US1834155A - High frequency generator circuit - Google Patents

Description

Dec. 1, 1931. J, HARRISON 1,834,155

HIGH- FREQUENCY GENERATOR CIRCUIT Filed July 31. 1928 F m i I I I I I'I I I INVENTOR. jam/90w 8. fifowmoow,

BY wfl 5 ATTORNEY Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE.

JAMISON R. HARRISON, OE I VIIDDLETO WN, CONNECTICUT HIGH FREQUENCY GENERATOR CIRCUIT Application filed. July 31, 1928. Serial No. 296,584.

arrangements for generating electrical oscillations of constant frequency.

Another object of my inventionis to provide a balanced vacuum tube'circuit arrangement wherein a plurality of Vacuumtubes may be employed for producinghigh fre- "quency oscillations of electrical energy;

Other and further objects of my invention will appear from'thespecification to'follow and from the accompanying drawing wherein is illustrated the high frequency generator circuit arrangement of my invention. In the accompanying drawing two electron tubes 1 and 2 are represented, each having filament electrodes 3 and 7, inner grid electrodes 4 and 8, shielding grid electrodes 6 and 10 and plate electrodes 5 and 9. Filament electrodes 3 and 7 are energizedby source 17. Shielding grid electrodes 6 and 10 are supplied with a source of biasing energy from source 18 through radio frequency choke coils V 11 and 12 respectively. Source of energy 19 supplies a positive potential to innergrids 4 and 8 and plate electrodes 5 and 9. Radio frequency choke coil 13excludes radio frequency energy from source 19, Inductance 14 and capacity 15 have frequency'characteristics corresponding approximately to the frequency value of the desired generated fre quency. A mechanically vibratile element 16 is employed for maintaining the circuit at a constant frequency value and has frequency characteristics corresponding to the app'roxivarying the coupling between the input cir-- 'ing gridt of vacuum tube 1 is supplied with tube '1" will be increasing at the same time that 'ductance coil'14 andthe direction of these energy at substantially constant frequency value; An adjustment d provides means for laterally moving conductive members A, B withrelation to C, D, andthus varying the phase relationship between the, two input circuits and two output circuits.

Conductive members-A, B, and Dare connected to electrodes 6, 10, 5-and9 respectively. Means are therefore provided for cuit 610 and output circuit 5-9. 7

Adjustable contact member 20 provides means for adjusting the relative positive potential supplied inner grid electrodes and 8; this adjustment should be carefully made tosecure satisfactory operation. Shielding grid 6 and anode 5 of the electron tube 1 are connected to the conductive members A and C respectively which are adj acent to the same face of thepiezo electric element 16. Likewise the conductive members-B and Dadjacent to the opposite side of theelement- 16 are connected to the shielding grid 10 and anode 9 ofelectron tube 2. When a stress is set up in the, element 16 the resulting polarization induces electrical charges of opposite signon the metallic conductive members adjacent to the two opposite faces of the element 16.

Conductive members A- and C, when connected to electrodes 6 and 5, will receive 0 charges of-the same signandlikewise theconductive members B and D will have charges of like sign but which are opposite in sign to the charges on A andC. When the shieldapositive, potential the shielding grid .10 of electron-tube 2 is suppliedwith a. negative potential. Because of these opposite charges, the-current in-the anodecircuit of electron 0 thecurrent in the anode-circuit of tube 2 is diminishing. However, anodes 5'and '9 are connected to the opposite ends of the inand oscillations of'highfrequency-electrical energy are maintained by energy feedback through the vibrating crystal element 16. Conductive members A and B are the input connections of the feedback circuit and are electrically connected to shielding grid electrodes 6 and 10 of vacuum tubes 1 and 2 respectively. Shielding grid electrodes 6 and 10 are supplied with a source of potential from the biasing battery 18 through the radio frequency choke coils 11 and 12. Shielding grid electrodes-6 and 10 operate as control grid electrodes and inner grid electrodes 4: and8 operate as space charge electrodes. Accordingly the inner grid electrodes 4 and 8 are supplied with a suitable positive potential from the anode supply battery 19. This neutralizes the space charge grid effect around the cathode due to electron emission.

It is obvious that many modifications of the high frequency generator circuit of my invention are possible without departing from thespirit of my invention and it is to be understood that my invention is not to be limited to the foregoing specification or to the accompanying drawing but only as defined in the appended claims.

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

1. In a balanced electron tube generating system, in combination, two electron tubes each having filament, grid, shielding grid and plate electrodes, a piezo electric crystal element, two pairs of electrodes in electrical relation with said piezo electric crystal ele- .ment and so positioned that the electrodes constituting each pair are substantially opposite each other and embrace a portion of said piezo electric crystal, sources of filament and plate potential, input and output circuits for each of said tubes, a common load comprising a tapped inductance and a condenser in parallel, a variable intermediate tap connection for said source of plate potential, said grids being connected together and to a tap on said source of plate potential, the positive terminal of said source of plate potential being connected to the tapped point of said load inductance, the terminals of said load inductance being connected respectively to said plate electrodes, said electrodes of said piezo electric crystal element being so connected that the electrodes constituting one pair are respectively connected to said shielding grid electrodes of said tubes, and the electrodes constituting the other pair are respectively connected to said plate electrodes of c said tubes.

2. In a system for producing high frequency el ctrical oscillations of constant frequency, in combination, two thermionic elecfilaments of said tubes, a source of plate potential connected to said plates, a source of potential for biasing said grid electrodes positively with respect to said filament electrodes, a circuit for connecting said grid electrodes together and to said filament through said source of grid biasing potential, a source of potential for biasing said shielding grid electrodes with respect to said filament electrodes, circuits for connecting said shielding grid electrodes together and to said filament electrodes through said source of shielding grid biasing potential, apiezo electric crystal element, two pairs of electrodes for said piezo electric crystal element, said electrodes being so positioned that the electrodes constituting each pair are substantially opposite and embrace a portion of said crystal and so that said two pairs are spaced from each other, circuits connecting the electrodes of one of said pairs respectively to said shieldmg grid electrodes, and circuits connecting the electrodes of the other of said pairs respectively to said plate electrodes.

3. In a balanced electron tube generating system, in combination, a plurality of electron tubes symmetrically arranged in two groups, each of said tubes having filament, grid, shieldinggrid and plate electrodes, the corresponding electrodes of the tubes composing each of said groups being connected together, a piezo electric crystal element, two pairs of electrodes in electrical relation with said piezo electric. crystal element and so positioned that the electrodes constituting each pair are substantially opposite each other and embrace a portion of said piezo electric crystal, sources of filament and plate potential, input and output circuits for each of said tubes, a common load comprising a tapped in ductance and a condenser in parallel, a variable intermediate tap connection for said source of plate potential, said grids being connected together and to a tap on said source of plate potential, the positive terminal of said source of plate potential being connected to the tapped point of said load inductance, the terminals of said load inductance being connected respectively to the plate electrodes of each of said groups, said electrodes of said piezo electric crystal element being so connected that theelectrodes constituting one pair are respectively connected to said groups of shielding grid electrodes of said tubes, and the electrodes constituting the other pair are respectively connected to said groups of plate electrodes of said tubes.

4. In a balanced electron tube generating system, in combination, a plurality of electron tubes symmetrically arranged in two groups, each of said tubes having filament, grid, shielding grid and plate electrodes, the corresponding electrodes of the tubes composing each of said groups being connected to get-her, a piezo electric crystal element, two

pairs of electrodes in electrical relation with said piezo electric crystal element and so positioned that the electrodes constituting each pair are substantially opposite each other and embrace a portion of said piezo electric crystal, sources of filament and plate potential, input and output circuits for each of said tubes, a common load comprising a tapped inductance and a condenser in parallel, the positive terminal of said source of plate potentialbeing connectedto the tapped point of said load inductance, the terminals of said load inductance being connected respectively to the plate electrodes of each of said groups, said electrodes of said piezo electric crystal element being so connected that the electrodes constituting one pair are respectively connected to said groups of shielding grid electrodes of said tubes, and the electrodes constituting the other pair are respectively connected to said groups of plate electrodes of said tubes.

5. In a balanced electron tube generating system, in combination, a plurality of electron tubes symmetrically arranged in two groups, each of said tubes having filament, grid, shielding grid and plate electrodes, the corresponding electrodes of the tubes composing each of said groups being connected together, a piezo electric crystal element, two pairs of electrodes in electrical relation with said piezo electric crystal element and so positioned that the electrodes constituting each pair are substantially opposite each and embrace a portion of said piezo electric crystal, sources of filament and plate potential, input and output circuits for each of said tubes, a common load comprising a tapped inductance and a condenser in parallel, a variable intermediate tap connection for said source of plate potential, said grids being connected together and to a tap on said source of plate potential, the positive terminal of said source of plate potential being connected to the tapped point of said load inductance, the terminals of said load inductance being connected respectively to the plate electrodes of each of said groups, means for adjusting the relative spacing of said pairs of electrodes of said piezo electric crystal element, said electrodes of said piezo electric crystal element being so connected that the electrodes constituting one pair are respectively connected to said groups of shielding grid electrodes of said tubes, and the electrodes constituting the other pair are respectively connected to said groups of plate electrodes of said tubes.

6. In a balanced electron tube generating system, in combination, a plurality of electron tubes symmetrically arranged in two groups, each of said tubes having filament, grid, shielding grid and plate electrodes, the corresponding electrodes of the tubes comaosin each of said rou s bein connected l s together, a mechanically vibratile element,

two pairs of electrodes in electrical relation with said mechanically vibratile element and so positioned that the electrodes constituting each pair are susbtantially opposite each other and embrace a portion of said mechanically vibratile element, sources of filament and plate potential, input and output circuits for each of said tubes, a common load comprising a tapped inductance and a condenser in parallel, a variable intermediate tap connection for said source of plate potential, said grids being connected together and to a ta on said source of plate potential, the posltive terminal of said source of plate potential being connected to the tapped point of said load inductance, the terminals of said load inductance being connected respectively to the plate electrodes of each of said groups, said electrodes of said mechanically vibratile element being so connected that the electrodes constituting one pair are respectively connected to said groups of shielding grid electrodes of said tubes, and the electrodes constituting the other pair are respectively connected to said groups of plate electrodes of said tubes.

In testimony whereof I afiix my signature.

JAMISON R. HARRISON.

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