US2476985A - Receiver for electrical pulses - Google Patents

Receiver for electrical pulses Download PDF

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Publication number
US2476985A
US2476985A US573101A US57310145A US2476985A US 2476985 A US2476985 A US 2476985A US 573101 A US573101 A US 573101A US 57310145 A US57310145 A US 57310145A US 2476985 A US2476985 A US 2476985A
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United States
Prior art keywords
intensity
limiter
curve
noise
amplitude
Prior art date
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Expired - Lifetime
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US573101A
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English (en)
Inventor
Levy Maurice Moise
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International Standard Electric Corp
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International Standard Electric Corp
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Publication date
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves

Definitions

  • Receivers of the type specified are particularly applicable, for example, to radio location equipment for determining the presence of objects, for example, such as aircraft, or for determining distance by the utilisation of the reflection of electrical pulses in the form of direct current pulses or in the form of trains of high frequency Waves which are detected to produce a direct current pulse which is then applied to the cathode ray osci llograph to obtain the required indication.
  • the invention is also applicable to other cases utilising the reception of an electromagnetic signal wave which requires a relative indication rather than an absolute value indication.
  • the invention resides in limiting the vertical or ordinate deflection ofthe electron beam to a. predetermined ordinate value irrespective of the instantaneous deflecting force of the received signal above that predetermined ordinate value.
  • Pulses having zero amplitude are the most probable and the of the noise amplitude by the relation pulses, this curve may be represented by the can 1 1M2
  • the curveC of Fig. 1a represents also the law of noise. This intensity is maximum on the abscissa line and decreases very quickly at points away from it.
  • Fig. 1c rep- 1 resents the resultant of the noise of Fig.' la and the pulse of Fig. 1b.
  • a signal pulse appears its elfect is to increase the noise deflecting force by an amount equal tothe amplitude of the signal pulse. Thishas been shown at B in Fig. 1c.
  • the principle is to use an amplitude limiter, preferably adjusted so that AaL is small or zero, and to observe on the horizontal scanning line produced by the limiter the difference of intensity between the points or instants where there is onlynoise and the points where the noise is mixed with a signal pulse.
  • This differencein intensity is explained as follows.
  • Fig. 2b represents the average intensity light on the scanning line for twopoints: one A, where there is no signal pulse, andone,B, where the noiseis mixed with a signal pulse.
  • the effect of the pulseis to lift the noise curve of a heighten equal to the amplitude of the pulse.
  • the average intensity on the scanning line at point A is I0, the maximum amplitude of the curve Ib, and at point B it is Ip.
  • the diflerence Io-Ip is pro portional to a when cc is small because the curve near the cusp is approximately constituted by plained; in connection with Fig. 1c.
  • Fig. 2b becomes as represented in Fig. 5 withthe notations of Fig. 2b), except that the limiter as regards Fig. 5 is suppressing the signal: above the limiter'line instead of' below this: l iiie as is the case for'Fig; 2b.
  • the limiter giving the conditions shown in Fig. 5' may be said to give results which arecomplementary to those given by the limiter studied in connection with Figs. 2w and 2b.
  • a simple circuit is represented-in Fig; 6-.
  • the noise mixed with signals is appiied at P on the input grid G of an amplifying val ve V.
  • the plate resistance R is shuntedby a diode E in series with a battery F.
  • the plate of valve V is also connected to plate of diode E.
  • the cathode of diode E is connected to battery F.
  • Valve 'V' is prefierably a pentode so that plate voltage variations do not afiect the plate current of the valve. It is clear that this circuit will act as a limiter oi the type. described above. If the cur-rent of valve V is small and assuming the H. T.
  • two limiters may be used, for example, two am plifier valves fed in parallel with the signaland noise and eachhaving a limiter connected in itsontput, for exampleas shown in- Ti-"ig. 6.
  • a cathode ray oscillograph' having a'doublebeam, that is, two beams or one split beam is used and one limiter is arranged to suppress me lower part of the signal and noise pattern, so as to produce the trace l with one beam as shown in Fig. 7, whilst the other limiter is arranged to suppress the upper part of the pattern and produce a trace as shown in trace 2, Fig. 7, with the other beam as hereinbefore described.
  • Trace I is identical to the trace shown in Fig. 2b, and trace 2 is identical with the trace shown in Fig. 5.
  • a pulse is shown as occurring between the times t1 and t2 and it will be seen that the intensity of illumination of trace l during the pulse is weaker whilst in trace 2 the intensity is stronger. The presence and occurrence of the pulse is seen more clearly by the contrast between the two traces.
  • Fig. 10 represents, diagrammatically, an arrangement incorporating this feature of the invention.
  • an opaque screen [0 covering the face of the oscillograph screen I2 is provided with a horizontal slit ll located so as to expose only the horizontal trace of the oscillograph. This slit is also covered and means are provided for uncovering in a sweeping movement a. small area 7 of the slit.
  • the disc I3 may be in the form of a Nipkov disc as used to scan a screen in television apparatus or the disc may have a continuous spiral slit in place of the spiral series of holes.
  • Such means may comprise a fur' W M a second cathode ray ioscillograph 'whos'e' beam 2.
  • Arrangementsv as claimed in claim 3 com-' prising means for successively and cyclically exposing elemental areas of the oscillograph trace, a photo-electric cell, means for focussing the light from said elemental areas on to said cell to produce a current which varies in accordance with the intensity of light inthe successive elemental areas exposed, an amplifier for amplifyingsaid current or voltage derived therefromand a second cathode ray oscillograph whose beam is cyclically deflected in one direction in synchronism with the cyclic exposing of the trace,'and in a perpendicular direction by the amplified currents or voltages derived therefrom.
  • a signal indicating system particularlyfor signals whose amplitudes are small compared to the noise amplitude comprising 'meansfor limiting the amplitudes of said signals inthe presence of noise and means to apply clipped signals to an oscilloscope whereby the signals appear on the oscilloscope trace in the form of sections of weaker or stronger illumination, means for scanning said oscilloscopic trace sections and means responsive to said scanning means and including a second oscilloscope for indicating said weaker'or stronger illumination.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
US573101A 1943-12-01 1945-01-16 Receiver for electrical pulses Expired - Lifetime US2476985A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB20114/43A GB581698A (en) 1943-12-01 1943-12-01 Improvements relating to receivers for electrical pulses

Publications (1)

Publication Number Publication Date
US2476985A true US2476985A (en) 1949-07-26

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US573101A Expired - Lifetime US2476985A (en) 1943-12-01 1945-01-16 Receiver for electrical pulses

Country Status (3)

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US (1) US2476985A (zh)
FR (1) FR956833A (zh)
GB (1) GB581698A (zh)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2702158A (en) * 1950-04-14 1955-02-15 Du Mont Allen B Lab Inc Electronic computer
US2828425A (en) * 1955-06-01 1958-03-25 Manuel H Greenblatt Pulse amplitude analyzer
US2889465A (en) * 1955-12-12 1959-06-02 Rudolph W Buntenbach Electric pulse generator
US2949672A (en) * 1952-02-18 1960-08-23 North American Aviation Inc Stationary field scanning system
US2978590A (en) * 1956-04-20 1961-04-04 Intelligent Machines Res Corp Scanning apparatus

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1962208A (en) * 1930-08-02 1934-06-12 Communications Patents Inc Photoelectric-vector-analyzer
US2059004A (en) * 1935-09-21 1936-10-27 Gen Electric Cathode ray oscillograph sweep circuit
US2269226A (en) * 1940-11-15 1942-01-06 Gen Electric Cathode ray oscillograph control
US2313967A (en) * 1939-10-18 1943-03-16 Rca Corp Cathode ray oscillograph for recording transients
US2355363A (en) * 1942-09-29 1944-08-08 Allen B Dumont Lab Inc Cathode-ray ignition analyzer
US2375709A (en) * 1940-08-03 1945-05-08 Gen Electric Expansion circuit for oscilloscopes
US2381414A (en) * 1943-01-16 1945-08-07 John B Wilkie Measuring instrument
US2422100A (en) * 1943-01-06 1947-06-10 Rca Corp Position determining system
US2424349A (en) * 1943-02-15 1947-07-22 Farnsworth Television & Radio Noise limiter and automatic volume control for television receivers

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1962208A (en) * 1930-08-02 1934-06-12 Communications Patents Inc Photoelectric-vector-analyzer
US2059004A (en) * 1935-09-21 1936-10-27 Gen Electric Cathode ray oscillograph sweep circuit
US2313967A (en) * 1939-10-18 1943-03-16 Rca Corp Cathode ray oscillograph for recording transients
US2375709A (en) * 1940-08-03 1945-05-08 Gen Electric Expansion circuit for oscilloscopes
US2269226A (en) * 1940-11-15 1942-01-06 Gen Electric Cathode ray oscillograph control
US2355363A (en) * 1942-09-29 1944-08-08 Allen B Dumont Lab Inc Cathode-ray ignition analyzer
US2422100A (en) * 1943-01-06 1947-06-10 Rca Corp Position determining system
US2381414A (en) * 1943-01-16 1945-08-07 John B Wilkie Measuring instrument
US2424349A (en) * 1943-02-15 1947-07-22 Farnsworth Television & Radio Noise limiter and automatic volume control for television receivers

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2702158A (en) * 1950-04-14 1955-02-15 Du Mont Allen B Lab Inc Electronic computer
US2949672A (en) * 1952-02-18 1960-08-23 North American Aviation Inc Stationary field scanning system
US2828425A (en) * 1955-06-01 1958-03-25 Manuel H Greenblatt Pulse amplitude analyzer
US2889465A (en) * 1955-12-12 1959-06-02 Rudolph W Buntenbach Electric pulse generator
US2978590A (en) * 1956-04-20 1961-04-04 Intelligent Machines Res Corp Scanning apparatus

Also Published As

Publication number Publication date
GB581698A (en) 1946-10-22
FR956833A (zh) 1950-02-08

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