US2190775A

US2190775A - Electric valve circuit

Info

Publication number: US2190775A
Application number: US148518A
Authority: US
Inventors: Martin A Edwards
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1937-06-16
Filing date: 1937-06-16
Publication date: 1940-02-20
Anticipated expiration: 1957-02-20
Also published as: DE916199C; GB505870A; FR839302A; GB499280A

Description

Feb. 20, 1940. M. A. EDWARDS 2,190,775

ELECTRIC VALVE CIRCUIT Filed June 16, 1957 Fi .l. I g r Fig.2. 4

Inventor: Martin A. Edwards,

by W 5:

His ttorney.

Piranha Feb. 20, 1940 Martin A. Edwards, Schenectady, N Y., assignor to General Electric Company, a corporation X I of New York 7 Application June 16, 1937; Serial No. 148,518

Claims. (01. Est-2n My invention relates to electric valve circuits V l and more particularly to control systems for electric valve apparatus employing ionizable mediums. I

I In the control of electric valve apparatus em- I ploying ionizable mediums, and particularly those having control members of the, immersionignitor type for initiating the arc discharge, it

' has been found that it is highly important to 10 provide control systems susceptible of supplying control'voltages of substantially perpendicular wave front to effect precise and positive control of the electric valve apparatus. Furthermore, it

is highly desirable to employ control circuits II which may be energized from commercial sources of alternating voltage and which are simple in construction and reliable in operation. More particularly, it has been found important to use circuits which apply to the immersion-ignitor control members relatively high voltages of predetermined wave form, preferably of perpendicular wave front, to assure positive initiationof the .arc discharge at the desired times in the cycle of operation of the electric valve apparatus.

" Heretofore, the control circuits havenecessitated' the use of apparatus of inordinate size and rating relative to the amount of energy transmitted by the electric valve apparatus.

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

It is another object of my invention to provide a new and improved electric valve oontrolsys tem for electric valve apparatus of the type employing ionizable mediums and control members of the immersion-ignitor type. V

In accordance with the illustrated embodiment of my invention, I provide a control circuit for energizing an immersion-ignitor control member of an electric valve means whereby the electrical discharges are initiated in a positive and reliable; manner at .accurately determinable instants in the cycle of operation. More specifically, I provide a-control system including a source of alternating current and a resonant-circuit,

4,5 which may be linear or nonlinear, energized,

from the source of alternating current. A conf trolled electric valve is employed to impresson the immersion-ignitor control .member a unidirectional voltage of substantially perpendicular wave front derived from one of the elements of the resonant circuit. The controlled electric valve is provided with a control member which renders the electric valve conductive at a predetermined time to impress on the immersion- 56 ignitor control member a voltage of predetermined magnitude and wave form. In onemodle fication of my invention, the controlled electric valve effects discharge of the capacitance of the resonant circuit to energize the immersion-ignitor control member, and in ancthenmodiflcation of I my invention the controlled electric valve impresses on the immersion-ignitor control mem-\ her a voltage derived from the inductance in the resonant circuit. n

I For a better understanding of my invention, 30 reference may be had to the following description, taken in connection with the accompanying drawing, and ltsscope will be pointed out in the appended claims. Fig. 1, of the drawing diagrammatically shows an embodiment of my inu v vention in which an immerslon-ignitor control member of an electric valve apparatus is energized by employing a voltage derived from a capacitance of a resonant circuit, and Fig. 2 represents certain operating. characteristics 39 thereof. Fig. 3 represents-another embodiment of my invention in which the immersion-ignitor control member isenergized in accordancewith a voltage derived from the inductance of the resonant circuit. I

, Referring now. to Fig. 1 of the accompanying drawing, my invention is diagrammatically shown as applied to an electric valve translating systemfor transmitting, energy ,from an alternating current circuit I to a direct current circuit, '9

2, through a transformer 3 and electric valve means [and 5. TThetra former 3 is provided with a primary, winding 6 aving an electrically intermediate connection 1 and a secondary wind ing 8. Each of the electric valve means 4 and 5 l5 includes an anode 9, a selfdeconstructing cathode, such as a mercurypool, cathode I0, and. an associated control member Huwhichmay be of the immersion-ignitor type; The immersionignitor control member ll may be of a material G such as boron-carbide or silicon-carbidaoriof, a material such as that described and claimed in U. S. Patent 1,822,742 granted to Karl B. McEachronSeptember 8, 1931, and signed to the assignee of the present applicatio I provide control circuits l2 and I3 which are associated with electric valve means 4 and 5, respectively, to impress on immersion-ignitor. control members H thereof unidirectional voltages of substantially perpendicularwave frontfl fi Each of the control circuits l2 and I3 includes a resonant circuit, which may be either linear or nonlinear, and comprises an inductance, which may or may not be self-saturating, and a capacitance 15 which, as illustrated, are connected in II and a variable resistance l9.- One terminal of the alternating current circuit 16 is connected to the electrically intermediate terminal 1 of primary winding 6 of transformer 3. Considering circuit 52, a suitable unidirectional conducting device, such as an electric valve 20, is connected between a point of the resonant circuit and cathode iii to impress on immersion-ignitor control member H a voltage derived from one of the elements of the resonant circuit, as, for example, the voltage appearing across the terminals of capacitance 15. The electric valve 20 is preferably oi the type employing an ionizable medium, such as a gas or a vapor, and includes an anode a cathode and a control member 23. An inductance 2:3 is connected in series relation with .thecontrol member ii. cathode IQ and electric valveid to extendfin the direction of the. time the current transmitted to the control memher it when the electric valve 20 .efiects discharge or" the capacitance 35. The feature of the arrangement of Fig. 1, whereby a resonant cirand a unidirectional conducting device are employed to energize a control member of an electric valve, is disclosed in my copending application Serial No. 148,517, filed June 16, 1937, and assigned to the assignee of the present application.

To obtain a control voltage to render electric valve 28 conductive and to effect energization of immersion-ignitor control member ll of electric valve 4 at a predetermined time in the cycle of voltage applied to anode 9, I provide a suitable phase shifting circuit such as a seriallyconnected capacitance 25 and a resistance 26 which are connected .to the source of alternating current 56. A suitable current limiting resistance '2? may be connected in series relation with the contrelmember 23 of electric valve 20.

The operation of the embodiment of my invention shown in Fig. 1 will be considered when the system is operating to transmit unidirec-.

tional current to the load'circuit 2 from the alternating current circuit 1,. through transformer 3 and electric valve means 4 and5. As will be well understood by those skilled in the art, the electric valves 5 and 5 will-be rendered conductive by the control circuits l2 and .I3 and will conduct current alternately to transmit unidirectional current to load circuit 2. Adjustable resistance ll! of phase shifting circuit i! is adjusted to impress on the resonant circuit, including inductance I l and the capacitance IS, an alternating voltage having apredetermined phase displacementrelative to the voltage impressed on anodes 9 of electric valve means 4 and 5. Inductance i l and capacitance I 5,0perate as a resonant circuit tuned to the frequency of the alternating current circuit l6. Under these conditions, it is to be understood that the voltages appearing across the inductance l4 andcapacitance i5 rise to values several times that applied to the resonant circuit, and these voltages are employed to impress on the control members ll voltages which assure positive initiation of the arc discharges.

The operating characteristics represented in Fig. 2 may be considered to facilitate the explanation of the operation or the control circuits l2 and 13 of the arrangement of Fig. 1. Curve A may represent the'voltage appearing across the terminals of capacitance IS in circuit I2. The electric valve 20 is energized by the excitation circuit therefor to be rendered conductive at a time ato impress on control member H a unidirectional voltage of substantially perpen- V valve 20 is rendered conductive, the resonant circult will be unbalanced, that is, rendereddissonant thereby limiting the current transmitted to the circuit l2 from the source of alternating current 18.

- It is to be understood that, by the proper design and proportioning oi the self-saturating inductance H, the resonant circuit may be made to operate as a non-linear resonant circuit.

Under this condition of operation, the voltage' appearing across the capacitance IE will be one of rectangular wave form having a substantially perpendicular wave front, and the voltage appearing across the self-saturating inductance l4 .will be of substantially peaked wave form. It

is to be understood that my invention in its broader aspects applies to the control circuit when it: is operating either as a linear resonant circuit or as anonlinear resonant circuit.

, The arrangement of my invention diagrammatically shown in Fig. 3 is substantially the same as that shown in Fig. 1 and corresponding elements have been assigned like reference numerals. In the arrangement of Fig. 3, the immersion-ignitor control member H is energized in accordance with the voltage appearing across the inductance l4. The resonant circuit, including inductance and capacitance l5, may be arranged to operate either as a linear resonant circuit or as a nonlinear resonant circuit. The

inductance l4 may be designed to be self-saturating.

The operation 0! the arrangement of. Fig. 3

' is substantially the same as that of Fig. 1. The

, age appearing across the inductance l4 will, of

course, be sinusoidal and the electric valve 20 may be rendered conductive at about the maximum value of applied voltage to impress on the control member H a relatively large voltage of steep wave front. When the circuit is operating as a nonlinear circuit, the voltage appearing across the terminals of inductance will be of peaked wave form and the electric valve 20 may be rendered conductive at substantially the peak value of this voltage to impress a commanding voltage on the control member II. a

One of the principal advantages or the convoltage. During the next half cycle of applied voltage 01 the same polarity, thecircuit will automatically' increase its voltage due to the resonating condition of the circuit, assuring ignition of the arc during that half, cycle. The direction of change or voltage under these conditions tends to cause the electric valve 4 to be rendered conductive. Another important feature of my invention is thefeature of the control circuits by virtue of which relatively large currents are supplied to the control members I I without imposing on the supply circuit, such as supply circuit l or circuit l6, heavy current conditions. This feature is of particular importance where it is desired to effect positive control by supplying relatively large currents to the control members, and where it is undesirable to obtain these currents directly from the supply circuit.

While I have shown and described my inven: tion as applied to a particular system 01 connections and as embodying various devices diagrammatically 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 all such changes and modifications as fall within the true spirit and scope of my invention. L

What I claim as new and desire to Letters Patent or the United States is:

1. In combination, an electric valve means having ,a control member, a source of alternating current, a resonant circuit connected to be energized continuously from said source for producing a voltage substantially greater than that applied to said resonant circuit, and means for impressing on said control member a component of voltage derived from said resonant circuit and for rendering said electric valve means conductive during hali' cycles of voltage of predetermined polarity of said source and'comprising a controlled electric valve connected between said resonant circuit and said control member, said resosecu're by ,nant circuit serving to-increase said component of voltage accumulatively in the event said controlled electric valve fails to conduct current to said control member during each half cycle of voltage of said predetermined'polarity.

2. In combination, an electric valve means having a control member, a source of alternating current, a resonant circuit connected to be energized continuously from said source and including an inductive impedance and a capacitive impedance for producing voltages substantially greater than the voltage applied to said resonant circuit, and means comprising a controlled electric valve for impressing on said control member a voltage derived from one of said impedances and for rendering selectively resonant and dissonant said resonant circuit, said resonant circuit serving to increase said component of voltage in the event said controlled electric valve fails to conduct cur-- rent to said control member during each half cycle of voltage of predetermined polarity of said source.

3. In combination, an electric valve means employing an ionizable medium having a control member for initiating an arc discharge, a source of alternating current, a resonant circuit con nected to be energized continuously from said source and including a serially-connected inductance and a capacitance for producing a voltage substantially greater than the voltage applied to said resonant circuit, and a controlled electric valve connected to impress on said control memher a component of voltage derived from said capacitance to render said electric valve means conductive during each half cycle of voltage of predetermined polarity of said source and for rendering said resonant circuit dissonant when in a conducting condition. a

4. In combination, an electric valve means having a control member, a source of alternating current, a resonant circuit continuously energized from said source and including a serially-connected capacitance and an inductance for producing a voltage substantiallygreater than the voltage applied to said resonant circuit, an electric valve having a control member and being connected to energize said first mentioned control member in accordance with a component of yolta age, derived from said resonant circuitfljand nected capacitance and an inductance for producing a voltage substantially greater than the voltage appliedto said resonant circuit, an electric valve having a control member and being connected to energize said first mentioned control member in accordance with the voltage appearing across said capacitance and to render said resonant circuit selectively resonant or dissonant, and means for energizing said control member of said electric valve to render said valve conductive when the voltage appearing across said capacitance attains a predetermined value thereby rendering said electric valve means conductive. i

6. In combination, an alternating current circuit, electric valve means connected to be energized from said circuit and having an anode, a cathode and a control member, a source of alter nating voltage having a predetermined pha se displacement relative to the voltage of said alternating current circuit, a resonant circuit connected to be energized continuously from said source and comprising a serially-connected capacitance and an inductance for producing a voltage substantially greater thanthe voltage applied to said resonant circuit, an electric valve connected to energize said control member by discharging said capacitance through said control member thereby rendering said resonant circuit dissonant, and means for rendering said electric valve conductive at the maximum instantaneous value of voltage during each cycle.

7. In combination, an alternating current 'circuit, an electric valve means connected to be energized from said circuit and including an anode, a cathode and an immersion-ignitor control member associated with said cathode, a

mined :phase displacement relative to the voltage cuit dissonant, said electric -valve having a con-- trol member and said resonant circuit serving to effect an accumulative increase in the voltage derived from said capacitance or said inductance in the event said electric valve'fails to conduct current to said control member during each half cycle of voltage of predetermined polarity, and a phase shifting circuit for energizing said last mentioned control member to render said electric vvalve conductive to effect energization of said immers'ion-ignitor control member at the maximum instantaneous value of voltage during each :cycle.

8. In combination, an electric valve means having a control member, a source of alternating current, a nonlinear resonant circuit connected to be energized-continuously from said source and including a serially-connected capacitance and a self-saturating inductance for producing a voltage substantially greater than the voltage applied to said resonant circuit, and means comprising an electric valve for impressing onsaid control member a component of voltage derived from said resonant circuit and to render said resonant circuit dissonant when in a conducting condition.

9. In combination, an electric valve means having a control member, a source of alternating current, anonlinear resonant circuit connected to be energized continuously from said source and including a serially-connected capacitance'and a self-saturating inductance for producing a voltage substantially greater than the voltage applied to said resonant circuit, and means comprising an electric valve for impressing on saidcontrol member a component of voltage of. perpendicular wave front derived. from said inductance and to render said resonantcircuit dissonant when said second mentioned electricvalve is in a conducting condition.

10. In combination, an electric valve means having a control member, a source oi! alternating current,a resonant circuit continuously energized ,from said source and including a serially-connected capacitance and an inductance for producing a voltage substantially greater than the voltage applied to said resonant circuit, an electric valve having a control member and being connected to energize said first mentioned control a member in accordance with a component of voltagederived from said resonant circuit, said resonant circuit serving to increase accumulatively the voltage derived from said resonant circuit in the event said electric valve fails to conduct cur-' rent to said control member during each half cycle of voltage or predetermined polarity of said source and means comprising a phase shifting circuit for energizing said control member of said electric valve to render said electric valve conduc-v tive at a predetermined time durlng each .cycle of voltage of said source. 7

.MAR N A; EDWARDS.