oi said.I one tubein accordance with. the; varying numbersk ofcycles of said' source: currentv counted' between-` saidz last-mentioned two voltages, andi saidsecondfmentioned` means incl-udesf means\for' varying the. duration of each` of said voltage pulses, said" last-mentioned varying means comprising means forn selectingoneof saidplurality ofl output terminalssofty saidother tube forl varying the time interval occurring between thevoltage produced at saidy one terminal of said onev tube and thenext succeeding voltage produced at said selected terminal. of. said other tube in accordance with. the varying number` of. cyclesof said source currentz counted betweenv said lastfmentioned1 two voltages.

6. Ina circuitY for timing. the production of a. series of4 voltage pulses, a source'of. stepping voltages, a... plurality of stepping, tubes arranged: ina countinge circuit to count thesteppingvoltages, each. of.. said.. tubes having at least one output` terminal' at which a voltage. is produced. to represent. the number. off. stepping voltages counted thereat,. a. plurality, of( gaseous. discharge. devices in a. nonconduction condition, each: having a .starter anode, a cathode, and. a main. anode, means. for applying` the voltage ofoneofgsaid! stepping tube output terminals to the starter. anodes. of two. of said devices thereby to establish. conduction in both thereof. at. the same time, one of. said. two' conducting. devices. supplying a voltage to terminate one. cycle ofk the operation of'said counting circuit and. simultaneously therewith. to conditiom the latter circuit for the commencement. of' the. operation of the next. succeeding counting.cycle,. a secondi of .said two conducting, devices commencing. the production of oneof said voltage. pulses, means responsivev to conduction. in said second device fon applying a coincidencevol'tage. to thestarter anodeof.' a third of. said devices,. and". means for applyingy the voltage of another of said stepping tube outputi terminalsto the starter anode` ofl said third device to cooperate withsaidlcoincidence voltage applied thereto for establishing. conduction. in. said' third device, said third conducting device supplying avoltage: to-saicl` second conducting device. to` quench. conduction therein. thereby to: terminate the.. production of said. one voltage.. pulse, the time interval occurring betweentbeproduct'ion of. the stepping tube output. voltage establishing. conduction in said. two. devices andi the production. of the next succeeding stepping tube. output voltage establishing. conduction inV saidthi'rddevice determining. the duration` of, each. pulse producedl in tl'ie series of pulses, and. tbe time interval occurring., between the production of tworsuccessivestepping tube output voltages establishing thev simultaneous conduction. inl said. two. devices on. two, successive occasions. xing; the rate. of repetition. of' the pulses.. in. the

' produced'series o pulses.

7. In a circuit for timing the production of a series of voltage pulses, a source of alternating current, a counting circuit including a plurality ci stepping tubes arranged to count the cycles of said source current, each of said tubes including a plurality of output networks for producing voltages to represent the number of cycles of the source current counted thereat, a plurality of gaseous discharge devices, each having a starter anode, a main anode and a cold cathode, means including multicontact switches having arms engageable with the respective contacts thereof for connecting certain of said networks to the starter anodes of said devices, said switch arms being positioned on preselected switch contacts for applying two discrete voltages from two of said networks to the starter anodes of said devices during each complete cycle of operation of said counting circuit, the rst of said last-mentioned two network voltages representing a predetermined number of cycles counted by said counting circuit and establishing the conducting condition in two of said devices, the first of said devices in the conducting condition commencing the production of one of said voltage pulses, a second of devices in the conducting condition applying at the same time a voltage to said counting circuit to condition the latter circuit in such manner that one complete cycle of operation of said counting circuit is terminated and the next succeeding cycle of operation of the counting circuit is commenced, and means connected between the starter anode of a third of said devices and the cathode of said first device and responsive to the conducting condition in said iirst device for applying a coincidence voltage to said last-mentioned starter anode, a second one of said last-mentioned two network voltages representing a preselected number of cycles counted by said counting circuit and cooperating with said coincidence voltage to establish the conducting condition in a third of said devices, said third device in the conducting condition producing a voltage which causes said first device to return to the non-conducting condition thereby to terminate the production ot' said one voltage pulse, the time interval between two successive conductions in said rst device constituting substantially the rate of repetition of the produced voltage pulses, and the time interval between the conduction of said rst device and second device constituting substantially the time duration of each of the produced voltage pulses.

8. In a voltage pulse generator, a counting circuit including a plurality of stepping tubes, each tube having a plurality of output terminals and a preselected electrode, each of said terminals having a voltage eective thereon to represent a predetermined number of pulses counted by said circuit, and means for applying stepping pulses to said counting circuit, a plurality of gaseous discharge devices in the non-conducting condition, each including a starter anode, a main anode and a cold cathode, selective means for applying the voltages of certain output terminals of at least two of said tubes to the starter anodes of said devices, the voltage at one terminal selected by said selective means establishing conduction simultaneously in two of said devices, means for applying a voltage due to conduction in the cathode and main anode circuit of one of said last-mentioned two devices to said preselected electrode of a predetermined one of said tubes to condition said counting circuit for a new cycle of counting action, means for applying to the starter anode of a third one of said devices a coincidence voltage due to conduction in the cathode and main anode circuit of a second one of said two conducting devices, means responsive to conduction in the cathode and main anode circuit of said second device to commence the production of a voltage pulse, the simultaneous voltages on the starter anode of said third device due to the tube terminal voltage selected by said selective means and to the coincidence voltage cooperating to establish conduction in the cathode and main anode circuit of said third device and means activated by the conduction in said third device to produce a voltage for quenching the conduction in said second device thereby terminating the production of the voltage by said second device.

9. A pulse generator in accordance with claim 8 in which said activating means comprises an inductor, a resistor and a capacitor.

l0. A pulse generator in accordance with claim 8 in which said voltage coincidence means includes a resistor connecting the cathode of said second device to ground, and means connecting the starter anode of said third device to a junction point of said last-mentioned cathode and resistor.

ll. A pulse generator in accordance with claim 8 in which said means for applying the voltage from said one conducting device to said preselected electrode of said predetermined tube includes a resistor and capacitor network.

l2. A pulse generator in accordance with claim 8 in which said means for applying the voltage from said one conducting device to said preselected electrode of said predetermined tube includes in series a capacitor and a parallel resistor and capacitor network.

13. in an electrical control system, a counting circuit including a plurality of stepping tubes, each of said tubes having a plurality of transfer and rest cathodes, a normal cathode, an auxiliary anode, means for connecting said auxiliary anode of each of said tubes to said transfer cathodes of the next succeeding tube, and a source of stepping pulses connected to the transfer cathodes of a rst one of said tubes, a plurality of electronic devices, each including a starter anode, a main anode and a cold cathode, selective means for connecting a certain rest cathode of a preselected one of said tubes to the starter anode of a rst one of said devices, further selective means for connecting a preselected rest cathode of another of said tubes to the starter anodes of a second and third of said devices, means for connecting the cathode and main anode circuit of said second device to said normal cathode of a preselected one of said tubes, resistance means for connecting the cathode of said third device to the starter anode of said first device, and means connected to the cathode and main anode circuit of said third device and operatively controlled thereby.

14, ln a generator of a series of voltage pulses, a counting circuit including a plurality of stepping tubes, each having a plurality of output terminals, a common anode, a preselected cathode and means for applying stepping pulses to one of said tubes, a plurality of gaseous discharge devices in the non-conducting condition, each including a starter anode, a main anode and a cold cathode, a multicontact switch having preselected contacts connected to certain output terminals of two of said tubes and having an arm engageable with the respective contacts thereof, said arm being connected to the starter anode of a first one of said devices, a three-stage multicontact switch, each stage having an arm engageable with the respective contacts thereof, said arms being mechanically connected together and thereby caused to engage corresponding contacts of the respective stages, a first of said switch stages having its contacts connected to output terminals of two of said tubes, said arm of said rst switch stage being connected to the starter anodes of a second and third of said devices, means including a capacitor, an RC network and a second stage of said three-stage switch for connecting the cathode and main anode circuit of said second device to said preselected cathode of a predetermined one of said tubes, means including a third stage of said three-stage switch for connecting a source of -l-B voltage to said common anode of one of said tubes, means including a network comprising an inductor, a resistor and a capacitor for connecting the main anodes of said rst and third devices, means including a resistor for connecting the cathode of said third device to the starter anode of said rst device, and work connected to the cathode and main anode circuit of said third device, said arms of said switches being positioned on preselected contacts thereof to apply the voltages of predetermined output terminals of said tubes to the starter anodes of said devices to establish the conducting and non-conducting conditions therein in accordance with a preselected number of stepping pulses counted by said counting circuit, the conducting condition in the cathode and main anode circuit of said second device conditioning said counting circuit for the commencement of each counting cycle, the conducting condition in the cathode and main anode circuit of said third device introducing a voltage pulse in said work and at the same time producing a coincidence voltage in said resistance means for application to the starter anode of said rst device, said first device being changed to the conducting condition in its cathode and main anode circuit in response to the simultaneous application of said two voltages to the starter anode thereof, said rst device in the conducting condition causing the application of a voltage to said main anode of said third conducting. device through. saidnem/Ork connecting` the main anodes of said last-mentioned two` devices in.`

o-Ilder to=qm1enchitheconducting condition. therein whereby the voitageipuflse introduced into said Work is terminated,-

References .Cited in nthe file of this patent Number 5* 2, 144,03 3 2,4 6 2`, 6 13 2,487,78 1' 'J-NITEDl STATES PATENTS Name Date Root, Ian. I7, 1939 Desch Feb. 22, 1949 Baiscorn et al Nov. 15, 1949

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