US1821821A - Frequency-increasing device employing mercury vapor lamps - Google Patents

Description

P 1931. M. L. TouLY 1,821,821

FREQUENCY INCREASING DEVICE EMPLOYING MERCURY VAPOR LAMPS Filed July 31 1924 5 Sheets-Sheet 1 [amp T22 W wwy S p 17931- I M. L. TOULY 1,821,821

FREQUENCY INCREASING DEVICE EMPLOYING MERCURY VAPOR LAMPS Filed July 31, 1924 5 Sheets-Sheet 2 INVENT R I I 7 I A Sept. 1, 1931. M. TOULY 1,821,321

FREQUENCY INCREASING DEVICE EMPLQYING MERCURY VAfOR LAMPS Filed July 31, 1924 s Sheets-Sheet 3 INVENTOR Patented Sept. 1, 1931 UNITED STATES PATENT OFFICE MARCEL LUCIEN TOULY, OF PARIS, FRANCE, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK FREQUENCY-INCREASING DEVICE EMPLOYING MERCURY VAPOR LAMPS Application filed July 31, 1924, Serial No.

The present invention has for its object a system for increasing the frequency of alternating currents, by utilizing the ropcrties of ion lampsprovided with gri s.

( The following description, with reference to the appended drawings which are given by way of example, discloses the manner in which the invention has been carried into effect.

Fig. l is a diagram of the circuits for a first embodiment of the invention. Fig. 2 is a curve of the undulatory E. M. F. obtained with the arrangement of Fig. 1. Fig. 3 is another arrangement according to the invention. Fig. 4 is the curve of the E. M. F. obtained with the arrangement of Fig. 3. Fig. 5 shows the circuits for the transformation of three-phase current.

Fig. 6 is the curve of the electro-motive forces. Fig. 7 is the curve of the electromotive forces in asextu le device. Fig. 8 shows a grid supplying circuit. Figs. 9 and 10 show other arrangements in accordance with the invention.

Fig. 1 shows a lamp of the ion type, for example a mercury vapour lam in which the cathode is constantly excited by an auxiliary arc; the said lamp has two anodes 4 and 5, two grids 2 and 3, and a cathode 1. A single phase alternating current generator 6 is connected to the anodes through the medium of an auto-transformer 7. The cathode is connected to the middle point of the said auto-transformer, through an oscillating circuit consisting of the inductance coil 8, the capacity 9, and a load disposed at 10 and 10'. This tuned circuit may represent, as desired, a r adio-telegraphy antenna, a high frequency electric furnace, or the like.

The grids are supplied by a. second oscillating circuit consisting of the capaclty 11 and the inductance coil 12; the latter is coupled by induction with the auto-transformer 7, and its middle point is connected to the cathode of the lamp.

The electromotive forces at the ends of the coil or widing 7 and induced in 12 are substantially in phase opposition, assuming that the forward displacement due to hysteresis,

729,882, and in France August 18, 1923.

at the ends of the capacity, which lags by relatively to the current, will be in fact set F relatively to the E. M. F.

5 supplying the coil 7. Since the coils 7 and 12 are oppositely wound, there is produced a phase difference of 11' and the E. M. F. at the terminals 11 will lag by behind the E. M. F. at the ends of the coil 7, so that when the circuit 11-12 is tuned to the frequency of the generator 6 it will be in resonance with the source of supply, and the 71' behind the anode-cathode tensions. It is a known fact that the arc will start when the grid is positive. In the conditions of Fig. 1, the arc will start in the middle of the alternations. The electromotive force acting upon the oscillating circuit 8, 9 will have the form which is shown in Fig. 2; this is an undulating and not an alternating electro-motive force, and its frequency is double 80 the frequency of the waves produced by the generator 6. If the circuit 8, 9 is tuned to the fundamental frequency of this undulating electro-motive force, the impulses produced by the lamp will maintain therein an oscillating current of constant amplitude. Should it be desired to vary this amplitude, the times at which the arcs are started in the bulb will be modified by changing thephase of the tension on the grid. For example, the circuit 11, 12 will be placed out of tune by any suitable means. In the case in which the generator already supplies high frequency, a capacity is to be added at 13 in order to produce resonance in the circuit 6, 7. The development of this electro-motive force in a Fouriers series shows a constant factor which would produce a continuous current. A condenser shown at 14 forward by grld-cathode tensions Wlll in fact lag by will prevent the passage of this prejudicial current.

If it is desired to produce norn'ial-i. e. inverted-alternating currents, a source of two phase current must be preliminarily provided. For instance if the question relates to currents having an industrial frequency, the single-phase current having the frequency F will be transformed into two-phase current of the frequenc F by a two-phase converter such as a suita le non-synchronous motor, and then the two-phase current into single-phase current whose frequency is 2F. The arrangement for this purpose is shown in Fig. 3.

The installation as a whole comprises a suitable source of single-phase current 20, a two-phase converter of which the phase windings 21 are shown in Fig. 3, two lamps 22 and 23 and a transformer 24. The said transformer comprises two primary windings 25 and 26 which are respectively connected between the cathodes of the lamps and the neutral point of the converter 21. The single-phase currents of double frequency are collected at the secondary 27 of the transformer 24. One of the converter phase windings 21 is connected to the single-phase current source 20. The anodes of the lamp 22 are connected to the single-phase current source, generator 20, through portions of that one of the converter phase windings 21 which is connected thereto, while the anodes of the lam phase win ing. The grids of the lamp 22 are supplied by a fraction of the tension supplying the lamp 23, and the grids of the lamp 23 are supplied by a fraction of the tension on the lamp- 22. The necessary connections are made directly upon the phase windings 21. Suitable resistances 28, 29, 30,

31 are interposed in the grid circuits in order to limit the current when the said grids are positive. Fig. 4 shows the form of the theoretical electro-motive forces which will be obtained at the terminals of the winding 27.

On the same principle, three-phase currents whose frequency is F can be transformed into single-phase currents whose fre uency is 3F; the arrangement is shown in ig. 5.

The three-phase current is transformed into six-phase current by the transformer 41 whereof the phases a, c, a supply the anodes of lamp 42 and the phases 7), d, f the anodes of lamp 43; the cathodes of the lamps being connected through the primary 44 of a transformer whose secondary 45 is connected to the recelvmg element or load, not shown, and delivers single-phase current whose frequency is 3F. The middle point of the primary 44 is connected to the neutral point of the six-phase transformer.

Fig. 6 represents the tensions in the different phases. The alternations a, c, c act 23are connected to the other upon the lamp 42, whilst the alternations 6, (Z, f act upon the lamp 43. The priming upon the phase a should take place in the time 1%,, precisely when the phase 0 commences to become positive, so that the grid of the phase a should be controlled by the phase a; in like manner, the grid of the phase a should be controlled by the phase e. In the lamp 43, the rid of the phase Z) is controlled by (1, etc. 11 practice, it is sometimes advisable not to give the whole tension to the secondary 45, for instance if the secondary actuates a non-synchronous motor with short-circuited rotor; in this event the grids are connected ,to a phase-shifter which allows of modifying the moments of the priming of the arcs. This phase shifter is shown at 46.

Obviously, the primarycoils are supplied by the source of current emplo ed for the six-phase tra'nsformer. The piase variations are effected by displacing the primary coils with respect to the coils in which the current is induced.

It will be observed-Fig. 6that if the phases I), (l, f are rectified, i. e. in the same direction as the phases a, c, e, and if the duration of the priming is only one-half, this will produce undulatory currents having six times the frequency of the original current, Fig. 7. The primings of the arc should then'take place in the times t t ta; thus the priming of the phase a should take place in the time t when the phase 1) passes through a maximum. The grid tension of the phase a should pass from a negative potential to a positive potential, as is shown in the figure by the portion of a sinusoid Ga. I may supply the grid circuit upon which an E. M. F. Ga is to act, from another sinusoid, for instance, the phase 0, provided there is inserted therein a circuit )roducing the proper phase displacement which in this case would be a lag of 1r. For this purpose I may use the arrangement shown in Fig. 8, An inductance coil L is connected in series with a resistance R. The current in the inductance coil will lag behind the E. M. F. of supply-and the values of R and L are so selected that the phase difference will he One end of the resistance is connected to thecathode and a connection marked grid is connected to the grid so that I may place all or a part of the difference of potential at the terminals of the resistance R in the grid-anode circuit. The two ends of this circuit (which may be termed phase shifter), that is, between the wire marked neutral and the end of the inductance coil, are supplied by the same I). M. F. which supplies the phase 0. The end of the inductance coil may be connected to the phase 0, the phase difference in this circuit being regulated so as to have the The arrangement of the sextuple devlce is shown in Fig. 9; however it might be carried out with two three-phase lamps, which are easier to construct.

A three-phase-six-phase transformer 51 supplies a lamp 52 comprising six anodes and six grids; the cathode of the lamp is connected with the neutral point of the transformer 51, through an oscillating circuit consisting of a self induction 54 and a capacity 55. The grids of the lamp are sup plied by a circuit analogous to what is shown in Fig. 8 and hereinbefore described; 56, 57, 58, 59, and 61 are resistances without inductance, connecting the grids with the cathode; the grids are supplied by a series of inductance coils 62, 63 67 which are respectively connected to the proper phases. The series of impulsesproduced by the lamp will maintain oscillating currents in the circuit '54, 55 if the lattcr has been tuned to the frequency of the impulses.

If it is desired to modulate the singlephase currents, it will sufiice to vary, and particularly to set back the moments of priming of the arcs; for this purpose, the time constant of the circuits supplying the grids is to be modified. For instance one may vary, by means of a continuous current, the saturation of the series of inducvalue r tance coils 62 67 so that the phase difference in the circuit shall be changed from %to In fact, it is Well known that the inductance of a circuit depends upon the invention, the single-phase transformer may be placed on the side of the anode circuits or on the side of the cathode. In the case of three-phase operation, the two lamps shown in Fig. 5 may be replaced by a single lamp having six anodes and six grids. Fig. 10 indicates the-principle of this arrangement; the connections for the grids are the same as in Fig. 5, and are not shown, for the sake of simplicity. In all these arrangements, the cathode should be permanently excited through the medium of an auxiliary arc of the continuous or alternating current type.

As a general rule, if it is desired to obtain single-phase currents in a receiving device requiring a wattless component, it will be necessary to carry out the supply with normal alternating current. If the said receiver is to be supplied with undulating current, the two-phase current should be supplied by a suitable generator of wattless current.

The generators of undulatory current as above described are only adapted for operation upon receivers employing watt current, upon radio-telegraphy antennae, or upon oscillating circuits of any suitable nature which are properly tuned.

What I claim is:

1. A system for increasing the frequency of alternating currents, including in combination lamps provided with grids and in which the current is conveyed by ions, the number of grids in said lamps being equal to the number of anodes therein, a source of alternating current, a phase changer, circuits connecting the anodes and cathodes of said lamps with said phase changer, a static transformer having a primary included in the circuit connecting the cathodes of said lamps with the neutral point of the phase changer, circuits connecting the grids of said lamps to the phase changer so as to obtain a difference in phase of the current in the grid anode circuits relative to the current in the anode-cathode circuits so as to produce an alternating current of higher frequency in the secondar of said static transformer and means or varying the phases of the voltages on said grids so as to produce variations in the amplitude of the augmented current.

2. A system for increasing the frequency of alternating currents comprising a transformer, a device having a cathode and a plurality of anodes mounted within a re ceptacle containing an ionizable medium, said device having as many grids as anodes, each grid being associated with a different one of said anodes, a source of alternating current, circuits connecting said anodes and cathode of said device with said transformer, a second transformer included in the circuit connecting said cathode with the neutral point of said first-named transformer, circuits connecting said grids to said first-named transformer to obtain a difference in phase of the current in the gridcathode circuits relative to that of the current in the anode-cathode circuits to produce an alternating current of higher frequency in said second-named transformer, and .means for varying the phases of the voltages on said grids to produce variations in the amplitude of the augmented current.

3. A system for increasing the frequency of alternating currents including in combination a device provided with a cathode and a plurality of anodes mounted within a receptacle containing an ionizable medium, said device being provided with a plurality of grids, the number of grids in said device being equal to the number of anodes therein, a phase changer, circuits connecting the anodes and cathode of said device with said phase changer, a load circuit supplied with voltage from the circuit connecting the cathode of said device with the neutral point of the phase changer, circuits connecting the grids of said device to the phase changer so as to obtain a difference in phase of the current in the grid-cathode circuits relative to the current in the anode-cathode circuits to producean alternating current of higher frequency in said load circuit, and means for varying the phases of the voltages on said grids so as to produce variations in the amplitude of the augmented current.

In testimony whereof I have signed this specification.

MARCEL LUCIEN TOULY.

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