US3670264A - Astable multivibrator - Google Patents

Astable multivibrator Download PDF

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Publication number
US3670264A
US3670264A US126458A US3670264DA US3670264A US 3670264 A US3670264 A US 3670264A US 126458 A US126458 A US 126458A US 3670264D A US3670264D A US 3670264DA US 3670264 A US3670264 A US 3670264A
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United States
Prior art keywords
voltage
diodes
resistor
circuit
multivibrator
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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
US126458A
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English (en)
Inventor
Shuzo Wakai
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.)
Panasonic Holdings Corp
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Matsushita Electronics Corp
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Publication date
Application filed by Matsushita Electronics Corp filed Critical Matsushita Electronics Corp
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
    • H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
    • H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
    • H03K3/282—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator astable
    • H03K3/2821—Emitters connected to one another by using a capacitor

Definitions

  • the present invention relates to a circuit for reducing oscillation starting and stopping-voltages for an emitter capacitorcoupled multivibrator circuit.
  • the emitter capacitor-coupled multivibrator circuit presents a problem of temperature and voltage characteristics in which an oscillating frequency is subject to variations of supply voltage and ambient temperature.
  • conventional devices have one or more'diodes connected in series with a resistor in a bias circuit.
  • FIG. 1 is a diagram showing a conventional emitter capacitor-coupled multivibrator circuit with improved temperature and voltage characteristics of oscillation frequency
  • FIG. 2 shows a diagram for explaining the relationship between the supply voltage and bias voltage of the astable multivibrator circuit of FIG. 1;
  • FIG. 3 is a diagram showing an emitter capacitor-coupled multivibrator circuit according to the present invention.
  • FIG. 4 shows a diagram for explaining the relationship between the supply voltage and bias voltage of the multivibrator circuit of FIG. 3.
  • numerals l and 2 show oscillating transistors, numerals 3 and 4 resistors for determining an oscillation frequency, numeral 5 a coupling capacitor, numeral 6 a collector resistor, numerals 7 and 8 resistors for supplying a base bias, numerals 9 and 10 terminals for supplying a DC voltage, and numeral 11 diodes for improving the temperature and voltage characteristics.
  • the resistance value of the resistor 7 or 8 is different from that in the absence of the diodes since the base of the transistor 2 should be always supplied with a predetermined constant voltage corresponding to the intersecting point of both the full and dotted lines in FIG. 2, whether the diodes 11 are connected to the circuit or not. It follows that with the increase in the number of the diodes inserted, the voltage V at the junction point 12 is decreased at a lower rate.
  • the base voltage V of the transistor 2 becomes larger by inserting the diodes in the circuit, which results in biasing the transistor in the forward direction, detriorating the oscillation capability thereof and thereby inconveniently increasing the voltages needed for starting and stopping the oscillation.
  • the present invention is aimed at obviating the problem of the high oscillation startingand stoppingvoltages caused by the diodes which are inserted in the base bias-supplying circuit for compensating for the influence of the ambient temperature and supply voltage on the oscillation frequency, and is characterized by a resistor shunted with the diodes in the base 2 bias-supplying circuit.
  • FIG. 3 is a circuit diagram of an emitter capacitor-coupled multivibrator according to an embodiment of the invention, in which a resistor 13 is connected in shunt with the diodes 11.
  • the presence of the resistor 13 eliminates the problem caused by the diodes.
  • the base bias voltage (the voltage at the junction point 12) of the transistor 2 is maintained at a value determined by the voltage drop in the forward direction through the diodes 11 and resistors 7, 8 and 13.
  • the multivibrator according to the present invention achieve a lower voltage than does the conventional multivibrator.
  • the voltage at the junction point 12 increase along the solid line C even when the supply voltage V rises from zero.
  • the multivibrator circuit according to the present invention makes it possible to start and stop oscillations at a lower voltage than the conventional multivibrator circuit. For this reason, the multivibrator circuit according to the present invention is suitable for application to a horizontal oscillator circuit of a television receiver which requires lower starting and stopping voltages than a vertical oscillator circuit.
  • a multivibrator circuit comprising an emitter capacitorcoupled multivibrator circuit including two switching transistors with emitters connected with each other through a capacitor, the base of one of said switching transistors being connected with a base-biasing means comprising a plurality of dividing resistors and at least one diode connected in series with one of said dividing resistors, said diode being connected in parallel with a resistor.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
  • Oscillators With Electromechanical Resonators (AREA)
  • Dc-Dc Converters (AREA)
US126458A 1970-03-27 1971-03-22 Astable multivibrator Expired - Lifetime US3670264A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45026351A JPS4938859B1 (enrdf_load_stackoverflow) 1970-03-27 1970-03-27

Publications (1)

Publication Number Publication Date
US3670264A true US3670264A (en) 1972-06-13

Family

ID=12191027

Family Applications (1)

Application Number Title Priority Date Filing Date
US126458A Expired - Lifetime US3670264A (en) 1970-03-27 1971-03-22 Astable multivibrator

Country Status (6)

Country Link
US (1) US3670264A (enrdf_load_stackoverflow)
JP (1) JPS4938859B1 (enrdf_load_stackoverflow)
CA (1) CA931232A (enrdf_load_stackoverflow)
DE (1) DE2114760C3 (enrdf_load_stackoverflow)
FR (1) FR2087856A5 (enrdf_load_stackoverflow)
GB (1) GB1289073A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040201429A1 (en) * 2001-05-28 2004-10-14 Toh Yeow Teng Power supply ripple rejection in tuner oscillator stage

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5254957A (en) * 1975-10-30 1977-05-04 Matsushita Electric Works Ltd Holding device for relays
JPS5599081U (enrdf_load_stackoverflow) * 1978-12-28 1980-07-10
JPS56148849U (enrdf_load_stackoverflow) * 1981-03-20 1981-11-09

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Temperature Dependence in Multivibrators Electro-Technology, W. F. Miller, August 1964 Pgs. 38 41, 154. *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040201429A1 (en) * 2001-05-28 2004-10-14 Toh Yeow Teng Power supply ripple rejection in tuner oscillator stage
US7068117B2 (en) * 2001-05-28 2006-06-27 Koninklijke Philips Electronics N.V. Power supply ripple rejection in tuner oscillator stage

Also Published As

Publication number Publication date
GB1289073A (enrdf_load_stackoverflow) 1972-09-13
DE2114760C3 (de) 1978-06-15
DE2114760B2 (de) 1972-06-22
FR2087856A5 (enrdf_load_stackoverflow) 1971-12-31
CA931232A (en) 1973-07-31
JPS4938859B1 (enrdf_load_stackoverflow) 1974-10-21
DE2114760A1 (de) 1971-10-14

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