US1411814A - Power system for radio apparatus - Google Patents

Description

H. M. STOLLER.

POWER SYSTEM FOR RADIO APPARATUS.'

APPLICATION FILED APR. 30, 19l8.

Patented Apr. 4, 1922.

m EMET //7|/e/7f0r."

I Hugh M Sfoflev y Aflym Fig. 3.

um'rso STATES PATENT orrice.

HUG-H STOLLER, OF NEW YORK, N. 'Y., ASSIGNOR TO-WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. 'Y., A. CORPORATION OF NEW YORK.

rowan. sxs'rmm roa mm annu us.

Specification of Letters Patent.

Patented A r..4, 1922.

Application filed April 30, 1918. Serial No. 231,586.-

To all whom it may concern:

Be it known that I, HUGH M. S'roLLnR, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Power Systems for Radio Apparatus, of which the following is a full, clear, concise, and exact-description.-

This invention relates to power systems, and more particularly it relates to power systems for radio apparatus of the type'ineluding vacuum tubes or other discharge devices having electrically heated cathodes and designed for use'where economy of space and lightness are of prime importance, as in aeroplanes. A. great obstacle to radio transmission from aeroplanes has been the weight of the power systems required.

The primary object of this invention is to produce a power system for such radio apparatus which combines practical utility with the highest degree of economy in space and weight.

With certain arrangements of vacuum tubes of the three-electrode type for transmission of radio messages from aeroplanes, it is necessary to'provide a filament heating source of approximately 10 volts and an anode-cathode source of from 200 to 600 volts. Both sources of electromotive force must be reasonably free from alternating current components and likewise must be of substantially constant voltage during the period required for signaling purposes;

otherwise continual manual adjustment as,

for example, by means of resistances, would be necessary.

In fulfilling the above and other requirements apparatus has been designed in accordance-.with the accompanying drawings in which 'Fig. 1 is a conventional diagram of one embodiment of my invention; Fig. '2 is 'a' diagram of a modified form; and Fig. 3 is '45 an explanatory diagram of the current filter'shown in both Figs. 1 and 2.

In Fig. 1 numeral 1 represents a suitable source of'electric energy, such as a storage battery adapted to give a considerable output at slightly above ten volts. Across battery 1 is connected the motor winding of a dynamotor or motor-generator in which numeral 2 represents the series -winding, 3' the shunt winding and 4 the armature mechanically connected to the generator armature 5. In a preferred form all the windings are on a common armature. The generator 5 produces a current of sufiiciently high potential, for example, 500 volts, to provide space current between the filaments 8 and anodes 9 of a set of vacuum tubes 10. Across battery 1 are placed the filaments or cathodes of tubeslO in any suitable manner so that the cathodes may be heated. Associated with' the tubes 10 will be such elements as are necessary to constitute a radio system of any desired kind. Since the details of such systems are known to'those skilled in the art, they are not herein illustrated. Choke coil 12, such as is usually used in series with the source of anode-cathode current in order to prevent high-frequency currents from'being short-circuited through the direct current source, is provided in conductor 6. Conductor 7 forms acommon negative terminal.

In the arrangement as so far described, the fluctuations induced by the reaction of the armature and by the commutator segments, particularly the latter, will tend to create undesirable fluctuations of audible frequency in the output of the vacuum tubes 10. The commutator segments, for exam ple, w1ll tend to produce a fluctuation depending on their number and speed of rotatute toogreat a bulk and weight to be carried upon aeroplanes. A filter is here used consisting of inductance coils 13 in series and resistances 14 across the line. Although less efficient in one respect since direct current energy is Wasted in the resistances, this. type of filter accomplishes the desired purpose and consists of elements having mini-. mum bulk and Weight, and is much less expensive.

F or a particular description of the filter reference is made to Fig. 3. The direct current machine 4, owing to the action of its commutator segments, will act also as a source of superimposed alternating current of, for example, 600 cycles, the direct current will pass throughand heat the filaments 8, but with some loss through the resistance! Ill 14. Suppose that the alternating voltages at points a, b, 0 and d are reEpectively represented by E E E and l that the impedances of coils 13 to the said alternating voltages are respectively represented by Z Z and Z that the respective resistances of elements 14 are R and R and of filaments 8 is R then if Z Z etc. are large com- 'pared with R and R etc., the following equation will be approximately true:

2 Thus, for a given frequency, if R v Z1 R, E will be approximately 5 The loss and R the alternating voltage minal voltage as it becomes discharged, it

is necessary in some cases to compensate for this'by a ballast resistance 15' (Fig. 1). For this purpose it is desirable to use an iron wire sealed in an atmosphere of' inert gas in an airtight vessel, with the terminals connected into the lO-volt circuit. When properly constructed the resistance of this device is comparatively high at maximum battery voltage, but falls rapidly as the voltage decreases slightly therefrom and hence tends to keep the voltage impressed across the filaments substantially constant.

In Fig. 2 is shown a modified form in which the battery or source 1 operates a motor-generatorwhich'has two output windings, one of ten volts for heating the filaments, across which a filter 13, 14 is placed, as in the arrangement of Fig. 1, and a higher voltagewinding of 500 volts for the anode-cathode current of the vacuum tubes 10. The motor-generator of this arrangement is preferably a constant speed machine,

and its output voltages will be substantiallyconstant at ten and 500 volts, respectively. The device 15' of ig. 1 is therefore not needed in this arrangement.

It should be noted that lightness andsmall volume are the features v which are considered of paramount importance in these systems, and are obtained at some sacrifice either of power efiiciency or of ability for sustained service over long periods, or both.

The arrangements shown are illustrative only, and other modificationsmay be devised by those skilled in the art which will fall within the scope of the invention as expressed by the appended claims. While described as part of a transmitting system for an aeroplane, certain features of the invention will be found useful in other places where a power plant of limited weight and volume is required. Since the current discharge tubes 10 may form elements of a receiving or high frequency generating system in any of the known arrangements employing such devices, it is obvious that the invention as applied to signaling stations is not limited to transmitting systems. Filters of the type shown are particularly useful in receiving systems.

What is claimed is:

1. The combination with the elements of a thermionic vacuum tube system which requires currents of high and low voltage respectively, for short periods of operation only, of a power system therefor comprising a battery of said low voltage, a motor operated by said battery, a generator of said high voltage operated by said motor, and connections from said battery and said generator to said elements respectively.

2. In a radio system, a discharge device having a cathode, a source for supplying current at a low voltage to heat said cathode, a generator, circuits whereby said source operates said generator, and circuits whereby said generator supplies space current at a high voltage to said discharge device.

3. In a radio system, a dischar e device having a cathode, a battery and ine concathode, a generator, circuits whereby said battery operates said generator, circuits whereby. said generator supplies space current to said discharge device, and a. filter associated with said line conductors comprising inductances in series with and a resistance in shunt to said cathode.

4. Ina system for radio communication, a source of current, means whereby said source supplies a high voltage to one path in said system and a low voltage to another paththerein, said means reacting on said 'ductors for supplying current to heat said second path to produce fluctuating current therein, and a filter associated with said second path consisting of a number of inductances in series with and a number of resistances in shunt to said path.

5. In combination in a radio system for use upon an aeroplane, a battery, a motorgenerator and, a vacuum tube, means whereby said battery operates said motor-generator, means whereby said battery supplies low voltage current to said tube, and means whereby said motor-generator supplies high voltage current tosaid tube.

6. In combination in a radio system for use upon an aeroplane, a battery, a motorgenerator and a vacuum tube, means where-- by said battery operates said motor-gen- "erator, means whereby said battery supplies low voltage current to said vacuum tube, means whereby said motor-generator supplies high voltage current to said tube, means whereb said motor-generator reacts on said low vo tage supply, and means for rendering negligible the effect of said reaction.

7. In a signaling system the combination of two energy consuming load paths re- 10 quiring different voltages, at single source of energy for supplying said paths, a direct connection between said source and one of said paths, a direct current voltage transformer connected between said source and the other of said paths, means whereby said voltage transformer causes an undesirable reaction upon one of said paths, and a filter forheliminating the eifect thereof upon said pat In Witness whereof, I hereunto subscribe 20 my name this 26th day of iikvpfil, A. D., 1918.

H. STOLLER.

Images