US3035201A - Cold cathode switching devices - Google Patents

Cold cathode switching devices Download PDF

Info

Publication number
US3035201A
US3035201A US732091A US73209158A US3035201A US 3035201 A US3035201 A US 3035201A US 732091 A US732091 A US 732091A US 73209158 A US73209158 A US 73209158A US 3035201 A US3035201 A US 3035201A
Authority
US
United States
Prior art keywords
cathode
anode
gap
voltage
discharge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US732091A
Other languages
English (en)
Inventor
Jackson Thomas Meirion
Sell Eric Andreas Frederik
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Application granted granted Critical
Publication of US3035201A publication Critical patent/US3035201A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/38—Cold-cathode tubes
    • H01J17/40—Cold-cathode tubes with one cathode and one anode, e.g. glow tubes, tuning-indicator glow tubes, voltage-stabiliser tubes, voltage-indicator tubes
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K23/00—Pulse counters comprising counting chains; Frequency dividers comprising counting chains
    • H03K23/82—Pulse counters comprising counting chains; Frequency dividers comprising counting chains using gas-filled tubes

Definitions

  • the present invention relates to cold cathode gas-filled tubes and circuits using such tubes for high speed electric switching arrangements.
  • Patent 2,631,261 glow discharge trigger tubes which have been operated at pulse repetition frequencies in the neighbourhood of one hundred kilocycles per second.
  • the limitations on higher speeds are the formative delay time (of the trigger gap in the tubes just mentioned) and the deionisation time. Both these quantities require careful definition, which will be gone into later, but for the moment it is suflicient to say that deionisation time is determined by applying to a gap across which glow discharge is being maintained an extinguishing pulse so as to reduce the anode-cathode voltage; with a given pulse amplitude the minimum width of the extinguishing pulse which ensures that the glow discharge does not restart after passage of the pulse is a measure of the deionisation time.
  • a pulse is applied to increase the anode-cathode voltage; for a firing pulse of given amlitude the minimum pulse Width which will ensure that glow discharge may be maintained after passage of the pulse is a measure of the formative delay time of the gap.
  • the present invention therefore, provides a switching device comprising a cold cathode gas-filled electric glow discharge tube having a discharge gap formed between a cathode surrounding its anode so that the lines of electric force diverge from the anode to the cathode, the device further comprising means for maintaining in the said gap a large pro-breakdown ionisation level, for example by means of corona discharge in the gap, such that on the application of a firing pulse of 60 volts overvoltage the formative delay time as herein defined is less than one microsecond.
  • a planar diode gap having a breakdown voltage of 400 volts and passing l0 miliiamperes of glow discharge current at 200 volts maintaining potential may pass a pre-breakdown current of very much less than one microampere, whereas a coaxial diode constructed in accordance with the principles of the present invention for operation at the same voltages and glow discharge current can support a pre-breakdown current of ramp.
  • the large pre-breakdown ionisation may be very efiectively provided by means of corona discharge, the anode radius being made sufliciently small for the standing electric field intensity in its neighbourhood to exceed the dielectric strength of the gasfilling.
  • the nature of the gas-filling is, of course, also a matter of some importance, but the principles governing the choice of gas mixtures are commonly known by those skilled in the art and need not be discussed at present.
  • the invention pro vides a diode tube with an outer cathode and inner anode so that the lines of electric force diverge from the anode to the cathode, having a glow discharge deionisation time, as hereinafter to be more precisely defined, of less than two microseconds and in which a continuous corona discharge may be maintained without breakdown into glow discharge during the application of an anode-cathode potential exceeding the glow discharge maintaining voltage but less than the glow discharge breakdown potential.
  • corona stabiliser tubes are designated for voltage stabilisation and depend for their operation upon the wide variation of corona current, measured in microamperes, accompanied by corresponding small changes in anodecathode voltage. They are not intended at all for operation in the glow discharge regime, though some types are capable of passing useful glow discharge currents. Some corona stabiliser tubes we have examined under these conditions of operation have been found to give short formative delay times, but the anode-cathode separation is invariably too great to meet our deionisation time requirement.
  • one mode of operation of the invention is to use corona current for selfpriming a diode glow discharge and so providing the large pre-b'reakdown ionisation, it is characteristic of corona discharge that a large change of corona current is accompanied by a very small change of voltage across the gap in fact this is what makes corona discharge useful in a stabiliser tube.
  • the transition between corona and glow discharge, with its much lower maintaining voltage, is very abrupt in such tubes. It follows that special circuit arrangements must be provided to cater for manufacturing variations from tube to tube and to allow for adequate tolerances on component and supply voltage values if it be desired to use corona self-priming in carrying out the invention.
  • corona discharge as a self-priming mechanism in a glow discharge tube is not the only way in which the principles of the invention may be applied. Indeed, due to factors such as the limited'backward resistance of commonly available crystal diodes, it may be more convenient to provide the large pre-breakdown ionisation by other means.
  • an auxiliary glow discharge in the field of the main gap may be utilised, the main gap geometry, as before, providing a short main gap deionisation time and permitting the large amount of ionisation from the auxiliary discharge to be maintained without spontaneous breakdown of the main gap into glow discharge.
  • the auxiliary glow discharge then furnishes what we may call an artificial corona in the main gap, but its maintenance may be made largely independent of the main gap potentials.
  • the invention provides a particularly favourable type of tube: construction which is a modification of the tube first specified above.
  • the single anode in place of a puncti form or filamentary anode used to facilitate corona dis-- charge, the single anode is replaced by a pair of elec.-- trodes, providing between them a gap for the passage of an auxiliary glow discharge, thus forming electrode: means for setting up the artificial corona in the tube.- The outermost electrode of the. resulting triode remains.
  • the main gap geometry providing the necessary short deionising time and also permitting a large number of' ions, compared to that permissible with planar electrode geometries, to be present in the gap without causing it to break down into glow discharge in spite of the application of a steady anode-cathode voltage exceeding the: maintaining voltage.
  • the formative delay time of the main gap is thus affected in analogous manner to that of the tubes with corona priming previously discussed, but, the tube can be used in a simpler circuit in which component and supply voltage limits may have quite wide tolerances.
  • a hollow cylindrical main cathode surrounds a cylindrical main anode, which may be split into two hollow cylinders with a gap between the two halves, and a fine wire auxiliary cathode is strung along the axis of the anode.
  • the priming discharge occurs between the auxiliary cathode wire and the edges of the two anode halves so that positive ions are continually present in the gap between the two anode halves opposite the cathode.
  • the main cathode is formed as a dome covering the tips of a pair of fine wires which are connected as anode and auxiliary cathode respectively.
  • FIG. 1 is a circuit diagram of a known arrangement using gas-filled diodes as relay tubes;
  • FIG. 2 shows the general form of the curve relating deionisation time of a glow discharge gap with anodecathode voltage existing during an extinguishing pulse
  • FIG. 3 shows curves relating to the potential variation across a discharge gap under various conditions of electrode geometry
  • FIG. 4 shows typical curves relating applied voltage and pre-breakdown and glow discharge currents in a gas-filled tube
  • FIG. 5 illustrates the construction of a corona-primed diode according to the invention
  • FIG. 6 is a modification according to the invention of the circuit arrangement of FIG. 1 for use with tubes to be described with reference to FIG. 5;
  • FIG. 7 shows the construction of an artificial corona primed tube according tothe invention.
  • FIG. 8 shows an embodiment of the invention alternative to that of FIG. 7.
  • FIG. 9 shows formative delay time and deionisation time curves for the tubes of FIGS. 7 and 8.
  • FIG. 1 of the accompanying drawings Part of a counting chain is there shown comprising an even number of glow discharge diode tubes T T T These tubes are inserted in series with respective rectifiers W to W,,; each poled to present a low impedance path to the discharge current through its own tube, and cathode load resistors R to R between one or other of a pair of positive busbars la and 1b and an earth line 2.
  • the odd numbered tubes have their anodes connected to busbar 1a and the even numbered tubes are fed from busbar 1b.
  • Respective capacitors C to C connect the cathodes of tubes T to T to the junction of the rectifier and resistor in the cathode circuit of the immediately preceding tube. Capacitor C joins the cathode of T to the junction of W and R
  • the busbars 1a and 1b are fed from the respective outputs of a bistable device BC which is supplied with pulses 3.
  • the output BCl feeding busbar 1a supplies in synchronism with pulses 3 derived rectangular pulses 3a whose potential excursion is from a value V sufiicient to maintain discharge in any one of the discharge tubes T, but supplying less than the breakdown voltage to these tubes, to a value V below the maintaining potential of the tubes.
  • the output BC provides similar pulses 3b to busbar 111 but in antiphase with the pulses 3a, so that when the voltage of busbar 1a changes from V to V that of busbar 1b falls from V to V and vice versa.
  • the busbar 1b is at voltage V and busbar 1a at V
  • the anode of T is taken down to V so that the discharge is extinguished, and, simultaneously, the anodes of T and the other odd numbered tubes are raised to the voltage V
  • This increase in anode-cathode voltage is insufficient to fire tubes T to T, but the cessation of current through R carries the cathode of T negative by an amount sufficient to cause this tube to fire.
  • the discharge circuit of C includes the high back resistance of rectifier W so that the cathode of T is held negative.
  • the discharge in T is extinguished and T is fired.
  • the glow discharge must be extinguished by temporary reduction of the said steady voltage and the tube must not refire when the steady voltage is restored. It is evident that the steady supply voltage must be reduced below the maintaining voltage of the tube for a minimum time, otherwise the tube will refire. This minimum time will evidently be a function of the amount of ionisation in the tubei.e. the value of the discharge current which has been maintained; and possibly the duration of the discharge may be a factor to be taken into account. The minimum time for permanent extinction is 'found to depend markedly on the amplitude of the extinguishing pulse.
  • FIG. 2 there is plotted a typical curve relating minimum extinguishing pulse duration T, for a given glow discharge current, with the pulse amplitude, the abscissa being plotted, in arbitrary units, in terms of V the anodecathode voltage obtaining during a rectangular extinguishing pulse.
  • the dynamic deionisation time of a tube as the minimum duration of a rectangular extinguishing pulse of optimum amplitude applied to reduce the voltage maintained across a gap which has been passing a given glow discharge current for a stated minimum time, the gap voltage 11'sing after passage of the pulse to a valuethe reapplied voltage-which is a given amount above the maintaining voltage of the gap.
  • the deionisation times be in terms of glow discharge currents of not less than 10 milliamperes and of greater than 10 seconds prior duration and that the gap voltage be allowed to rise after the extinguishing pulse and to remain before the gap is next fired at least 50 volts above the gap maintaining voltage.
  • FIG. 3 in which the dotted curve a depicts the variation of potential V across a glowing discharge gap, the abscissa being in terms of r, the distance from the cathode, the positions of the cathode and anode being indicated at K and A respectively.
  • the cathode glow is situated 'at r and between K and r the potential rises sharply and uniformally to a value but little less than the maintaining voltage V Beyond r the potential falls slightly and then rises up to the potential of the anode.
  • the potentials at r and at A may typically difiFer by about 10 volts.
  • Electrons are emitted from the cathode by photon excitation due to the light of the cathode glow at r,; and by positive ion bombardment of the cathode.
  • the emitted electrons are accelerated by the relatively intense field between K and r and at r they have acquired sufficient energy to excite the atoms of the gas-filling.
  • Those electrons which have sufiicient energy to penetrate the space charge of the cathode glow and the subsequent potential trough proceed to the anode or ionise further atoms whose freed electrons join them on this journey.
  • the ionisation products, ions and electrons are continually being removed from the anode-cathode gap by loss to the electrodes themselves, by recombination to form neutral atoms and, in some cases, by lateral diffusion out of the field of the gap. Stability of the glow discharge is established when the rate of removal of ionisation products is just balanced by the rate of formation of new ions and electrons. If, now, the exciting potential be removed from the gap electrodes, the electric field collapses and the ionisation products are left to recombine; unless they be carried there by their existing velocities when the field collapses, or by later random movements, ionisation products are no longer removed by absorption at the gap electrodes.
  • b-ut curve C a straight line, relates to the potential between a plane cathode and a plane anode while the other two are for the cases of concentric cylindrical geometry.
  • B is for the case where the outer electrode is positivei.e. the anode surrounds the cathode while curve D is for the cathode surrounding the anode. Curves similar to B and C would obtain for spherical geometries.
  • the speed of a charged particle in a gas is given by the product of the field strength and the mobility of the particle: mobility takes into account collision processes and is a function of the gas pressure; the enengy a particle attains is not, therefore, as it would be in free flight, proportional to the potential through which it has fallen, but is, rather, at any time, proportional to the field strength in its immediate neighbourhood.
  • eionisation time is a linear function of the anode-cathode spacing d and of the reciprocal of the gap maintaining voltage V That this is reasonable can be seen by considering that in practice the optimum voltage across a gap during an extinguishing pulse is not very much below V,,,, and that the mobility of an ion is inversely proportional to the gas pressure p while the breakdown voltage V proportional to the product p d, will be chosen in the light of circuit considerations. Thus pd can be taken as constant and, then, the mobility is seen to be a constant times the gap length.
  • Factors controlling the gas filling are positive ion mobility and dielectric strength, the latter also governing the tube breakdown voltage. Hydrogen best satisfies requirements except for the fact that its undiluted use results in a maintaining potential of the order of 300 volts, which entails correspondingly higher supply voltages. In order to work with more moderate voltages we use gas mixtures including hydrogen, the proportion of hydrogen being chosen in accordance with user requirements on operating conditions.
  • Equation .1 therefore posstulates that no current can flow without some form of irradiation and must cease if the source of radiation is removed. in the present specification we shall assume that such a source is always available. It is also mentioned here that it is common knowledge that breakdown of a gap cannot occur in the complete absence of light or of some ionisation in the gap; where random e ents, such as passage of cosmic rays, are the only source of this initial ionisation, there will be a corresponding random delay in firing the gap, known as the statistical delay.
  • FIG. 4 we have drawn graphs representing prebreakdown and glow discharge currents plotted on a logarithmic scale of current I with a linear scale of ordinates V in respect of two gaps of different geometry, both passing the same normal glow discharge current and having the same maintaining and striking potentials.
  • the graph ABCDE is for a cylindrical geometry with external cathode and A'B'D'E is for a planar electrode geometry.
  • the criterion for breakdown into glow discharge is the onset of an unstable state in which the secondary processes summed up in the coefiicient 7 becomes cumulative.
  • the time which elapses between the application of a firing pulse and the onset of this unstable state is the formative delay time, as strictly defined, of the gap at the overvoltage used.
  • the formative delay time as thus defined is a quantity which is not very easy to measure and, in practice, a somewhat less exact definition is more convenient and will be adopted for purposes of the present specification.
  • the space charge build-up time has been found to be in the region of milli-microseconds; the error in neglecting this time in terval is therefore small and, in any case, will give an overestimate of the formative delay time if it be included therewith.
  • the gap is said to be fired; that is to say glow discharge may now be maintained provided the anode-cathode potential across the gap does not fall below the glow maintaining potential.
  • the formative delay time of a glow discharge gap as the time interval between the application of a given over-voltage to the gap electrodes and the gap being fired, the word fired being used in the sense above explained.
  • the factor a is the most important in that it is possible to arrange that a large number of the ions which would otherwise have to be formed by collision process can be pre-existant and the time required for their formation eliminated.
  • the more ionisation products there are available in a gap before application of a firing pulse the greater will be the rate of formation of fresh ionisation products when the pulse is applied.
  • this aspect of pre-breakdown ionisation level has previously been recognised. The realisation of its importance has enabled us to operate tubes with formative delay times ten times shorter than has hitherto been possible.
  • FIG. 5 An embodiment of a corona primed diode glow discharge tube according to the invention is illustrated, very much enlarged, in FIG. 5 in which a standard subminiature glass envelope 4 encloses a cylindrical cathode 5 which is supported by rods 6 from the glass press 7 and coaxially surrounds an anode rod 8.
  • rods 6 and the anode rod 8 are shown taken through the glass press.
  • the critical parameters of the tube and consequential dimensions which together characterise the construction as an embodiment of the invention are as follows:
  • Corona breakdown 360 volts max. voltage Corona breakdown 360 volts max. voltage.
  • Cathode internal diameter Cathode length Anode diameter From what has been explained above, it will be understood that, broadly speaking, the gas filling and pressure are chosen to give the required breakdown and maintaining voltages, the anode-cathode spacing determines the deionisation time, the anode diameter, the corona breakdown voltage and the cathode area is chosen to provide the required glow discharge current.
  • the formative delay time is a function of the pre-breakdown current, determined largely by the properties of the gas and the potential gradient at the anode. Since few of the parameters and dimensions are altogether independent of one another, some compromise in design characteristics will normally be involved in making tubes to a specification, as has previously been mentioned.
  • the corona current at 380 volts is about 50 amp. and for glow extinguishing purposes the anode-cathode voltage should be reduced to about volts.
  • the circuit of FIG. 1 is not, as it stands, suitable for the operation of tubes of the type just described with reference to PEG. 1.
  • corona current should flow immediately prior to application of a firing pulse.
  • the arrangement of FIG. 1 could be modified by the substitution of a single train or" rectangular extinguishing pulses, such as the train 3a, applied to all the tubes in common, in place of the complementary pulse trains 3a and 3b, but, even so, the circuit would not provide much margin against variation of supply voltages, component values or tube characteristics.
  • the cathode circuits are the same as in FIG. 1 and are identified by the same reference symbols; the split pulse supply system is also similar, in that complementary pulse trains 3a and 3b are fed to the busbars 1a and 1b respectively. Instead, however, of the anodes being connected directly to their respective 1 mm. 2 mm. 0.076 mm. (0.003 inch).
  • each anode is connected through a high resistance, provided by resistors R; to R respectively, to a source of corona maintaining supply labelled 430 v.
  • resistors R; to R are each of value 13,500 ohms, so as to provide, with a glow discharge current of ma.
  • R to R are each 1 megohm, allowing corona current of 50 microamperes to flow through each quiescent tube so that the anodes of these tubes are held at 380 volts, thus normally blocking the anode recti bombs W' to W',,.
  • a value of 20 pf. is satisfactory for the capacitors C to C,,.
  • the operation of the circuit of FIG. 6 is as follows. Assume that glow discharge is being maintained in T The major part of the normal discharge current of 10 ma. is supplied from the busbar 1b and flows through diode W so that the anode of T is maintained at 335 volts and about 95 microamperes flows through R',,. The voltage across R is the difierence between the anode voltage and the maintaining voltagei.e. 135 volts. All the other tubes, T to T are passing corona discharge, the diodes W to W all being blocked as explained above, and their cathodes are substantially at earth potential.
  • the tube anodes are normally each fed from a 'high impedance source, efiectively passing only corona current, and that glow discharge current is fed to each tube from a low impedance source through a gate, the anode crystal diode, which gate is controlled by the firing and extinguishing pulses.
  • the crystal diodes W' to W have infinite backward resistance. In practice, however, it is difiicult to obtain diodes whose backward resistance is sufficiently high not to reduce appreciably the anode voltage for the corona current during the low voltage excursions of the pulses 3a, 312. It will be seen that if the anode diode has a backward resistance comparable with that of the anode resistor, appreciable current will flow through the high impedance anode circuit during these intervals; this increased current through the anode resistors will further drop the anode voltage so that the anode cathode potential may fall below the corona striking potential of 360 volts, with consequent loss of priming and long formative delay times.
  • FIG. 7 One embodiment of an artificial corona tube according to the invention is illustrated in FIG. 7.
  • a cylindrical cathode 9 coaxially surrounds a tubular anode 10 which is formed by a Pair of axially separated tubular members 11 and 12 of which only the ends protrude. into the enclosure of the cathode.
  • a central wire 13 provides an auxiliary cathode and continuous glow discharges are maintained between the wire and the anode members 11 and 12 during operation of the tube.
  • the cathode 9 is bonded at each end to a respective one of a pair of shallow metal cups 14.
  • Each cup 14 serves to locate a ceramic sleeve 15 coaxially with and at the respective ends of the cathode.
  • the anode members 11 and 12 are each received in a central aperture in the base of a respective deep metal cup 16 which fits, into the open end of the respective sleeve 15.
  • Each cup 16 has an outwardly extending rim which seats on the end of the corresponding sleeve 15 and the anode members 11 and 12 are bonded to the cups as indicated at 17.
  • the ends of the anode members 11 and 12 protruding into the cathode enclosure are drawn down slightly so as to provide internal seatings for respective ceramic sleeves 18 fitting inside the anode members with their other ends protruding beyond the rims of the cups 16.
  • the auxiliary cathode wire 13 is threaded through the sleeves 18 and an eyelet 19 is passed over and welded to the wire 13 at each end of the electrode assembly, the eyelets bearing against the respective sleeves 18 so as to clamp the assembly together and to keep the Wire 13 taut within the assembly.
  • This electrode assembly is housed within a conventional miniature radio valve envelope 20 having a glass button base 21 carrying leads 22.
  • the assembly is supported on the leads 22 by means of wire connections thereto.
  • the auxiliary cathode wire 13 is secured to one of the leads 22, a wire 23 sheathed in an insulating sleeve 24 joins the cathode 9 to another lead 22, and further wires 25 and 26 join the cups 17, and hence the anode members 11 and 12, respectively, to two further leads 22.
  • the wires 25 and 26 are shrouded by insulating sleeves 27 and 28 respectively.
  • the diameter of the auxiliary cathode wire 13 is not critical and may be anywhere between 0.005 inch and 0.050 inch, the smaller dimension favouring a more stable glow discharge.
  • the cathode outer diameter is, of course, unimportant electrically, 0.215 inch being a convenient size.
  • FIG. 7 besides illustrating the construction of this embodiment of the invention, also shows diagrammatic circuit connections to the several electrodes of the tube.
  • the circuit connections shown in FIG. 7 correspond with those for tube T of FIG. 1, the corresponding components and leads being given the same reference numerals in the two figures.
  • the only circuit difference from FIG. 1 in FIG. 7 is the provision of the auxiliary cathode 13 connected through a current limiting resistor R to a terminal which is maintained at l50 volts with respect to the earth line 2. Discussion of the working of this auxiliary discharge circuit, the artificial corona, and the resulting characteristics of the tube of FIG. 7 will be given after description of an alternative spherical electrode embodiment illustrated in FIG. 8.
  • the cathode proper is the hemispherical dome 31 drawn out in the base of a cupshaped member 32 of high purity nickel.
  • the anode 33 and auxiliary cathode 34 are provided by the respective tips of a pair of wires 35 and 36, which are symmetrically positioned underneath the dome 31.
  • These wires are sealed through a glass bead 37 which is fused to one side of a ceramic disc 38, apertured to receive the wires and to locate their ends, which fits inside the member 32.
  • the disc 38 is held in member 32 by means of a metal sleeve 39 bonded to the inner surface of the skirt of member 32.
  • the electrode assembly is mounted by means of the wires 35 and 36 together with wires 40 and 41, both joined to the outer surface of cathode member 32, in a standard sub-miniature radio valve envelope 42, the wires being sealed in the pinch 43. Access to the interior of the electrode assembly is provided by means of an aperture 44 in the dome 31, in conjunction with a split spacing collar 45.
  • circuit connections are shown for connection as tube T in the circuit of FIG. 1, together with the provision of a -l volt connection to the auxiliary cathode from a terminal 30 through current limiting resistor R With the same gas filling and gas pressure as in the case of the embodiment of FIG. 7, the essential dimensions for the tube of FIG. 8, are
  • the overall diameter of the electrode structure is about 0.280 inch and the length of the skirt portion of the cathode member 32 is 0.140 inch.
  • the gap between the tips of the anode and auxiliary cathode wires is 0.005 inch.
  • the static breakdown voltage for glow discharge is just over 400 volts, the glow discharge maintaining potential being about 200 volts. Both tubes pass a normal glow discharge current of 10 milliamperes.
  • the resistors R should each be 220,000 ohms; the priming current from the auxiliary cathode then has the values 0.5 ma. when the anode is at 160 volts and 1.3 ma. when the anode rises to 335 volts. Talc'ng into account the stray capacitances of the electrodes and wiring, it is found that these values give approximately the same eifects on the formative delay and deionisation times of the main gap as does a constant priming current of 1 ma.
  • the formative delay time is a function of the overvoltage applied to fire a gap and the deionisation time is a function of the voltage re-applied to a gap following an extinguishing pulse.
  • the tubes with cylindrical and spherical geometries described above with reference to FIGS. 7 and 8 respectively and having the dimensions quoted have very similar deionisation characteristics, and curve A of FIG. 9 is a graph of the relationship between re-applied voltage (the value being indicated to the right of the graph) and deionisation time for either tube.
  • curve D of FIG. 9 shows the variation of formative delay time with overvoltage for a tube having the same dimensions as described above with reference to FIG. 8, but filled with hydrogen, a priming current of one milliampere, as for the other curves, passing through the auxiliary cathode-anode gap.
  • the invention provides a diode form of gas tube with hitherto unrealised short deionisation and formative delay times, a high speed operating circuit for use with these tubes, but also of advantage with some forms of known corona voltage stabiliser tubes when used as glow discharge tubes, and, avoiding some of the difficulties associated with this new circuit arrangement, a modified form of what is, in its essentials, a diode relay tube primed 'by an auxiliary discharge so as to have characteristics similar to and even improved upon the corona self-primed diode of the invention.
  • a gas discharge tube comprising a cup-shaped main cathode member formed with a dome projecting from the middle of the base of the cathode member, the interior of the dome providing the cathode discharge surface, a ceramic disc held within the cup-shaped cathode member, an anode member and an auxiliary cathode member, said members being coaxial with said cathode and projecting through respective apertures in said ceramic disc,
  • a gas discharge tube according to claim 1 in which the said anode member and cathode members are sealed through a glass button secured to the said ceramic disc on the side remote from the cathode dome.
  • a gas discharge tube comprising a hollow cylindrical cathode, a tubular anode member smaller in diameter than said cathode and coaxial therewith, one end of Said anode member providing the discharge surface, said end projecting into one end of said cathode, and an auxiliary cathode located coaxially of and extending through said anode member and said cathode.
  • a discharge tube in which a pair of ceramic sleeves, coaxial with the anode member, abut against the respective ends of the cathode, a pair of metal cups are received one in each of the said sleeves, and the said anode members are each secured in a central aperture in the base of a respective one of the said cups.
  • a discharge tube according to claim 6 in which a further pair of ceramic sleeves is held one in each of 18 the tubular anode members, the said auxiliary cathode is threaded through these further sleeves, and a pair of eyelets bearing against the ends of the said further sleeves are secured to the auxiliary cathode to maintain it in tension and to clamp together the assembly of electrodes and ceramic sleeves.

Landscapes

  • Plasma Technology (AREA)
US732091A 1957-05-17 1958-04-30 Cold cathode switching devices Expired - Lifetime US3035201A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3035201X 1957-05-17

Publications (1)

Publication Number Publication Date
US3035201A true US3035201A (en) 1962-05-15

Family

ID=10920212

Family Applications (1)

Application Number Title Priority Date Filing Date
US732091A Expired - Lifetime US3035201A (en) 1957-05-17 1958-04-30 Cold cathode switching devices

Country Status (2)

Country Link
US (1) US3035201A (fr)
BE (1) BE569134A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7214949B2 (en) * 2004-11-12 2007-05-08 Thorrn Micro Technologies, Inc. Ion generation by the temporal control of gaseous dielectric breakdown
US20140184064A1 (en) * 2012-12-27 2014-07-03 Chang Gung University Gas discharge tubes

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1722588A (en) * 1927-03-23 1929-07-30 Magnavox Co Point-to-plate gas-filled rectifier
US2098301A (en) * 1935-10-03 1937-11-09 Bell Telephone Labor Inc Glow discharge device
US2331398A (en) * 1942-10-19 1943-10-12 Bell Telephone Labor Inc Electronic discharge device
US2433755A (en) * 1942-06-12 1947-12-30 Vickers Electrical Co Ltd Spark gap electrical apparatus
US2457891A (en) * 1945-01-12 1949-01-04 Andrew F Henninger Electron discharge device
US2471263A (en) * 1946-05-24 1949-05-24 Bell Telephone Labor Inc Ionic discharge device
US2492295A (en) * 1947-11-20 1949-12-27 Westinghouse Electric Corp Spark gap device
US2646534A (en) * 1950-10-20 1953-07-21 Reconstruction Finance Corp Electronic counter
US2724789A (en) * 1945-11-30 1955-11-22 Wilcox P Overbeck Thyratron counting circuit

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1722588A (en) * 1927-03-23 1929-07-30 Magnavox Co Point-to-plate gas-filled rectifier
US2098301A (en) * 1935-10-03 1937-11-09 Bell Telephone Labor Inc Glow discharge device
US2433755A (en) * 1942-06-12 1947-12-30 Vickers Electrical Co Ltd Spark gap electrical apparatus
US2331398A (en) * 1942-10-19 1943-10-12 Bell Telephone Labor Inc Electronic discharge device
US2457891A (en) * 1945-01-12 1949-01-04 Andrew F Henninger Electron discharge device
US2724789A (en) * 1945-11-30 1955-11-22 Wilcox P Overbeck Thyratron counting circuit
US2471263A (en) * 1946-05-24 1949-05-24 Bell Telephone Labor Inc Ionic discharge device
US2492295A (en) * 1947-11-20 1949-12-27 Westinghouse Electric Corp Spark gap device
US2646534A (en) * 1950-10-20 1953-07-21 Reconstruction Finance Corp Electronic counter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7214949B2 (en) * 2004-11-12 2007-05-08 Thorrn Micro Technologies, Inc. Ion generation by the temporal control of gaseous dielectric breakdown
US20140184064A1 (en) * 2012-12-27 2014-07-03 Chang Gung University Gas discharge tubes
US9299527B2 (en) * 2012-12-27 2016-03-29 Chang Gung University Gas discharge tubes for surcharge suppression

Also Published As

Publication number Publication date
BE569134A (fr)

Similar Documents

Publication Publication Date Title
US2636990A (en) Ion source unit
US2400456A (en) Spark gap electrical apparatus
US2293177A (en) Electron discharge device circuits
US2599352A (en) Radiation detector
US2373175A (en) Electron discharge apparatus
US2631261A (en) Electric discharge device
US3035201A (en) Cold cathode switching devices
US2578571A (en) Electron discharge device
US1629009A (en) Low-impedance electric discharge device
US2468417A (en) Cascade amplifying circuit using gaseous discharge tubes
US2228276A (en) Electrical gaseous discharge device
US2504231A (en) Gaseous discharge device
US2444072A (en) Gaseous electrical space discharge devices and circuits therefor
US2433755A (en) Spark gap electrical apparatus
US2422659A (en) Spark gap discharge device
US2479846A (en) Gas-filled electric discharge device
US2775722A (en) Electric discharge tubes
US2285796A (en) Gaseous discharge device
US3898518A (en) Gas filled thyratron type switching discharge tubes
US2409716A (en) High-voltage discharge device
US3636407A (en) Gas-discharge device with magnetic means for extinguishing the discharge
US2603765A (en) Electric discharge device
US2607021A (en) Gas filled discharge device
US2636681A (en) Gaseous discharge tube
US2611884A (en) Amplifier gas tube