US2212921A - Potential divider - Google Patents

Description

Aug. 27, 1940. KRS 2,212,921

POTENTIAL DIVIDER Filed May 14, 1936 Patented Aug. 27, 1940 i POTENTIAL DIYIDER.

Lszl Krs, Berlin-Tempelhof, Germany, as-

.signor to Stabilisator A.

' Luxemburg G., Luxemburg,

Application May 14, 1936, serial No. 79,722 In Germany June 6, 1928 6 Clams.` (Cl. 250-27-5) -zlThis invention relates to a new potential divider andthe present .application isa continuation in .part of my application Ser.. No. 667,154, which was iss'uedas Patent No. 2,077,840, being a division of V rnyapplication Ser. No.1365,324 which was issued .as Patent-No. 1,973,082 on September 11, 1934.

i An .object ofthe present inventionis a poten-f .tial :divider .which Vis capable of supplying constantpotentials of predetermined values.

. The'. potential. dividers used vheretofore em- -ployedohmic resistances for the purpose of. subdividing the potential of an electric current. `The disadvantage ofthese Apotential dividers resides in `the/fact that the potential .drop in ohmic resistances depends'uponthe intensity of the current traversing suchresistances at any given moment. It is therefore self evidentthat' the potential vdrop will thus varyin accordance with the fluctuations in the current intensity.

L The present invention .overcomes these disadvantages by substituting discharge gaps for the :ohmic resistances used heretofore. Discharge :gapsfwithin certain limits, .are not affected by fluctuations in the current intensity. .In other words, discharge gaps are resistances in vwhich the potential Adrop remains constant between certain limits of the load. A good example of a discharge gap is found in .the so-called glow dischargetubes. AThese tubes consist of a pair of 35 electrodes disposed in a-container lled with a rareed gas,such as neon.

The potential divideraccording to the present invention consists of a plurality of interconnected discharge gaps. These maybe` disposed .either sep- 40 arately in individual containers or together in a common container. If-each discharge gap is disposed in an individual container, it is preferable to mount two or more of suchcontainers on a single base or socket andxto establish communi- 45 cation between the individualtubes. If several tubes' are thus assembled onia common 'socket considerable savings may be made in the manufacture of the tubes, because `they can be jointly evacuated and filled with rareed gas. This ad- 50 vantage is also present, of course, where all discharge gaps lare-disposed Ain acommon container.

In vthis event a `considerable further saving is produced due to the fact that the same electrodes serve both as anodes and4 cathodes, as will be more'fully explained hereafter.v The operation of a potential-divider in which all electrodes forming the discharge gaps are disposed in a common container is the same asthat of .a device where the discharge gaps are disposed in individual containers. y' 1 .l

The potential divider according to the present invention is particularly well adapted for-supplying the anode circuits of thermionic tubes from a direct current source with a comparatively high internal resistance, as for example a public current supply. An outstanding feature of the present invention resides in the fact that the new potential divider produces potentials without adverse effects upon the operation of thermionic tubes. Likewise, when a potential divider according to the present. invention is connected with a thermionic tube, the latter willbe supplied with a constant potential independent of the variations in the load. Moreover, it has been found that afconsiderable ohmic resistance in the anode circuits represents a high resistance for the modulatons of the speaking currents, whereby the sensitiveness and amplifying action of the thermionic tubes are reduced. Therefore, in order to conduct the modulations, it has been necessary to connect a condenser in parallel to the ohmic resistance. However, such a condenser transmits the various frequencies in. an unequal measure thereby causing distortions in the modulations. Where several anode .circuits are connected in parallel, the use of an ohmic resistance disposed in seriesptherewithforms/.a coupling resistance, whereby thegampliiier. tubesare easily put in oscillation. f

The potential divider according to the present invention, onthe other hand, `presents an eX- tremely smallV `resistance to themodulations of the speaking currents-whose value, moreover, remains independent of .the r,current frequencies. Due to thehigh conductivity of the new potential divider for.;y modulation currents, neither the abovefmentionedprejudicial effects on the sensitiveness and amplification of the thermionic tubes nor the. adverse effects Aor the coupling resistance need be feared, and, due to its independence ofthechanges. in ycurrent frequency, dis- .tortions ofthernodulation current are avoided.

. zligs; .4 -'and;5:illustrate.tdiagrammatically:two 5c forms of a potential divider according to the invention;

Figs. 6 and '7 illustrate potential dividers in which all electrodes are enclosed in a common tube.

The potential divider shown in Fig. l consists of a base d on which four pairs of electrodes are mounted. These electrodes are disposed in spaced relation to each other to form the discharge gaps a1, a2, a3 and a4. The individual discharge gaps are insulated from one another by means of tubes or envelopes made of glass or any other suitable insulating material. The tubes are filled with rareed gas, such as neon, and mounted together on the base d. The latter is made of insulating material and provided with a hollow inside space in order to establish communication between the tubes. The electrodes forming the discharge gaps a1, a2, as and @4 are connected together and to the contact pins or terminals bu, b2, b3, b4 and b5 provided on the base d, as shown in Fig. 3.

In the form of construction illustrated in Fig. 3, each of the discharge gaps or tubes a1, aIz and a4 produces a voltage drop of volts, while discharge tube a3 produces a voltage drop of 120 volts. The tubes a2, a1 and a4 are disposed in series withr respect to one another and connected to the terminals b1, b2, bl and b5, respectively, which are provided on the base d. Tube as is connected in such way that its cathode is in connection with the terminal b3, while the anode is connected with the anode of tube az and the terminal b1. Electric current is introduced at the terminal ln. Thus, if e. g. a current of volts is admitted the following voltages may be taken off at the various terminals: +80 volts may be tapped at terminal b2, the initial potential of +160 volts having been reduced by tube a2 to +80 volts; the remaining +80 volts are reduced by tube mi for another 80 volts, so that terminal bi'has a Zero potential, while terminal b5 offers a constant negative potential of -80 volts; tube as, on the other hand, reduces the initial current potential to +40 volts which may be taken off at the terminal b3.

The operation of the potential divider according to the present invention is simple and no special instruments or measuring devices are required for adapting the same to different current sources. An ordinary rheostat should be inserted in the feed line and adjusted till the tube ai comes to a glow. As soon as this occurs, the potential divider is in proper working order and the potentials indicated in Fig. 3 opposite the terminals b1, bz, b3, b4 and b5 may be taken olf. In order that tube a1 may be readily observed, the remaining tubes are preferably provided with an opaque coating while tube a1 is made transparent as indicated in the drawing by shading.

Instead of assembling the tubes a1, az, as and a4 on a common base as shown in Figs. 1 to 3, the potential divider mayv likewise consist of separate tubes with their electrodes connected together in any manner desired. Thus e. g. in Fig. 4 the tubes are interconnected in exactly the same fashion as in the construction shown in Figs. 1

In Fig. 5, on the other hand, the tubes of the potential divider are connected in series. The rst and last tube, a5 and as, produce a potential drop of 80 volts each, while the two intermediate tubes as and au cause a potential drop of 90 volts each. If e. g. a current of +260 volts is introduced atcthe terminal. be, a potential of volts may be taken off at the terminal bv. A potential of +90 volts may be taken off at terminal bs and a zero potential prevails at terminal b9, while a potential of -80 volts may be tapped at the terminal bio. With the exception of tube a7, all the tubes are preferably provided with an opaque coating for the reasons stated above. It will be clear, of course, that two or more of the tubes shown in Fig. 5 may be mounted together on a `common base as in the construction illustrated in Figs. 1 to 3. In such event, the base should be so constructed as to provide communication between the gas spaces of the individual tubes.

Fig. 6 shows a potential divider comprising a common envelope or tube 6 containing five electrodes I, 2, 3, 4 and 5 forming discharge gaps a9, aio, an and am. The electrodes I, 2, 3, 4 and 5 are provided with terminals bn, biz, bis, 1214 and U15, respectively from which different potentials may be taken olf. The operation of this potential divider is as follows: When electric current is supplied from a current source (not shown), the current will enter the tube 6 at bm, and discharge will rst take place from electrode I to electrode 2, and then a separate discharge will take place from electrode 2 to electrode 3, whereupon a separate discharge will take place from electrode 3 to electrode 4 and so on. The discharge gaps a9, am, an and am thus represent separate, discrete and independent discharge gaps which operate exactly like the discharge gaps a1, a2, a3 and a4 for inst., shown in Figs., 1 to 3. It will be obvious that in order to achieve stable and reliable service, the electrodes I, 2, 3, 4 and 5, forming the discharge gaps of the construction of Fig. 6, should be so constructed and arranged that no leakage between them will occur. It will be clear to all persons skilled in the art that most eicient service will be obtained if the full discharge from the entire surface of one electrode is received by the entire surface of the next following oppositely disposed electrode. The electrodes I, 2, 3, 4 and 5 of Fig. 6 have been shown merely diagrammatically and it will be understood that the same may be given any desired shape as long as the principle of the present invention is observed, to wit, that the electrodes arranged in a common container shall form discrete discharge gaps which will operate in exactly the same manner as if each pair of electrodes were disposed in a separate tube or container.

It should be noted particularly that in a construction where all electrodes are disposed in a common container, the individual electrodes perform a double function. For eample, in the potential divider of Fig. 6, when the current is turned on, discharge will take place from electrode I, acting as anode, to the top surface of electrode 2 serving as cathode; thereafter, discharge will take place from the bottom surface of electrode 2, acting as anode, to the top of electrode 3 serving as cathode and so on. In other words, the intermediate electrodes 2, 3 and 4 act both as anodes and cathodes. This fact that'a smaller number of electrodes is required simplifles the construction and produces a considerable saving in the manufacture of this potential divider. In the tube shown in Fig. 6 a heating device 'I is disposed adjacent the most negative electrode 5. Terminals 8 serve for connecting the heater 'I to a source of electric current. It will be clear, however, to those skilled in the art that any other method of heating the electrodes potential drop between the electrodes will be decreased. The potential drop may thus be regulated. by varying the amount of heat supplied to the electrodes. Moreover, a discharge tube with heated electrodesA requires smaller dimensions for a given load than a tube without heated electrodes. The tube or envelope 6 of the potential divider shown in Fig. 6 is lled with a rareed gas such as neon. A resistance 9 should be inserted in the feed line in front of the potential divider whenever a current of small internal resistance is used.

The potential divider shown in Fig. 7 comprises a common envelope I0 which contains a large electrode I I and three smaller electrodes I2, I3 and I4 disposed at varying distances from the electrode II. The latter extends over and embraces the smaller electrodes I 2, I3 and I4. Electrode I-I offers the same polarity to and cooperates with each of the smaller electrodes I2, I3 and I4. Due to this arrangement ofthe electrodes in the container I0, a distinct and separate discharge gap is formed between each one of the smaller electrodes and the large electrode I i. Diierent potentials may be taken off at the terminals bis, bw, bis and bis. Current is admitted through terminal ble. The various discharge gaps set up between the smaller electrodes and the large electrode II are distinct and separate from one another and operate in exactly the same way as if each discharge gap were enclosed in a separate container as for inst. shown in Fig. 3 of the drawing. The electrodes used in connection with the present invention may e. g. be solid, imperforate metal plates or cup-shaped structures which are nested one within the other. However, it should be noted .that no particular shape is required and that electrodes of any other desired shape may equally well be used.

I claim:

1. A glow discharge device for dividing the potential of electric current supplied from a continuously operating current source, which comprises a base, a plurality of containers disposed on said base, a glow discharge device disposed in each container, each glow discharge device predetermined reduced values may be tapped at said discharge gaps.

2. The device claimed in claim l', in which said containers intercommunicatewith one another.

3. The device claimed in claim l, in which said containers intercommunicate with one another, a current inlet means and a current outlet means being connected to electrodes of separate gaps, the remaining electrodes being provided with tapping means said containers surrounding completely the said individual glow discharge gaps, intercommunication between the said containers being established in said supporting base at points removed from and entirely out of the range of the said discharge gaps, to pre-vent interference therebetween; the said current inlet, current outlet and tapping means being attached to said base,

whereby the device may be -operated from a single plug-in socket.

4. A potential divider :for electric current,

which comprises a base, a plurality of containers disposed on said base, a pair of electrodes disposed in each container and spaced apart to form a glow discharge gap, said containers being lledA with a rareiied gas vand intercommunicate with one another, and conducting means interconnecting the electrodes r,of different discharge gaps, said gaps being connected in series, a current inlet means and a current outlet means being connected to electrodes of separate gaps, the remaining electrodes being provided with tapping means; all of said containers except one being light impervious.

5. A potential divider for electric current, which comprises a base, a plurality oi containers disposed on said base, said containers being lled wi-th a rareed gas such as neon, a pair of electrodes disposed in each container and spaced apart to form a glow discharge gap, and conducting means interconnecting the electrodes of diierent discharge gaps, a current inlet means and a current outlet means being connected to electrodes of separate gaps, the remaining elec- LszL KRs.

Images