US1639805A - Radio apparatus - Google Patents

Description

Aug. 2 3, 1927.

RADIO APPARATUSl c o o o c c F. s. MccULLoVUGl-l a Sheets-Sheet 2 www m* Patented Aug. 243, 19.27.

UNITEDA -LsTATEs PATENT QFFICE."

FREDERICK s. MCCULLOUGH. 0E CLEVELAND, OHIO, AssIGNon To GLENN L. MARTIN,

or oLEvELAND, oHIo.

RADIO .APPARATUS Application filed. January 9, 1920. Serial No. 350,362.

My invention relates to radio apparatus, and particularly to that part of the apparatus which is designed to detect, amplify or transmit radio oscillations. The general object of the invention is to increase the eiiiciency of and simplify such apparatus.

My invention consists of means. hereinafter fully described and particularly set forth in the claims,

This application is a continuation in part of my pending application Serial No. 128,375 iiled October 30, 1916, now issued as Patent No. 1,403,700 of January v17, 1922, in so far as relates to that part of the subject matter herein which'is common to both applications.

The annexed drawings and the following description set forth in'detail certain means embodying my invention, the disclosed means, however, constituting but one of vari? ous forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is an explanatory diagram designed to illustrate the theory underlying the principle and the operation of my invention;

Fig. 2 represents a diagram ofl a simplel form of my radio apparatus;

Figs. 3, 4 and 5 represent modications'of 4apparatus employing the principle of my invention. i

Referring first to Fig. 1: 44 is a non# oXidizable heating filament which may, as.

will hereinafter appear, be -kept at a certain predetermined temperature. In series with this filament is a battery 10 and rheostat 3 connected by wires 41 and 57, the-temperature being adjusted by rheostat 3. Surrounding this ilament 44 is an element 4'0 consisting of semi-dielectric material, such as glass. Surrounding this element 40 and in physical contact therewith is a control coil 45, which is connected to the antennae 8 by the wire 9. The opposite end of'this coil is left free, .Surrounding the coil 45 is a second coil 455, which is in series with a seoond battery 56 and a rheostat 58. This latter coil surrounds and is in physical contact with a second tube 40, also consisting of a semi-dielectric material such as glass, and out of physical contactwith the control coil. This coil is connected with the positive pole of a source 56 of power, herein shown to be a battery, the other pole being connected by means of wire 57 with one end of iilament 44, as shown.

When filament 44 is heated so that it will glow', it emits electrons. The coil 55, being connected in series 'with the battery 56, ,is also heated and this heat is transmitted to the glass tubes 40 and 40 which it surrounds, thus placing them in a state of ionization. The glass thereby becomes conductive, rendering these glass tubes electrolytic and the electrons pass therethrough as a result of such heating. and the coil 55 being connected positively with the battery 56, the electrons will pass through the glass, which is an electrolyte, to coil 55. As a result, current will flow from coil 55 to filament 44 in the opposite direction from theI flow of electrons. That the current does so flow may be shown by means of the ammeter A or other indicating device which may be introduced into the circuit as shown in Fig. 1. l

When electromagnetic waves impinge on the antennaeS, passing along the wire 9 to control electrode 45, they will alter the iow ,of current from coil 55 to fila-ment 44, and this alteration will be indicated on amgmeter A.

This being the case,

This arrangement of parts, itwill also be noted, makes of the filament 44 a cathode, and of the coil 55 an anode,- and the interposed coil 45 a control member. It must also be understood that the qg'ioil 55 is also a, local control member, for i'by raising or lowering the current flow in said coil, electrolytic action, i. e., the conductivity to velectron flow will be` increasedor decreased accordingly, and any iiuctuations which may resultyfrom said loca-.l control may then be noted on ammeter A, due to the consequent variation in the current in the filament c ircuit.

In Fig. 2 I have illustrated a modification of the. abovev described apparatus also embodying the principles of my invention. IIn 0o- 7 5 and 80-85, by means of which the current passing through the filamentdue to the charge effect on the condensers may be regulated and the latter heated to the predeterlnined incandescence. By enclosing the filament in an evacuated tube, I am enabled` to increase this incandescence to a greater degree than if this filament were not en'- closed. In the interior of the tube and adjacent to and interposed between the tubes walls and the filament, is the control element 45 herein shown to consist ofa fiat plate. This plate is connected in series with the positive pole of the source of power 47,

herein shown to be a battery, the negative pole of this battery7 being connected with one end of thefilament by means of the wire 11.

Surrounding the exterior of the glass tub/eA 40 and preferably in physical contact therewith is the heating coil 55, which is connected in series with a source of power 5,6 herein shown to be a generator of high or radiofrequency currents. This high frequency generator produces alternating currents of frequencies corresponding to or approaching the frequency of the circuit including generator 10, so that the coil will produce in tube 40 an oscillating field of a frequency substantially coincident with the frequency of the received impulses impressed or induced oncapacities75 and 85. The effect of this oscillating field is to heat the cathode and tube and io'nize the attenuated gas within the tube and to attract and repel the electron flow from the heated cathode toward andfrom the walls of the vessel in a variable manner, in a direct relation to the oscillating frequency of the received impulses from generator 10. In this circuit, also, is the rheostat; 58, by means ofwhich' the passage of current through the coil 55 may be regulated.

When current is passed through the filament '44 and the latter raised to incandescence, electrons are emitted and impinge the interior surfacey of the tube or vessel 40.

yCurrent is simultaneously passed through the heating coil 55 so as to'raise the same to the required temperature.- This heating coil heats the latter and converts it to a state of ionization, thereby rendering it conductive, thus setting up an electrolytic action, the glass acting as an electrolyte. Current -is therefore thus permitted to pass from the c anode coil 55 to the cathode filament 44.

, The element 45 within the tube is the elec-I tron control; that is to say, it modifies \the flow of electrons between the filament 44 and the coil 55. This control may be eected by varying the potential ofthe battery 47, as shown, or by any other suitable means which will vary the conditions of the circuit containing the element 45. Any interaction between the circuit containing the anode 55l yand the filament 44 and the circuit containing the control member would necessarily affect the conditions of the control due to the 40 is a surroundingevacuated glass tube,

55 being the ionizing means and the anode, surrounding tube 40 and in vphysical con'- tact therewith. The tube 40l is provided to prevent the ionizing means from'oxidizing. To regulate the current flow, rheostat 58 is placed in series. This coil 55 is connected to the positive pole of source of power 56. lVithin this tube 40 is the incandescent lament 44. The source of power for making thisv filament incandescent is shownv to be a generator -10 for exciting the oscillator. The variable condensers 70-75 and 80-85 regulate the current. Interposed between this filament and the coil 55 is the control mem-1 ber 45.. This control member leads out of the tube 40 and is connected by a wire 12 to the inductance 20, and the center of this inductance is connected to the filament. .The opposite end of this inductance 2O is connected through the ammeter A to the negative side of the source of power 56. The tuning condensers 21 and 22 show means for tuning these circuits. The condenser 23 is provided to facilitate the stopping of audiofrequency :noises from the power source 56. 86 and 87 are mica shields to prevent the stems 88 and 89 from becoming ionized f which is very important in an electrolyte detube.. 44 is the filament, and 10 a source of power for making the filament incandescent, 3 being a rheostat for regulating the current flow. The condensers 24 and 25 have been included for purposes of tuning -and also the variable -inductance 20 introduced. The power for the anode circuit is derived from source 56 passing through impedances 26 and 27 and across these the audio-frequency smoothing-.out condenser 23 is placed. By this structure, anode 55 becomes an inductance and the control 45 also an in- Condensers 24 and 25 are means for lvarying the frequency of the oscillations in the respective circuits containing said inductances. By the action of the inductances 55 and 45 `I am able to make this device self-exciting.

stat 3. The action which takes place is `as poses.'

- doing, 'I

follows: .When filament 44 becomes incandescent, it will, as already described, emit free electrons which impinge upon the inner wall of the ,semi-dielectric tube 40 and would remain'there if this glasslike wall were not placed in a state of ionization. The anode is connected to the positive pole of' the source of power 56, to the inductance 29. This -inductance 29 is' so 'constructed as to lbe variable and to have a portion slide over the. tube 40 and to bring it to inductive relation with coil 45. Across the inductancel 29 is placed` a condenser 30 for tuning pur- 'The opposite end of this inductance is connected to' the filament 44 by wire 31. To facilitate further tuning, condenser' 24 is'placed in series with the coil 45` and the negative side of source of power 56. By So obtain a powerful oscillator. To propagate these oscillations, I attach to the coil 29 an antenna 8 and ground connection 13 which runs to theifilament passing through ammeter A, thus placing ay load on the device so that it will radiate electromagnetic waves.

The principles of my invention, as will be understood by those skilled in the art, may be used in a detector, amplifier, oscillator, or oscillation generator.

. In every case, with the exception of Fi `l, the external coil is in circuit with a hig frequency generator, as in Fig. 2, or in a regenerative` circuit wherever radio fre- 'quency oscillations are impressed on the coil, as in the other figures. These radio frequency oscillations in the coil have an ionizing action on the residual'gases inthe tube,

rendering the gas conductive and at the same.

Vtime this state of ionization of the gas, due

to the friction of the ions and molecules,

will raise the temperature of the glass envelope, ionizing it; that is, rendering it conductive, while also heating any metal parts tube. Where the circuit is organized as in Fig. 2, the inductive action of the oscillating field within the tube produced by coil 55 isthe principal means for heating cathode 44, as the charge effect on capacities 7 0-7 5 and 80-85 would generally be insufficient to effect this, as is the case where the sending and receiving stations are -remotely located. In other words, the heating of the filament by the charge effect on the capacities- -7 5 and 80-85 is incidental and normally negligible.

What I claim is: 1. In a radio apparatus, the combination of a filament, a glass-like wall surroundiilng I asaid filament, means for heating the mentfmeans for heating the wall; said filament and heating means constituting electrodes of an electrical circuit.

-2. Ina radio apparatus,-thecombination of a sealed globe; a filament within said globe; means for heating the filament; means Vfor heating the globe; and an electron control adjacent said filament within said globe; said filament and heating mea'ns constituting electrodes of an electrical circuit.

3. In a radio apparatus, the combination ond electrode; and a mica shield interposed between said filament and the end portion of said globe.

5. In radio apparatus, the combination of a partially evacuated globe; a filament within the globe; means for heating the filament; and means outside of the globe for heating said filament; said filament and said globe heating means constituting electrodes of an electric circuit. j

6. An electron valve comprisinga sealed conductor Ielements entering opposite ends thereof; a lament within sai-d globe connected to said conductor elements; an anode conductor outside said globe; and mica shields interposed between said -filament and end portions of said globe.

7 The combination with a thermionic tube having an electron emittin cathode therein` and having an attenuate gaseous content, an energy receiving capacity incircuit with the cathode, a second electrode within the vessel, a local battery having one terminal .connected with said electrode and globe having one terminal in circuit with said cathode, a coil surrounding the tube,.and a local generator for impressing radio frequency currents `on said coil, whereby said coil may cathode for efectingelectron emission therefrom.

9. The combination with v a thermionic tube having an emitting cathode therein and having an attenuated gaseous content, of means for ionizing said gaseous content and heating the cathode to sustain electron emission therefrom comprising an external coil and a generator of radio frequency oscillations in circuit with the coil.

10. The combination With an electron tube having a cathode therein and having an attenuated gaseous content, of aA coil sur rounding the cathode in inductive relation thereto, and a local generator of high frequency currents in circuit with the coil, said 'coil and generator' constituting means for maintaining an oscillating field in the tube to effect ionization of gases therein and effect heating of thecathode to sustain electron emission therefrom.

11. The method of heating a cathode to effect electron emission therefrom n an evacuated vessel n which there is 'a gaseous residuum by means vof a surrounding coil Whichlconsists in passing radio frequency currents through said coil and thereby produce an oscillating field Within said vessel having suiicient energy to heat thefcathode whereupon electron emission is effected.

Signed by me, this 29th day of December, 1919.

FREDERICK s. MCCULLOUGH.

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