US2381847A - System of communication by means of electrical waves - Google Patents

System of communication by means of electrical waves Download PDF

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US2381847A
US2381847A US418281A US41828141A US2381847A US 2381847 A US2381847 A US 2381847A US 418281 A US418281 A US 418281A US 41828141 A US41828141 A US 41828141A US 2381847 A US2381847 A US 2381847A
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impulses
signal
receiver
impulse
receiving
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Ullrich Edward Hill
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International Standard Electric Corp
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International Standard Electric Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J7/00—Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
    • C10M107/02—Hydrocarbon polymers; Hydrocarbon polymers modified by oxidation
    • C10M107/08—Hydrocarbon polymers; Hydrocarbon polymers modified by oxidation containing butene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M125/00—Lubricating compositions characterised by the additive being an inorganic material
    • C10M125/26—Compounds containing silicon or boron, e.g. silica, sand
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
    • C10M169/04—Mixtures of base-materials and additives
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/06—Metal compounds
    • C10M2201/061—Carbides; Hydrides; Nitrides
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/08—Inorganic acids or salts thereof
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/08—Inorganic acids or salts thereof
    • C10M2201/081—Inorganic acids or salts thereof containing halogen
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/08—Inorganic acids or salts thereof
    • C10M2201/082—Inorganic acids or salts thereof containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/08—Inorganic acids or salts thereof
    • C10M2201/084—Inorganic acids or salts thereof containing sulfur, selenium or tellurium
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/087—Boron oxides, acids or salts
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/10—Compounds containing silicon
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/10—Compounds containing silicon
    • C10M2201/102—Silicates
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/10—Compounds containing silicon
    • C10M2201/105—Silica
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/16—Carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/18—Ammonia
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/026—Butene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/026—Butene
    • C10M2205/0265—Butene used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2227/00—Organic non-macromolecular compounds containing atoms of elements not provided for in groups C10M2203/00, C10M2207/00, C10M2211/00, C10M2215/00, C10M2219/00 or C10M2223/00 as ingredients in lubricant compositions
    • C10M2227/06—Organic compounds derived from inorganic acids or metal salts
    • C10M2227/063—Complexes of boron halides
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/02—Bearings

Definitions

  • the present invention relates to a systemof communication by means of electrical waves and more particularly, though not exclusively, to electrical wave communication system in which the waves' are modulated by impulses whether thev transmission is over metallic connections, dielectric guides, or by radio.
  • One ot the objects of thg invention is the provision of means for increasing for a given band width, the number of communications that can be transmitted simultaneously.
  • Another object of the invention is ⁇ the provision of. means forpermitting satisfactory 4reception of a transmission modulated by impulses and independently of parasites or undesired signals which may exist at the same wave length of transmission.
  • the ,ceiver or toseparate a desired communication from another communication or from natural different emissions either in accordance with the cess of that of the threshold.
  • Fig. 1 represents two signals having the same energy. but different durations, because the first signal has double amplitude but the second signal quadruple duration;
  • Fig. 2 arepresents a series of square impulses which are repeated at equal timeintervals
  • Fig. 2b represents the variations of the amplitudein function of the frequency for developing in the Fourier series two drierrent impulses
  • Fig. 3 represents three series of impulses corvresponding to three diierent simultaneous communications
  • Fig. 4 represents schematically the embodiment of the invention in a receiver for the simultaneous reception of two different communications the series of impulses of which correspond to two of the series of Fig. 3;
  • Fig. 4a shows a modication of -the circuiil of Fig. 4 to the left of the dotted line L -a.
  • The'invention will be described as applied to a system in which the emission is modulated by impulses in which the band width being larger,
  • the invention may be particularly applied tov a system of transmitting a certain number of communications from one and the same point over metallic links or radio channels or to transmissions from a network of radio transmission stations, having a plurality of transmitters at different points.
  • the receivers use a threshold'which in the absence of signals suppresses only the peaks of the parasitics or undesired signals so that nothing will be received.
  • the intensities of the desired and undesired signals may be added or subtracted. In the first case, the level will be above the threshold no matter what the intensity of the desiredvsignals may be.
  • the peak of the level exceeds the threshold only if the intensity of the desired signal is greater than the intensity of the undesired signal by a potential which is just in expeak to rise above the threshold even when the undesired signals have a maximum negative value, it is necessary that the amplitude of the desiredl signal 'exceed the sum of the potential of the negative peak and of the threshold. Since. generally speaking, the negative peak of undesired signals is equal to the positive peak which, in turn, is equal to the threshold, it follows that the desired signal must at least be greater than twice the peak of undesired signals (i.
  • the signal may be appreciably weaker than twice the VApeak of undesired signals as will be explained below.
  • the means provided for distinguishing between two emissions (e. g. having the same strength) coming from the same point are based on the difference in the duration of impulses. Asl a matter of fact, itis possible to distinguish the short last case between signals having dverent duration in var# ⁇ ious ways, two oi' which will now be described.
  • ⁇ It will be seen that although the' amplitude has substantially a constant value until nF becomes equal to approximately f/2, the value of the amplitude will have peaks around frequencies 43]/2, ]/2, etc. and depressions around frequencies f, 2f, 3f, etc.
  • the object of the invention is to separate in the receiver the received signals having d iil'erent durations of emission by suitably selecting the passing band width so as to increase the relationship of the peaks of two impulseshaving diil'erent duration.
  • a receiver arranged in accordance with this aspect ofthe invention will, therefore, have such theimpulses, a band is passedin the assumed case for I, which is wider than 4f for different duration,
  • the main advantage of the invention from this standpoint is the possibility of providing a minimum band width whereby parasitics caused by other stations will be reduced to a minimum.
  • Such receivers may be usedl nomatter what may be the relative duration of the impulses in the different messages as long as the amplitude which is supposed to be constant for each series of impulses does not have the same intensity as the impulses corresponding to another message.
  • Fig. 3 represents three series of impulses, 6, 1, 8, corresponding to three different messages.- After amplification, these impulses may in accordance with the present invention actuate respectively, three receivers which for convenience will be
  • the threshold of receiver A has the value 9 of Fig. 3, of receiver B. the value is III, and of receiver C, the value is II.
  • the impulses received by the different receivers correspond in the case of receiver A, the impulses 6, in the case of receiver B, to impulses 6 1 and in the case of receiver C to 6 1 8.
  • Receiver A picks up, therefore, the message transmitted by the impulses 8 without disturbance by the other messages. I'he impulses thus received by A are amplified and re-introduced in the opposite sense either before ⁇ or after detection into the receiver B in a manner to render the latter inoperative during the impulses. Unless an impulse 6 coincides with an impulse 1, in the output ofthe receiver B, we will obtain aseries of impulses which4 are not disturbed by the messages I and l.
  • the two receivers A and B may be arranged to render the receiver C inoperative during the impulses B and 1. In this manner, one will obtain only the impulses 8 in the output of receiver C. Obviously, the same arrangement may be applied to a larger number of messages at a point in the reception. In each case, the impulses in the individual receiversfwill actuate known receivers which will transform the series of impulses into intelligible messages.
  • FIG. 4 A schematic representation of this embodiment of the invention is shown in Fig. 4 for only two messages in order to simplify the drawings.
  • an antenna I2 collects the two transmitters I2A and I 2B, which are arranged to, transmit signals corresponding, for instance, to the impulses 6 and 1 respectively, and after amplification in any suitable amplifier I3, these are transmitted to two receivers schematically repre sented at Il and I5 in the form o1 a usual electronic discharge tube circuit, although obviously termed A, B, C.
  • Each receiver Il or II has its output connected' to an amplier II tector Il or I! and the output of the detector ⁇ or I1 and these, in turn, to a deafter amplieation at or 2
  • the impulses of the receiver Il must be reintroduced into the receiver I5. If these impulses are reintroduced before detection, then their .intensity and phase may be regulated.
  • This regulator which may be of any well-known type is indicated at26.
  • the impulses in the upper receiving path may be introduced into the lower receiving path after the detectors inwhich case the phase. regulator 26 is dequired. ⁇ v f 'v Itshould be understood that 'the word amplier as above used includes, if desired, frequency modulation amplifiers also.
  • the duration of the impulses is three microseconds and the frequency of theimpulses 10,000 per second (impulses spaced by 100 microseconds) there will be partial blotting out once in 33, i. e. 300 times per second. However, this is not important and the only thing that counts is complete blotting out. Complete blotting out occurs when the two impulses coincide, the time difference being less than one period of the high.
  • the arrangement for transforming the output of I5 into intelligible messages is rendered inoperative.
  • Fig. 4a illustrates how the difference between the amplitude peaks of two impulse modulated transmissions, the impulses of which are of different duration, may bey increased by inserting passlters and 26 ahead of the limiters Il, I5, the pass bands of these filters being selected as previously explained.
  • .carrier frequency waves may be used which are slightly different for the different messages, although the band width in the repartial blotting out DCver is wide enoughto receive more than one message. If the band is wider than is necessary for the impulses of, e. g. two-messages, just to attain their peaks in a time equal to the duration of the impulses which are assumed to be square, then according to the present invention, the relative change in phase between these two channels is utilized. As above stated, generally a difference in intensity of the order of six decibels is needed between two signals in order to separate them. This condition is imposed by the fact that the weaker signal may be in phase opposition with the stronger signal. By admitting several high-frequency oscillations by im ⁇ pulses, the lmessage which it -is desired to suppress must beof the same phase as the signal so that such a difference of six decibels is, necessary.
  • the signal must gener-l ally surpass this threshold evenl in the absence of a disturbance, the signal must exceed the disturbance simply by a value. which depends upon the duration of the impulses, on the number of impulses per second, and on the difference in the relative energy carried by the impulses, but which may be substantially lower than 6 decibels,
  • a receiving arrangement for an electric wave comprising means for simultaneously deriving from two signal transmitting channels respectively two signal wave trains of substantially constant but different amplitudes, ilrst and second receiving paths each including a limiting device, and means located in the ilrst path receiving said ⁇ signal wave train of greater amplitude for injecting in opposition the resultant of said latter wave train into the second path receiving additionally said signal wave train of lesser amplitude, whereby in said second-path the effect of said signal wave train of greater amplitude is substantially cancelled out.
  • a receiving arrangement for an electric wave signalling system' comprising means for simultaneously deriving from ⁇ n signal transmitting channels respectively, n signal wave trains o! substantially constant but different amplitudes, n receiving paths each including a limiting device the several limiting devices each being adjusted to a diil'erent threshold point, and means including said limiting devices for discriminating between said signal wave trains in said receiving paths, said discriminating means'also including means for injecting in opposition a tlrst signal from one path receiving said :first signal alone, into another path receiving said signal and a second signal, whereby in said last mentioned path the eiect of said nrst signal is substantially cancelled out.
  • a receiving arrangement for an electric wave signalling system comprising means for simultaneously deriving iromtwo transmitting signal channels respectivelytwo signal wave trains of substantially constant but dverent amplitudes, first and second receiving paths each including a limiting device, the limiting device in said ilrst path being adjusted to have such a threshold that it passes the peaks of both said wave trains and the limiting device in the second path being adjusted to have such a threshold that it passes the peaks of one wave trainonly, and means controlled by the wave train in said second path for excluding the same wave train from the output of said rstpath.
  • a receiving arrangement for an Ielectric wave signalling system comprising means for simultaneously deriving from n transmitting signal channels respectively n signal wave trains of substantially constant but different amplitudes, n receiving paths each including a limiting device n the several limiting devices each being adjusted to train,
  • a receiving arrangement according to claim 4 for simultaneously and selectively receiving a plurality of impulse modulated signal wave transmissions distinguished by different constant im. pulse amplitudes.
  • said means coupled between each 4said receiving path which is receptive to at least two signal channel wave trains and at least one of the other receiving paths includes means for introducing into each said rstmentioned receiving path wave trains which are of equalintensity and opposite phase to the wave trains which arerrequired to be excluded from such path.
  • a receiving arrangement for simultaneously and selectively receiving a, plurality of impulse modulated signal wave transmissions each distinguished by a. different duration of impulses constituting the signals, wherein a passillter is included in each said receiving path at a point preceding the limiting device in the respective path, the pass bands of said illtcrs being selected so as to increase the dinerence between the peaks of the impulses constituting the several signal wave transmissions.
  • An electric wave signaling system comprising means for transmitting two signals from which two signal wave trains of substantially constant but dilerent amplitudes may be respectively derived, means to receive said signals and 'l to derive said two signal wave trains therefrom.
  • first and second receiving paths each including a limited device, and means located in the first path receiving said signal wave train of great amplitude for injecting in opposition the resultant of said latter wave train into the second path receiving additionally said signal wave train of lesser amplitude. whereby in said second path the eilect of -said signal wave train or greater amplitude is substantially cancelled out.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Inorganic Chemistry (AREA)
  • Lubricants (AREA)
  • Noise Elimination (AREA)
US418281A 1940-04-04 1941-11-08 System of communication by means of electrical waves Expired - Lifetime US2381847A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US602453A US2520184A (en) 1941-11-08 1945-06-30 Electrical wave signaling system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR2381847X 1940-04-04
US295060XA 1947-03-29 1947-03-29

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US2381847A true US2381847A (en) 1945-08-07

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US (1) US2381847A (no)
BE (1) BE480947A (no)
CH (1) CH295060A (no)
FR (2) FR958875A (no)
GB (1) GB655464A (no)
NL (2) NL139137B (no)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2424977A (en) * 1944-06-12 1947-08-05 Standard Telephones Cables Ltd Pulse width modulation multichannel transmitting system
US2429616A (en) * 1944-07-29 1947-10-28 Standard Telephones Cables Ltd Pulse width multichannel system
US2582968A (en) * 1945-10-10 1952-01-22 Standard Telephones Cables Ltd Electrical pulse secrecy communication system
US2794071A (en) * 1951-10-20 1957-05-28 Itt Power line fault locator
US3261920A (en) * 1961-12-01 1966-07-19 Bell Telephone Labor Inc Asynchronous pulse multiplexing
US3261919A (en) * 1961-12-01 1966-07-19 Bell Telephone Labor Inc Asynchronous pulse multiplexing
US3825691A (en) * 1971-07-16 1974-07-23 Nippon Electric Co F-t rada receiver with level discrimination
US3832494A (en) * 1970-06-10 1974-08-27 Control Data Corp Signal multiplexer and demultiplexer
US4295221A (en) * 1977-04-28 1981-10-13 Stiftelsen Institute For Mikrovagsteknik Vid Tekniska Hogskolan I Stockholm Method and apparatus at one-way or two-way information link to effect interference suppression
US4549294A (en) * 1984-03-12 1985-10-22 The United States Of America As Represented By The Secretary Of The Navy Time-of-arrival pulsed waveform multiplexer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1594330B1 (de) * 1964-04-28 1970-10-15 Alcan Res & Dev Waessrige Schmiermitteldispersion fuer das Heisswalzen von Aluminium

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2424977A (en) * 1944-06-12 1947-08-05 Standard Telephones Cables Ltd Pulse width modulation multichannel transmitting system
US2429616A (en) * 1944-07-29 1947-10-28 Standard Telephones Cables Ltd Pulse width multichannel system
US2582968A (en) * 1945-10-10 1952-01-22 Standard Telephones Cables Ltd Electrical pulse secrecy communication system
US2794071A (en) * 1951-10-20 1957-05-28 Itt Power line fault locator
US3261920A (en) * 1961-12-01 1966-07-19 Bell Telephone Labor Inc Asynchronous pulse multiplexing
US3261919A (en) * 1961-12-01 1966-07-19 Bell Telephone Labor Inc Asynchronous pulse multiplexing
US3832494A (en) * 1970-06-10 1974-08-27 Control Data Corp Signal multiplexer and demultiplexer
US3825691A (en) * 1971-07-16 1974-07-23 Nippon Electric Co F-t rada receiver with level discrimination
US4295221A (en) * 1977-04-28 1981-10-13 Stiftelsen Institute For Mikrovagsteknik Vid Tekniska Hogskolan I Stockholm Method and apparatus at one-way or two-way information link to effect interference suppression
US4549294A (en) * 1984-03-12 1985-10-22 The United States Of America As Represented By The Secretary Of The Navy Time-of-arrival pulsed waveform multiplexer

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NL139137B (nl)
FR958875A (no) 1950-03-21
GB655464A (en) 1951-07-25
NL68315C (no)
CH295060A (fr) 1953-12-15
BE480947A (no)
FR962594A (no) 1950-06-16

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