Патент USA US2411706код для вставки
Nov. 26, 1946. s. BERKOF'F ~ 2,411,706 PHASE INVERTER CIRCUIT Filed June 3, 1942 I - 2 sheets-sheet 2 UUTPl/T l 0UTPUT 2 . I?vemto‘r: Segmour Ber-kof?, ` -His AttoT-neg. Patented Nov. 26, 1946 Y STATE-s roFFici;_.- ~ 2,411,706... .I ?HXsÉ’iNvimrERîcntciiii‘? Seymour' Berkoff, Bridgeportfßonni; »assignorf to General Electric= Company;-y a,»-corporation-fo£- ì New' York 1o Claims. (01.4 iis-171!) l» e In f'theï circ‘uitfy of “Figi 1'? a'i‘rîelectron‘` discharge' device*- I I e, '.Whichii'nay‘fbe an1 audio-frequency’ a'mz pliñ'e'rfof: ai iràdio" receiver; furnishes a signal ito' f'aì second? electron discharge" device*y l 2l acting: asi a> Myè inventioncrelates-»tc lpha'sefinverte'r circuits andlias for its‘objec‘t to' improve the character isticsiof'such circùits`s~ Af-'fur-ther object> is yto provide ~ affphas'e ‘inverterY circuit in» which the‘magnitlldes‘ofï the; output 5 ' singlerl’tubec phase@ inverter." The electron> dise“ signals are-proportionalï'to the 'rrîagriitude'f off the-~ input Signal, an'diinfwhich th'e output signals/are ofî the# san`1'e'=t'iri1e`1~ occurrence a's’* thefisignalsì in the input circuit. ` . s Y f In ra‘dio apparatu'sused ibi" signal purposes; .for 10' example; in'v which fthere ïisi providedfaf single’sig-vr naif-comprising a' 'seriesr of -' veryf short - pulses i at - somewhai?-irregular- intervals',ì the 'phaseiiniierïter use@ to‘convert this single'signalvinto'two' sig-v nais `lforÍ feeding, foit example; ltWo -pu’sh pull- a’rií-` pli?i'ersî should f provide l'outpllt- signals > which are'y equal;andfoppositeinphase: Itis desirable both that there beno/ti-medelay' between» the input- pulse and eitherlof the output pulses and that there be no amplitude'distörtîoiï i?fthe phase in verter circuit. iiziyjiiivein'i'ioiiH proposes io elimi nate both iimeîdeigiyîa'ric iciiiiiitiiae'disiortion in ,_ such a pulse ain‘plifie'r’byeiiiployirig'la balanced impedance bridgè'ât'o'f reduëe'tlíëïeffect of feedf back onv the control gridi A to vary the; relative magnitude' of tli‘èltwo output4 30 single-:ended: source* is’ connected ac?ossf‘pòint’sï" r'er?otef` from theî t‘v‘vo output points." 'Another' feature is the proportionin‘g of` the'values' ofKL theimpedances comprisingr thisf bridge f' so “that” the magnitudes of= the output signals will be exactly" proportionaltothe-magnitudeo?the input signal. A Theifeatures'of- my_inventiomwhich Iv` believe to,-- be» novelr a-re set forthî with particularityl in the- appendedei-aimsf» My invention itself ; how-w ever, togetherr Withr furtherfobjectshand» advanlf` tages thereof;A may best be understood` b‘yA refer- L ence tothe' following-‘description taken‘in» connec tion'fwith--the- accompanyingdrawin‘g's; l in 'f which' Fig;Ayv 1-»r is 'a‘diagram-'off a phase=inverter circuit embodyingmy- invention; Figi 2'; is-y af' scl'i'ematic'y diagrammi/the'phaseinverter- circuitßof Fig;> 1f- ‘f in- whiclfrl the* impedance - bridge is“ illustrated ;v Figs. Scand «if» areephase inverter“ circuits showing” m'odiñcatioils IAOffthe invention; andi 'Figi'- 5 '~ is“s a? s‘f'zhem'aticF diagram- of; the' circuit' of'ï Fig;-' 4'A iiirv‘vl-iiclrtlieimpefdancelorldge'isiillustrèitedir ’ Since? trie'ï anode resistance' »2'4-- not' a liñeaf rësî's‘taifice; b’utïvarie's‘; fo'ifa fixedH grid pot'eñtiz'il;A witiif'aiio’deff potentiel,A introduction of distortion iiítöftlíëf‘g?id ‘circuit of' device ' I'Zf'is‘ prevented' by” iise* oi"-’iesisifciT 22 ‘to establish' theVT bridge re: lationship illustrated in Fig. 2. If resistorsZD andi 21‘ are eîi'uà-l‘-, i"e'z‘si`stol1’s"22‘V andl 231ar`èl eqïial,_ tiiefïeii‘ect'i's> triat- cifa’ completely balanceo Bridge scf trici discoiiioircaiinoif arise' erection dis: ape the oiiipiitfcirciiitsof inefoiiäseiriveiieii me@ 2f fe?, tiieife‘wiiivceîffo‘ieeciriefseek o‘ff'po'@ teniieíis- erisi?g‘f'iii » the output circuit' of ytime liz-ï institue -oriiiibefl l; 'mieiëfoiaihe volt; 2,411,706 3 2l are automatically equal and opposite and of the same time occurrence as the input signal sup plied tothe control electrode I6. ~ By the above-outlined circuit my invention provides a single tube phase inverter circuit (Il which may be used in pulse circuits. When a sig nal is supplied to the preceding ampliñer Il and after amplification is supplied to the control elec trode of tube I2, by means of the balancedbridge circuit, two pulses, one positive-going and the other negative-going, and of exactly the same time occurrence, are provided at the two output points. In this circuit, because of the balanced bridge relation, the phase inverter will have equal impedance with respect to both output I and out put 2. Such a relationship between output im pedances is desired, for example, where each of the two output signals is transmitted through an .4 of resistor 22 with the anode’ circuit. Likewise output 2 is taken directly from the cathode I8. The schematic diagram Vof Fig. 5 illustrates the bridge arrangement of this circuit and the func tion of the variable resistor 2l. Variation of this resistor varies the relative magnitudes of the out put voltages, that of output I increasing linearly with the value of resistor 2‘I, while that of output 2 is but slightly affected by such variation. Since resistor 20 equals resistor 2|, the feed-back volt ages supplied tothe control electrode from the anode and cathode circuits are always equal, re gardless of the setting of resistance 2'I. Conse quently, the balance of the bridge circuit is un disturbed by Variations of resistance 27 to adjust the relative magnitudes of the output voltages. By means of the circuits described in the fore going, two output signals which are opposite in phase and of precisely the same time occurrence appreciable length of cable having a definite im pedance characteristic before arriving at its des 20 as the input signal, are obtained from a single tination and is attenuated during such transmis input signal. The relative magnitudes of the sion. If the eiïect of such a capacitive load across output signals may be made equal or may be ad resistor 2I alone is considered, it will be seen that, justed to meet the requirements of following cir because of attenuation, less degeneration occurs cuits. in the cathode circuit for higher frequencies. As 25 ' By way of illustration only, and not in any a result the tube gain becomes larger lfor higher sense by way of limitation, the following repre frequencies than for lower, that is, a greater sentative values are those which have been found higher frequency voltage appears across resistor suitable in a particular phase inverter circuit em . 20 than appears across resistor 2l. On the other bodying my invention. In this receiver a type hand, if the same capacitive load is shunted GVG triocle tube was employed as the phase in across resistor 20 alone, the higher frequency verter tube in accordance with the modification voltages across resistor 20 are less than those shown in Fig. 5 of the drawings. The values of across resistor 2 I. Hence if equal capacitive loads the circuit constants were as follows: are shunted across these two resistors, the upper frequencies across resistor 20 will be reduced in magnitude to practically the same value as those ’ existing across resistor 2 I. The net effect of equal Resistor 1522,000 ohms Resistor 20=1,000 ohms Resistor 21:1,000 ohms Resistor 22:.5 megohm Resistor 23:.5 megohm capacities across the anode and cathode circuits is therefore to keep the frequency response in the two circuits approximately the same, and the 40 Resistor 19:500 ohms pulse shapes remain equal. Thus, with the equal output impedances of the phase inverter circuit provided by my balanced bridge arrangement, Resistor 27:1000 ohms potentiometer Capacitor 26=.1 microfarad Capacitor 28:.1 microfarad equal wave forms of the signal voltages at their destinations will be obtained. In the phase inverter circuit of Fig~ 1 resistor Thus it will be noted that the resistance in the cathode circuit of Fig. 5 between output 2 and ground is 1500 ohms, while the resistance be tween anode and ground may be varied from 1000 to 2000 ohms without disturbing the balance of the bridge. While I have described a particular embodi ment of my invention, it will be obvious to those skilled in the art that various changes and modi fications may be made without actually depart ing from the invention. I therefore desire by . 22 is shown connected directly between the an ode and control electrode of electron discharge device I2, a negative bias for the control elec trode being maintained by the resistor I9. In certain applications it may be desired to block the control electrode from the anode potential. In Fig. 3 is shown a modification of my inven tion wherein the capacitor 2B is connected in the circuit between the control electrode and anode f. the appended claims to cover al1 such changes in series with the resistor 22. In order that the and modifications as fall within the true spirit operation of my balanced bridge remain appre and scope of the foregoing disclosure. ciably unaffected by the added impedances of ca What I claim as new and desire to secure by pacitor 26, this capacitor should have a negligi Letters Patent of the United States is: ble impedance, at the lowest frequency to be am GO 1. In a system for isolating a single-ended plified, as compared with the impedance of‘re source of signals which Vary with respect to a sistor 22. Since the value of resistor 22 is quite point of ñxed potential from the output of a sin large and since the frequency of signals being gle tube phase inverter comprising an electron amplified is usually very high, the requirement of discharge device having an anode, a cathode, and negligible impedance for capacitor 26 is easily a control electrode, means for impressing signals met. from said source between said control electrode In Fig. 4 is shown a modification of my phase and said cathode, first and second output termi inverter circuit which is applicable where it is nals connected to said anode and said cathode desired to vary the relative magnitudes of the respectively, a series circuit connected between two output voltages. Such flexibility may be de said terminals, said series circuit comprising a sired, for example, to compensate for inequalities pair of resistances, means connecting said elec in two push pull amplifiers following the phase trode to a point between said resistances in said inverter. In this arrangement the variable re series circuit, said last-named point being vari sistor 2'I is connected in the anode circuit between able in potential with respect to said point of the point of output I and the point of connection 75 iixed potential, and resistance means connected 2,411,706 5 6 between each of said output terminals and said point of fixed potential. able resistance and said fixed resistor respective ly, and equal resistances connected between said point of fixed potential and said variable resist 2. In combination with a source of signals, a ance and said iixed resistor respectively. phase inverter for producing opposed signals at '7. In combination, a first electron discharge two points comprising an electron discharge de 5 device having input means and output means for vice having an anode connected to one of said providing a signal which varies with respect to points, a cathode connected to the other of said a point of ñxed potential, a second electron dis points, and a control electrode coupled to said charge device having an anode, a cathode, and source of signals, impedances connected between said control electrode and each of said points, and 10 a control electrode, means for connecting said `control electrode with said output means, output impedances connected between each of said terminals connected respectively to said anode points and said source of signals, said impedances and said cathode, a fixed resistor connected to being of such magnitude as to form a balanced said cathode, a variable resistor connected to said bridge circuit of which said points form two op anode, and means for isolating said iirst elec posite corners and said source of signals is con tron discharge device from said terminals to pre nected across the remaining corners, whereby vent feedback of distortions thereto, said means said source is isolated from said two points to comprising a pair of equal resistances connected prevent feedback of distortion thereto. respectively between said control electrode and 3. In combination in an amplifier, a source of said fixed and variable resistors, and a pair of signals which vary with respect to a point of ñxed equal resistances connected respectively between potential, an electron discharge device having ksaid point of fixed potential and said fixed and an anode, a cathode, and a control electrode, variable resistors. output means connected between said anode and 8. In combination with an electron discharge said point of fixed potential, output means con nected between said cathode and saidpoint of 25 device having an anode, a cathode, and a con trol electrode, a bridge circuit comprising a pair fixed potential, means for impressing signals from of impedances connected between a point of i-lxed said source on said electrode, and means for iso potential and said anode and said cathode re lating said source of signals from said output spectively, and a second pair of impedances con means, said means comprising equal resistances connected between ' said control electrode and nected rbetween said control electrode and said each of said output means, and equal resistances connected between each of said output means and said point of fixed potential. 4. In combination. a first electron discharge device having input means and output means for providing a signal which varies with respect to a point of ñxed potential, a second electron dis charge device having an anode, a cathode, and a respect to each other and to the impedances of said first pair of impedances to prevent varia tions of the potential of said anode from being supplied to said electrode. control electrode; means for connecting said con anode and said cathode respectively, and a source of signals connected between said control elec trode and said point of iixed potential, said sec ond pair of impedances being proportioned with 9. In an amplifier having a single ended source trol electrode with said output means of said first 40 of signals which vary with respect to a point of fixed potential, the combination of, an electron electron discharge device, an output terminal discharge device having an anode, a cathode, and connected to said anode, an output terminal con a control electrode, means for impressing signals nected to said cathode, and meansfor isolating from said source between said control electrode said ñrst electron discharge device from said ter minals to prevent feedback of distortions thereto, 45 and said cathode, a first outputcircuit connected between said anode and said point, a second out said means comprising a pair of equal resistances put circuit connected between said cathode and y connected between said terminals and said con said point, one, of said output circuits comprising trol electrode, and a second pair of equal resist a pair of serially connected resistances and the ances connected between said terminals and said other of said output circuits comprising a fixed point of fixed potential. resistance and a variable resistance in series 5. In combination with an electron discharge therewith, and means for isolating said single device having an anode, a cathode, and a con ended source of signals from said output circuits, trol electrode, a bridge circuit comprising a pair said means comprising equal resistances con.. of equal impedances connected between a point nected respectively between said electrode and the of fixed potential and said anode and said cath , common point of` said pair of serially connected ode respectively, and a second pair of equal im resistances and between said electrode and the pedances connected between said control elec common point of said iixed and variable resist trode and said anode and saidcathode respec ances. ' tively. and a source of signals connected between 10. In combination, a source of signals, an said control electrode and said point of fixed po electron discharge device having a control elec trode coupled tosaid source, an anode, and ra 6. In an amplifierhaving a single-ended source cathode, a first resistance connected between said of signals which vary with respect to a point of anode and a point of fixed potential, a second re-f iixed potential, the combination of an electron dischargedevice having an anode, a cathode, and ” sistance connected between said cathode and said point„and means fory isolating said source from a control electrode, means for impressing signals `said output circuit comprising a third resistance from said source between said control electrode connected between said electrode and said anode, 1 and said cathode, first and second output termi -.a fourth resistance connected between said elec nals connected to said anode and said cathode respectively, a variable resistance connected to 70 trode and said cathode, the ratio of said ñrst tential. ` I „ said anode, a fixed »resistor connectedvto said - resistance to said third resistance being equal to cathode, and means for isolating said single-end ed source of signals from said output terminals, said'means comprising equal resistances connect- , the ratio of said second resistance to said fourth ed between saidr contres encarece, and. said vari-` resistance. » SEYMOUR BERKOFF.