US1985923A

US1985923A - Circuit arrangement for electronic amplifiers

Info

Publication number: US1985923A
Application number: US520541A
Authority: US
Inventors: Gutmann Herbert
Original assignee: Telefunken AG
Current assignee: Telefunken AG
Priority date: 1930-04-23
Filing date: 1931-03-06
Publication date: 1935-01-01
Anticipated expiration: 1952-01-01

Description

Jan. 1, 1935. H. GUTMANN 1,985,923'

CIRCUIT ARRANGEMENT FOR ELECTRONIC AMPLIFIERS Filed March 6, 1951 maxim,

lawman INVEN TOR HERBERT GUTMA BY j ATTORNEY I ,1 p enmmrdn Et -(mm .f

n pumibn mmn s,1931, Ser'al No. 520,541

:HerbertGutmann; Berlin, Germany,-assignor'-"to Telefunkengfiesellschaft,fiir Drahtlose Teleg c .1!!! 1 H: Ber .Gcrma ra'corpora n oelny Aprili23, r939 ferent types.

amplifier"arrangement};particularly for audio free quency and radio fre uenc "amplificationwork which comprises twoseries-connected tubes of Y the same type. Ifboth" tubes are simultaneously supplied with grid potential of like value, such an arrangement results in the same slope and only half the plate reaction of a single tube. Hence, this circuit scheme results in the inverse condition obtained with the usual parallel connection in which, for two similar tubes, the slope is doubled while the plate reaction re mains unchanged.

Series connection, of course, is useful also for more than two tubes as well as for tubes of dif- It could-also be combined with parallel connection so that any desired plate re,- action and any desired slope inside certain limits are obtainable. r

Circuit schemes according to this invention may be used to advantage in cases where an existent grid alternating current potential is to be amplified a certain amount, and where a tube which possesses the plate reaction required therefor,

dueto its limited permissible plate direct current has such a narrow grid width that the available alternating current potential can not be accommodated under conditions free from distortion. In thiscase, according to this invention, two tubes with double plate reaction (that is to say, double grid width for the sameplatepoties and harmful efiects since it is distributed over the two tubes.

The circuit scheme here disclosed may be used to advantage for reception where it is desired to tune two circuits independently of each other to different band widths and where the incoming energy is to be combined again. g

A third application of the circuit scheme here disclosed is for frequency doubling or frequency multiplication.

tential supply V. has its positive pole connected by way of the consumer or load (transformencoil or resistance) with the plate of tube 1-, while the negative pole is united with the filamentpf tube I II. In parallel relation to each tube iis suitably 3a. shows in what way such frequency doubling tiple of'the input frequency. The invention is shown in six illustrations.

provided a, high. impedance or theseries combinaw tion comprising {a resistance] R-and capacity C (though, 1in eertam cimmnst nce; R Inlay. be: re: placed by an inductance coil).'.By ondensers Gland C2 each tube'receive'st e filament 5 potential required for the. starting ofia'plate our rent. Resistances R1 and R2 serve the purpose to make the time-constant of R and C so high that the audiofrequency variations of the lowest'ocg curing frequency will not yet occasion any apprel0 ciable discharges of the condensers. Furthermore, R1 and R2 must be so chosen that they will not impair the amplification of the tube. Hence, R1 and R2 mustbe high compared with the internal resistance of the tube and also great compared with for direct current and alternatin'gcurrent heat- 25 lead (see Figs. la and 'lb).

What is concernedin the case of Fig. 2 is a radio frequency amplifier in which the input circuits of the two series-connected electron tubes are tuned 0 to different band widths. 1 V i Figs. 3a. and 3b illustrate arrangements for frequency multiplication. The two tubes-are connected audion-fashion in this illustration. The

ing also from a resistance Wl', W2 in the plate ends of the grid winding of one tube are transposed with those of the other tube, with the re-' sult that one half-cycle is amplified by one tube, v and the other by the respective other tube. Fig.

may be continuedin additional stages. In Fig. 3b frequency multiplication is effected in a single such stage by that the plate coil is caused to react inductively upon the grid coils, and by that the plate circuit 'is'ituned to the desired 2 mul- 45 I claim:

1. In combination with a source of oscillations,

a pair of space discharge devices having separate input circuits and a common'output circuit, a

source of space current for said devices, the space 0 V paths, of said devices acting as potential dividers in connection with said source and means for coupling the input circuit of each of said devices independently/to said source of oscillations, a load circuit, means for coupling the common output devices forming a series circuit with both the space paths of said devices, meansior coupling the input circuit of each of said devices-independently to said first named source, a common utilizing circuit, means for transferring energy from the common output circuit of said devices to aload circuit, said last named meansbeing also in series with the spaced paths of said devices and the source of space current. a r

3. In combination with a source of a pair of space discharge devices having input and output circuits, a source of space current for said devices, the space paths ofsaid devices and said source of current forming a series circuit, means for coupling the input circuit of each of said devices independently to said source ofooscillations, said input circuits being tuned .to' different frequencies.

4. A circuit as described in the next preceding claim wherein one of the input circuits is tuned slightly above the frequency of the oscillations from the source whereas the other input circuit is tuned slightly below the frequency of said oscillations; '1 f r 5. An amplifier for amplifying .a band of frequencies comprising at least two space discharge devices having separate and distinct input circuits and acommon output circuit, a source of space current for's aid devices, said common output" circuits including the spaced paths of said devices, andthe source ofispace current all in series and a shunt-[circuit connected across the space path of each of said devices comprising a con-' denser in series with an impedance device the shunt circuits and said source of space current forming a series circuit, the impedance of each of the impedance devices being higher than the in- 'ternal resistance of the related space discharge device and considerably greater than the reactance of its associatedicondenser. at the lowest fre quency of said bandflof freq'u'eriCies'Lj i HERBE T GUTIMANN.