US1977255A - Parallel operated gas filled tube - Google Patents

Description

Oct. 16, 1934. sw R 1,977,255

PARALLEL OPERATED GAS FILLED TUBE Filed March 17, 1933 Gas filled tube:

Gus filled INVENTOR Sunni :6

ATTORNEY Patented Got. 16, 1934 PATENT FFICE PARALLEL OPERATED GAS FILLED TUBE Leland K. Swart, .Mountain Lakes, N. .L, assignor to American Telephone and Telegraph Comp y, a corporation of Application March 17,

8 Claims.

This invention relates to electrical circuits and systems. More particularly, this invention relates to electrical circuits and systems employing gas filled tubes. Still more particularly, this invention relates to electrical circuits and systems employing gas filled tubes operated in parallel relationship.

It is well known that a tube having two spaced electrodes which are enclosed within an envelope filled with a gaseous medium such as neon, argon, helium or krypton gas or a combination of these gases or a combination of these gases and mercury vapor or hydrogen gas or the like will exhibit special characteristics when the voltage impressed across the electrodes exceeds a predetermined value. 'When this predetermined value of voltage is exceeded, the gas within the tube will become ionized and a discharge will occur between the electrodes of the tube. This will result in a substantial drop in impedance within the tube, the impedance before ionization being extremely high and almost infinite and after ionization very low and almost negligible. It is I also well known that after discharge occurs between the electrodes of such a tube, the voltage required to sustain the discharge between the electrodes will be of substantially lower value.

The voltage characteristics of twosuch tubes, although intended to be precisely the same, will differ slightly due primarily to minute variations in their dimensions. It will be found that the discharge gaps of thesetubes will be broken down at slightly different voltages. When the voltage in a line to which two such tubes are connected in parallel relationship exceeds that required to break down the gap of one of these tubes, for instance,.the tube of slightly lower breakdown voltage, the impedance across the latter tube will become greatly reduced. If the voltage in the line tends to rise above that required to breakdown the gap of the second tube, the tube which has broken down will receive practically all of the current transmitted by the line and this tube will prevent the discharge gap of the second tube from being broken down. It follows, therefore, that when two or more of such tubes are connected in parallel relationship, immediately after the gap of one of the tubes has become broken down,

; it will be practically impossible to break down the gap of any of the other of the tubes without damage to the first mentioned tube.

. One of the objects of this invention is to provide an arrangement for interconnecting two or more I: gas filled tubes in parallel relationship so that New York 1933, Serial No. 661,411

the discharge gaps of all of these tubes may be simultaneously broken down.

Another of the objects of this invention is to provide an arrangement including a plurality of impedances which may be connected in series with a plurality of gas filled tubes, one impedance being connected in series with each tube, so that all of these tubes may become simultaneously discharged.

Another object of this invention is to connect a plurality of gas filled tubes in parallel relationship and simultaneously discharge the gaps of all of said tubes so that each will carry a predeter mined portion of the total load intended to be carried by said tubes.

This invention will be better understood from the detailed description hereinafter following when read in connection with the accompanying drawing in which Figure 1 shows one arrangement for carrying out the principles of this invention; Fig. 2 shows another arrangement which is intended to be operated from both halves ofeach impressed alternating cycle; and Figs. 3 and 4 are modifications of Figs. 1 and 2, respectively, these modifications including apparatus for resetting all or" the tubes to their normal conditions immediately after they have become operated.

Referring to Fig. l of the drawing, the reference character D designates a circuit transmitting voltages which may vary over a wide range of values. The circuit D is connected to an impedance Z0 and the voltage across this impedance will correspond to that impressed thereon by the circuit D.

The reference characters N1 and N2 represent two gas filled tubes each of which includes two cathodes designated K1 and K2 and an anode designated A. Each of these tubes is filled with a gaseous medium of the composition described hereinabove.

The cathode K1 of the tube N1 is connected to the upper terminal of the impedance Z0 through an impedance Z1. The cathode K1 of the tube N2 is connected to the upper terminal of the impedance Z0 through an impedance Z2. The impedances Z1 and Z2 are preferably substantially equal and, moreover, their magnitudes are very large when compared to the impedances between the cathodes K1 and K2 of either of the tubes N1 or N2.

An operating relay designated R includes two windings W1 and W2, the upper terminal of winding W1 being connected to the anode A of the tube N1 and the upper terminal of the winding W2 being connected to the anode A of the tube N2.

The lower terminals of the windings W1 and W2 are connected to each other and the conductor common to them is connected to the lower terminal of the impedance Z0 through a source of potential designated B which is preferably a source of direct current potential but which may, if desired, be one of alternating potential, as will be described hereinafter. 7

The'cathode K2 of the tube N1 and the cathode K2 of the tube N2 are connected to eachother and the conductor common thereto is connected to the lower terminal of the impedance Z0 through a source of potential designated C." This source C may be either a direct current potential or an alternating current potential and it is employed primarily for biasing the cathodes K1 of both tubes N1 and N2 to a predeterminedpotential with respect to the cathodes K2 of these tubes.

When a voltage is impressed by the circuit D upon the impedance Z0, that voltage will also be impressed through the impedance Z1 between the cathodes K1 and K2 of the tube N1. The same voltage will also be impressed through the impedance Z2 between the cathodes K1 and K2 of the tubeNz. If the voltage impressed between the cathodes K1 and K2 of thetube N1 is sufficient not only to ionize the gas within that tube but also to break down the gap between these electrodes, then this same voltage will generally be sufficient to-ionize the gas within the tube N2 and break down the gap between the cathodes K1 and K2 or the latter tube. Inasmuch as both tubes have substantially the same breakdown voltages between their cathodes K1 and K2, and because the impedances Z1 and Z2 in series with the cathodes K1 and K2 of the tubes N1 and-N2, respectively, have magnitudes substantially higher than the impedances between these cathodes, the gaps between these cathodes will be discharged virtually, simultaneously. The impedance between the cathodes K1 and K2 of the tube N1 will represent a small portion of the total impedance in the circuit in series with these cathodes and the impedancebetween the similar cathodes K1 and K2 of the tube N2 will representa correspondingly small portion of the total impedance in the :cir-

cuit in series with the latter cathodes. By vir tue of this condition, it will almost invariably happen that the discharge gaps of both tubes will be simultaneously broken-down if only the voltage impressed between the cathodes' of these tubes is suiiicient to icnize the gas within the tube having the'higher breakdown voltage.

It will be noted that the winding W1 of the relay R- is in a circuit in series with the anode A and the cathode K2 of the tube N1 and that the Winding W2 of the relay R is in a circuit in series with the anode A and the cathode K2 of the tube N2, both circuits being in parallel relationship, the elements in common with both parallel circuits including the sources 13 and (has shown. Inasmuch as both tubes N1 and N2 have substantially the same characteristics, there will be, substantiallyequal discharges between the cathode K and the anode A' of both tubes N1 and: N2 after the gaps between cathodes K1 and Kz of both tubes have been-broken down. Inasmuch as the tubes N1 and N2 are of similar construction, substantially equal currents will flow from the source of'therelay wh'ichis employed for closing a circult controlled by this armature. 1

One' of the features ofthis' invention" lies in the employment of a winding or an impedance in series with the anode of each of the tubes N1 and N2. By including substantially high impedances in the windings W1 and W2, 1. e., impedances which are much greater than the impedances between the anode A and cathode K2 of the corresponding tube, substantially equal currentswill be transmitted through the circuits formed bythe anode A and the cathode K2 of these tubes. In other words, the anode or output circuits of both tubes 'will carry substantially equal portions of the total current flowing from source B through the two windings-of the relay R.

Fig. 2 shows an arrangement for operating with considerable efficiency during both halves of each cycle of alternating potential transmitted by the circuit D. Fig. 2 includes four gas filled tubes N1, N2, N3 and N4, two of which are caused to operate from the one-half cycle of an applied alternating current cycle and the other two of which will be caused to operate from the other half of the alternating current cycle. N

The source D is connected inseries' with impedances Z11 and Z12. The impedance Z11 is connected to the cathodes K1 and K2 of the-tube N1 through the impedance Z1 and the source of po tential C. The impedance Z12 is connected to the cathodes K1 and Kz-of the tube N2 through the impedance Z2 and the source or potential C. The impedance Z 1 is connected to the-cathodes K1: and K2 of the tube N2 through the impedance Z3 andthe source of potential C. The impedance Z12 isconnectedto the cathodes K1 and K2 of the tube N4 through the impedance Z4 and the source of potential C. 1 It will be evident that the source of potential C is employedto, bias one of the cathodes of each of the tubes N1, N2, N3 and N to a predetermined potential with respect to the other'cathode of each of these tubes. It will also be evident that the impedances Z1, Z2, Z3 and Z; are connected in series with the two cathodesof each corresponding-tube so thatthe gaps between the cathodes of all of the tubes will be practically simultaneously broken down immediately after the circuit D transmits a sufficiently high direct or alternating voltage.

The relay R includes four, windings W1, W W3 and W4 and one terminal of each ,of these windings is connected to the anode A of the corresponding tube N1, N2, N3 or N4, as shown. The other terminals-of these windings are connected to each other and their common conductor is connected throughthe source ofpotential B to the. terminal common to the impedances Z11 andZ12L' V I v During the first half of each alternating current cycle, a voltage will be impressed acrcssthe impedances Z1 and Z12 which will be in only one direction and this voltage, if large enough, will break down the gaps between the cathodes K1 and'Kz of two of the tubes which will at that time'b'e operated in parallel relationship. during the first half of each alternating current cycle the voltage impressed across the impedance Z12 may, for instance, be'poled so as to cause the gaps between the cathodes K1 and K2 0 the tubes N1 and Nzflto be simultaneously broken down. During'the succeeding ha f of each alter nating current cycle, the voltage impressed across the impedance Z12 will be so poled as to cause the discharge gaps between the cathodes I-i1and K2 of the tubes N2 and N4,- which are also operated in parallel relationship, to become simultaneously broken down. v For'one half of an appliedalternating' current in windings W1 and W2. that the armature of the'relay R will be caused cycle, the windings W11 and We will be supplied to operate from the first half of an applied a1terhating current cycle impressed upon the circuit D, provided the voltage of the alternating current issufficien-t to bring about a breakdown of the gaps of any of the various tubes.

Fig. Bellows an arrangement f or returning the gas filled tubes to their original condition-after their gaps have been broken down by the transmission of a voltage exceeding a predetermined value. Withoutsome form of arrangement for resetting the gas filled tubes to their initial condition in which the gaps arefree to become again discharged when impressed withfurther voltages exceeding the predetermined value, it will be impossible to continuously discriminate between the application of voltage or the a sence of voltage applied to the input circuit. 1 1

Fig. 3 shows an arrangement somewhat similar to theone shown in Fig. 1. Fig. 3 includes, however, a vibrating relay, the armature of which is capableof vibrating at an extremely high speed and it also includes a circuit for resetting the gas filled tubes to their initial condition immediately ter their gaps have become discharged by applied voltage. V V

,The vibrating relay is designated R11 and it has .two windings W11 and.-W1'2. The winding W11-is connected between the anode A of the gas filled tube N1 and thecathode K2 of the tube N1 through a circuit which includes impedance Z11, which may be a resistance of low magnitude, and a condenser C which is of large capacity.- The other winding W12 of the vibrating relay R11 is connected between the anode A of the; tube N and the cathode K2 of that tube through the same circuit of impedance Z 1 and condenser C. The sources B and C are preferably direct current sources, such as storage batteries,;and. they are connectedin series relationship so that their voltage effects are additive, the series circuit including an. impedance Z12, the winding of an operating relay R, the impedance Zn and the condenser C. It will be noted that the armature and con} tact of the vibratory relay R 1. are bridged across the series elements of impedance Z11 and capacity C. f

It will be apparent thatv when thecircu'it D transmits a voltage above a predetermined value, the gas within the tubes N1 and N will become ionized, the gaps between the cathodes K and K2 of these tubeswill become broken down and current will flow simultaneously between the anodes A'and the cathodes Kz of both tubes N1 and N2. The current emanating frorn sou rces B and C will fiow through impedance Z the operating winding oftherelay 'R and it will divide substantially equally between the windings W11 and W12, respectively, The flow of current through the circuit just described willfattract the armature of the-operating relay R, c1osing the circuit controlled by this armature.

After the vibrating relay R11 has become opercited, as willbe thecase immediately after a high voltage has become impressed'upon the line D,

the armature of the vibrating relay willclose a circuit which will completely shunt out thecurrent flowing through the windings W11 and W12 of the vibrating relay and'between the anodes A and cathodes K2 of thetubes N1 and N2, respec- 1i,

tively. This will cause a substantial increase in the flow of current through the winding of the operating relay R, current then flowing from batteries C and B through the impedance Z12, the operating winding of the relay Rand the armature and contact of the vibrating relay R11. At the same time, any charge upon the condenser C will tend to become dissipated through the impadance Z11. Furthermore, the flow of current through the'armature and contact of the vibratirig relay R11 will reduce the current tending to,

flow through the windings Wuand W12 and between the anodes A and the cathodes K2 of the tubes N1 and N2, respectively, to a practically negligible value and thereby transform the gas within these tubes to its initial de-ionized condition, provided that the voltage transmitted by the circuit D remains insufiicient to cause ionization between the cathodes K1 and K2 of these tubes. After the current through the parallel circuit just described has become reduced to a negligible value, the magneto-motiveforce of the windings of the vibrating relay R11 will be insuflicient to hold the armature closed against its contact, and consequently, the circuit formed by this armature and its contact will become opened. Hence current may thereafter flow from batteries C and B through impedance Z12. the operating winding of the relay R and through the parallel paths formed by the windings W11 and W12 of-the vibrating relay Rnand the corre sponding paths formed bythe anodes A and cathodes K2 of the tubes N1 and N2, respectively, only if the voltage transmitted bythe circuit D is sufficiently great to continue the ionization of the gas within the tubes Ni-and N2 and break down thegaps between the cathodes of these tubes. So it will be-seen that as long as a sruiiciently high voltage is transmitted by the circuit D, the gas within the tubes N1 and N2 will become ionized and remain ionized and the impedance or all of the gaps of both tubes will-be reduced toua practically negligible value and it will be noted that the relay R11, which is of the vibrating type, will cause the continuous opening and closing of the contact'of that relay by its armature at a high speed. lvloreover, the vibration of the armature of relay R11 will cease almost instantly after the voltage transmitted by the circuit D becomes reduced below that required to produce ionization within the tubes N1 and N2.

Immediately upon the openin of the contact of the vibrating relay R11, the winding of the operating relay R will produce a. substantial voltage kick which may of itself produce ionination of the gas within tubes N1 and N2, if this voltage is allowed to become transmitted through the winding W11 and W12 0:" the vibrating relay R11. In order to reduce thispossibility of deionization of these tubes in the absence of a sufficiently high voltage in the circuit D, the condenser C and impedance Z1'1 of small resistance areconnected in series-with the operating winding of the relay B, thereby causing the voltage produced by the very high inductance of the operating winding of the relay l-t' to be shunted through the impedance Z11 and condenser C. In fact,'the condenserC becomes charged by the inductive kick of the winding of the operating relay R. The armature of the operating relay R are connected in series with the anodes A of,

tubes N1, N2, N3 and N4, respectively, the operating winding of therelay R, the battery B, the battery 0, and the cathodes K2 of the tubes N1, N2, N3 and N4, respectively, as shown. It will be Mnoted'that'the armature and contact of the vibrating relayRn are connected in shunt across the circuit which includes the impedance Zn and the condenser C. In this arrangement, the vibrating relay R11 will produce a continuous vibration of its armature as long as the voltage transmitted by the circuitD is sufficiently great to bring about the breaking of the gaps between cathodes K1 and K2 of the various tubes N1, N2, N3 and N4. It will be further noted that the armature of the operating relay R will close its contact and that this contact will remain closed as long as the relay R11 contmuesto vibrate its armature. The circuit shown will bring about the de-ionization of each of the various tubes almost immediately after the voltage transmitted by the circuit D becomes insufiicient to ionize the gas within any one of the various tubes and produce a discharge between its electrodes.

It will be understood that the tubes designated N1, N2, N3 and N4 may be either of the hot cathode gaseous type or cold cathode gaseousv type, both of which are well known.

It will be further understood that the various tubes may have electrodes so spaced and their gaseouspressures so adjusted that current will not bedivided equallybetween the output electrodes of these tubes; the currents transmitted through the output circuits of these tubes may, if desired, be divided therebetween in any other predetermined relationship, all of which is within thescope of this invention. a

It will also be understood that the impedances designated Z1, Z2, Z3 and Z4 may be any typeof impedance, that is, inductance or capacitance, and need notnecessarily be simple resistance.

It will be further understood that the operating relay may be replaced by any form of translating device or circuit or, if desired, the relay may be employed to control any well-known translating device or circuit.

And it will be further understood that the source designated C may be of the direct current type, the alternating current type or of the interrupted direct current type. In the arrangements shown in Figs. land 2, the source designated B may be of the alternating current'type ,or of the interrupted direct current type. I

While this invention has been shown and described in one particular embodiment merely for the purpose ofv illustration, it willbe understood that the general principles'of this invention may be applied to other and widely varied organizations without departing from the spirit of the invention and the scope-of the appended claims.

What is claimed is: 7 w v 1. The combination of two gas filled tubes each having three electrodes, two impedances, each of 'said-irnpedances being connected in series with two of the electrodes of one of the gas filled tubes,

means for impressing voltages through said impedancesupon the two electrodes of both tubes which are in serieswith said impedances, and means interconnected. between the third electrode of each tube and either of the other elec- 1' voltage exceeding a predetermined value impressed upon two of the electrodes of both tubes to simultaneously ionize the gas within both tubes and substantially reduce the impedance between all of the gaps within both tubes; and means connected between the third electrodes of both tubes and one of' the other electrodes of both tubes which becomes responsive to the change in the'impedance of the gaps of both tubes.

3. The combination of a plurality of gas filled tubes each having an input circuit terminating in electrodes within each tubeand forming a gap and an output circuit also terminating in electrodes within each tube and forming'a'nother gap, means forsimultaneously breaking the gaps between the input circuit electrodes of all of said tubes, a-relay having a plurality of windings each of which is connectedto one of theoutput circuit electrodes of each of .said tubes,'the output circuit electrodes of all of said tubes being arranged in parallelrelationship, and means for vibrating the armature of said relay continuously as long as the gaps terminating the input circuit electrodes of said tubes are broken down;

I 4.. The combination of a'plurality of gas filled tubes each having at least two gaps between its electrodes, means responsive to a voltage exceed ing a predetermined value for simultaneously breaking one of. the gaps of each of said tubes, and a translating circuit connected in common to one of the remaining gaps of each of said tubes, ill

the latter gaps being arranged inparallel relationship. 1 a

5. The combination of a plurality of 'gas'filled tubes each having electrodes forming a firstga'p and a second gap, the first gap'of one-of'said tubes being connected'in parallel relationship with the first gap of each of the'other of said tubes, means responsive to a-voltage exceeding'a predetermined value for simultaneously breaking all of said first gaps, a relay having a plurality of windingseach of which is connected in parallel relationship with the second gap'o'f one of said tubes, and a circuit controlled by the armature of said relay. r

6. The combination of a plurality of gas filled tubes each having a plurality of electrodes forming gaps, meansresponsive to a voltage exceeding a "predetermined value for simultaneously breaking the gaps of, all ofrsaid'tubes, a relay having a fast vibrating armature, and means responsive to the breakingof the gapsof said tubes for vibrating the armature of said relay and for maintaining the armature in continuous vibrationas long as said'gaps are broken.

7. The combination of two gasfilled tubes each V having'a plurality of electrodes forminggaps, means. responsive to a voltage exceeding a predetermined value for simultaneously breaking the gaps of. all of said tubes, a translating circuit, means interposed between the translating circuit and the various tubes for operating the translating circuit when the gaps of the tubes are brokne down,.and means for restoring. the'tubes to their initialcondition after the voltagewhich ting voltages through said impedances to the electrodes in series with said impedances and for simultaneously breaking down the gaps between said electrodes when the transmitted voltage exceeds a predetermined value, and a translating circuit connected in common with the third electrode and one of the other electrodes of each of said tubes.

LELAND K. SWART.

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