US2053431A - Vapor electric converter - Google Patents

Description

Sept. 8, 1936 c. E. HALLER VAPOR ELECTRIC CONVERTER Filed Sept. 27, 1933 lvllllliltOO'O'OlO'l'Q'.

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INVENTOR Cea/Ehafler' WITNESSES: 47% A J%%- Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE VAPOR ELECTRIC CONVERTER Pennsylvania Application September 27, 1933, Serial No. 691,176

2 Claims.

My invention. relates to a vapor electric converter and particularly to an ignition system for such a converter.

In operation of vapor electric rectifiers having make-alive electrodes, it is desirable to limit the total current carried by the electrode in order to eliminate heating thereof. In the operation of make-alives as heretofore used, it has been customary to provide a make-alive voltage active throughout substantially the entire current-carrying period. This make-alive current not only introduces excessive losses into the device, but is detrimental to the keep-alive electrode because of excessive heating of the same.

It is an object of my invention to provide a supply system for the make-alive electrode which supplies current only for the short interval necessary to create a cathode spot in the device.

It is a further object of my invention to provide a surge generator for applying make-alive current which can be adjusted in phase relation to the potential applied to the main electrodes of the .converter.

In a make-alive system according to my invention, the make-alive current is supplied by a peaking or surge generating transformer supplied by a suitable alternating current source.

Other objects and advantages of my invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing in which:

Figure 1 is a schematic illustration of a fullwave converter embodying my invention,

Fig. 2 is a simplified embodiment showing one method of shifting the phase of the surge voltage, and

Fig. 3 is a further modification showing a phase-shifting system for the surge voltage.

In the apparatus according to my invention alternating and direct current systems I and 2 are connected by means of a full-wave rectifier having a plurality of arc chambers 4. Preferably each arc chamber 4 comprises a single pair of main electrodes 5 and 6 and a make-alive electrode 3. The potential applied to the main electrodes is preferably controlled by means of a suitable transformer 9. The make-alive electrodes 3 are supplied by a suitable secondary winding ID, the mid-point ll of which is connected to the cathodes 6 of the converter. If desired, suitable unidirectional conductors l3 may be placed in series with the make-alives l to eliminate the danger of ionization in the arc chambers when inverse voltage is applied thereto.

The primary of my transformer is connected of the core member enclosed or connected with the secondary winding I0 is substantially saturated throughout most of the working cycle. Consequently, there will only be voltage generated in the secondary l0 when the flux in the core I6 is passing through zero. In order to prevent the gradual increase of flux through that portion of the core I! interlinked by the secondary I0, I prefer to introduce a leakage path between the primary and secondary windings.

For many purposes it is desirable to be able to shift the phase of the voltage surge produced in the secondary H). In Fig. 2 I have illustrated a convenient method of producing this phase shift. An auxiliary winding 22 is placed on the core l6 and preferably provided with direct current excitation from a suitable source 23. This direct current excitation, by biasing the flux in the transformer core, in efiect, shifts the zero point or the point of flux reversal in the portion of the core I3 linked with the secondary winding Hi.

In the modification according to Fig. 3, the desired phase shift is accomplished by opposed alternating current windings 25 and 26 of adjustable strength. I have found that the most convenient method of securing the opposed alternating current fluxes is to provide a plurality of windings and connect the same to a common source 21 in reverse direction and to control the exciting current of one of said windings 20 by means of a suitable resistor 30. When using opposed alternating current windings I prefer to provide a leakage path 3| between the opposed primary windings 25-26.

In the operation of my make-alive circuit, alternating current is applied to the primary l5 of the peaking transformer which builds up a flux through the secondary l0, thereby generating a voltage therein. However, as that portion I! of the transformer core l6 interlinked with the secondary is of relatively small dimensions, the same will soon become so saturated that any further flux produced by the primary winding will be diverted to the leakage path provided in the core. Consequently, no voltage will be induced in the primary until the flux in the core reverses, at which time the flux in passing through zero will change rapidly in that portion of the core interlinked with the secondary winding and produce a voltage surge in the secondary. If no biasing device is utilized. the surges applied to the makeallves will be substantially identical in time relation with the application of positive potential to the anode of the arc chamber.

If it is desired to operate the converter to produce alternating current from direct current, a suitable auxiliary alternating current source not shown is necessary for the primary of the peaking transformer, and a suitable condenser must be supplied for reversing the current in the arc chambers, unless the alternating current system is regulated by other suitable sources of alternating current.

While I have shown and described specific embodiments of my invention, it will be apparent to those skilled in the art that changes and modifications can be made therein without departing from the true spirit of my invention or the scope of the accompanying claims.

I claim as my invention:

1. A control system for an electric valve having an anode and a cathode comprising a make-alive electrode in permanent contact with the cathode of said valve, a winding connected to said makealive electrode and to said cathode, an exciting winding associated with said first mentioned winding, a core magnetically interlinking said windings, said exciting winding and said core being so proportioned that the core is saturated except at the time of reversal of polarity of the current in said exciting winding whereby peaked voltage waves are generated in said first mentioned winding and a unidirectional conductor connected in series with said first mentioned winding whereby the alternate impulses generated in said winding are impressed on said makealive electrode.

2. A control system for an electric valve having an anode and a cathode comprising a makealive electrode in permanent contact with the cathode of said valve, a winding connected to said make-alive electrode and to said cathode, an exciting winding associated with said first mentioned winding, a core magnetically interlinking said windings, said exciting winding and said core being so proportioned that the core is saturated except at the time of reversal of polarity of the current in said exciting winding whereby peaked voltage waves are generated in said first mentioned winding and a unidirectional conductor connected in series with said first mentioned winding whereby the alternate impulses generated in said winding are impressed on said makealive electrode, a second exciting winding associated with said core, said second exciting winding being dephased with respect to said first exciting winding and means for controlling the current in said second winding for shifting the phase of voltages generated in said first mentioned winding.

CECIL E. HALLER.

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