US2084509A - Voltage-controlling arrangement - Google Patents

Description

June 22, 1937. SEIDELBACH 2,034,509

VOLTAGE CONTROLLING ARRANGEMENT Filed June 11, 1935 Patented June 22, 1937 PATENT OFFICE VOLTAGE-CONTROLLING ARRANGEMENT Rudolf Seidelbach, Berlin-Mariendorf, Germany,

assignor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a company Application June 11, In Germany 4 Claims.

It is well known to maintain the voltage of electric devices constant by means of non-ohmic v conductors which are preferably connected in parallel with the terminals of such devices. Fur- 5 thermore a potentiometer arrangement is known that consists of a plurality of interconnected nonohmic conductors. Glow discharge paths are by preference adapted to serve as non-ohmic conductors, i. e. conductorswhose drop of potential is practically constant, this constancy being in- I dependent of the current passage.

The invention has for its object to keep voltages constant by means of such non-ohmic conductors which are not able to carry the entire current of the respective current consuming device. According to the invention, when the'arrangement is cut in, first a higher current passes through the non-ohmic conductor and then an auxiliary current path, connected in parallel with the non-ohmic conductor, is inserted. This method has the advantage that the ignition in the non-ohmic conductor will not meet with difficulties while despite this the non-ohmic conductor will not be overloaded.

As already indicated the invention concerns the problem of maintaining constant the grid and anode potentials of a valve amplifier without over-loading of the non-ohmic path or conductor of the control element. The invention may be especially used in connection with the valve amplifiers of wireless receivers for telegraphy and telephony, picture transmission systems, television systems,- etc., as Well as in such amplifiers for use in transmitters of such systems. Even in crystal controlled transmitters the constancy of the frequency thereof is still further increased by employing the device for keeping constant the grid and anode potential of the transmitter valves according to the teachings hereof.

The invention is explained hereafter with reference to the circuit arrangement shown by way of example in the accompanying drawing.

To the terminals I and 2 of a source of current a glow discharge path E of Well known kind is that this device E which is a voltage divider serves to actuate a number of electron tubes or valve amplifiers. From the lowest discharge path e of the device E the grid potentials are derived and conducted to the grid terminals G1 and G2 of the said amplifier arrangement which besides has only a cathode terminal K shown. The grid potentials are received over potenti- 55 ometers RI and R2. The cathodes of this ampliconnectedover a resistance R. Let it be assumed 1935, Serial No. 26,017 vJune 13, 1934 fier arrangement are connected to the upper electrode of the discharge path e. The anode potentials for the different amplifier valves may be derived from the terminals B1, B2, B3 and A1.

' In the case represented the entire anode current of the amplifier arrangement fiows over the discharge path 6. This may under the circumstances require the device E to be given very large dimensions since only this discharge path e is strongly loaded whereas the other discharge paths are loaded to a much less degree. The path 6 can be unloaded by connecting in parallel with it an ohmic resistance intended to receive part of the anode current. It may also be proposed to dimension the potentiometers so as to accord with the derived grid potentials, so that no such additional resistance shall be necessary. The voltage constancy of the grid potential will not be disturbed hereby since also in this case the. drop of potential across the ohmic resistance, or the grid potential will depend upon the drop of potential across the discharge path e. However, the insertion of such a resistance or of potentiometers of a sufliciently low resistance entails difficulties regarding the ignition of the device E if the resistance value of all potentiometers connected in parallel and, of all the resistances is below a definite value.

If for instance the discharge paths 031, B1, B2 and B2B: have ignited then they are under the influence of the counter voltage U. There is thus a circuit with the electromotive force UG-3U and the two resistances R and p connected in series, the resistance p being calculated from all the resistances RI, R2, etc. connected in parallel with the discharge path O-G. From this it follows that before ignition the voltage Vp at resistance p and thus at the discharge path O--C is This value must at least be equal to U-I-Cz where ez denotes the ignition voltage of the path e. The smallest value for p thus is parallel with path 0-0, that is to say there must be the relation With respect to those cases where Equation (II) be not compatible with Equation (1) it is proposed to so dimension the combinationresistance of all the potentiometers necessary .for the grid voltages as to accord with EquationlI) and after the ignition of the discharge path O-C to connect another resistance W in parallel with this path O-C so that also Equation (II) shall be satisfied, The device E is momentarily overloaded in this way, this however having no detrimental effect upon it. The auxiliary current path W is only inserted after the device E has become active.

This in the arrangement shown is attained with the aid of a relay Ra. Ir? the negative lead to the cathode K the main winding of the relay R41 is included. The contacts of this relay are designated r and 1". The relay Ra. is provided with a locking winding Rh. The auxiliary path W, which is intended to unload the discharge path e or OC, is an ohmic resistance. As soon as the arrangement is cut in the anode current is flowing, relay Ra attracts its armature so as to close contact 1''. This contact acts to insert the locking winding Rh as well as the unloading resistance W connected in series with winding Rh. Contact 1" is arranged to close later than contact r. The winding R0. is thus short-circuited so that the relay will hold itself over its winding Rh. This has the advantage that the inductive resistance of the relay winding Ra does not remain included in the cathode lead and thus will not be able to impair the action of the discharge path O-'C.

What is claimed is:

.1. In a voltage-controlling arrangement, adapted to be inserted between a source of current and a device to be fed from this source of current, comprising a non-ohmic conductor, means for connecting said non-ohmic conductor across said current source thereby to render said non-ohmic conductor active, an auxiliary current path, and means for connecting said auxiliary path in parallel with at least a part of said nonohmic conductor after said non-ohmic conductor has become active under the influence of said current source.

2. An arrangement according toclaim 1, wherein the means for connecting said auxiliary path is a relay controlled by current fed from said current source through said non-ohmic conductor to said device.

3. An arrangement according to claim 1, wherein the means for connecting said auxiliary path is a relay controlled by the current fed from said source of current through said non-ohmic conductor to said device, and means for keeping this relay excited.

4. In a voltage-controlling arrangement, adapted to be inserted between a source of current and an electron device to be fed from this current source, comprising a voltage divider comprising non-ohmic conductors, one of these conductors included in the negative lead to the cathode of said electron device, an auxiliary current path, and means to connect this path in parallel with a part of said non-ohmic conductor included in the said negative lead, this connecting means becoming operative after the lastsaid non-ohmic conductor has become active under the influence of the said current source.

RUDOLF SEIDELBACH.

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