US2451796A - Phase shifting circuit - Google Patents

Phase shifting circuit Download PDF

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Publication number
US2451796A
US2451796A US503545A US50354543A US2451796A US 2451796 A US2451796 A US 2451796A US 503545 A US503545 A US 503545A US 50354543 A US50354543 A US 50354543A US 2451796 A US2451796 A US 2451796A
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United States
Prior art keywords
resistance
phase
cathode
circuit
voltage
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Expired - Lifetime
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US503545A
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English (en)
Inventor
Berkoff Seymour
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General Electric Co
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General Electric Co
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Publication date
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Priority to US503545A priority Critical patent/US2451796A/en
Priority to FR945118D priority patent/FR945118A/fr
Application granted granted Critical
Publication of US2451796A publication Critical patent/US2451796A/en
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Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/16—Networks for phase shifting
    • H03H11/20—Two-port phase shifters providing an adjustable phase shift
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R25/00—Arrangements for measuring phase angle between a voltage and a current or between voltages or currents

Definitions

  • My invention relates to electric circuits and, more particularly, to electric circuits for shifting the phase of the alternating potential derived i'rom the source with respect to the potential of that source. It is an object of my invention to provide a new and improved electric phase shifting circuit.
  • While my invention is of general application in electric control or regulating circuits, it is particularly adapted to use in connection with the sweep circuit of a cathode ray tube. In such applications, particularly when used in pulse signalling systems, it is desirable to control the starting time of a trace so that a selected image appears at the beginning of a trace and facilitates comparison of other images. In order that this result be obtained, it is essential that the phase shifting device have a range of substantially 360 electrical degrees.
  • my invention employs two electronic discharge devices having similar output circuits and connected serially to obtain a phase shift of more than 360 electrical degrees.
  • Fig. 1 diagrammatically illustrates an embodiment of my invention in which the phase shifting circuit illustrated provides an adjustablephase shift of more than 180 electrical degrees
  • Fig. 2 is a vector diagram illustrating certain voltage and current relationships in the phase shifting circuit of Fig. 1
  • Fig. 3 is a modification of the circuit of Fig. 1 and illustrates a circuit capable of producing a phase shift of more than 360 electrical degrees.
  • a suitable load circuit such as the sweep circuit of a cathode ray tube
  • the electronic discharge device 2 comprises an anode 4, a control electrode 5, and a cathode 5, the cathode 8 being connected to ground through a cathode resistance I.
  • the source of alternating voltage I is connected between control electrode 5 and ground.
  • Operating potential for the anode 4 may be supplied from any suitable source, such as the battery 8, through an anode load resistance 9.
  • the cathode resistance I and the anode resistance 9 have substantially equal ohmic values so that the electronic discharge device 2 operates as a phase splitting means and produces voltages across the resistances I and 9 which are equal and approximately 180 degrees out of phase.
  • phase shifting resistance II is connected between anode l and cathode 6, this resistance having a movable contact l2.
  • a capacitance i3 is connected between the anode 4 and the movable contact 12.
  • the upper terminal of the pair of output terminals 3 is connected to the juncture of capacitance l3 and contact l2.
  • phase shifting circuit comprising resistance Ii and capacitance I3
  • device 2 When the portion of the phase shifting circuit comprising resistance Ii and capacitance I3 is combined with device 2 and its load resistances, as the movable contact I: is moved along resistance [I from its upper to its lower terminal, a phase shift of substantially 180 degrees in the voltage impressed across the output terminals 3 is obtained.
  • I In order to increase this shifting of the phase of output voltage of the circuit to a value of greater than 180 electrical degrees, I provide a capacitance I4 connected between anode 4 and ground.
  • R internal plate resistance of tube 2
  • Rc cathode load resistance 1
  • Rat equivalent plate load resistance
  • Equation 1 it may be seen that Eop must lag the vector Eog. whatever the value of XEL. This follows because the denominator of Equation 1 has a greater resistance component than the numerator, while containing the same reactance component.
  • the current I may be varied in phase with Ecp when contact I2 is at the upper terminal of resistance II and the capacitance I3 is short-circuited to a condition where it leads the voltage Esp by degrees, which condition occurs when contact I2 is at the cathode terminal of resistance II.
  • the locus of the potential of point D at the junction of capacitance I3 and contact I2 varies approximately along the arc of a semicircle having the voltage Ecp as its diameter. It should be noted that the resistance of the portion of potentiometer II which is across the capacitor I3 is large compared with the reactance of capacitor I3, and causes but small deviation from a true circle diagram.
  • the output for each of the systems impressed across output terminals 3 is be tween ground and the point D, ground being denoted by the common point 0 of the vectors Eop and E00 in the vector diagram of Fig. 2. From the diagram, therefore, it is seen that the phase position of the vector Eon, the voltage across the output terminals 3, may be varied over a range greater than degrees.
  • the variation in amplitude of the voltage Eop depends upon the phase angle between the voltages Eoc and E011. When this angle is 180 degrees, the amplitude of the output voltage remains substantially constant.
  • This phase angle between E00 and Eop is determined by the value of the capacitance I4 which controls the value of the quantity XEL in the equations given above.
  • this capacitance need be only suflicient to make the angle between Eoc and Eop equal to 180 degrees, which value may be found by equating the resistive and reactive terms in Equations 1 and 2. Any value of XEL greater than this will allow the circuit to provide a phase shift considerably greater than 180 degrees; in fact, phase shifts up to slightly less than 270 degrees may be obtained. Of course, the amplitude variation increases as the obtainable phase shift increases over 180 degrees.
  • Fig. 3 I have shown a modification of my phase shift circuit in which a variation of greater than 360 electrical degrees may be obtained between the voltage source I and the voltage across any small load impressed across output terminals 3.
  • a pair of electronic discharge devices 2, 2' have circuit elements corresponding to the elements used in the circuit of Fig. 1 connected thereacross
  • impedance elements, associated with electronic discharge device 2 and corresponding to impedance elements shown in Fig. 1 are designated by similar characters, while corres nding impedance elements associated with electronic discharge device 2 are designated by similar numerals differentiated by priming.
  • the source of alternating voltage I is connected between ground and control electrode Ii through a coupling capacitor and a voltage dividin resistance 2
  • is not necessary in all applications and this resistor may be omitted when the source of alternating voltage I does not swing the tube grid beyond class A operation, i. e., cause the tube 2 to be cut off during any portion of a cycle.
  • a cathode bias resistor 22 is connected between cathode 6 and cathode load resistance 1 and a grid leak resistance 23 is connected between controlielectrode 5 and the common point of resistances 22 and I.
  • the phase shifting potentiometer l l is connected between anode l and the common point of cathode resistances 22 and
  • the movable contact I2 is connected to the control electrode 5' of electronic discharge device 2' through a coupling capacitance 25,
  • the output terminals 3' of the phase shifting circuit are connected respectively to ground and the movable contact l2 on phase shifting potentiometer l I.
  • the contacts l2, l2 may be mechanically linked for unicontrol operation.
  • my invention provides an improved phase shift circuit which may be employed to obtain shifts beages through a range of greater than 360 electrical degrees, a range particularly desirable for use in conjunction with sweep circuits of cathode ray tubes.
  • the component elements of my phase shifting circuit are readily available and easily assembled and require no transformer connections with tap adjustments.
  • an electron discharge device having an anode, control electrode, and a cathode, a source of operating voltage having its positive terminal connected to said anode through a resistance and its negative terminal connected to said cathode through a resistance, means to supply an alternating voltage between said control electrode and cathode, a resistance connected between said anode and cathode, and
  • an electrondischarge device having an anode, control electrode, and a cathode, a source of operating voltage having its positive terminal connected to said anode through a resistanceand its negative terminal connected to said cathode through a resistance, a source of alternating voltage connected between said control electrode and said cathode, a resistance connected between said anode and cathode, a load circuit connected between said negative terminal and a point variable along said last resistance in accordance with the phase shift desired, and means to increase said phase shift to a value in excess of 180 degrees as said point is moved from one end of said last resistance to the other.
  • an electron discharge device having an anode, control electrode, and a cathode, a source of operating voltage having its positive terminal connected to said anode through a resistance and its negative terminal connected to said cathode through a resistance,
  • a source of alternating voltage apparatus for producing an alternating voltage variable in phase relative to the voltage of said source and of substantially constant magnitude and comprising means connected to said source for producing equal and opposite voltages with respect to a point of fixed potential, said means including a pair of terminals, a resistance connected across said terminals and including a movable contact, a first reactance connected between said movable contact and one of said terminals, a second reactance connected between said one terminal and said point, and an output circuit connected between said movable contact and said point, said second reactance having such a value that the phase variation produced in said output circuit as said contact is moved between the terminals of said resistances is at least 180 degrees.
  • a source of alternating voltage apparatus for producing an alternating voltage variable in phase relative to the voltage of said source and comprising a pair of electron discharge devices each having an anode, a cathode, and a control electrode, a source of operating voltage having its positive terminal connected to said anodes through resistances and its negative terminal connected to said cathodes through resistances, each of said devices having a resistance and a capacitance connected between the anode thereof and ground, each of said last resistances having movable contacts thereon, means connecting said source of alternating voltage between the control electrode of one of said devices and ground, means connecting the control electrode of the other of said devices to the movable contact associated with said one device, and output terminals connected between the other of said movable contacts and ground, said capacitances having such values that movement of said contacts along said resistances is efiective to shift the phase of the alternating voltage impressed across said output terminals through an angle of at least 360 electrical degrees.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Particle Accelerators (AREA)
US503545A 1943-09-23 1943-09-23 Phase shifting circuit Expired - Lifetime US2451796A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US503545A US2451796A (en) 1943-09-23 1943-09-23 Phase shifting circuit
FR945118D FR945118A (fr) 1943-09-23 1947-04-16 Perfectionnements aux circuits déphaseurs

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US503545A US2451796A (en) 1943-09-23 1943-09-23 Phase shifting circuit

Publications (1)

Publication Number Publication Date
US2451796A true US2451796A (en) 1948-10-19

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US503545A Expired - Lifetime US2451796A (en) 1943-09-23 1943-09-23 Phase shifting circuit

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US (1) US2451796A (fr)
FR (1) FR945118A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2588797A (en) * 1950-03-04 1952-03-11 Iowa State College Res Found Generator
US2635226A (en) * 1950-01-20 1953-04-14 Collins Radio Co Phase modulation system and apparatus
US2749516A (en) * 1950-06-12 1956-06-05 John R Ragazzini Phase meter
US3031909A (en) * 1955-09-28 1962-05-01 White James Paul Apparatus for tone quality control
US3217261A (en) * 1963-08-27 1965-11-09 David S Henry Monitoring system for a vestigial sideband transmitter whereby the quadrature component is eliminated
DE1290255B (de) * 1957-10-14 1969-03-06 Varian Associates Selbstabgleichendes Gleichspannungsmessgeraet

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1719356A (en) * 1927-02-24 1929-07-02 Carnegie Inst Of Washington Phase modifier
US2376392A (en) * 1943-02-23 1945-05-22 Sperry Gyroscope Co Inc Phase shifter

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1719356A (en) * 1927-02-24 1929-07-02 Carnegie Inst Of Washington Phase modifier
US2376392A (en) * 1943-02-23 1945-05-22 Sperry Gyroscope Co Inc Phase shifter

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2635226A (en) * 1950-01-20 1953-04-14 Collins Radio Co Phase modulation system and apparatus
US2588797A (en) * 1950-03-04 1952-03-11 Iowa State College Res Found Generator
US2749516A (en) * 1950-06-12 1956-06-05 John R Ragazzini Phase meter
US3031909A (en) * 1955-09-28 1962-05-01 White James Paul Apparatus for tone quality control
DE1290255B (de) * 1957-10-14 1969-03-06 Varian Associates Selbstabgleichendes Gleichspannungsmessgeraet
US3217261A (en) * 1963-08-27 1965-11-09 David S Henry Monitoring system for a vestigial sideband transmitter whereby the quadrature component is eliminated

Also Published As

Publication number Publication date
FR945118A (fr) 1949-04-26

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