US2155363A - Direct current voltage multiplication - Google Patents

Description

April -18,"1g39fn L. wfpARKER v m1-55,363

DIRECT CURRENT .voLTAG MULT'IPLIGATION Filed Feb. 21, 1938 x r w l l for/mm/ormer l .secondary n IN1/Enron Lol/ls PJ. Parker AHORA/a.

Patented Apr. 18, 1939 UNITED STATES PATENT 'OFFICE mais w. Parker, Astoria, N. Y., signor to c. s. r.

Development Corporation, New York. N. Y.

Application February 21, 1938, Serial No. 191,770

v12 Claims.

This invention relates to direct current voltage multiplication, and to methods and apparatus for providing such multiplication.

Such apparatus is useful where an output voitage of the order of 110 V. direct current is desired, and where the only voltage available is direct current voltage of the order of 24-32 volts. Such conditions are frequently encountered on farms, trains, boats, trucks, automobiles, airplanes and the like. The apparatus of my invention, as described herein by way of example, is particularly usei'ul under such conditions for operating radio apparatus, sound amplifying and distributing equipment, electric razors, and similar apparatus not requiring excessive power.

Among the objects of my invention are the l following:

To provide a voltage multiplying system which is free from rotating, vibrating, or other mechanically moving parts, that interrupt the circuit by mechanical movement, and to provide such a system in which the voltage multiplication is obtained by purely electrical action from flow of current.

To provide such a system which will supply an output'voltage which may be controlled between limits of the order of 70 to 140 volts, with an input voltage of the order of 24 to 32 volts.

To provide such a system which may utilize from one to a number of tubes connected in parallel, as desired, depending on the power output` wanted, and in which failure oi' one or more of the tubes causes no interruption of operation, butI merely a reduction in output.

To provide such a circuit in the form of a reiaxauon oscillator, but in which the shape or the wave form is altered so that the time .during which the grid is drawing current is greatly increased.

To provide such a system in which the output has so' little ripple and other undesirable components that it may be applied to operate an electrical appliance with little or no filtering.

Stili other objects and advantages of my inven- 0 tion will be apparent from the specification.

The features of noveltywhich I believe to be characteristic oi' my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its fundamen- J tal principles, and as to its particular embodiments will best be understood by reference to the specification and accommnying drawing, in.

which:

Figure i is a circuit diagram of one form of apparatus according to my invention; and

Figs. 2, 3 and 4 are curves of grid voltage, plate current, and grid current, respectively, when the system is operating.

Referring now more particularly to the drawing, ,reference numeral l designates the direct (Cl. ITI-97) current source whose voltage is desired to be multiplied, and while it is diagrammatlcally shown as a direct current generator, it may be storage batteries, or any other source.

The voltage multiplying action of my system may be obtained from one tube only, as well as from a number of tubes working in parallel, and for simplicity of explanation, the system will first be described with reference to one ltube only.

While tubes of various types may be employed, I have found that very satisfactory results are obtained when the tubes are of the type known as 48, in this instance illustrated as comprising an anode la, a grid lb, a second grid lc, anl indirectly heated cathode Id, and a heater or filament le.

'Ihe positive terminal of the direct current source may be connected to one terminal of coil 3 of a. transformer, and the opposite terminal of the. coil may be connected to the anode la. The

grid Ib also may be connected to the positive ter- "1 minal of the source of supply. The auxiliary or screen grid Ic may be, connected to one terminal of coil 2, the opposite terminal of which may be connected to one side of condenser 5, that in turn is connected to the cathode Id.

The connection that is common to coil 2 and condenser 5 may be carried over to output terminal I8. The negative terminal of the source of supply also may be connected to the cathode Id.

Coils 2 and 2 are connected in coupled relation y and may be provided with a core of magnetic material l. The heater circuit, it will be noted. may be completed by the -connection of one end of the heater filament le to the cathode and thence to the negative terminal of the source of 3 supply 8, while the other terminal of the heater shown in Fig. 2. the plate current then having a form such as shown in Fig'.A 3, and the grid current having a form such as shown in Fig. 4.

While the cut-off as shown by these curves is sharp, and this is preferable. the system may operate with a less abrupt knee to the curve.

It will be noted that no tuned' circuits are employed and the oscillator is aperiodic, the frequency of the oscillation generated being determined by the inductance of the transformer which is made highof the order of 35 henriesand by the conductance of the tube or tubes to which it is connected. In-this connection, it may be noted that the greater the number of tubes used, the higher will be the frequency of oscillation because of the increased eifective conductance of the tubes when a larger number are employed.

The potential of the grid I b is higher than that of the anode Ia, when the tube is drawing plate current, due to the drop through coil 3, while the grid I c draws current which is rectiiied on its passage through the tube and serves to charge condenser 5, the circuit being such that the voltage across condenser 5 is added to that of the source 6 in supplying the load. Furthermore, it is the grid current to grid Ic which supplies the output load, rather than the plate current.

The load may be connected across terminals I5 and I 6, I5 being the positive terminal and I6 the negative terminal. The condenser 5 has a lrelatively high capacity, of the order of 20 microfarads, and for about nine-tenths of the cycle it is being charged with a low direct current while during the remaining one-tenth of the cycle it is supplying the voltage. The multiplied voltage from the tube I contains very little ripple.

If a still purer direct current is required, a iilter may be added such as indicated by inductance I2 and condenser I3, and in this instance the output circuit may be connected between terminals I'I and I6 instead of I5 and I5. Any ltering that is ordinarily required may be done very cheaply, however, because of the fact that the components to be ltered out are of, rather high frequency for which expensive filtering is not required.

If improved regulation, that is to say, a better regulation than is afforded by the circuit shown, is desired, this may be obtained by connecting across the output terminals, a gaseous discharge device, or other device, the resistance of which decreases with increase in voltage. One such a device is the well known neon tube.

Using only one tube as described, I have'found that with an input of 27 volts from the direct current generator, the output voltage when measured was found to be 70 volts.

I n case higher voltages are desired, additional tubes may be utilized and connected in parallel thereto, as indicated, for example. by'tubes 8, 9 and I0, each preferably being of the same type as tube I. Tube 8 comprises anode 8a, grid 8b, grid 8c, cathode 8d, and heater 8e, the connections being in parallel with each corresponding element of tube I, and the heater circuit of tube 8 may be opened by switch I8.

Similarly, tube 9 may be connected in parallel with tube I, and the filament circuit of tube 9 be completed when switch I9 is closed. Like tubes I and 8, tube 9 may comprise anode 9a, grid 9b, grid 9c, cathode 9d and heater 9e, each being connected in parallel with the respective electrodes of tubes I and 8, and similarly tube I9, preferably of the same type, and comprising anode I0a, grid I0b, grid |00, cathode IIId and heater Ille, is similarly connected to the other tubes.

With such an arrangement as described and shown and with four tubes output voltages of 140 volts may be obtained.

While I have shown and described one form of my invention, modifications may be made in the arrangement and location of parts within the spirit and scope of my invention, and such modiilcations are intended to be covered by the appended claims.

I claim:

l. In a system for boosting direct current voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode and at least one grid, said grid being connected so as to draw space current the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source of direct current the voltage of which is to be'boosted, and a capacity element connected to said grid so as to be charged by the current drawn by said grid, and connected in series with said source of direct current as viewed from the output terminals.

2. In a system for boosting direct current voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode, and a pair of grids, one of said -grids being connected to the anode and the other being connected so as to draw space current the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source of direct current the voltage of which is to be boosted, and a capacity element connected to said current-drawing grid so as to be charged by the current drawn thereby, said element being connected in series with said source of direct current as viewed from the output terminals. Y

3. In a system for boosting direct current voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode, and a pair of grids, one of said grids being connected to the anode through a voltage reducing element, and the other being connected to draw space current, a source of direct current the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave un-- symmetrical with respect to time, the voltage of which is to be boosted and a capacity element connected to said current-drawing grid so as to be charged by the space current drawn thereby, said element being connected in series with said source of direct curr'ent as viewed from the output terminals.

4. In a system for boosting direct current voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode, and a pair of grids, one of said grids being connected to the anode and the other being connected to draw space current, the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source of direct current, the voltage of which is to be boosted, connected to said interconnected anode and cathode and also to a positive output terminal, and a capacity element connected between said current drawing grid and said cathode, and having its terminal which is remote from said cathode connected to the negative output terminal.

5. In a system for boosting direct current voltage, in combination, a non-resonant oscillatingV a,1ss,sss'

relaxation oscillator generatinga substantially square top wave unsymmetric'al with respect to time, a source of direct current having its positive terminal connected to said anode and its negative terminal connected to said cathode.,

and its negative terminal connected to said cathode, and connections for drawing power from said source and said capacity element in series. i

6. In a system for boosting direct current volt-' age. in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode, and a pair oi' grids, one of said grids being connected through an inductance to said anode, and the other being connected through a second inductance, that is coupled to the tlrst inductance, and through a capacity element to said cathode, the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source of direct current having its positive terminal connected directly to said first mentioned grid through an inductance to said anode and the other being connected through a second inductance that is coupled to said first inductance, and through a capacity element to said cathode. at least one more tube similar to the rst tube, and arranged to have the respective elements thereoi' connected in parallel with the respective elements of saidI iirstl tube, the elements of said circuit being so related as to i'orm a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source oi' direct current having its positive terminal connected to said iirst mentioned grid and its negative terminal connected to said cathode, and connections for drawing output power from said source and said capacity element in series.

8. In a system ior boosting direct current voltage and for supplying a range of power at' boosted voltage, in combination, non-resonant oscillating circuit comprising at least one vacuum tube having an anode, a cathode, and a pair of grids, one of said grids being connected through an inductance to said anode and the other being connected through a second inductance that is coupled to said first` inductance,

and through a capacity element to said cathode, a plurality of tubes similar to the lirst tube. and arranged to have the respective elements thereo! connected in parallel with the respective elements of said nrst tube, the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, means l for selectively rendering individual tubes of said group operative. a source of direct current having its positive terminal connected to said iirstmentioned grid and its negative terminal connected to said cathode, and connections for drawingwtmtpowerfromsaidsourceandsaid capacity element in series.

9. In a system i'or boosting direct current voltage, a source oi' direct current the voltage of which is to be boosted, a non-resonant oscillator connected thereto and comprising a. transformer, at least one vacuum tube having an anode, alcathode and a'pair oi grids, the anode and one of said grids being connected together through one coil of said transformer, and the other of said grids and the cathode being connected together through the other vcoil ot said transformer and a capacity element, the positive terminal of said source being connected to the interconnected grid and -anode and the negative terminal thereof being connected to said cathode, the elements of said circuit being so related as to i'orm a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, and a pair of output terminals connected respectively to the iirst mentioned grid and to the capacity element on the opposite side thereto to its connection tothe cathode. v

10. In a system for boosting direct current voltage, a source of direct current the voltage of which is to be boosted, al non-resonant oscillator connected thereto and comprising aplurality of vacuum tubes each having an anode,

`a cathode and at least one grid arranged tov draw space current, 'the anodes being connected in parallel circuit, the grids being connected in parallel to the cathodes through an element havin! a high inductance characteristic and an element having a high capacity characteristic, the elements of said circuit being so related as to form a relaxation oscillator generating a substantialLv square top wave unsymmetrical with respect to time, a pair of output terminals, and circuit connections whereby the capacity element and thel source are connected in series circuit to said output terminals.

11. In a system for boosting direct current voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having an anode, a cathode and at least one grid, said grid being connected so as to draw space current, the elements oi' said circuit beingso related as to form a relaxation oscillator generating a substantially square top wave unsymmetrical with respect to time, a source of direct current the voltage of whichv is to be boosted, and a capacity element connectedtosaidgridsoastobechargednbythe current drawn by said grid, and connected in series with said source of direct current as`vle'wed from the output terminals.

l2. Inasystem for boostingdirectcurrent voltage, in combination, a non-resonant oscillating circuit comprising a vacuum tube having yan anode, a cathode,.and a pair of grids, one of said grids being connected to the anode through a voltage reducing element, and the other being connected to draw space current, the elements of said circuit being so related as to form a relaxation oscillator generating a substantially square 'to said current-drawing grid so as to be charged by the space current drawn thereby, said element being connected in series with said source oi' direct current as viewed from the/output terminals.- 7

LOUIS W. PARm.

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