US2210492A - High voltage generator - Google Patents

Description

ug W40, N. E. UNDENBLAD ZWQZ HIGH VOLTAGE GENERATOR original Filed Aug. 9, 19.53

A NILS E. UND NBLD BY a E //Ww /ZX ATTORNEY Patented Aug. 6, 1940 UNITED STATES HIGH VOLTAGE GENERATCR Nils E. Lindenblad, Port Jefferson, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application August 9, 1933, Serial No. 684,328 Renewed August 11, 1938 13 Claims.

My present invention has as its main object the provision of methods and means for generating very high potentials or voltages at high energy levels.

In one way of carrying out my invention for the generation of high D. C. voltages I charge metallic units, preferably particles of metal, by actual conductive contact with a D. C. source. Then, by moving the particles away from the source, the voltages of the charges thereon are increased, in a manner which shall be explained more fully hereinafter, and the charges are ultimately deposited upon a low voltagev gradientsection of a charge-storing device or container.

l5 In another arrangement for producing high voltages according to my present invention, an induction electrode; either grounded or preferably maintained at a high voltage, is insulatingly separated from a chargeable medium which may be 2@ a solid, a liquid or a gas, and, by the use of a point discharge electrode system connected to a direct current source or preferably to ground, ionization or corona is caused to take place through and/or about the chargeable medium.

25 The charged medium is then moved or carried to a low potential area on a chargeable element the high voltage surface of which is brought up to an exceedingly high voltage by the continued deposits from the charged medium. In a fur- 3;@ ther modification of my present invention both my contact and induction principles, about which more will be said later, are utilized.

A further and more specific object of my present invention is to provide systems which utilize 35 my improved contact and induction principles for charging solid mediums such as belts and disks, for charging liquids such as oil and oil containing metallic particles in suspension and for charging gases.

40 In some instances, in carrying into eect the purposes of my present invention, rather high initial excitation voltages are required. If it is attempted to cascade alternating current transformers to build up a high alternating current 45 voltage, which voltage may be used directly in some forms of my present invention, or if it is attempted to use the cascaded transformer system so that the high A. C. voltage developed may be rectified so as to obtain a high direct m)l current voltage, it will be found that insulation difficulties in the nal transformer `stage will prove practically insurmountable. 'I'hat is to say, if the core of the final transformer is grounded, the high voltage generated in the coils will re- 55 quire exceedingly heavy insulation, and for all practical purposes lt will be found almost impossible to provide the needed insulation. Accordingly, a further object of my present invention is to provide an improved cascaded system of transformers for developing an exceeding high 5 alternating current or direct current voltage in which the core of each stage will be subjected to no more than the voltage developed by any particular stage, rather than as explained before, be subject to the integrated voltage up to the 10 voltage of that stage.

My invention further contemplates, in connection with the cascaded transformer system, the rectication of the voltage of each stage. As itis desirable to make the voltage of each stage 4as' high as possible, it will be found that ordinary tube rectiflers subjected to high A. C. voltages for rectification, will have their filaments subjected to high electrostatic stresses leading to their rapid destruction. Consequently, a further object of my present invention is to provide an improved tube rectifier circuit. For this purpose I provide an arrangement wherein the cathodes or laments are protected from subjection to high electrostatic forces by suitably connecting a protective grid about the cathode directly, or through a bias source, to the cathode.

Still further objects of my present invention are to provide an improved belt system for generating high voltages; to provide an improved disk system for generating high voltages; to provide improved combinations of disks alone or combinations of disk or disks and/or belt or belts arranged in such a way as to have an effective output voltage much higher than the voltage generated by any one system; to provide a symmetrical network system in which various elements are charged in parallel but discharged in series so as to obtain a much higher resultant output voltage as compared to the voltage applied-to each element; and many others which will be apparent as the description of my present invention proceeds. This description, by the Way, will be given in greater detail with the aid of the accompanying drawing which, however, is not to be considered in any way limitative of my present invention but is to be considered only illustrative. Turning to it,

Figure 1 diagrammatically illustrates one form of my invention wherein my improved belt system is cascaded with a plurality of disk arrangements for producing a high direct current voltage,

Figure 2 is a cross-sectional diagrammatic view of the belt exciter of Figure 1; 55

Figure 2a is a cross-sectional view of the schematic arrangement shown in Figure 2;

Fig. 2b is a detailed showing of an Inductor electrode and belt;

Fig. 2c is a detailed showing of a charging electrode and belt.

Referring to Figure 1, a motor 2, through shaft 4, drives a direct current` high voltage generator 6 and pulley 8. The pulley 8 in turn drives a belt I0, I2 (see also Figures 2, 2a, 2b and 2c) which at its other end rides within a collector I4 in the form of a metallic sphere or cylinder. 'Ihe collector suitably insulated from ground by means of an insulating support I6. The pulley IB within the shell I4 may be supported in any suitable way as for example by means of a bearing (not shown) fastened to the interior of the collector shell I4. As shown in Figure 2a the belt Ill, I2 rides into the shell by virtue of elliptical or other smoothly curved orifices I4a and I4b.

'I'he belt I0, I2 is preferably made of varnished silk. However, for use with my present invention, it is revarnished with a suitable varnish, resinous or nitrocellulose compound, or similar substance such as an oven baking varnish and whenthis layer of resinous material is almost dry, a metallic powder such as aluminum dust is rubbed into the surface which does not come into contact with the metallic pulleys 8, I8. The belt is then allowed to dry and another layer or coat-v 1 20 and the metallic particles insulatingly supported upon the belt. These metallic particles or units then form one side or eective plates of a condenser and the metallic pulley 8 the other.

Now, with the generator 6 switched into action so as to apply a moderately high voltage, say 500 volts to the brush 20, the particles or units carried by the supporting member or belt I0, I2 will be charged up as they contact with the metallic brush 20. As the belt straightens out and is moved away from the brush, the charged units, (which have become charged by actual contact) because of their relative motion and increased distance between themselves and their eiective other condenser plate or electrode,

' namely, pulley 8, will have their capacitiesdecreased. Because of this decrease in effective capacity, the voltage on the particles will rise charge points 22 which preferably are not in direct contact with the outer surface of the belt, it will be found that the voltage on the metallic particles is suiiiciently high to arc across the air gap between the metallic points 22 and the belt. This arcing is in the form of corona. The

various charges deposited on the internal low voltage gradient area of the collector shell then scamper to the outer surface of the collector shell I4 building up 4a large unidirectional potential thereon. The leakage throughout the length of the belt is too small to cause any drainage of the built up charge on the collector.

The charge accumulated upon the outer surface of the collector shell,I4 may then be utilized in any desired way. As shown in Figure 1. I use the charge on the collector shell to excite the preferred form of my high voltage disk type of generator.

As shown in Figure l, the charge on the outer surface of collector I4 is applied through the tubular metallic conductor 24 to a circular metallic induction electrode 26 having a surface 26 facing a portion of the insulating disk 30. The surface 28 of the induction electrode 26 may be made iiat and parallel to the disc or it may be made elliptical, spherical, parabolic, hyperbolic, or may be made to curve in accordance with any law which will give small corona loss. Because of the high voltages developed on the induction electrode, and to prevent corona arc-over due to, among other things, ionization of the air between the induction electrode and the insulating disk 30 which, incidentally, may be made of any suitable high-grade insulating material, a sheet of insulating material 32 isplaced between the induction electrode 26 and the disk 3D.

On the opposite side of the disk 30 I place a charging electrode 34 having metallic discharge points 36. The charging electrode 34 or the brush ionization system 34, 36 is connected by means of conductor 38, which may be tubular, to ground 40. As illustrated, the charging system faces a section of the disk 30 opposite the induction electrodey 26 or opposite the projected area of the induction electrode upon the disk 36.

Assuming that the generator 6 has impressed a. positive charge upon the particles riding upon the belt I0, I2, the outer surface of the co1- lector shell I4 will become charged to a high positive potential. So also the induction electrode 26 will become at -a high positive potential and will tend to attract to it charges from the charging system orbrush ionization system 34, 36. The discharge from the points 36, however, cannot reach the induction electrode 26 because of the interpos'ition of the disk 30, as a result of which negative charges settle upon the section of the disk 30 between the discharge points 36 and the induction electrode 26. Because of the preferably high insulating qualities of the disk 36,' the charges do not leak or distribute themselves all over the surface of the disk but remain carried upon a particular sec- A tion of the disk 30.

Rotation of the disk by means of the motor 2, belt I6, I2, pulley I 8, and shaft 42 will cause the charged sections of the disk 30 to discharge on metallic points 44 carried by and located in the low voltage gradient section of a second U- shaped, hollow, curved surfaced, metallic collector 46. As the disk is rotated faster and faster, new or empty," that is, discharged sections of the disk are introduced between the induction and charging electrodes 26, 34, as a result of which more and more ions will be drawn from the points 36 and settle on the disk. Hence, greater speeds of rotation will cause greater number of charges per unit of time to be deposited on the disk giving, as a consequence, a current fed into the second collector 46 proportional to the rotative speed ofjthe disk 30. Therefore, an appreciable amount of current may be fed into the second collector 46 which is limited, in general,

usY

' ing action adverted to will not take place.

only by the rotative speed of disk 30. However, inasmuch as the second collector 46 is oi opposite polarity to that of the induction electrode 26, there will be a very high voltage gradient between these two bodies which will on smaller apparatus with small diameter disks tend to cause undesirable loss in the form o! corona. Moreover the second electrode being negative and of opposite polarity to the induction electrode 26 will tend to produce a neutralizing action on the desired corona between the brush points 36 and the disk 30.

' At this point it may be well to point out that the polarity assumed for the generator has been taken arbitrarily to impress a positive potential upon the metallic brush 26. If desired, the brush 20 may be connected to the negative terminal of the generator 6 in which case the polarities throughout the system would be reversed.

Also, in order to avoid the high potential gradient between the induction electrode 26 and the second collector 46, the induction electrode 26 with the extra insulating sheet 32 and charging electrode 34 may be reversed in position so that the induction electrode is grounded and the charging electrode 34 isY connected to shell I4. However, in this case there will not be an unlimited amount of ions produced upon the brush tips 36 since the output or charges placed upon the disk 30 will be limited by the charge delivered from the 'first collector shell I4. This is so since the charge on the disk can only be derived from the discharging points 36 and as their source now will drop in potential due to actual discharge at points 36 the amount of charge which can be deposited upon the disk will be limited by the charge on collector shell I4. The faster the disk is rotated, the faster will collector I4 be drained and the lower will its voltage be. In the first mentioned connection, the faster the disk is rotated the faster is the deposit of charge at constant voltage since there is no drainage of the source.

As an added advantage there is, in the second case, an appreciable gain in voltage due to the movement of the charges away from the charging system and in addition, with a reversal of the electrodes 26, 34 shown in Figure l, since the second collector 46 and the charging electrode or brush ionizer 34 are of the same polarity, there will be no exceedingly high voltage gradient between the charging electrode and the collector, as a consequence of which there will be no bad corona losses. Moreover, the neutraliz- However, this reversal will not be necessary on a large machine where there is ample room for grounded metallic shields between the second collector and the induction electrode as well as first collector I4.

Turning back now to the arrangement as illustrated in Figure 1, the negative charge on the U-shaped, curved, second collector 46 is then conductively brought by means of tubular metallic pipe 48 to a'second brush ionizer or charging electrode 56 carrying the metallic discharge points 52. On the opposite side of the charging electrode 50 is connected an induction electrode 53 similar in structure to induction electrode 26 but grounded through conductors 54, to ground 56. Here also in the second disk system, an insulating sheet 58 is insulatingly mounted between the induction electrode and the second rotating disk 60 also of an insulating material of u high tensile strength. As the disk 60 rotates,

the negative charge on the second collector is deposited through the discharge points 52 thereon. Movement of the charge away from the electrode 50 causes it to increase in potential and the increased potential charge is deposited on a third collector 62 which picks up the charge by means of the metallic pick-up points 64. In connection with the third collector system the charge deposited upon the disk is limited by the amount of energy fed into the second collector 46 since the induction electrode 53 is connected to ground.

As in connection with the belt system, the disk may contain metallic particles by rubbing the same into the surfaces of the disk and then lixing them thereon by suitable insulating compounds such as varnishes or any resinous compound or any nitrocellulose compound. With the metallic particles on the surfaces of the disk the various brush points such as 36, 44 and 64 may, if desired make actual contact with the particles carried by the disks as do the metallic hairs or filaments of the metallic brush 26 riding upon the belt lil, I2.

Charging of the belt system shown in Figure 1 is not, however, limited to the contact method and means which I have described. On the other hand, the induction arrangement such as used for the disks 30, 60 of Figure 1 may be applied equally as well to the belt.

In Figure 2b, the belt I0, I2 is charged up by my improved induction apparatus, induction electrode 26 being insulated from the belt by means of insulating sheet 32. The induction electrode 26 is connected as indicated to a high voltage exciter source which may be any one of the high voltage sources which shall be described more fully herinafter or which may be a D. C. source such as generator 6 of Figure 1. Corona discharge will take place towards the belt at the points 36 and this charged up section of the belt may then move along into the collector I4 as before. In the arrangement shown in Figure 2c, the discharge points 36 on the contrary are connected to the high voltage source and the induction electrode 26 is grounded.

It should be clear, in connection with Figure 1 that additional collector stages may be cascaded to the third system. For example, an additional disk may be placed still further to the left on shaft 42 and a brush ionizer system or an induction electrode such as 48, 5I) connected to the third collector 62 to charge up the disk, a suitable induction electrode or brush ionizer being connected to the opposite side of the disk to ground and so on. Moreover, while the system shown in Figure 1 indicates various rotating elements or disks mounted on a common shaft this is not at all necessary since the rotating elements may be mounted independently and, if desired, rotated at the same or different speeds. In addition, it is to be clear that it is not necessary to use the belt exciter system for charging the disk system.

Various other changes will suggest themselves to those skilled in the art in carrying out the principles of my present invention. Therefore, this invention should not be considered as limited to the various illustrations which are merely given as specific examples, but should be given the full scope indicated in the appended claims. f

Having thus described my invention, what I claim is:

1. A combined belt and disk system for generating high voltages comprising a belt of insaid charging means by the rotation of said rotatable device.

2. A belt system for charging bodies comprising a belt of insulating material, metallic units in the form of metallic dust particles insulatingly supported from each other and carried by said belt, means to charge' said units, and means to discharge the units after movement from said charging means.

3. A belt system for charging bodies comprising a belt of varnished silk, metallic units in the form of metallic dust particles insulatingly supported from each other and carried by said belt, means to charge said units, and means to discharge the units after movement from said charging means.

4. A belt system for charging bodies comprising a belt of insulating material coated with a plurality of varnished layers alternately arranged with a plurality of metallic units in the form of metallic dust particles insulatingly supported from each other and carried by said belt, means to charge the units, and means to discharge the units after movement from said charging means.

5. A belt system for charging bodies comprising a belt of insulating material coated with a plurality of varnished layers alternately arranged with a plurality of metallic units in the form of aluminum dust particles insulatingly supported from each other and carried by said belt, means to charge the units, and 'means to discharge the units after movement from said charging means.

6. A combined belt and disk system for generating high voltages comprising a belt of insulating material and a plurality of disk surfaces of insulating material mounted on a shaft, a rotatable device for rotating said belt and said Shaft, metallic units carried by the belt and disk surfaces and insulatingly supported from each other, means to charge said metallic units, and means to dischargev said metallic units after movement from said charging means bythe rotation of said rotatable device.

7. A combined belt and disk system for generating high voltages comprising a belt of insulating material and a plurality of disk surfaces of insulating material mounted on a shaft, `a. rotatable device having a rotor for rotating said belt and said shaft, metallic units carried by the belt and insulatingly supported from each other, means comprising a generator having a rotor arranged to rotatewith the rotor of said rotatable device to charge said metallic units, and means to discharge said metallic units after movement from said charging means by the rotation of said rotor of the rotatable device.

8. A combined bel-t and disk system for generating high voltages comprising a belt of insulating material and a plurality of disk surfaces of insulating material mounted on a shaft, a rotatable device having a rotor for rotating said belt and said shaft, metallicj-unitsfcarried by the belt and insulatingly supported from each other, means comprising a generator having a rotor arranged to rotate with the rotorofr said l rotatable device to charge said metallic units, means to transfer the charge from said belt to a surface of one of said disks, and ni(graditi,H 10.v

discharge said charge from said one of said disk surfaces.

9. A combined'belt and disk system for generating high voltages comprising a belt of insulating material and a plurality of -disk surfaces.

of insulating material mounted on a shaft, a rotatable device having a rotor for rotating said belt and, said shaft, metallic units carried by the belt and disk surfaces and insulatingly supported from each other, means comprising a generator having a rotor arranged to rotate with the rotor of said rotatable device to charge said metallic units, and means to discharge said metallic units after movement from said charging means by the rotation of the rotor of said rotatable device.

l0. A belt system for generating high voltages comprising a rotatable device having a rotor mounted on an extended shaft, a generator for charging said system, said generator having a rotor mounted for rotation with the rotor of said rotatable device on said extended shaft, a

pulley mounted on said extended shaft for rotation therewith, a second shaft having a second pulley thereon, a belt stretched between said pulleys to provide rotation of said second shaft from the rotor of said rotatable device, an insulating surface on said belt, metallic units carried on said belt and insulatingly supported from each other, means to charge said metallic units from said generator, and means to discharge said metallic units after movement from said charging means.

11. A combined belt and disk system for generating high voltages comprising a rotatable device having a rotor, a first movable shaft, a generator having a rotor for charging said system, said generator rotor mounted for rotation with the rotor of said rotatable device, a pulley mounted on said rst movable shaft for rotation therewith, a second shaft having at least one disk surface of insulation mounted, thereon, a second pulley thereon, a belt stretched between said pulleys to provide rotation of said second shaft from the rotor of said rotatable device, an insulating surface on said belt, metallic units carried on said belt and said disk surface, said metallic units insulatingly supported from each other, means to charge said metallic units from said generator, and means to discharge said metallic units after movement from said charging means.

12. A belt system for generating high voltages comprising a rotatable device having a rotor, a rst movable shaft, a generator for charging said system, said generator having a rotor mounted for rotation with the rotork of said rotatable device, a pulley mounted on said rst movable shaft for rotation therewith, a second shaft having a second pulley thereon, a belt stretched between said pulleys to provide rotation of said second shaft from the rotor of said rotatable device, an insulating surface on said belt, metallic units carried on said belt and insulatingly supported from each other, means to charge said metallic units from said generator, a rst collector electrode, an induction electrode located apart from said belt and connected to said collector electrode, a second collector electrode, and means to discharge the charge from said second elecrode.

- :113. A combined belt and disk system for generating high voltages comprising a rotatable device having a rotor, a first movable shaft, a generator for charging said system, said generator having a rotor mounted for rotation with the rotor of said rotatable device, a pulley mounted on said rst movable shaft for rotation therewith, a second shaft having a plurality of disk surfaces mounted thereon, a second pulley thereon, a belt stretched between said pulleys to provide rotation of said second shaft from the rotor of said rotatable device, an insulating surface on said belt, metallic units carried on said belt 10 and said disks and insulatingly supported from each other, means to charge said belt metallic units from said generator, a plurality of collector electrodes, a plurality of induction electrodes. means to discharge said disc metallic units after movement from said induction electrodes to said collector electrodes by having said induction and said collector electrodes arranged in cascaded connection to progressively increase the voltage of said system.

NILS E. LINDENBLAD.

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