US2255403A - Periodic wave repeater - Google Patents
Periodic wave repeater Download PDFInfo
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- US2255403A US2255403A US264935A US26493539A US2255403A US 2255403 A US2255403 A US 2255403A US 264935 A US264935 A US 264935A US 26493539 A US26493539 A US 26493539A US 2255403 A US2255403 A US 2255403A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
- H04N5/12—Devices in which the synchronising signals are only operative if a phase difference occurs between synchronising and synchronised scanning devices, e.g. flywheel synchronising
- H04N5/123—Devices in which the synchronising signals are only operative if a phase difference occurs between synchronising and synchronised scanning devices, e.g. flywheel synchronising whereby the synchronisation signal directly commands a frequency generator
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- This invention relates to improvements in periodic wave repeaters adapted to be excited by periodic pulses and, While of general utility, it is particularly useful in any saw-tooth Wave generator for television apparatus having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic pulses, being of special utility in that type of generator comprising an oscillator having a vacuum tube which is conductive during the trace intervals.
- Periodic wave repeaters adapted to be excited by periodic pulses may have an undesirable characteristic, due to the fact that undesired pulses present with the desired pulses tend to affect the operation of the repeater and this is particularly ltrue if the undesired pulses are in amplitude comparable with thedesired pulses. Also, the operation of such repeaters may not be entirely satisfactory because undesired pulses of the amplitude of desired pulses tend to impair the operation of the repeater at particular points in the cycle.
- the synchronizing of thel saw-tooth oscillator utilized may be affected Iby undesired pulses as well as desired pulses and, in general, this is particularly true if the vacuum tube utilized in the saw-tooth scanning oscillator is conductive during the trace interval.
- submultiple-frequency generators such as are commonly used in the timing chain of television transmitting apparatus
- a saw-tooth wave generator having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic pulses, comprising an oscillator having a vacuum tube which is conductive during the trace intervals but which is protected from being affected by undesired pulses in the synchronizing source over the major portion of the period of the oscillator.
- the periodic pulses are applied to the diode with such polarity as to tend to render the diode conductive and the value of the above-mentioned derived voltage of substantially different value is such that the diode is rendered conductive if such value occurs simultaneously with one of the exciting pulses.
- the amplitude of the derived voltage, over the rnajor portion of the period of the oscillator is of such value that the diode is maintained nonconductive even in the presence of a pulse o an amplitude comparable with that of the pulses utilized to excite the periodic wave repeater.
- the repeater comprises a saw-tooth wave oscillator for generating pulses having relatively long trace and relatively short retrace intervals and the oscillator is adapted to be synchronized by periodic pulses from a suitable source.
- the above-mentioned derived voltage applied as abias to the diode is a saw-tooth voltage used as a regenerative voltage for the oscillator and, in accordance with one form of this embodiment, the
- vacuum tube of the oscillator is conductive during the trace intervals.
- Fig. l of the drawing is a circuit diagram, partly schematic, of a complete television receiver comprising a line-frequency scanning generator embodying the invention, while Fig. 2 comprises graphs illustrating certain of the operating characteristics of the system of Fig. 1.
- the system illustrated'in Fig. l comprises a ⁇ modulated-carrier television signal receiver of the superheterodyne type including an antenna system I0, Il connected to a radio-frequency amplifier I2 to which are connected in cascade, in the order named, an oscillator-modulator I3, an intermediate-frequency amplifier I4, a detector I5, a video-frequency amplifier I6, and an imagereproducing device I ⁇ I.
- a line-frequency generator I8 and field-frequency,generator I9 are coupled to the output circuit of the detector I through a synchronizing-signal separator and processor 20, the line-frequency generator I8 being coupled to a scanning winding 2
- the stages or units Ill-I1, inclusive, I9 and may all be of conventional well-known construction so that detailed illustrations and descriptions thereof are unnecessary herein.
- television signals intercepted by the antenna I0, II are amplifled in radio-frequency amplifier I2 and coupled to the oscillator-modulator I3 wherein they are converted into intermediate-frequency signals which, in turn, are selectively amplified in the intermediate-frequency amplifier I4 and delivered to detector I5.
- the modulation components of the signalare derived by the detector I5 and the video-frequency components thereof are supplied to the video-frequency amplifier I6 wherein they are amplified and from which they are supplied in the usual manner to a brightnesscontrol electrode of the image-reproducing device I'I.
- the modulation components are also supplied to the synchronizing-signal separator and processor 20, from which suitable synchronizing aasaeoe signals are supplied to the control circuits of generatcrs i8 and i3.
- the intensity of the scanning beam of device il is modulated or controlled in yaccordance with the video-frequency voltages impressed upon its brightness-control electrode inthe usual manner.
- Fig. 1 of the drawing The arrangement of the' present invention is illustrated in Fig. 1 of the drawing as applied to a particular type of periodic Wave repeater, specifically, a line-frequency scanning generator I8 adapted to be excited by periodic pulses which forms the subject matter'of applicants copending application Serial No. 256,033, led February 13, 1939.
- Similar circuit elements ofthe linefrequency generator I8 of Fig. 1 and of the modiflcation of Fig. 5 of the above-mentioned copending application have identical reference numerals.
- Generator I8 comprises a high-mu screen-grid vacuum tube 3
- Tube 32 is essentially a wave form stabilizing device which is designed to act as a negativeresistance during the trace interval, increasing the amplitude of the current in the load circuit and compensating at least partially for the resistance therein. lt-has no effect during the retrace intervals and particularly does not obstruct the occurrence of a half-cycle of free 0scillation of the load circuit during the retrace interval.
- the plate electrode 22 of tube 32 is here used -as a control electrode and is subjected to a control voltage which controls a relatively large current in the output circuit of tube 32, which is here the circuit comprising the grid 23 and cathode 29.
- Voltage variations in the output circuit of tube 32 during trace intervals are less than the variations of the control voltage applied to its control circuit by the variations of the load voltage of the system, which are relatively large. This is due to the fact that, while arelatively small current is required in its input circuit, a relatively large saw-tooth control voltage is required in the input circuit of tube 32 and this is obtained from the load circuit of the system by virtue of the high peak voltage which exists across the load circuit during the retrace interval. A saw-tooth voltage is obtained for this purpose across a condenser 4
- a bias voltage is provided for tube ⁇ 3
- a feed-back circuit is also provided for tube 3
- This feed-back and neutralizing circuit includes windings 66 and 61 of the ,output transformer, transformer winding 66, resistor 13, and condenser 68 being provided to generate a saw-tooth feed-back voltage across condenser 68 in the input circuit of tube 3
- Periodic synchronizing pulses from source 28 are coupled into the input circuit of vacuum tube 3l through a diode 88 and provide current pulses which are developed into voltage pulses by means vof resistor BI in the input circuit of tube 3
- the operation of the linefrequency generator I8 is substantially as described in detail in the above-mentioned copending application and may be briefly stated as follows: Assuming that the required current of saw- ⁇ tooth wave form flows through scanning inductance 2
- the desired current and voltage wave forms associated with the load circuit of the system are obtained by developing currents in tubes 3
- the required energy is thus supplied to the load circuit only during trace intervals, a half-cycle of free oscillation taking place in the load circuit during each trace interval.
- the saw-tooth voltages developed across condensers 4I and 68 are applied to the input circuits of tubes 32'and 3 I, respectively, to provide the required saw-tooth current during the trace intervals, and the pulse voltages reduce their current output to zero during the retrace intervals.
- pulses from source 28 produce voltage pulses on the cathode of the diode 88, as represented by curve A of Fig. 2, the initial potential of the cathode of the diode being taken as a reference value. It is seen that, as applied to the diode-cathode, these negative pulses tend to render the diode conductive. Peaks b of curve A represent pulses by which it is desired to synchronize the linefrequency generator I8, while peaks c represent undesired pulses which may, for instance, be caused by transient disturbances in the system.
- a suitable unidirectional bias is also applied to diode 88 from the lower part of resistor 68.
- the diode 88 becomes conductive only when its anode is positive with reference to its cathode, it is apparent that no pulses are passed by the diode except at the precise time when its effective bias, due to the unidirectional-bias voltage developed across resistor 68 and the derived saw-tooth bias voltage across condenser 68, ⁇ is zero, that is, when it is desired to synchronize the generator I8; that is, the amplitude of the saw-tooth voltage developed across condenser 68 is of such value at the time corresponding to a pulse b as to render the diode 88 conductive, since such value occurs simultaneously with a synchronizing pulse, but its value over the major portion of the period is such that the diode 88 is maintained nonconductive even in the presence of a pulse such as c of amplitude comparable to that of the desired synchronizing pulses b.
- is conductive during the trace intervals of the generated Wave and is, therefore, susceptible to disturbances in the source of synchronizing signals during the trace interval.
- the arrangement of the present invention is, therefore, designed to provide a means by which any disturbances in the source 28 of an amplitude comparable with the desired synchronizing pulses are kept out of the input circuit of tube 3
- a feed-back voltage of saw-tooth wave form is continuously applied to the control grid of tube 3
- a periodic wave generator adapted to be eX- cited by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulse-l responsive input circuit, a diode effectively in series in said input circuit for coupling said pulses thereto to synchronize said oscillator, means for deriving from said oscillator a periodic voltage having a substantially dierent value at a predetermined point of each period than over the major portion of each period, and
- said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude 'of said voltage over said major, portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of amplitude comparable with that of said pulses.
- a periodic Wave generator adapted to be eX- cited by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulseresponsive input circuit and an output circuit, a diode effectively in series in said input circuit for coupling said pulses thereto to synchronize said oscillator, means for deriving from said output circuit a periodic voltage having a substantially diierent value at a predetermined point of each period than over the major portion of said period and for applying said voltage to said input circuit for feedback in said oscillator, and means V for.
- a saw-tooth Wave generator for generating pulses having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulsei responsive input circuit and an output circuit, a
- a saw-tooth wave generator adapted to lbe synchronized by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulse-responsive input circuit, a diode effectively in series in said input circuit for coupling said pulses thereto, a regenerative circuit for said vacuum tube comprising a condenser in said input circuit and a resistor for deriving across said condenser a saw-tooth voltage, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a substantially lesser degree at one extreme value thereof, said pulse being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of said one extreme value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude of said derived voltage over said major portion of said period being such that said diode is maintained nonconductive even in the' presence of a pulse of an
- a periodic wave generator adapted to be eX- cited by periodic voltage pulses comprising, a vacuum-tube oscillator having a pulse-responsive input circuit and an output circuit, a diode eiectively in series in said input circuit and responsive to said voltage pulses for couplng into said input circuit corresponding current pulses, impedance means in said input circuit for developing a pulse voltage in said input circuit in response to said current pulses to synchronize said oscillator, means for deriving from said output circuit a periodic voltage having a substantially different value at a predetermined point at each period than over the major portion oi' said period and for applying said voltage to said input circuit for regeneration o!
- a saw-tooth wave generator adapted to be synchronized by periodic voltage pulses comprising, a vacuum-tube oscillator having a pulseresponsive input circuit, a diode effectively in series in said input circuit and responsive to said voltage pulses for coupling into said input circuit corresponding current pulses, a feed-back circuit for said vacuum tube comprising a condenser in said input circuit and a resistor for deriving across said condenser a periodic voltage having a substantially diierent value at a predetermined point of each periodthan over the major portion of said period, a resistor in series with said firstmentioned condenser included in said input circuit for developing voltage pulses in response to said current pulses, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the
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Description
. Sepf- 9, 1941- H. A. WHEELER PERIODIC WAVE REPEATER Filed March so', 1939 (I7 REPRODUCN 2l IMAGE DEVICE )IIS --o VIDEO- FREQUENCY AMPLIFIER O- -V--O DETECTOR INTERMEDIATE FREQUENCY AMPLIFIER OSCILLATOR MODU LATOR RADIO- FREQUENCY AMPLIFIER IL-o FIELD FREQUENCY GENERATOR SYNCH RONIZING SIGNAL SE PARATOR -o PROGESSORo-l- FIG.I.
, r fs INVENTOR H OLD A. WHEELER BY a M f (n 1 l f ATTORNEY Patented Sept. 9, 1941 2,255,403 PEmonIc WAVE REPEATER Harold A. Wheeler, Great Neck, N. Y., assignor to Hazeltine Corporation, a corporation of Dela- Wale Application March 30, 1939, Serial No. 264,935
(Cl. Z50-36) Claims.
This invention relates to improvements in periodic wave repeaters adapted to be excited by periodic pulses and, While of general utility, it is particularly useful in any saw-tooth Wave generator for television apparatus having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic pulses, being of special utility in that type of generator comprising an oscillator having a vacuum tube which is conductive during the trace intervals.
Periodic wave repeaters adapted to be excited by periodic pulses may have an undesirable characteristic, due to the fact that undesired pulses present with the desired pulses tend to affect the operation of the repeater and this is particularly ltrue if the undesired pulses are in amplitude comparable with thedesired pulses. Also, the operation of such repeaters may not be entirely satisfactory because undesired pulses of the amplitude of desired pulses tend to impair the operation of the repeater at particular points in the cycle. For instance, in a saw-tooth wave generator having relatively long trace and relatively short retrace intervals, such as is commonly used in television scanning apparatus, the synchronizing of thel saw-tooth oscillator utilized may be affected Iby undesired pulses as well as desired pulses and, in general, this is particularly true if the vacuum tube utilized in the saw-tooth scanning oscillator is conductive during the trace interval. Also in some cases,rfor instance, in submultiple-frequency generators such as are commonly used in the timing chain of television transmitting apparatus, it may be desired to effect synchronization by particular ones of the pulses from a source of periodic synchronizing signals, that is, the ones of the pulses occurring at predetermined intervals, and in such casesy it is particularly desirable that the apparatus be insensitive to all undesired pulses.
Various methods have been utilized in arrangements of the prior art for eliminating one or more of the above-mentioned disadvantages. For instance, it has been proposed in one system to limit the amplitude of the source of synchronizing signals so that no undesired pulses appear therein with an amplitude greater than that of desired pulses. Such arrangements are not sufficient for satisfactory operation of a saw-tooth scanning generator having an oscillator comprising a vacuum tube which is conductivev during trace intervals of the system, because even a Weak undesired pulse occurring during a trace interval necessarily affects the operation of the system. Also, arrangements have been proposed for a generator adapted to be synchronized by an external source of pulses the purpose of It is another object of the invention to provide.
a saw-tooth wave generator, having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic pulses, comprising an oscillator having a vacuum tube which is conductive during the trace intervals but which is protected from being affected by undesired pulses in the synchronizing source over the major portion of the period of the oscillator.
It is still another object of the invention to provide a periodic wave repeater, adapted to be excited by periodic pulses, comprising an arrangement by virtue of which no exciting pulses are applied to the repeater except at predetermined intervals during which it is desired that ythe repeater be excited by the external source of pulses.
In accordance with the invention, a periodic wave repeater adapted to be excited by periodic synchronizing pulses comprises a .vacuum tube having a pulse-responsive input circuit, a diode effectively in series in the input circuit for coupling the periodic pulses thereto, means for deriving from the vacuum tube a periodic voltage having a value at a predetermined point of each period substantially diierent than that over the major portion of the period, and means for applying this derived voltage as a bias to the diode with such polarity that it is biased in opposition to conductivity to a lesser degree at the predetermined point oi each period than over the major portion of each period. The periodic pulses are applied to the diode with such polarity as to tend to render the diode conductive and the value of the above-mentioned derived voltage of substantially different value is such that the diode is rendered conductive if such value occurs simultaneously with one of the exciting pulses. The amplitude of the derived voltage, over the rnajor portion of the period of the oscillator, however, is of such value that the diode is maintained nonconductive even in the presence of a pulse o an amplitude comparable with that of the pulses utilized to excite the periodic wave repeater.
In a preferred embodiment of the invention, the repeater comprises a saw-tooth wave oscillator for generating pulses having relatively long trace and relatively short retrace intervals and the oscillator is adapted to be synchronized by periodic pulses from a suitable source. Also in a preferred embodiment of the invention, the above-mentioned derived voltage applied as abias to the diode is a saw-tooth voltage used as a regenerative voltage for the oscillator and, in accordance with one form of this embodiment, the
vacuum tube of the oscillator is conductive during the trace intervals.
For a better understanding of the invention, together with other and further objects thereof, reference is had to the following description/taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.
Fig. l of the drawing is a circuit diagram, partly schematic, of a complete television receiver comprising a line-frequency scanning generator embodying the invention, while Fig. 2 comprises graphs illustrating certain of the operating characteristics of the system of Fig. 1.
Referring now more particularly to the drawing, the system illustrated'in Fig. l comprises a` modulated-carrier television signal receiver of the superheterodyne type including an antenna system I0, Il connected to a radio-frequency amplifier I2 to which are connected in cascade, in the order named, an oscillator-modulator I3, an intermediate-frequency amplifier I4, a detector I5, a video-frequency amplifier I6, and an imagereproducing device I`I. A line-frequency generator I8 and field-frequency,generator I9 are coupled to the output circuit of the detector I through a synchronizing-signal separator and processor 20, the line-frequency generator I8 being coupled to a scanning winding 2| of imagereproducing device I1 in a manner to be hereinafter fully described, and the outputl circuit of field-frequency generator I9 being coupled to a field-scanning winding of image-reproducing device II in a similar or other suitable manner. The stages or units Ill-I1, inclusive, I9, and may all be of conventional well-known construction so that detailed illustrations and descriptions thereof are unnecessary herein.
Referring briefly, however, to the operation of the above-described system as a whole, television signals intercepted by the antenna I0, II are amplifled in radio-frequency amplifier I2 and coupled to the oscillator-modulator I3 wherein they are converted into intermediate-frequency signals which, in turn, are selectively amplified in the intermediate-frequency amplifier I4 and delivered to detector I5. 4The modulation components of the signalare derived by the detector I5 and the video-frequency components thereof are supplied to the video-frequency amplifier I6 wherein they are amplified and from which they are supplied in the usual manner to a brightnesscontrol electrode of the image-reproducing device I'I. The modulation components are also supplied to the synchronizing-signal separator and processor 20, from which suitable synchronizing aasaeoe signals are supplied to the control circuits of generatcrs i8 and i3. The intensity of the scanning beam of device il is modulated or controlled in yaccordance with the video-frequency voltages impressed upon its brightness-control electrode inthe usual manner. Scanning waves are generated in the'line-frequencyand field-frequency generators I8 and I9., respectively, which are synchronized by the output of synchronizing-signal separator and processor 20, and these waves are applied to the scanning elements of thc imagereproducing device I'I to reproduce scanning fields and thereby to deflect the beam in two directions normal to each otherl so as to trace a rectilinear l5v pattern on the screen and thereby to reconstruct the transmitted image.
The arrangement of the' present invention is illustrated in Fig. 1 of the drawing as applied to a particular type of periodic Wave repeater, specifically, a line-frequency scanning generator I8 adapted to be excited by periodic pulses which forms the subject matter'of applicants copending application Serial No. 256,033, led February 13, 1939. Similar circuit elements ofthe linefrequency generator I8 of Fig. 1 and of the modiflcation of Fig. 5 of the above-mentioned copending application have identical reference numerals. Generator I8 comprises a high-mu screen-grid vacuum tube 3|' having a pulse-responsive input circuit and a low-mu reversed triode tube 32. The tubes 3I and 32 have output circuits coupled with opposite polarity to the load circuit of the system including a parallelresonant circuit comprising a shunt capacitance 38, shown in dotted lines for the reason that it may be comprised wholly or partially of the inherent capacitance of rthe'circuit, and the load inductance olf scaning coil 2I. Scanning coil 2| is coupled into the parallel-resonant circuit by means of -an autotransformer comprising primary windings 39' and 40' andY secondary winding 40' is used to transform the low inductance of scanning winding 2| to the higher inductance required in the output circuit of tube 3|. The effective inductance of the resonant output circuit of tube 3| is thus that of the transformer primary windings 39', 40 as measured with the scanning winding 2I connected across the secondary winding 40. s
' Tube 32 is essentially a wave form stabilizing device which is designed to act as a negativeresistance during the trace interval, increasing the amplitude of the current in the load circuit and compensating at least partially for the resistance therein. lt-has no effect during the retrace intervals and particularly does not obstruct the occurrence of a half-cycle of free 0scillation of the load circuit during the retrace interval. The plate electrode 22 of tube 32, conventionally used as an anode, is here used -as a control electrode and is subjected to a control voltage which controls a relatively large current in the output circuit of tube 32, which is here the circuit comprising the grid 23 and cathode 29. Voltage variations in the output circuit of tube 32 during trace intervals are less than the variations of the control voltage applied to its control circuit by the variations of the load voltage of the system, which are relatively large. This is due to the fact that, while arelatively small current is required in its input circuit, a relatively large saw-tooth control voltage is required in the input circuit of tube 32 and this is obtained from the load circuit of the system by virtue of the high peak voltage which exists across the load circuit during the retrace interval. A saw-tooth voltage is obtained for this purpose across a condenser 4| connected in series with a resistor 42 directly across the load circuit. The voltage of condenser 4I is coupled to the control electrode of tube 32 through a coupling condenser 43 and a leak resistor 64.
A bias voltage is provided for tube `3| by means of a cathode resistor 68 by-passed by condenser 6|. A feed-back circuit is also provided for tube 3|, designed to supply pulse and saw-tooth voltages to its input electrode and at the same time to neutralize any kickback into the source of synchronizing signals 20. This feed-back and neutralizing circuit includes windings 66 and 61 of the ,output transformer, transformer winding 66, resistor 13, and condenser 68 being provided to generate a saw-tooth feed-back voltage across condenser 68 in the input circuit of tube 3|. Periodic synchronizing pulses from source 28 are coupled into the input circuit of vacuum tube 3l through a diode 88 and provide current pulses which are developed into voltage pulses by means vof resistor BI in the input circuit of tube 3|.
Aside from the particular improvement of the circuit of Fig. 1 which forms the subject matter of the present invention, the operation of the linefrequency generator I8 is substantially as described in detail in the above-mentioned copending application and may be briefly stated as follows: Assuming that the required current of saw- `tooth wave form flows through scanning inductance 2| during the trace interval, a voltage pulse of high amplitude is developed by the rapid change of current in the load nductance 2| during the retrace interval, in which both tubes 3| and 32 are maintained nonconductive, and a relatively small pulse voltage-is developed during the trace interval. The desired current and voltage wave forms associated with the load circuit of the system are obtained by developing currents in tubes 3| and 32 which have saw-tooth wave forms during trace intervals, but which are reduced to zero during retrace intervals. The required energy is thus supplied to the load circuit only during trace intervals, a half-cycle of free oscillation taking place in the load circuit during each trace interval. The saw-tooth voltages developed across condensers 4I and 68 are applied to the input circuits of tubes 32'and 3 I, respectively, to provide the required saw-tooth current during the trace intervals, and the pulse voltages reduce their current output to zero during the retrace intervals.
Reference is made to Fig. 2 for an explanation of the operation of the present invention in the circuit of Fig. 1. pulses from source 28 produce voltage pulses on the cathode of the diode 88, as represented by curve A of Fig. 2, the initial potential of the cathode of the diode being taken as a reference value. It is seen that, as applied to the diode-cathode, these negative pulses tend to render the diode conductive. Peaks b of curve A represent pulses by which it is desired to synchronize the linefrequency generator I8, while peaks c represent undesired pulses which may, for instance, be caused by transient disturbances in the system. The derived saw-tooth voltage developed across condenser 68 by` means of transformer winding 66 and resistor 13, which is a periodic voltage having a substantially different value at a predetermined point of each period than over the major portion of each period, is applied as a bias to the anode of The negative synchronizing diode 88 with such polarity that diode 80 is biased in oppositlton to conduction to the leastdegree at the point of each period at which it is desired to synchronize the oscillator by means of pulses b, that is, at the above-mentioned predetermined point of each period. A suitable unidirectional bias is also applied to diode 88 from the lower part of resistor 68. This bias and saw-tooth voltage as applied across diode 88, together with the pulses from source 28, are represented by curve D of Fig. 2, representing the voltage of anode relative to cathode. 'I'he amplitude of the portion of the saw-tooth bias voltage of substantially dierent value is such that the diode 88 is rendered conductive if such value occurs simultaneouslyl with one of the pulses b, while the amplitude of the portion of the saw-tooth bias voltage during the major portion of the period is such that diode 8,8 is maintained nonconductive even in the presence of a pulse c of amplitude comparable to that of the pulses b. Since the diode 88 becomes conductive only when its anode is positive with reference to its cathode, it is apparent that no pulses are passed by the diode except at the precise time when its effective bias, due to the unidirectional-bias voltage developed across resistor 68 and the derived saw-tooth bias voltage across condenser 68,`is zero, that is, when it is desired to synchronize the generator I8; that is, the amplitude of the saw-tooth voltage developed across condenser 68 is of such value at the time corresponding to a pulse b as to render the diode 88 conductive, since such value occurs simultaneously with a synchronizing pulse, but its value over the major portion of the period is such that the diode 88 is maintained nonconductive even in the presence of a pulse such as c of amplitude comparable to that of the desired synchronizing pulses b. When the diode 88 becomes conductive, current pulses flow from source`20 through diode 88, condenser 68, and resistor 8|, and the corresponding voltage pulses developed across the impedance means comprising resistor 8| are injected into the input circuit of vacuum tube 3I, that is, the circuit comprising resistor 8|, condenser 68, and winding 61, the voltage pulses having a magnitude suilcient to synchronize the generator.
It will be seen that, in the embodiment of the invention illustrated, tube 3| is conductive during the trace intervals of the generated Wave and is, therefore, susceptible to disturbances in the source of synchronizing signals during the trace interval. The arrangement of the present invention is, therefore, designed to provide a means by which any disturbances in the source 28 of an amplitude comparable with the desired synchronizing pulses are kept out of the input circuit of tube 3| during the major portion of 4its cycle and thereby are prevented from undesirably affecting the output current of tube 3I. At the same time, a feed-back voltage of saw-tooth wave form is continuously applied to the control grid of tube 3| from condenser 68 for maintaining the proper wave form of the output current of tube 3|..
While there has been described What is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.
What is claimed is:
i. .el periodic wave repeater adapted to be excited by periodic synchronizing pulses comprising, a vacuum tube having a pulse-responsive input circuit, a diode eectlv'ely in series in said input circuit for coupling said pulses thereto, means for deriving from said4 tube a periodic voltage having a substantially different value at a predetermined point of each period than over the major portion of each period, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude oi said derived voltage during said major portion of said period being such that said diode is maintained nonconductivey even in the presence oi a pulse of amplitude comparable with that ci said pulses.
2.' A periodic wave generator adapted to be eX- cited by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulse-l responsive input circuit, a diode effectively in series in said input circuit for coupling said pulses thereto to synchronize said oscillator, means for deriving from said oscillator a periodic voltage having a substantially dierent value at a predetermined point of each period than over the major portion of each period, and
means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over the major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude 'of said voltage over said major, portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of amplitude comparable with that of said pulses.
3. A periodic Wave generator adapted to be eX- cited by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulseresponsive input circuit and an output circuit, a diode effectively in series in said input circuit for coupling said pulses thereto to synchronize said oscillator, means for deriving from said output circuit a periodic voltage having a substantially diierent value at a predetermined point of each period than over the major portion of said period and for applying said voltage to said input circuit for feedback in said oscillator, and means V for. applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portionv of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, said voltage of substantially different value being such that saidfdiode is rendered conductive i! such value occurs simultaneously with one of said pulses, and the amplitude of said voltage during said major portion o! said period being En adriatica tive even in the presence of a pulse of an ampliture comparable with that ci said pulses.
d. A saw-tooth Wave generator for generating pulses having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulsei responsive input circuit and an output circuit, a
such that said diode is maintained nonconducdiode edectively in series in said input circuit for coupling said pulses thereto, means for deriving`from said output circuit a periodic sawtooth voltage and applying said voltage to said input circuit for feedbacky in said vacuum tube, and means for applying said derived voltage also as a bias to said diode with such polarity that it is biased in opposition to conduction to a substantially lesser degree at one extreme value or" said saw-tooth voltage, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said one extreme value voltage being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses and the amplitude of said derived voltage over the major portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of an amplitude comparable with that of said pulses.
5. A saw-tooth wave generator for generating pulses having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulseresponsive input circuit and an output circuit, a diode eiectively in series in said input circuit for coupling said pulses thereto, means for deriving from said output circuit a periodic sawtooth voltage having an amplitude relatively large with respect to the amplitude of said periodic pulses, means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at one extreme value of said sawtooth voltage, means for supplying to said' diode a unidirectional-bias voltage of such polarity and magnitude as to reduce the effective bias due to said unidirectional bias and said derived voltage approximately to zero" at said one extreme value of said saw-tooth voltage, said pulses being applied to said diode with such polarity as to tend to render said diode conductive.
6. A saw-tooth current wave generator having relatively long trace and relatively short retrace intervals and adapted to be synchronized by periodic synchronizing pulses comprising, a vacumn-tube oscillator having a pulse-responsive input circuit, said vacuum tube being conductive during said trace intervals and, therefore, susceptible to undesired disturbing pulses during said' trace intervals, a diode effectively in series in said input circuit for coupling said pulses thereto, means for deriving from said tube a periodic voltage having a substantially different value at a predetermined point of each period than over the major portion of said period, and means for applying said derived voltage as a bias to said diode withsuch polarity that it is biased 1n oppos1tion to conduction thereof to a lesser dedered conductive if suchy value occurs simultaneously with one of said pulses, and the amplitude of said derived voltage over said major portion of said period being such that said diode is maintained nonconductive even in the presence of an undesired pulse of -amplitude comparable with that of said pulses.
7. A saw-tooth wave generator adapted to lbe synchronized by periodic synchronizing pulses comprising, a vacuum-tube oscillator having a pulse-responsive input circuit, a diode effectively in series in said input circuit for coupling said pulses thereto, a regenerative circuit for said vacuum tube comprising a condenser in said input circuit and a resistor for deriving across said condenser a saw-tooth voltage, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a substantially lesser degree at one extreme value thereof, said pulse being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of said one extreme value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude of said derived voltage over said major portion of said period being such that said diode is maintained nonconductive even in the' presence of a pulse of an amplitude comparable with that of said pulses.
8. A periodic wave generator adapted to be eX- cited by periodic voltage pulses comprising, a vacuum-tube oscillator having a pulse-responsive input circuit and an output circuit, a diode eiectively in series in said input circuit and responsive to said voltage pulses for couplng into said input circuit corresponding current pulses, impedance means in said input circuit for developing a pulse voltage in said input circuit in response to said current pulses to synchronize said oscillator, means for deriving from said output circuit a periodic voltage having a substantially different value at a predetermined point at each period than over the major portion oi' said period and for applying said voltage to said input circuit for regeneration o! said oscillator, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude of said voltage over said major portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of amplitude comparable with that of said pulses.
9. A periodic wave generator adapted to be excited by periodic voltage pulses comprising a vacuum-tube oscillator having a pulse-responsive input circuit and an output circuit, a diode eiectively in series in said input circuit and responsive to said voltage pulses for coupling into said input circuit corresponding current pulses, a resistor in said input circuit for developing a pulse voltage in said input circuit in response to said current pulses to synchronize said oscillator, means for deriving from said output circuit a periodic voltage having a substantially different value at a predetermined point at each period than over the major portion of said period and for applying said voltage to said input circuit for feedback in said oscillator, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses, and the amplitude of said voltage over said major portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of amplitude comparable with that of said pulses. I
10. A saw-tooth wave generator adapted to be synchronized by periodic voltage pulses comprising, a vacuum-tube oscillator having a pulseresponsive input circuit, a diode effectively in series in said input circuit and responsive to said voltage pulses for coupling into said input circuit corresponding current pulses, a feed-back circuit for said vacuum tube comprising a condenser in said input circuit and a resistor for deriving across said condenser a periodic voltage having a substantially diierent value at a predetermined point of each periodthan over the major portion of said period, a resistor in series with said firstmentioned condenser included in said input circuit for developing voltage pulses in response to said current pulses, and means for applying said derived voltage as a bias to said diode with such polarity that it is biased in opposition to conduction to a lesser degree at said predetermined point of each period than over said major portion of each period, said pulses being applied to said diode with such polarity as to tend to render said diode conductive, the amplitude of said voltage of substantially different value being such that said diode is rendered conductive if such value occurs simultaneously with one of said pulses and the amplitude of said voltage over said major portion of said period being such that said diode is maintained nonconductive even in the presence of a pulse of an amplitude comparable with that of said pulses.
HAROLD A. WHEELER.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US264935A US2255403A (en) | 1939-03-30 | 1939-03-30 | Periodic wave repeater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US264935A US2255403A (en) | 1939-03-30 | 1939-03-30 | Periodic wave repeater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2255403A true US2255403A (en) | 1941-09-09 |
Family
ID=23008268
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US264935A Expired - Lifetime US2255403A (en) | 1939-03-30 | 1939-03-30 | Periodic wave repeater |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2255403A (en) |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2416306A (en) * | 1942-09-28 | 1947-02-25 | Fed Telephone & Radio Corp | Demodulator |
| US2419570A (en) * | 1943-05-24 | 1947-04-29 | Standard Telephones Cables Ltd | Receiver circuit |
| US2422205A (en) * | 1943-10-05 | 1947-06-17 | Bell Telephone Labor Inc | Range indicator |
| US2444890A (en) * | 1943-12-04 | 1948-07-06 | Us Navy | Self-synchronous frequency divider |
| US2462265A (en) * | 1944-08-16 | 1949-02-22 | Hazeltine Research Inc | Frequency divider |
| US2462078A (en) * | 1944-09-15 | 1949-02-22 | Int Standard Electric Corp | Oscillation generator |
| US2468058A (en) * | 1943-11-23 | 1949-04-26 | Standard Telephones Cables Ltd | Blocking system for multichannel operation |
| US2478606A (en) * | 1945-03-14 | 1949-08-09 | Rca Corp | Electromagnetic deflection generator |
| US2493517A (en) * | 1942-07-24 | 1950-01-03 | Jr Alexander R Applegarth | Blocking oscillator |
| US2510983A (en) * | 1945-02-23 | 1950-06-13 | Standard Telephones Cables Ltd | Radio receiver |
| US2524677A (en) * | 1945-08-27 | 1950-10-03 | Decca Record Co Ltd | Signal generator |
| US2562889A (en) * | 1946-07-22 | 1951-08-07 | Farnsworth Res Corp | Frequency divider |
| US2571296A (en) * | 1944-09-20 | 1951-10-16 | Emi Ltd | Pulse-controlled oscillator |
| US2585803A (en) * | 1945-04-18 | 1952-02-12 | Us Sec War | Pulse width discriminator circuit |
| US2650357A (en) * | 1947-11-13 | 1953-08-25 | Philco Corp | Delay controlled pulse generator |
| US2672558A (en) * | 1945-06-28 | 1954-03-16 | Fischman Martin | Pulse generator |
| US2698903A (en) * | 1949-12-30 | 1955-01-04 | Rca Corp | Beam deflection control for cathoderay devices |
| US2701841A (en) * | 1945-10-10 | 1955-02-08 | Arden H Fredrick | Range unit |
-
1939
- 1939-03-30 US US264935A patent/US2255403A/en not_active Expired - Lifetime
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2493517A (en) * | 1942-07-24 | 1950-01-03 | Jr Alexander R Applegarth | Blocking oscillator |
| US2416306A (en) * | 1942-09-28 | 1947-02-25 | Fed Telephone & Radio Corp | Demodulator |
| US2419570A (en) * | 1943-05-24 | 1947-04-29 | Standard Telephones Cables Ltd | Receiver circuit |
| US2422205A (en) * | 1943-10-05 | 1947-06-17 | Bell Telephone Labor Inc | Range indicator |
| US2468058A (en) * | 1943-11-23 | 1949-04-26 | Standard Telephones Cables Ltd | Blocking system for multichannel operation |
| US2444890A (en) * | 1943-12-04 | 1948-07-06 | Us Navy | Self-synchronous frequency divider |
| US2462265A (en) * | 1944-08-16 | 1949-02-22 | Hazeltine Research Inc | Frequency divider |
| US2462078A (en) * | 1944-09-15 | 1949-02-22 | Int Standard Electric Corp | Oscillation generator |
| US2571296A (en) * | 1944-09-20 | 1951-10-16 | Emi Ltd | Pulse-controlled oscillator |
| US2510983A (en) * | 1945-02-23 | 1950-06-13 | Standard Telephones Cables Ltd | Radio receiver |
| US2478606A (en) * | 1945-03-14 | 1949-08-09 | Rca Corp | Electromagnetic deflection generator |
| US2585803A (en) * | 1945-04-18 | 1952-02-12 | Us Sec War | Pulse width discriminator circuit |
| US2672558A (en) * | 1945-06-28 | 1954-03-16 | Fischman Martin | Pulse generator |
| US2524677A (en) * | 1945-08-27 | 1950-10-03 | Decca Record Co Ltd | Signal generator |
| US2701841A (en) * | 1945-10-10 | 1955-02-08 | Arden H Fredrick | Range unit |
| US2562889A (en) * | 1946-07-22 | 1951-08-07 | Farnsworth Res Corp | Frequency divider |
| US2650357A (en) * | 1947-11-13 | 1953-08-25 | Philco Corp | Delay controlled pulse generator |
| US2698903A (en) * | 1949-12-30 | 1955-01-04 | Rca Corp | Beam deflection control for cathoderay devices |
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