US2133857A - Electric valve circuit - Google Patents

Description

Oct. 18, 1938.

F. HAMACHER 2,133,857 ELECTRIC VALVE CIRCUIT Filed Nov. 7, 1936 3 Sheets-Sheet 1 Fig.1.

Fig.2. 4

Inventor: Fritz Han achen H is Attovney Oct. 18, 1938. F. HAMACHER 2,133,857

ELECTRIC VALVE CIRCUIT Filed NOV. 7, 1936 3 Sheets-Sheet 2 I lnventor-: Fr-itz Hamachem Attorney.

' Oct. 18, 1938. F. HAMACHER 2,133,857

ELECTRIC VALVE CIRCUIT Filed Nov. '7, 1936 3 Sheets-Sheet 3 Inventor: Fritz Hamacher,

by K/ His ttorney Patented Oct. 18, 1938 UNITED STATES PATENT OFFIE ELECTRIC VALVE CIRCUIT ration of New York Application November 7, 1936, Serial No. 109,736 In Germany December 12, 1935 7 Claims.

My invention relates to electric valve circuits and more particularly to control and excitation circuits for electric valve means of the type employing ionizable mediums.

In electric translating circuits employing electric valve means, it is frequently desirable to control the operation of the electric valve means through control members associated with the arc discharge paths. It has become desirable in many instances to provide control apparatus which is inexpensive, and which is simple and rugged in construction and arrangement. Heretofore, in many applications it has been customary to employ electromagnetic devices of parl5 ticular design to provide the suitable control voltages and it has been common practice to employ batteries to obtain the required negative biasing potentials. In electric valve applications Where the initial cost of installation and maintenance are important and where rugged construction and continuity of service are highly desirable, there has been evinced a decided need for improved control and excitation circuits for the electric valve means.

It' is an object of my invention to provide new and improved electric valve circuits.

It is another object of my invention to provide new and improved control and excitation circuits for electric valve means of the type employing ionizable mediums.

In accordance with one illustrated embodiment of my invention, I provide improved control or excitation circuits for electric valve means of the type employing ionizable mediums, such as gases or vapors, and in which the operation of the electric valve means is controlled by controlling the energization of control members associated with the arc discharge paths of the electric valve means. By virtue of my invention, the voltage impressed on the various control members is of peaked wave form which has proved highly desirable in obtaining the precise and satisfactory control of electric valve means of this type. Each excitation circuit for the control members comprises a source of alternating voltage which is combined with a'negative unidirectional pulsating voltage to impress on the associated control member a voltage having a wave form which has peaked or sharp positive portions of relatively short duration and negative portions of substantially greater duration than the positive portions and being of sufiicient magnitude to maintain the electric valve means non-conductive during predetermined intervals. The maximum values of the negative unidirectional pulsating voltages are displaced in phase relative to the maximum values of the alternating voltage and are of a substantially greater magnitude than the maximum values of the alternating voltage. In accordance with another illustrated embodiment of my invention, a plurality of excitation circuits are associated with the electric valve means in a pclyphase electric valve translating circuit. In each of these excitation circuits, there is introduced an alternating voltage, a unidirectional pulsating voltage, and a voltage which varies in accordance with an electrical condition such as the voltage or current of a predetermined different one of the other excitation circuits. The resultant voltage, which has positive portions of peaked or sharp wave form of relatively short duration, is employed to render the associated electric valve means conductive at predetermined points during the cycle of operation and the negative portions of the resultant voltage serve as a negative biasing potential to maintain the electric valve means non-conductive during the proper intervals.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompany-' ing drawings, and its scope will be pointed out in the appended claims.

Fig. 1 of the accompanying drawings diagrammatically illustrates an embodiment of my invention as applied to a control or excitation system for an electric valve means for transmitting energy between a three phase alternating current circuit and a direct current circuit; and Fig. 2 represents certain operating characteristics of the embodiment of my invention diagrammatically shown in Fig. 1. Figs. 3 and 4 diagrammatically represent modified embodiments of my invention as applied to electric valve translating circuits; Fig. 5 represents certain operating characteristics of the control circuits of Fig. 3, and Fig. 6 represents certain operating characteristics of the control circuits of Fig. 4.

Referring now to Fig. 1 of the accompanying drawings, my invention is diagrammatically illustrated as applied to an electric valve translating system for transmitting energy between a three phase alternating current circuit l and a direct current circuit 2 through a transformer 3 having primary windings 4 and secondary windings 5, and through an electric valve means 8 preferably of the type employing an ionizable medium, such as a gas or vapor. The electric valve means 6 is provided with anodes 7-!2, inelusive, a cathode l3 and control members l4-l9,

inclusive. While I have chosen to represent this embodiment of my invention as being applied to an electric valve means of the type employing a plurality of anodes and a single cathode enclosed within a single receptacle, it should be understood that my invention may be applied to electric valve means of the type employing a single anode and a cathode within an enclosing receptacle.

In order to control the electric valve means 6 and hence to control an electrical condition of the alternating current circuit l or the direct current circuit 2, I provide a plurality of new and improved excitation circuits 2%, 2i and 22.

tional pulsating voltage.

The excitation circuits 2d, 2i and 22 may be energized from any suitable source of alternating voltage of a frequency equal to the frequency of the alternating current circuit l, and I have shown the excitation circuits 2t, 2! and 22 as being energized from the alternating current circuit l through any conventional phase shifting arrangement such as the rotary phase shifter 23. cuits 2t, 2! and 22 an alternating voltage, I provide transformers 2 5, 25 and 26 having primary windings 2'1, 28 and 29 and secondary windings 30, 3E and 32, respectively. The transformers i l, 25 and 28, inclusive, may be energized from the alternating current circuit i through the phase shifter 23 and a phase shifter 33.

To introduce in each of the excitation circuits 2ll-22, inclusive, a negative unidirectional pulsating voltage, I employ transformers 3 s, 35 and 36 having magnetically separate secondary windings 3'1, 38 and 39. Bi-phase rectifiers including the secondary windings 3T, 38 and es of transformers 34, 35 and 36, respectively, and suitable rectifying means, such as contact rectifiers 9 and ii, are employed to introduce in the excitaticn circuits 2%, 2i and 22, respectively, the negative unidirectional pulsating voltage which has a voltage component of a frequency double the frequency of the alternating current circuit l. Connected in each of the excitation circuits 2d, 2! and 22, I employ any suitable impedance such as resistances and which are connected between a common juncture of the rectifiers ii and ll and an electrical intermediate point or tap of secondary windings 3?, 32 and 3% or trans formers 3d, and respectively. The current which flows through the resistances 32, it and M is a substantially unrectified pulsating current and hence the voltage appearing across the terminals of these resistances will be a unidirec- The voltage impressed on con rol members i l-l9, inclusive, of electric valve means 6 will be the resultant voltage of the unidirectional pulsating voltages appearing across the resistances 42, 53 and it and the alternating voltage introduced in each of these circuits by secondary windings 33, and of transformers 2d, 25 and 25;, respectively. For example, the voltage impressed on control members i l and 55 will be the resultant of the unir directional pulsating voltage appearing across the terminal or resistance i l excitation circuitZi-l and the alternating voltage introduced in the circuit by means or" secondary winding 32 of transformer By the proper connection of the resistances s2, 43 and 3 3 in the bi-phase rectifier circuits and by the proper correlation of the voltages appearing across these resistances and the alternating voltages of the secondary windings 36, 3E and 32 of transformers 24, 25 and 25, the unidirectional pulsating voltage may be ar- To introduce in each of the excitation cirranged to impress a negative voltage on the control members. I have found that it is desirable in certain applications to design the transformers 3 3, 35 and 3% so that the maximum value of the unidirectional pulsating voltage is substantially greater, such as three times the maximum value of the alternating voltages introduced in the excitation circuits by transformers 2 3, 25 and 26. I have also found that it may be desirable to displace in phase relationship the maximum value of the unidirectional pulsating.-

voltage relative to the maximum value of the alternating voltage.

The operation or" the embodiment of my invention diagrammatically shown in Fig. 1 may be best explained by considering the operation of the electric valve translating system when the system is operating as a rectifier to transmit energy between the alternating current circuit 5 and the direct current circuit 2. As will be well understood by those skilled in the art, the various arc discharge paths of the electric valve means 5 will conduct current in a predetermined order and during predetermined intervals, the commutation of the current from one anode to another anode being determined by the voltages impressed on the anodes and the voltages of the associated control members. It will also be understood that the voltage of the direct current circuit 2 may be controlled by controlling'the phase relationship between the voltages impressed on the anodes l-lZ, inclusive, and the voltages impressed on the control members M-l ll, inclusive. When there is substantial phase coincidence between these voltages, the voltage of the direct current circuit 2 will be a maximum and when there is substantial phase opposition between these voltages the voltage of the direct current circuit 2 will be a minimum.

Certain operating characteristics of the arrangement of Fig. i are represented in Fig. 2 where the curve A represents the alternating voltage introduced in one of the excitation circuits, for example excitation circuit idby secondary winding 30' of transformer 24, and the curve B represents the unidirectional pulsating voltage appearing across one of the resistances, such as resistance 52, in excitation circuit 20. Curve C represents the resultant voltage which is impressed on control member l8 associated with anode H of electric valve means 6. The voltage impressed on control member l9 associated with anode !2 will be disposed I80 electrical degrees relative to the voltage represented by curve C. Considering the resultant voltage as represented by curve C which is impressed on control member IE, it will be noted that during the interval 0-2) the pcsitiveportion of the voltage is of peaked or sharp wave form and that during the interval 11-0 the negative portion of the voltage is of relatively large magnitude to provide a negative biasing voltage for maintaining the arc discharge path associated with anode ll non-conductive during predetermined intervals when the valve is normally non-conductive. The phase displacement between the voltage of secondary winding so of transformer 24 relative to the voltage appearing across the terminals of resistance 52 may be effected by the proper adjustment of the rotary phase shifting device 33 and in the particular relationship shown in Fig. 2 the rotary phase shifting device 33 has been adjusted so that there is a substantially 90 electrical degree displacement between the maximum values of these voltages.

By virtue of the fact that the voltages appearing across the terminals of resistances 42, 43 and 44 are substantially unfiltered unidirectional pulsating voltages, it is to be noted that these voltages possess relatively large voltage components of a frequency double the frequency of the alternating current circuit and hence pos- 585s components of voltages of a frequency double the frequency of the voltages appearing across the terminals of secondary windings 30, 3| and 32 of transformers'24, 25 and 26. It should be understood that I may employ in place of the bi-phase rectifiers of excitation circuits 20, 2| and 22 any other suitable source of voltage having a substantial second harmonic component of voltage. It is to be further noted that by virtue of my invention I provide a highly satisfactory arrangement for controlling the operation of the electric valve means 6. By controlling or adjusting the rotary phase shifter 23, the voltage impressed on the control members |4-|9 may be adjusted in phase relative to the voltages impressed on the associated anodes 1-|2, inclusive, to control the conductivity of the associated arc discharge paths and hence to effect a control of the voltage or other electrical condition of the direct current circuit 2. By controlling or adjusting the rotary phase shifter 33, the phase relationship between the alternating voltages of the secondary windings 30, 3| and 32 of transformers 24, 25 and 26 may be controlled relative to the unidirectional pulsating voltages appearing across the terminals of resistances 42, 43 and 44 and hence there is provided a means for controlling the phase position and wave form of the resultant voltage as represented by curve C of Fig. 2. By so controlling or adjusting the rotary phase shifter 23, the conductivity of the arc discharge paths of electric valve means 6 may be controlled to control the voltage or other electrical condition of the direct current circuit 2. Control or adjustment of the phase shifter 33 will control the phase position of the resultant voltages impressed on the control member relative to the voltages impressed on the associated anodes.

In Fig. 3 of the accompanying drawings I have diagrammatically shown my invention as applied to an electric valve translating system for transmitting energy between an alternating current circuit 45 and a direct current circuit 46 through a plurality of electric valve means 41-52, inclusive, preferably of the type employing an ionizable medium such as a gas or a vapor, through an associated transformer 53 having primary windings 54 and secondary windings 55. Each of the electric valve means 41-52. inclusive, includes an anode 56,'a cathode 51 and a control member 58.

To control the conductivity of electric valves 51-52 and hence to control an electrical condition of one of the associated circuits, such as the direct current circuit 46, I provide a plurality of excitation circuits 59, 60 and 6| each associated with two of the electric valves 41-52. inclusive. For example, the excitation circuit 59 is associated with electric valves 41 and 48 and serves to impress on the control members 56 of these electric valves control voltages of peaked wave form. The excitation circuits 59, 60 and 6| may be energized from any suitable source of alternating voltage properly correlated in frequency and phase position relative to the voltage impressed on the anodes 56 of electric: vfalves 41-52. In the arrangement of Fig. 3 I have chosen to represent the excitation circuits 59, 60 and GI as being energized from the alternating current circuit 45 through any suitable phase shifting arrangement such as the rotary phase shifting device 62.

Each of the excitation circuits 59, 60 and 6| includes a transformer 63 having a secondary winding 64, suitable rectifying devices such as the contact rectifiers 65 and 66, and a suitable impedance element such as a resistance 61 which is connected to a common juncture of the rectifiers 65 and 66 and an electrical intermediate point or tap of secondary winding 64 of transformer 63. The resistance 61 in each of the excitation circuits 59, 60 and 6| introduces in each of the excitation circuits a negative unidirectional pulsating voltage having a substantial second harmonic component of voltage relative to the voltage of the secondary winding 64 of transformer 63 or relative to the voltage of the alternating current circuit 45.

I provide each of the excitation circuits 59, 6t and 6| with a transformer or other suitable inductive apparatus for introducing in the excitation circuits an alternating voltage. In the arrangement of Fig. 3 I have chosen to represent this apparatus as comprising a transformer 66 having a primary winding 69, a secondary winding 10 and a tertiary winding 1|. The tertiary Winding electrical condition of one of the other of the excitation circuits such as the voltage appearing across the terminals of the resistance 61 of excitation circuit 60. To provide a means for effecting a predetermined phase displacement between the voltage appearing across the terminals of resistance 61 in excitation circuit 60 and the voltage introduced in the excitation circuit 59 through tertiary winding 1| of transformer 68, I connect in series relation with the tertiary winding 1| a suitable reactive element such as a capacitance 12. It should be understood that I may employ other suitable arrangements for effecting this predetermined phase displacement. In like manner, there is introduced in excitation circuit 60 a voltage which varies in accordance with the voltage appearing across the terminals of resistance 61 in excitation circuit 6|, and there is introduced in the excitation circuit 6| a voltage which varies in accordance with the voltage appearing across resistance 61 in excitation circuit 59. While I have chosen to represent this particular correlation of voltages between the various excitation circuits, it should be understood that I may choose other suitable means to obtain the desired voltage for effecting the same or a different phase displacement.

I'he operation of the embodiment of my invention diagrammatically shown in Fig, 3 will be explained by considering the electric valve translating system when energy is being transmitted from the alternating current circuit 45 to the direct current circuit 46 through transformer 53 and electric valves 41-52, inclusive. The electric valves 41-52, inclusive, will be rendered conductive in a predetermined. order and during predetermined intervals, each electric valve means conducting current during substantially 60 electrical degrees.

The operating characteristics represented in Fig. 5 will be considered in explaining the operation of the excitation circuits- 59, 60 and GI of Fig. 3. Curve D represents the negative unidirectional pulsating voltage introduced in each of the excitation circuits by the resistance 61 and the 1| is energized in accordance with an associated rectifying circuit including rectifiers 65, 6t and transformer 64. The alternating voltage introduced in the excitation circuit through the primary winding 59 of transformer 68 may be represented by the curve E of Fig. 5. The voltage introduced in the excitation circuit which also varies in accordance with an electrical condition, such as the voltage appearing across the resistance 61 of another excitation circuit, may be represented by the curve F of this figure. It will be noted that the unidirectional pulsating voltage appearing across the terminals of resistance bl, represented by curve D, is displaced substantially 3O electrical degrees relative to the alternating voltage introduced in the excitation circuit. Furthermore, the voltage as represented by curve F is displaced 60 electrical degrees relative to the voltage as represented by curve D and displaced substantially electrical degrees relative to the voltage as represented by curve E. This relative phase displacement of the voltage F introduced into the excitation circuits, for example the voltage introduced in excitation circuit 59 through tertiary winding ll of transformer 68, is eifected in part by virtue of the capacitance 72 which is connected in series relation with the tertiary winding H. The resultant voltage impressed on the control member 58 of electric valve ll may be represented by the curve G of Fig. 6. The positive portion of the curve G lying between the points at and e, is of peaked or sharp wave form and is of short duration relative to the negative portion of this curve lying between the points e and The phase relationship of the resultant voltage as represented by curve G may be controlled or adjusted in phase position rela tive to the voltage impressed on anode 5B of electric valve 57 by adjusting or controlling the rotary phase shifter 52.

Fig. 4 of the accompanying drawings diagrammatically represents a modified embodiment of my invention diagrammatically shown in Fig. 3 and corresponding elements have been assigned like reference numerals. In the diagrammatical representation of Fig. 4, there is introduced in each of the excitation circuits a component of voltage which varies in accordance with a component of current in a difierent excitation circuit. For example, the voltage component introduced in excitation circuit 59 from excitation circuit (it varies in accordance with the current furnished by the bi-phase rectifier including the transformer E33 and associated contact rectifiers 65 and 65 of excitation circuit 58. By the proper choice of excitation circuits, the voltage introduced in excitation circuit 59 by the tertiary winding l! of transformer 68 may be arranged to efiect substantially the same result as that effected by the arrangement of Fig. 3 where the tertiary winding ll of transformer 68 is energized in accordance with the voltage appearing across the resistance 6'? of excitation circuit 66.

The operation of the arrangement of my invention diagrammatically shown in Fig. 4 is substantially the same as the operation of the arrangement'of Fig. 3. The voltage impressed on the control members of the electric valves, such as the voltage impressed on control member 58 of electric valve ll, will be the resultant of three voltages, namely, the alternating voltage introduced in the circuit by primary winding es, the voltage introduced in the circuit by virtue of the voltage appearing across the terminals of resistance 5?, and the voltage variation introduced in the circuit by virtue of the current variation through tertiary winding ll of transformer 68. The resultant voltage impressed on the control member. 53 of electric valve All will have a wave form similar to curve G of Fig. 6.

While I have shown and described my invention as applied to a particular system of connections and as embodying various devices dia grammatically shown, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover allsuch changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In combination, an electric circuit, an electric valve means connected therein and having a control member, and a control circuit for impressing on said control member a voltage of peaked wave form comprising a source of alternating voltage and a source of negative rectified alternating voltage having a component of a frequencydouble the frequency of said voltage of said first mentioned source and having a magnitude substantially greater than the'maximum value of said alternating voltage and being displaced in phase relative thereto by substantially ninety electrical degrees. 7

2. In combination, a supply circuit, a load circuit, electric translating apparatus interposed between said circuits including a plurality of electric valve means each having a control member, and a plurality of excitation circuits each comprising a source of alternating voltage, a source of rectified unfiltered voltage having a voltage component of a frequency double the frequency of the voltage of said first mentioned source, means for introducing in each. of said excitation circuits a voltage which varies in accordance with a component of the voltage of another predetermined one of said excitation circuits and means for impressing on the control member of the associated electric valve means a voltage which is the resultant of said voltages.

3. In combination, a supply circuit, a load'circuit, electric translating apparatus interposed between said circuits comprising a plurality of electric valve means each having a control member, and a plurality of excitation circuits each comprising a source of alternating voltage, a biphase rectifier and an impedance element energized therefrom for introducing in said excitation circuit a voltage having a component of voltage of a frequency double the frequency of the voltage of said first mentioned source, means another predetermined one of said excitation circuits and means for impressing on the control member of the associated electric valve means a voltage which is the resultant of said voltages.

.4. In combination, -a supply circuit, a load circuit, electric translating apparatus interposed between said circuits comprising a plurality of electric valve means each having a control member, and a plurality of excitation circuits for impressing on the control member of the associated electric valve means 'a voltage of peaked Wave form and each comprising a source of alternating voltage, a bi-phase rectifier for introducing in said excitation circuit a voltage having a component of a frequency double the frequency 'of the voltage of said first mentioned source, means for introducing in each of said excitation circuits a voltage which varies in accordance with an electrical condition of another predetermined one of said excitation circuits and means for eflecting a predetermined phase displacement between said last mentioned voltage and the voltage of said source.

5. In combination, a supply circuit, a load circuit, electric translating apparatus interposed between said circuits including a plurality of electric valve means each having a control member, and a plurality of excitation circuits each comprising a source of alternating voltage, a source of rectified unfiltered voltage having a voltage component of a frequency double the frequency of the voltage of said first mentioned source and having a substantially thirty degree electrical phase displacement relative thereto, means for introducing in each of the excitation circuits a voltage having a component which varies in accordance with the rectified unfiltered voltage of a predetermined difierent one of said excitation circuits and having an electrical displacement of substantially sixty electrical degrees relative to the voltage of said second mentioned source and means for impressing on the control member of the associated electric valve means a voltage which is the resultant of said voltages.

6. In combination, a supply circuit, a load circuit, electric translating apparatus interposed between said circuits comprising a plurality of electric valve means each having a control member, and a plurality of excitation circuits for impressing on the control members of the associated electric valve means a voltage of peaked Wave form and each comprising a source of alternating voltage, a bi-phase rectifier and an impedance element energized therefrom for introducing in said excitation circuit a negative unidirectional pulsating voltage having a component of a frequency double the frequency of the voltage of said first mentioned source, means for introducing in each of said excitation circuits a voltage which varies in accordance with the voltage appearing across the impedance element in another predetermined one of said excitation circuits and means comprising a reactive element for effecting a predetermined phase displacement between said last mentioned voltage and the voltage of said source.

7. In combination, a supply circuit, a load circuit, electric translating apparatus interposed between said circuits comprising a plurality oi electric valve means each having a control member, and a plurality of excitation circuits for impressing on the control members of the associated electric valve means a voltage of peaked wave form and each comprising a source of alternating voltage, a bi-phase rectifier and an impedance element energized therefrom for introducing in said excitation circuit a negative unidirectional pulsating voltage having a component of a frequency double the frequency of the voltage of said first mentioned source and means for introducing in each of said excitation circuits a voltage which varies in accordance with the current of the biphase rectifier of another one of said excitation circuits.

FRITZ HAMACHER.

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