US2639409A - Gas discharge tube - Google Patents

Description

May 19, 1953 J. D. coBlNE GAS DISCHARGE TUBE Filed Dec. 1o, 1945 /NVENTOR JAMES D. COB/NE J N w T T A TIME T/ME

W .M M

OUTPUT UW@ F/G- 2 F/Gf/ AAAAAAAAA Patented May 19, 1953 GAS DISCHARGE TUBE James D. Cobine, Schenectady, N.-Y., assigner to the United States of America as represented by the Secretary of War Application December 10, 1945, Serial No. 634,090

This invention relates generally to electrical apparatus and more particularly to a random pulse generator utilizing a gas discharge tube and a magnetic iield.

While itji's generally appreciated `that a lga-S discharge tube may be utilizedas a random noise generator and as a pulse generator, it is not common knowledge that'a gas discharge tube may be used to provide a random noise voltage, reinforced by random noise pulses, by the application of a magnetic field to the gas discharge occurring within such a tube. y

It is an object of this invention to provide a noise generator whose output consists of ran- Fig. 3 is a graph showing the probable process by which the random relaxation pulses are developed and strategic points on the graph have been designated by the letters A, B, and C, respectively, to promote clarity in the following discussion of the operation of this invention.

5 claims. (o1. 315-236) the tube.

A 'gas discharge tube such as a type 6D4. connected in a circuit as shown in Fig. 1, is arranged at the center of a gap between two magn'et pole faces as shown in Fig. 2, with the magnetic eld transverse to the longitudinal axis of Such a device having the values of capacitor I I, plate resistor I2, the applied directcurrent potential B-{, and the flux density of the transverse magnetic iield, all properly ad justed'wi1l`operate in such a fashion that they:v

output pulses consist of noise reinformed by random pulses. The voltage output of this random pulse generator system will be substantially constant over a band of frequencies from dom noise voltages and random pulses. Such 25 cycles per second to at least 100 kc. an Output Voltage is accomplished by utilizingr A typical circuit such as illustrated in Fig. 1 a conventional sweep circuit including a gas diS- might use a value of capacitance of 0.004 mfd., charge tube and a resistor and capacitor coma resistance of 48,000 ohms, and a source of div bination with the sas discharge tube subjected rect current I4, applied to the two electromagtothe influence of a magnetic iield. 2o nets i3, I3 of Fig. l, to produce a magnetic field A random noise voltage and random pulse 0f approximatdy 370 gangs, generator are useful for many purposes, one 0f The curves shown in Fig. 3 show the probable which is to test the response of a receiver t0 process by which the random relaxation pulses noise. are developed. The capacitor II causes suf- Other objects, features, and advantages of this cient instability at the instant of a random posinvention will suggest themselves to those skilled itive noise pulse, at a time corresponding to point in the art and will become apparent from the A, when the current is transferred from the are following description of the invention taken in in tube I0 to the capacitor I I, to cause extincconnection with the accompanying drawings in tion of the arc in tube I0. At the extinction of which: the arc, corresponding to time B, the voltage Fig- 1 iS a Schematic diagram 0f a Circuit utiacross capacitor II increases during the time lizing the principles of this invention; interval B-C as required by the applied voltage Fig. 2 is an elevation showing an assembly in- B-I- and the Rf-C time constant of capacitor II corporating a gas discharge tube and two elecand resistor l2,

tromagnets; and The effect of the magnetic field is to delay the Fis- 3 iS a graph Showing the relationship 0f re-ignition of the are in tube I u until a relatime versus Output voltage, condenser current, tively high voltage is again developed across caand tube current of the circuit shown in Fig. 1. pacitor lI which then discharges to the arc volt- Refelrng 110W t0 Fig. 1, a gas discharge tube age and conditions remain normal until another I0 is shunted by a capacitor II, and across the 4o high positive noise pulse appears. combination a source of direct-current potential While there has been here described what is is applied througharesistor I2. at present considered to be the preferred em- Fig, 2 shows a physical arrangement of gas bodiment of the invention, it will be obvious to discharge tube l0 Centered betWeen tWO eleCtIO- those Skilled in the ari', that Various changes magnets f3, |3- COIlCeI'ning the physical aI- 45 and modifications may be made therein Without rangement of the magnetic field with respect to departing from the scope of the invention the tube, it should be noted that the magnetic What is claimed is: eld is transverse to the longitudinal axis of the 1. A noise generator, comprising a normally tube, which, it will be understood, is such as t0 conducting gas discharge tube having an anode effect a deection of the electron flow. and a cathode, a source of positive potential,

resistance means electrically connecting said anode to said source of potential, capacitor means electrically connecting said anode to said cathode and means for applying a constant magnetic field transverse to the longitudinal axis of said tube whereby the output of said tube con- 3 s'ists substantially of random noise and random pulses.

2. A random pulse and noise signal generator comprising a normally conducting electron tube relaxation oscillator circuit which is in a nonoscillatory state, said electron tube having an electron current ow path therein,l and a source for a constant magnetic eid positioned with respect to said tube for said field to deflect said electron current flow path.

3. A random pulse and noise signal generator, comprising a saw-tooth pulse oscillator circuit` including a gaseous discharge device shunted by a storage condenser, being in a normal state of conductivity and having irregularly occurring periods of non-conductivity,4 said device having a space current flow path therein, and means for eiecting a delay in the reestablishment of4 con ductivity of said device, including a source for a.k constant magnetic, eld. positioned for at least one component o said eld. to eiect a deiiection of, said electron current flow path.

4. A, pulsing system, comprising a gaseous electron discharge device, havingA a space cur- )IEP-f3r Path therein, a resistance in series with Said device for connection therewith, across a source of. direct potential, said device being normall7 conductive., a storage condenser in shunt with. Said device, and a continually operative electromagnet having its pole faces positioned to Drovide a constant magnetic eld having at least one component transverse to said space current path.

5. A noise generator comprising a gaseous electron discharge device having a space current path therein, a resistance in series with said device for connection therewith across a source of direct potential, said device being normally conductive, a storage condenser in shunt with said device, and a continually operative electromagnet having its pole faces positioned to Drovide a constant magnetic iield acting to deect the: 110Wy of space current, said normally conductive device, being intermittently rendered noncondnctive due to random noise pulses of an amplitude greater than a given amplitude, whereby a charging of said condenser occurs, said magnetic field acting to delay the reestablishment of the state of conductivity' of said device.

JAMES D. COBINE.

References' Cited in thev 111e Of this' patent UNITED STATES PATENTS Number Name Date 2,180,815 Meier Nov. 21, 939 2,269,338 Edgerton Jan. 6, 1942 2,375,130 Perrin et al May 1, 1945 30 2,416,307 Grieg Feb. 25, 1947

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