US1819604A - Constant potential device - Google Patents

Description

8, 1931. A. JAUMANN 1,819,604

CONSTANT POTENTIAL DEVICE Filed Feb. 27. 1929 I I? 45 v 02 49 {Inventor @51 14 5 Gamma 1 fl Patented Aug. 18, 1931 UNITED\S\TATES PATENT OFFICE ANDREAS JAUMANN, or imatm-crmatorrnnnnne, GERMANY, assrenoa r snnmns & HALSKE, nxrmnensnusomrr, or smunnss'rm, NEAR BERLIN, ennmmr,

A CORPORATION OF GERMANY CONSTANT rornn'rmr. nnvrcn Application filed February 27; 1929, Serial No.

' For the smoothing of current. supplied from direct current generators, rectifie'rs and similar sources of current which fail to fur.- nish a pure direct current, but rather a kind of direct current having, for instance, al-

ternating current components superposed thereon, the use of a thermionic-tube has been suggested whose internal resistance is so influenced by the source "of current that the potential fluctuations are eliminated. Along the line of this suggestion action is brought particularly by the fall of potential across a resistance which influences the grid of the tube. However, through the control resistance there flows also the consuming or load current so that the suppression of the potentialfluctuations is not insured in a perfect manner. owing to the de- "pendence on the load current. According to the invention, the disturbances are eliminated independently of the load current, and for this purposethe control resistance is connected in a circuit in parallel relationship to the} consumer apparatus. Also the tube arrangement is pref." c in erably included in this parallel bran series. with the control resistance. The fall of potential in the latter may influence the tube arrangement in various ways, as will be seen from the following specification when read in connection with the accompanying drawings in which Figure 1 shows thecircuit arrangement of a constant potential device constructed in accordance withmy invention; while Figures 1A, 2 and 3 show modifications of the device of Figure 1. 1

Referring to the drawings, Figures. 1 and 1A show a simple arrangement in which the control resistance R is associated with the positive pole of the source of current and with' the plate of thermionic tube A. The filament circuit of this tube is united with the negative pole of the source. In parallel relation with the resistance R is the primary winding of a transformer whose secondary windin is included in the grid circuit of the tube. s a rule, a negative biasing potential is required at the grid in order to insure proper operation of t e scheme, said biasinadequate.

should-be rather large. -The fa 342, 91, and in Germany February 17, ms.

ing potential being furnished from a battery 3. As the current through ows there is produced a grid potential, we the result that the plate potential of the tube is varied. -If the ratio of the transformer is properly chosen, the variation in the plate potential will just compensate the variation of the fall of potential across resistance B, so that the potential" acrossrterminals 1, 2, with which the load resistance, for instance, the plate circuit of tube arrangement is connected, preserves a constant value. In order that the superposed alternating current components may be properly suppressed, it will be desirable in manyinstances to keep the direct current magnetization in the transformer as low as possible. For this urpose may be employed a third winding on the transformer,.as shown in Fi re 1, one end of which is associated wit .the primary winding and is brought by way of resistance" 'r to the negative p0 e. a v

This circuitscheme operates properly in- .side a frequency range which depends upon the properties of the transformer. As a general rule, in the presence of very low and very high frequencies, compensation will be In this respect the scheme shown in Figure 2 operates more favorably.

Also in this arrangement, a control resistanceRl-and-a thermionic tube A are disposed in series between the terminals of the source of current. In parallel relation to the .tube A is an auxiliary tube B in series with a resistance R2 which, as a 1general rule, of potential across resistance R1 directly controls .the

grid of tube B which, under certain circumstances may be with the negative pole; of the source of current. At the plate of this tube B arise potential variations of opposite si and larger amplitude, and these are fed t rou h a grid battery to the grid of the main tu e A. If, then,*the current through the first tube grows and as a consequence the fall of otential' across resistance R1, this is attende with a decrease of otential at the grid of the auxiliar tube. f the value of resistance R2 is consi erable (which it preferably should be) the plate current in m tube B does not change substantially, and there occurs a considerably greater positive potential variation at the plate of B and consequently also at the grid of tube A. This potential variation may be so chosen that the potential at terminals 1, 2, for the load resistance remains constant.

The auxiliary tube serves essentially for electrostatic control and may therefore be ordinarily quite small. The arrangement moreover, is predicated for its operation only on ohmic resistances so that it is practically independent of frequency.

Since the circuit arrangements hereinbefore disclosed maintain a direct current potential across their terminals, while alternating current potentials or rapid fluctuations of potential of appreciable size are precluded, they act similarly as a very large condenser so that they could also be used in conjunction with choke-coils or low-pass filters for filtering out alternating current components.

A scheme of this kind is illustrated in Figure 3, connected with the positive terminal of the source is a choke-coil D followed by a circuit arrangement which essentially is similar to the one shown in Figure 2. In lieu of the biasing potential battery between the plate of tube B and the grid of tube A there is used here a condenser, and the grid of tube A is associated with the negative terminal of the source by way of a resistance W. The grid of tube B is united with a point of control resistance R1, and then the biasing potential battery in the grid circuit of tube B may be dispensable.

The operation of the tube scheme shown in Figure 3 is fundamentally similar to Figure 2. However, what should also be kept in mind is that the current flows through choke-coil D to the consumer which is united with terminals 1 and 2. Since the value of this current is not constant or invariable once for ever, the potential will be a function of the load current even if the internal resistance of the source is negligible, because a fall of potential is set up across the direct current resistance of the choke-coil D. However, since the tube arrangement is designed to preserve a constant potential, it will produce and result in a regulating current such that, in the presence of variable load, the fall of potential across the choke-coil remains constant. As a result the operation of the tube arrangement may be unfavorably affected. However, it is possible to render it independent of the load by the aid of a compensating resistance 1" which, as a general rule, need have only a small value, and which, in the embodiment shown by way of example in Figure 3, may be connected between the control resistance R1 and the grid resistance W.

I claim:

1. An arrangement for smoothing out current to be applied from a pulsating direct current source to a load circuit including, a thermionic tube having an anode cathode and control electrode, a fixed impedance, means connecting the impedance of said tube and said fixed impedance in parallel with said load circuit, coupling means between said fixed impedance and said control electrode and amplifying means in said coupling means whereby variations in potential in said fixed impedance due to pulsations in said source are amplified and applied to the control electrode of said tube.

2. An arrangement for supplying direct current at constant potential from a pulsating direct current source to a load circuit including, a thermionic tube having anode cathode and control electrodes, a control resistance, a circuit connecting the impedance of said tube and said control resistance in parallel with the load circuit, an auxiliary thermionic tube having an anode, a cathode and a control electrode, a circuit connecting the anode cathode impedance of said last named tube in parallel with the anode cathode impedance of said first named tube, coupling means connected between said resistance and the control electrode of said last named tube, means connecting the anode of said last named tube to the control electrode of said first named tube, and a resistance connecting the control electrode of said first named tube to the negative terminal of said source.

3. In apparatus for smoothing out the potential of current obtained from a pulsating direct current source, a circuit including the anode and cathode impedance of a thermionic triode connected across the output terminals of said source, a series resistance in said circuit, an auxiliary triode, a circuit connecting the anode cathode impedance of said auxiliary tube in parallel to the anode cathode impedance of said main tube, a series resistance in said last mentioned circuit, a connection between the resistance in said first named circuit and the grid electrode of said auxiliary tube, a connection between the anode elect-rode of said auxiliary tube and the grid electrode of said main tube, and a condenser in said last named connection.

4. In radio apparatus adapted to supply constant potential from a pulsating direct current source to a load circuit connected across the terminals of said source, a circuit including a fixed impedance and a variable impedance connected in series across said source, impedance control means associated with said variable impedance, voltage amplifying means connecting said fixed impedance to said variable impedance, whereby potential variations in said fixed impedance due to pulsations in said source are vamplified and applied to 'said varying means to regulate the impe impedance ance of said arallel circuit.

5. n means for supplying direct current at constant potential from a source of pulsating direct current to a load circuit, a fixed impedance, a thermionic tube having its anode cathode impedance connected in series with said fixed impedance across the I termlnals of sald source, a transformer having its primary winding connected in parallel with said fixed impedance and its secondary winding connected to the control electrode of said thermionic tube whereb the potential variations in said fixed impe ance are amplified and applied to the control electrode of said tube.

A 6.- Means for sup )lying direct current at constant potential i fixed impedance and a variable impedance connected in series across the terminals of said source, impedance control means associated with said variable impedance, a trans-- former having its primary winding connected in parallel with said fixed impedance and its secondary winding connected with said impedance control -means,'whereby potential variations insaid fixed impedance, due to pulsations in said source, are amplified and applied to said impedance control means.

7 An arrangement, as claimed in claim 6, in which said transformer has a third winding connected in parallel with said variable impedance.

8. In means for su plying direct current at constant potential rom a pulsating direct current source to a load circuit, a circuit including the anode and cathode impedance ofa thermionic triode connected across the output terminals of said source, an impedance in series with said circuit, an auxiliary triode having its anode cathode impedance connected through a series impedance in parallel with the anode cathode impedance of said first named tube, means for connecting the control electrode cathode impedance of said last named tube in parallel with the and a source of series impedance of said first named circuit anode of said am iary tube to the control electrodeof said first named tube.

ANDREAS JAUMANN.

rom a pulsating direct. current source to a load clrcult including a otential connecting the'

Images