US2562031A - Corona voltage regulator tube - Google Patents

Description

'JuEy 241-, 395i M. GERBER CORONA VOLTAGE REGULATOR TUBE Filed April 28, 1950 4 4 INVENTOR.

Patented July 24, 1951 2,562,031 CORONA VOLTAGE REGULATOR TUBE Max Gerber, West New York, N. 1., asslgnor to Chatham Electronics Corporation, Newark, N. J., a corporation of New Jersey Application April 28, 1950, Serial No. 158,850

This invention relates to corona voltage regu lator tubes for maintaining a predetermined constant voltage between two conductors. In greater detail it relates to electron discharge tubes which function as voltage regulators while passing cur-. 5

rent duringthe condition known as corona discharge. While the invention is subject to a wide range of application and circuits, it is especially suited for use in high voltage supply circuits which range in potential from 2,000 to 20,000 volts. The

regulator tubes pass currents which range from .001 to .1 microamperes and hence consume small amounts of power.

As used throughout the specification and claims,the term "corona discharge".refers to an electrical discharge between two conductors in a gas in which the ionization is confined to a small area on the smaller electrode;

Voltage regulator tubes utilizing the glow discharge condition in gas filled diodes are well voltage applied across a corona type tube causes ionization only in the neighborhood of the smaller electrode, which in all the present examples will be made the anode. Because of the high field intensity at theanode surface, electrons are given sufiicient energy to cause ionization and liberate positive ions. The ions may cause additional ionization in the vicinity of the anode, but when out of the high intensity field, they drift to the cathode to maintain the current flow. When the current through a corona regulator tube increases, the intensity and diameter of the ionized space increases and the voltage across the tube remains approximately constant.

One of the objects of this invention is to provide an improved voltage regulator having difler- 5 cut discharge characteristics as compared to prior art regulators.

Another object of the invention is to reduce the currentconsumed in voltage regulator tubes.

Another object of the invention is to improve the operating characteristics 01' corona regulator tubes so that regulation is efiected over a greater range 01' current values.

Another object of the invention is to provide aregulator tube which may have its voltage ad- 5 justed by varying the electrode spacing.

The invention includes an envelope which encloses two electrodes and a filling or hydrogen gas. One electrode is formed in the shape of a 2 Claims. (Cl; 313-146) This within the cup and has an effective area which is much smaller than the first electrode. A feature of an alternate design of the regulator tube includes an electrod'e'mounted on a screw thread with an eccentric weight for keeping the electrode in a non-rotating position when the regulator tube is mounted in a horizontal alignment. By turning the tube the electrode spacing is varied. j

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

Fig. 1 is a sectional view of a corona voltage regulator tube in which the electrodes are a fixed distance apart.

Fig. 2 is a .cross sectional view of the tube shown in Fig. 1, taken along line 2--2 of that figure.

Fig. 3 is a sectional view of. an adjustable corona voltage regulator tube in which one electrode is made adjustable.

Fig. 4 is a cross sectional view of the tube shown in Fig. 3, taken along line 4-4 of that figure.

Referring now to Figs. 1 and 2, a glass envelope ill encloses two electrodes H and i2. The first electrode II is a cup shaped cathode which is welded to a lead-in conductor l3 sealed into the envelope ll. The second electrode I2 is a rod shape anode, rounded on the end, which is also welded or otherwise joined to a lead-in conductor l4 sealed into the envelope. The regulator tubes which have a predetermined voltage constant 01 from 2,000 volts to 6,000 volts are filled with hydrogen gas at pressure lower than atmospheric and hence an ordinary glass tubulation II is used which may conveniently be sealed oil by a gas flame. Voltage regulators using a gas filling which has a pressure higher than atmospheric employ a pinch type seal which will be described later.

One type or corona tube which regulates to a value of 6,000 volts uses an axial electrode spacing of 10 mm. and hydrogen gas at a pressure of 65 cm. of mercury.

The corona regulator tube shown in Figs. 3 and 4 employs an envelope IS, a cone shaped cathode H, and a rod shaped anode It. The cathode I1 is welded to a hollow lead-in conductor 20 which communicates with the inside of the envelope i6 by means of a hole 2|. This tube is sealed to the exhausting and filling system while the tube is being cleaned, filled, and aged, and when ready for sealing, a copper sleeve 22 is moved into place over the lead-in conductor and the two tubes collapsed by a strong clamp. The tube is cut oil from the exhausting system and cup or cone, The second electrode is positioned the end immediately dipped in molten solder.

asoaoar 3 v This provides a gas tight seal and is used for tubes which are filled with a pressure greater than atmospheric pressure.

The anode l0 oi Fig. 3 is rotatably mounted on a screw 23 which is cut on the inner end oi leadin conductor 24. A weight 2!, usually made of iron, is secured to one side of the anode so that when the tube is held in a horizontal position and turned on its longitudinal axis, the weight II will retain the anode in a non-rotating position, thereby shifting its position with respect to the cathode i'l. This is one convenient way of adjustlng the regulated voltage to a desired value. A pin 26 and a stop 21 cooperate to prevent sticking at the end of the thread.

It it is desired to operate the voltage regulator tube in a vertical position, a magnet 28, shown in dotted lines, may be used to retain the weight 25 in non-rotatable position.

One type or high pressure adjustable corona regulator tube which regulates to a voltage of 17,600 volts 110% is filled with pure hydrogen at "a pressure of 228 cm. of mercury.

It has been found that corona tubes of this kind are sensitive to impurities in the hydrogen gas. Oxygen is particular causes instability in the corona discharge at currents below .1 microamperes and care must be exercised to have all traces.

01' oxygen removed; To this end a getter of mag- 'nesium and aluminum is employed to absorb all tracs'of oxygen after the tube has been scaled.

Corona regulator tubes as described above may be used in the same general type of circuit that is used with glow discharge regulator tubes.

While there have been described and illustrated specific embodiments of the invention, it will be obvious that various changes and modifications may be made therein without departing from the field of the invention which should be limited only-by the scope of the appended claims.

I claim:

l. A corona voltage regulator tube tor regulating voltage during a corona discharge comprising,

an envelope filled with hydrogen gas, a cathode and an anode mounted-within the envelope, said anode comprising a conductor having a radius of curvature less than one-third the diameter or the envelope, said cathode comprising a cup shaped conductor surrounding the end oi. the anode and having an area at least three times the area or the anode, a getter within said envelope for forming a stable solid compound with oxygen, and screw adjusting means within the envelope including an eccentric weight for varying the spacing between said anode and cathode.

2. A corona voltage regulator tube for regulating voltage during a corona discharge comprising.

an envelope filled with hydrogen gas, a cathode and an anode mounted within the envelope. said anode comprising a conductor having a radius of curvature less than one-third of the diameter of the envelope, said cathode comprising a cup shaped conductor surrounding the end of the anode and'having an area at least three times the area of the anode, and screw adjusting means within the envelope for varying the spacing between the anode and cathode including an eccentric magnetic rod positioned for actuation by a magnet on the outside of the envelope.

MAX GERBER.

REFERENCES CITED The following references are of record in the file of this patent:

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