US2538541A - Saw-tooth wave generator - Google Patents

Saw-tooth wave generator Download PDF

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Publication number
US2538541A
US2538541A US776465A US77646547A US2538541A US 2538541 A US2538541 A US 2538541A US 776465 A US776465 A US 776465A US 77646547 A US77646547 A US 77646547A US 2538541 A US2538541 A US 2538541A
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US
United States
Prior art keywords
resistor
grid
capacitance
coil
tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US776465A
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English (en)
Inventor
Simeon I Tourshou
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RCA Corp
Original Assignee
RCA Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE484981D priority Critical patent/BE484981A/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US776465A priority patent/US2538541A/en
Priority to GB22814/48A priority patent/GB663464A/en
Priority to FR970954D priority patent/FR970954A/fr
Priority to CH279456D priority patent/CH279456A/fr
Priority to ES0185166A priority patent/ES185166A1/es
Application granted granted Critical
Publication of US2538541A publication Critical patent/US2538541A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K4/00—Generating pulses having essentially a finite slope or stepped portions
    • H03K4/06—Generating pulses having essentially a finite slope or stepped portions having triangular shape
    • H03K4/08—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape
    • H03K4/10—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape using as active elements vacuum tubes only
    • H03K4/12—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape using as active elements vacuum tubes only in which a sawtooth voltage is produced across a capacitor
    • H03K4/16—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape using as active elements vacuum tubes only in which a sawtooth voltage is produced across a capacitor using a single tube with positive feedback through transformer, e.g. blocking oscillator

Definitions

  • the present invention relates to generators for producing non-sinusoidal waves, and more particularly, but .not necessarily exclusively, to such generators for producing waves substantially of sawtooth form.
  • the electron beam is deflected at a slow speed, usually in the vertical direction, and at A Va high speed, usually in the horizontal direction.
  • the high speed deection provides line scanning and the low speed deflection provides eld or frame scanning.
  • the low speed deflection provides eld or frame scanning.
  • cathode ray beam is usually deiiected horizontally at a predetermined rate, while the beam is Viiected uniformly with respect to time, the applied deiiection voltage must appear approximately as a sawtooth wave form or be of such shape as to produce a current of sawtooth wave form ⁇ in an inductance.
  • a recurring sawtooth of voltage suitable for slow speed orhigh speed scanning, is
  • An lobject of this invention is to provide a sawtooth wave generator consisting of simple parts so that it is cheap to manufacture.
  • Another object is to provide a sawtooth wave 1 generator which does not require a transformer having a laminated iron core and separate primary and secondary windings.
  • a further object of the invention is to provid a sawtooth wave generator, the free running speed of which mayy be controlled in a novel manner by providing means for changing the inductance of a coil.
  • Fig. 1 is a, diagrammatic illustration of a sawtooth wave generator embodying the invention
  • Fig. 2 shows a series of curves
  • Fig. 3 shows a curve obtained during operation of the generator with a different degree of damping
  • Fig. 4 shows a modification of the generator vof Figure 1
  • Fig, 5 shows a further form .which is preferred -for certainA applications.
  • a single coil i2 which may be regarded as an autotransformer having a secondary or grid section I4 and a primary or plate section It.
  • the plate section i6 is connected to the anode I8 of a discharge tube, such as the three electrode vacuum tube I9.
  • the grid 2l of this tube is connected through a capacitance 23 to the end of the grid section It.
  • synchronizing impulses such as television sync signals, usually in the form of timed recurlring pulses 26, are fed into the cathode 28 of the tube i9.
  • the cathode is returned to ground by way ⁇ of an unbypassed resistor 3 I.
  • a capacitance 32 is connected to a suitable vsource of positive potential (not shown), which ,may be connected to a terminal 33 through resistors 36 and 31 in series. Under certain conditions of operation of the generator of this invention, the capacitance 32 is charged through the resistors 31 and 36. Discharge, or partial discharge, of this capacitance is brought about by a sync pulse 26, which initiates an oscillation slightly before the would-be free-running oscillation which, as the grid swings positive, discharges er partly discharges the capacitance 32.
  • a resistor 38 serves as a damping resistor, and in Fig. l it is shown as being connected across the entire autotransformer coil I2. This resistor may be connected across any portion of the winding.
  • the output voltage of sawtooth wave 'form is taken from the resistor 36, which serves as a potentiometer having a, movable contact el. With the potentiometer connection shown, rthe frequency of oscillation of the generator ⁇ is independent of the setting. A change in position which,
  • the capacitance 32 is charged through the resistors 3S and 31 in series, the charge curve 44 (Fig. 2) being substantially linear, initially.
  • Awell as in its charging path has the function of providing the pulse portion 48 of the Wave, since the capacitance 32 cannot be completely discharged due to the time constant of the capacitance 32 and the resistor 3B as well as the plate resistance of the tube.
  • the plate Voltage does not have to rise slowly from the cathode potential, but instead rises immediately to an appreciable value, due to the charge that remains on the capacitance 32.
  • the plate voltage then slowly rises along the curve 44 asV indicated, is substantially linear.
  • the grid voltage is raised immediately and increases in the positive direction due to transformer action, as indicated at (Fig. 2). Following this, the grid is driven abruptly negative when the capacitance 32 is nearly discharged and a negative charge is stored in the capacitance 23, which leaks olf asIv represented by the portion of the curve designated 52.
  • the discharge of the capacitance 23 occurs through a grid resistor 53 in series with anadjustable resistor 54.
  • the timgof discharge can be regulated by varying the resistance ofthe resistor 54.
  • the occurrence of the next successive sync pulse 26 causes the cycle to be repeated.
  • Fig. 3 of the drawings shows the wave form when the degree of damping, whichis determined by the resistor 38, is less.
  • Fig. 4 of the drawings shows a slightly modied arrangement of the apparatus of Figure 1 in which the damping resistor, designated 38a,
  • the damping resistor 38a may be connected across any portion o1 the winding.
  • a core 56 is also indicated, which may be of powdered and com- :the sync input is supplied to an auxiliary Wind-
  • the resistor 36 which lfrio l'ent is the following:
  • An adjustable core 62 is mounted in any suitable manner (not shown) so thatvit may be moved into or out of the coil, somewhat like the tuning inductance on a radio receiver. This change in inductance changes the resonant frequency and the impedance of the circuit, as Well as the coupling between the plate and grid sections of the winding, and through any one, or any combination of these changes, Varies the peak voltage developed on the grid, as well as the plate. The frequency of oscillation is varied since the charge on the capacitance is varied and the time for this charge to leak off is varied. This method of control eliminates the cost of the variable resistor 54 of Fig. 1.
  • 20. and l2?) are preferably of the universal type with low distributed ca- Dacity with parameters essentially independent of "voltage In general, this coil is more stable than the laminated iron core transformer..
  • the universal'type of coil When the universal'type of coil is connected' as an autotransformen it maintains the ratio of plate currentY to grid current in the positive grid region. The frequency is a function .of this ratio.
  • a blocking oscillator comprising'a vacuum tubehaving a controll grid, a plate and a cathode, an autotransformer comprising two inductively coupled-coil sections,- one of said coil sections being connecteddirectly to the plate of said tube,
  • a capacitor a connection from the other of said coil sectionsV to said grid through said capacitor, means including a resistor connected. to the junction of said coil sections to maintain said plate positive with respect to said cathode, a second capacitor connected to the junction lof said coil sections, said second capacitor also being eifectively connected to the point of connection of the cathode in said oscillator, said second capacitor being charged'from said positive potential ap- ,plying means and being discharged by said tube upon occurrence of a pulse of grid voltage, and a damping resistor connected across at least apart of said autotransformer.
  • a blocking oscillator comprising a vacuum tube having a control grid, a plate and a cathode, an autotransformer comprising two inductively coupled coil sections, one of said coil sections being connected directly to the plate of said tube,

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Lasers (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
US776465A 1947-09-27 1947-09-27 Saw-tooth wave generator Expired - Lifetime US2538541A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BE484981D BE484981A (fr) 1947-09-27
US776465A US2538541A (en) 1947-09-27 1947-09-27 Saw-tooth wave generator
GB22814/48A GB663464A (en) 1947-09-27 1948-08-30 Oscillator for non-sinusoidal waves
FR970954D FR970954A (fr) 1947-09-27 1948-08-31 Oscillateur pour la production d'ondes non-sinusoïdales
CH279456D CH279456A (fr) 1947-09-27 1948-09-01 Dispositif produisant à partir d'impulsions qui lui sont appliquées des ondes non sinusoïdales.
ES0185166A ES185166A1 (es) 1947-09-27 1948-09-09 Un oscilador para ondas no senoidales

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US776465A US2538541A (en) 1947-09-27 1947-09-27 Saw-tooth wave generator

Publications (1)

Publication Number Publication Date
US2538541A true US2538541A (en) 1951-01-16

Family

ID=25107449

Family Applications (1)

Application Number Title Priority Date Filing Date
US776465A Expired - Lifetime US2538541A (en) 1947-09-27 1947-09-27 Saw-tooth wave generator

Country Status (6)

Country Link
US (1) US2538541A (fr)
BE (1) BE484981A (fr)
CH (1) CH279456A (fr)
ES (1) ES185166A1 (fr)
FR (1) FR970954A (fr)
GB (1) GB663464A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2633554A (en) * 1948-01-24 1953-03-31 Rca Corp Beam deflection control
US2668911A (en) * 1948-05-19 1954-02-09 Motorola Inc High voltage generator
US3263182A (en) * 1965-02-12 1966-07-26 Detrex Chem Ind Pulsed radio-frequency generator
US20130211789A1 (en) * 2010-11-04 2013-08-15 Shi Dong Method and device for signal period stretch and ultra-fast serial-to-parallel/parallel-to-serial conversion

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2083246A (en) * 1933-12-04 1937-06-08 Willard Rich G Electronic musical instrument
US2212202A (en) * 1936-02-04 1940-08-20 Emi Ltd Electronic oscillation generator
US2300451A (en) * 1940-09-21 1942-11-03 Hazeltine Corp High-voltage power-supply system
US2360697A (en) * 1942-01-27 1944-10-17 Gen Electric Saw-tooth wave generation
US2419772A (en) * 1944-06-30 1947-04-29 Rca Corp Pulse generator system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2083246A (en) * 1933-12-04 1937-06-08 Willard Rich G Electronic musical instrument
US2212202A (en) * 1936-02-04 1940-08-20 Emi Ltd Electronic oscillation generator
US2300451A (en) * 1940-09-21 1942-11-03 Hazeltine Corp High-voltage power-supply system
US2360697A (en) * 1942-01-27 1944-10-17 Gen Electric Saw-tooth wave generation
US2419772A (en) * 1944-06-30 1947-04-29 Rca Corp Pulse generator system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2633554A (en) * 1948-01-24 1953-03-31 Rca Corp Beam deflection control
US2668911A (en) * 1948-05-19 1954-02-09 Motorola Inc High voltage generator
US3263182A (en) * 1965-02-12 1966-07-26 Detrex Chem Ind Pulsed radio-frequency generator
US20130211789A1 (en) * 2010-11-04 2013-08-15 Shi Dong Method and device for signal period stretch and ultra-fast serial-to-parallel/parallel-to-serial conversion
US10031998B2 (en) * 2010-11-04 2018-07-24 Chongqing Misen Tech Ltd. Method and device for signal period stretch and ultra-fast serial-to-parallel/parallel-to-serial conversion

Also Published As

Publication number Publication date
CH279456A (fr) 1951-11-30
FR970954A (fr) 1951-01-11
GB663464A (en) 1951-12-19
BE484981A (fr)
ES185166A1 (es) 1949-01-16

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