US2579217A - Harmonic electrical alternating-current generation - Google Patents

Description

Dec. 18, 1951 H. J. TYZZER 2,579,217

HARMONIC ELECTRICAL ALTERNATING CURRENT GENERATION Filed Feb. 7, 1947 2 SHEETS-SHEET 1 C 9' Li- C 1 I T 9' 1- LL M II as? P U 8 L9 I I INVENTOR- HQWARD J TYZZE R BY QQ/W v M ATTORNEY Dec. 18, 1951 H, J. TYZZER 2,579,217

" HARMONIC ELECTRICAL ALTERNATING CURRENT GENERATION Filed Feb. 7, 1947 2 SHEETS-SHEET 2 A CH INVENTOR. HOWARD J. TYZZER AT ORNEY Patented, Dec. 18, 1951 HARMONIC ELECTRICAL ALTERNATING- CURRENT GENERATION Howard J. Tyzzer, Mountain Lakes, N. J assignor to Ferris Instrument Laboratories, Boonton, N. J., a corporation of New Jersey Application February 7, 1947, Serial No. 727,066

'7 Claims. (01. 250--36) London. 7

In designing instrumentalities of the kind in- .volved for best realizing desired operating conditions at any one of the harmonic frequencies involved I have found, as unanimously brought out by said literature, that on account of certain unavoidable conflicting operation affecting factors,

effective compromising between said conflicting factors is always essential to realizing even near approaches to said desired operating conditions. In this connection, it is a primary object of my present invention to minimize to material extents the causes underlying said conflicting operationafiecting factor to thereby simplify designing for and to make more certain realizing said desired operating conditions at all usable harmonic frequencies inherently a part of the functioning of the particular so-called frequency multipliers and/ or harmonic generators instrumentalities in- .volved.

It is confidently believed by me that other objects of my present invention will be readily apparent to those more or less familiar with the art in general and its numerous variation to which my present invention is obviously related following the description of the same with the aid of the showings of the four figures of the accompanying drawings hereinafter recited more or less in detail to such extents as seemingly required for making possible an adequately clear understanding of the same.

Referring to the figures of said drawings in which like reference symbols represent like parts and/or elements, I respectively identify them as follows:

'Fig. 1 schematically illustrates an electronic tube and circuits associated therewith together with all of the elements thereof essential to effectively practicing my present invention in all of its aspects.

Fig. 2 schematically illustrates a so-called saw tooth wave form that any one of the fundamental electrical alternating currents contemplated by my present invention may be expected to take on before being converted into a second electrical alternating current at a predetermined harmonic frequency of said fundamental.

Fig. 3 schematically illustrates a so-called pulse wave form that the energy of the forward moving electrical activities may be expected to take on preparatory to acting upon the single electronic tube shown by Fig. 1.

Fig. 4 schematically illustrates a modified embodiment of the instrumentality schematically illustrated by Fig. 1, on account of which modification it takes on the capacity for functioning more effectively and efiiciently than would otherwise be the case.

Referring t Fig. 1, the combination of source element A. C. and the variable and accordingly tunable circuit consisting of an inductance coil L and variable condenser C together represent any known, suitable source of electrical alternating current of any frequency chosen to be a fundamental from which to extract energy of any desired harmonic of the same plus means for converting a componentof said energy into a second electrical alternating current of a desired higher frequency corresponding to a multiple of said fundamental.

In cases where said fundamentals themselves are of such high frequencies as to make the same desirable, I prefer to use the now extremely well known electronic tube type of generator for generating the fundamental electrical alternating currents of the frequencies chosen for the particular work in hand, particularly because of the ease with which such an instrumentality can be made to closely hold to any one of the respective chosen fundamental frequencies. However, I contemplate that said currents may originate at any remotely installed generator of any one of the respective chosen fundamentals, the energy of which may be transmitted over the distance involved in any adequately competent way to the point at which an instrumentality embodying my present invention is installed.

As indicated, on departing from said source the energy involved is constantly subject to action of a rectifier of electrical alternating efiects R, preferably of either the well known crystal or electronic tube type, which rectifier is indicated as having closely and conductively associated therewith a combination of capacitance indicated as condenser cand in parallel with a resistance indicated as resistor r.

As to what can be most usefully accomplished by and with said last so located named elements in connection with realizing my above pointed out primary object, I have found that by predeterminedly selecting the capacitance value of said con-denser 0 along with taking into account the effective resistance of said rectifier in keeping with the amount of energy that must be handled thereby at the frequency involved for controlling the time required to effectively charge the condenser plus discharging the same, I provide for impressing upon the control grid or input circuit of the e-electrode electronic tube '1 a succession of energy representing pulses of a nature by each of those pulses shown by Fig. 3.

Naturally, said successive chargings of condenser c by the rectified Waves of energy that depart from rectifier R are followed by correspondingly successive discharges of energy from said condenser through resistor r, with the result that these charging and dischar ing effects are reflected in potentials impressed upon condenser cl, primarily used as a so-called blocking condenser for the direct current of the grid biasing battery B as well as that developed across grid biasing resistor H, which so impressed potentials naturally cause opposing potentials to appear across the series combination. of inductance L! and resistor 1'! which latter potentials I have found take on the form of potential pulses of the kind schematically illustrated by Fig. Referring to the right hand portion of Fig. 1, 1t is readily apparent that said successive potential pulsesare, by the connections shown, impressed upon control grid g of electronic tube T which, as indicated by the well known elements shown therein and circuits associated therewith, acts With said circuits to effectively amplify the indicated intensity of said pulses in causing them to be manifested in its so-called plate circuit, or, as shown. its anode a to filament f circuit.

Filament f of said tube is heated for causing electron emission by current set in motion by battery b; and anode a of the same is indicated as having impressed thereon the usual positive and adequately high potential of battery B which is indicated as being high frequency by-passed by condenser 03. Control grid 9 is indicated as having impressed thereon the usual negative biasin potential of battery B in addition to that developed by resistor 1'! during operation. A screen grid g is indicated as having impressed thereon the usual lower but substantial part of the anode a positive potential of battery B, the lesser potential involved being preferably brought about by a potential drop through indicated resistor r2 indicated as being high frequency bypassed. by condenser '02: which biasing procedure has for its purpose bringing to bear the usual more stable amplifier operation of so-called screen grid tubes compared to such operation with non-screen grid tubes. However, use of such an extra grid is not essential to practicing my present invention. The ground connections G and G suggest taking advantage of the well known desirability of operating such electronic tubes and associated circuits instrumentalities with the low potential points therein at so-called ground potential, but this procedure is also not essential to practicing my present invention.

The anode to filament circuit associated with said tube is indicated as including therein a tunable circuit consisting of variable condenser 02 in parallel with inductance coil L2, which coil is indicated. as coupled to inductance coil L2 as terminated in output terminals OP and OP; the last named intentionally constituting an output or so-called work circuit in which to collect and from which to dispose of the energy delivered to said tunable circuit by said tube, which energy, if said circuit is tuned to any reasonable numbered harmonic of the fundamental freque cy of any electrical alternating current of the primary source, will have the form of electrical alternating current having the frequency of the chosen harmonic.

In the caseof the usual or up to the present time orthodox so-called harmonic generator, the procedure relied upon for so-called harmonic generation consists of impressing the energy of the fundamental electrical alternating current directly on the control grid of the usual grid to filament or input circuit of any orthodox, electronic tube and associated circuit combination capable of amplifying and essentially including in the so-called plate circuit of the combination involved a circuit containing capacitance and inductance having such respective values that the same is tuned to resonate at some chosen harmonic of said fundamental frequency.

In, relying. upon said orthodox procedure, I have found as being most objectionable that grid biasing materially higher than normal or optimum for the electronic tube involved is required and essential because of unavoidably calling for materially higher so-called driving power. Further in connection with it being axiomatic in cases of said orthodox procedure for converting an optimum period or duration of plate circuit alternating current flow, usually referred to in terms of electrical degrees, into the alternating current of the harmonic frequency desired, there occurs the objectionable factor of the higher the frequency called for the shorter must be said duration and the greater must be the driving power called upon to assure any effective degree of high efiiciency. Also, as said duration is shortened for the purpose of selecting out higher harmonics of the funadmental alternating current, the consequential conversion efficiency can be expected to correspondingly fall off appreciably. Published examples of falling oif of efliciency had on so converting to harmonics are: 2nd harmonic, 3rd harmonic, 40%; 4th harmonic, 30%; 5th harmonic, 25%; these being percentages of the efiiciency rate of such a combination operating at the fundamental frequency only. a

On the other hand, in cases of converting harmonies of fundamental electrical alternating currents into such currents at the frequencies of the respective harmonics with the particular combination of my present invention, with the obvious advantage of securing more stable and smoother operation by doing so, I have found that I am able to rely upon no more than normal or optimum biasing of the control grid of the electronic tube involved, and, accordingly, normal or optimum driving power in keeping therewith; that is, the comparative materially lower driving power thereby made possible.

And also, instead of comprising in the matter of tube operation in connection with regulating the period of plate current flow, or so-called electrical degrees, in keeping with meeting an optimum requirement in the case of each harmonic dealt with, I have found that I can effectively regulate the same by selecting therefor in each case a suitable value of capacitance for condenser c and a co-operating suitable value for rectifier R; and in all such cases, I consequently and preferably make said period somewhere within the order of one quarter to one half of a cycle of the harmonic frequency involved.

For the resistance value of resistor r, I preferably choose such a value therefor that adequate discharging of condenser c therethrough between cycles of the fundamental frequency occurs without unduly loading the source of the fundamental energy.

For the inductance value of inductance coil Ll in series with biasing resistor rl, I choose it to be sufiicient for developing across the input of'electronic tube T a. relatively high reactanceto the pulses of the kindshown by Fig. 3 impressed thereacross. 1

Referring to Fig. 2, its showing of the so-called saw tooth waves somewhat above its base line is intended to indicate the fact that when in action condenser 0 does not fully discharge after being charged to a maximum bythe oncoming and rectification of each alternating wave of the-fundamental electrical alternating current involved; and the greater steepness of the up surges of the same-compared to the down surges is intended to indicate the factmthat the charging time of condenser c is less than the corresponding discharging time mainly through resistor r.

Referring to Fig. 3, the'maximum distance between the two legs of an up and down surge of energy symbolically marked 0p is intended to indicate the extent of duration of the same in terms of one-quarter to one-half cycle of the desired harmonic frequency.

With the instrumentality of my present invention above described carefully adjusted and regulated for bringing about different chosen cases of frequency multiplying and/or harmonic generating, I have carried the same to as high as the 82nd harmonic with, in all cases, relatively high efiiciency compared to what I have attained with the orthodox way of doing the same hereinbefore treated; and the same has been done with decidedly more smoothness and/or stability of operation.

Referring to Fig. 4, since it, with the exception of a single modification heretofore mentioned, schematically illustrates a duplication of the showing of Fig. 1, and, accordingly, employs the same reference symbols as Fig. 1 does, except for a desirable description of said modification, description of it is naturally the same as that given with respect to the instrumentality in toto schematically illustrated by Fig. 1.

Consequently, inviting attention to the fact that Fig. 4 differs from Fig. 1 only by a shunting of inductance coil Li by a variable condenser Cl, I point out that by tuning the resulting tunable circuit to resonance with any one of the predetermined desired harmonics, and, therefore, in resonance with tunable circuit L202 when the same is tuned to the same predetermined desired harmonic, the energy variations by the indicated pulses shown by Fig. 3 are consequently converted to energy variations indicatable as acting below as well as above the indicated pulse base shown by Fig. 3. Consequently, said modification is obviously made to be the source of more harmonic frequency energy being passed on to electronic tube T and its associated output or work circuit than is possible with the precise instrumentality shown by Fig. 1 to make for in the case of said Fig. 4 system consequential higher overall instrumentality elficiency.

While I have described my present invention in certain confined respects, it is apparent that modifications may be made and that no limitations are intended other than those imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A frequency multiplier comprising a source constant circuit being formed by a condenser and a resistor connected in parallel to one-another, and 'a further condenser, an-inductance. andfurther resistor coupled in series'across said first resistor; and aclass A amplifier coupled to said inductance and further resistor to be'excited by said pulses, said amplifier having a resonant output circuit tuned to said-harmonic frequency, whereby a substantially sinusoidal output signal of said harmonic frequency may be derived from said output circuit. Y 1

2. A frequency multiplier-for converting a sub-:- stantially sinusoidal alternating current of a fundamental frequency to a desired harmonic thereof; comprising means excited from said fundamental frequency current for producing periodic wave pulses of a duration of substantially one-half the period of said desired harmonic, said means comprising a rectifier in series with a time constant circuit formed by a condenser and a resistor in parallel and a pulse sharpening circuit coupled to said resistor, and a class A amplifier coupled to said pulse sharpening circuit to be excited by said pulses, said amplifier having a resonant output circuit tuned to said harmonic frequency, whereby a substantially sinusoidal harmonic output signal is obtained from said output circuit.

3. A frequency multiplier as in claim 2, wherein said pulse sharpening comprises -a series circuit formed by a condenser, an inductance and a resistor, said series circuit resistor being connected across the said time constant circuit resistor.

4. A frequency multiplier as in claim 2, wherein said pulse sharpening circuit comprises a parallel-connected inductance and capacitance coupled to said resistor.

5. A frequency multiplier as in claim 4, wherein said parallel-connected inductance and capacitance are resonant at the desired harmonic frequency.

a class A amplifier tube coupled to said pulse sharpening circuit to be excited by said pulses, said amplifier tube having a resonant output circuit coupled thereto and tuned to said harmonic frequency whereby a substantially sinusoidal output signal of said harmonic frequency may be obtained from said output circuit.

'7. A frequency multiplier for converting a substantially sinusoidal fundamental frequency a1- ternating current signal into a substantially sinusoidal harmonic frequency signal comprising a rectifier connected in series with a time constant circuit, said series-connected rectifier and circuit being adapted to have said fundamental frequency signal impressed there-across, said time constant circuit comprising a condenser and resistor in parallel, whereby a voltage is produced across said resistor comprising periodic wave pulses, the repetition frequency of said pulses being determined by said fundamental frequency signal, means including a pulse sharpening circuit coupled to said resistor for producing a pulse duration time for each said pulse substantially equal to one-half the period of said desired harmonic frequency, and a-normally biased amplifier having its input coupled to said pulse sharpening circuit to be excited by said pulses and having a resonant circuit in its output tuned to said desired harmonic whereby said desired substantially sinusoidal harmonic frequency signal is produced in said output circuit.

HOWARD J. TYZZER.

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

UNITED STATES PATENTS Number Name Date' 1,851,408 Runge Mar. 29, 1932 2,013,806 Osnos Sept. 10, 1935 2,151,332 Roberts Mar. 21, 1939 2,153,202 Nichols Apr. 4, 1939 2,181,568 Kotowski Nov. 28, 1941 2,266,668 Tubbs Dec. 16, 1941 2,364,756 Roberts Dec. 12, 1944 2,411,166 Olson Nov. 19, 1946 2,411,573 Holst et a1. Nov. 26, 1946 2,443,619 Hopper June 22, 1948 2,469,598 Harris May 10, 1949 2,484,763 Sturm Oct. 11, 1949 FOREIGN PATENTS Number Country Date 490,649 Great Britain Aug. 18, 1938

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