US2471143A - Piezoelectric apparatus - Google Patents

Piezoelectric apparatus Download PDF

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Publication number
US2471143A
US2471143A US576754A US57675445A US2471143A US 2471143 A US2471143 A US 2471143A US 576754 A US576754 A US 576754A US 57675445 A US57675445 A US 57675445A US 2471143 A US2471143 A US 2471143A
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United States
Prior art keywords
temperature
crystal
frequency
variation
contacts
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
US576754A
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English (en)
Inventor
Jay J Cress
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.)
General Electric Co
Original Assignee
General Electric Co
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 BE476550D priority Critical patent/BE476550A/xx
Application filed by General Electric Co filed Critical General Electric Co
Priority to US576754A priority patent/US2471143A/en
Priority to GB3286/46A priority patent/GB607398A/en
Priority to FR947465D priority patent/FR947465A/fr
Application granted granted Critical
Publication of US2471143A publication Critical patent/US2471143A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient

Definitions

  • the natural frequency of vibration Or the tuning of a piezoelectric crystal element or the like may be controlled by connecting reactive impedance elements in series or parallel circuit relation therewith.
  • the frequency of the crystal may be controlled in such a manner as to approximately compensate for the effect of temperature variation upon the natural frequency of the crystal element itself.
  • a trimming capacitor normally connected in parallel circuit relation with the crystal element is disconnected by a thermal responsive switching member upon either an increase or a decrease of temperature from a mean or center value.
  • Fig. l is a schematic circuit diagram of a piezoelectric apparatus embodying my invention
  • Figs. 2, 3 and 4 are graphical representations of certain of the temperature characteristics of piezoelectric crystal elements illustrating the efiect of my invention
  • Figs. 5 and 6 are schematic circuit diagrams of piezoelectric apparatus illustrating other embodiments of my invention
  • a piezoelectric crystal element 1 having electrodes 2 and 3 and connected to a crystal controlled circuit 4 illustrated in block form.
  • the circuit 4 may be an electric discharge oscillator circuit, a wave filter circuit, or the like.
  • a frequency determining trimming capacitor 5 is normally connected in parallel circuit relation with the crystal element 1 through a thermal responsive switch member 8.
  • the switch 6 comprises two pairs of separable switch contacts I, 8 and 9, ill, the contacts 8 and 9 being movable and the contacts 7 and I0 being stationary.
  • the movable contacts 8 and 9 are attached to the free ends of light cantilever leaf springs I l and l2,.respectively, which are mounted upon opposite sides of one end of a thermal responsive bimetallic strip l3.
  • the opposite end of tllie bimetallic strip I3 is secured to a fixed support
  • the operation of the crystal apparatus shown at Fig, 1 may best be illustrated by referring in connection therewith to Figs. 2 and 3.
  • Fig. 2 is shown a typical curve of natural crystal frequency variation with temperature.
  • Fig. 3 is a similar characteristic curve for a crystal apparatus embodying my invention. It will be observed from Fig. 2 that the natural frequency of vibration of a crystal exhibits a, maximum value at some predetermined mean or center temperature tm, and decreases with temperature variations either above or below the mean temperature,
  • the thermal responsive switch 6 is arranged to assume the mid-position shown with both pairs of contacts 1, 8 and 9, l closed when the crystal temperature is within a predetermined range on either side of the center frequency. If. the crystal temperature increases beyond this range, as for example to a temperature ti at Fig. 3, the bimetallic strip I3 bends sufiiciently in one direction to separate one of the pairs of contacts 1, 8 or 9, I0.
  • the contacts 9, I0 are separated. As soon as these contacts are separated, the crystal shunt including the condenser is broken, so that the shunt capacitance is decreased.
  • Decrease in the shunt capacitance has the effect of raising the crystal frequency, as illustrated at Fig. 3.
  • the bimetallic strip l3 bends sufiiciently in the opposite direction to separate the contacts! and 8, thereby to disconnect the shunt capacitor 5 and again increase the crystal frequency.
  • FIG. 5 I have shown another embodiment of my invention in which the crystal frequency is more closely controlled by mounting upon the bimetallic strip I3 an additional pair of oppositely disposed contact springs I 4 and I5 arranged to control additional pairs of separable switch contacts I6, II and I8, I9, respectively.
  • Other parts of the circuit of Fig. 5 are similar to Fig. 1 and have been assigned the same reference numerals.
  • the contacts I6, I1 and It In the normal position of the bimetallic strip I3 of Fig. 5, the contacts I6, I1 and It, It connect an additional trimming capacitor 5a in parallel circuit relation with the trimming capacitor 5.
  • the contact springs ll, l2 and I4, I5 are so biased that, upon movement of the bimetallic strip in one direction, for example, to the left upon increase in temperature, the contacts 9, I0 separate at a lower temperature than do the contacts I8, l9, while upon movement of the bimetallic strip to the right upon decrease in temperature, the contacts I, 8 separate prior to the separation of the contacts l6, II.
  • the effect of the multiple capacitor control shown at Fig. 5 upon the frequency characteristic of the crystal apparatus is illustrated by the frequency-temperature curve at Fig. 4.
  • Fig. 6 a piezoelectric crystal apparatus generally similar to that shown at Fig. 1, but in which the trimming capacitor 5 is normally connected in parallel circuit relation with the crystal I through a pair of thermal responsive bimetallic switches and 2I.
  • are arranged to maintain the shunt capacitor circuit normally closed within a predetermined range of temperature upon either side of the mean temperature.
  • One of the switches for example the switch 20, is arranged to open its contacts upon increase in temperature beyond the range, as at strip in opposite a temperature ii in Fig. 3, while the other switch, for example the switch 2
  • a piezoelectric element having a natural frequency of vibration subject to variation with temperature
  • a trimming capacitance connected in frequency determining circuit relation with said element
  • thermal responsive means for disabling said trimming capacitance upon variation of temperature beyond a normal range.
  • a piezoelectric element having a natural frequency of vibration subject to variation with temperature
  • a trimming capacitance connected in parallel circuit relation with said element to determine said frequency
  • thermal responsive means for disconnecting said capacitance upon a predetermined temperature variation from a desired temperature.
  • a piezoelectric element having a natural frequency of vibration subject to variation with temperature, reactive impedance means, and switching means responsive to the temperature of said element for controlling the connection of said impedance means in frequency determining circuit relation with said element to compensate for temperature variation from a normal value.
  • a piezoelectric element having a natural frequency of vibration subject to variation with temperature, said frequency having a maximum value at a predetermined mean temperature, impedance means associated in frequency determining relation with said element, and thermal responsive means arranged to vary the eifectiveness of said impedance means in a predetermined direction upon predetermined variation of temperature in either direction from said mean value.
  • a piezoelectric crystal element having a natural frequency of vibration subject to variation with temperature, said frequency having a maximum value at a predetermined mean temperature, a reactive impedance element associated with said crystal element in frequency determining circuit relation, and thermal responsive switching means for controlling the connection of said impedance element to said crystal element in like manner upon a predetermined variation in temperature in either direction from said mean temperature.
  • a piezoelectric crystal element having a natural frequency of vibration subject to variation with temperature, said frequency having a maximum value at a predetermined mean temperature, a trimming capacitor connected in frequency determining circuit relation with said crystal element, and thermal responsive switching means for disabling said trimming capacitor upon a predetermined variation in temperature in either direction from said mean temperature.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Oscillators With Electromechanical Resonators (AREA)
US576754A 1945-02-08 1945-02-08 Piezoelectric apparatus Expired - Lifetime US2471143A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE476550D BE476550A (enrdf_load_stackoverflow) 1945-02-08
US576754A US2471143A (en) 1945-02-08 1945-02-08 Piezoelectric apparatus
GB3286/46A GB607398A (en) 1945-02-08 1946-02-01 Improvements in and relating to piezoelectric apparatus
FR947465D FR947465A (fr) 1945-02-08 1947-06-02 Appareil piezo-électrique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US576754A US2471143A (en) 1945-02-08 1945-02-08 Piezoelectric apparatus

Publications (1)

Publication Number Publication Date
US2471143A true US2471143A (en) 1949-05-24

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Family Applications (1)

Application Number Title Priority Date Filing Date
US576754A Expired - Lifetime US2471143A (en) 1945-02-08 1945-02-08 Piezoelectric apparatus

Country Status (4)

Country Link
US (1) US2471143A (enrdf_load_stackoverflow)
BE (1) BE476550A (enrdf_load_stackoverflow)
FR (1) FR947465A (enrdf_load_stackoverflow)
GB (1) GB607398A (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3060748A (en) * 1959-10-29 1962-10-30 Gulton Ind Inc Accelerometer
US3158928A (en) * 1962-03-30 1964-12-01 Aeroprojects Inc Method and means for operating a generating means coupled through a transducer to a vibratory energy work performing device
US3404298A (en) * 1966-08-19 1968-10-01 Kenton Engineering Corp Thermally sensitive compensating device
US4043109A (en) * 1973-01-11 1977-08-23 Kabushiki Kaisha Suwa Seikosha Electronic timepiece
US5438859A (en) * 1991-09-24 1995-08-08 Murata Manufacturing Co. Ltd. Acceleration sensor having fault diagnosing device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1994228A (en) * 1931-02-19 1935-03-12 Telefunken Gmbh Temperature control of piezo-electric crystal apparatus

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1994228A (en) * 1931-02-19 1935-03-12 Telefunken Gmbh Temperature control of piezo-electric crystal apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3060748A (en) * 1959-10-29 1962-10-30 Gulton Ind Inc Accelerometer
US3158928A (en) * 1962-03-30 1964-12-01 Aeroprojects Inc Method and means for operating a generating means coupled through a transducer to a vibratory energy work performing device
US3404298A (en) * 1966-08-19 1968-10-01 Kenton Engineering Corp Thermally sensitive compensating device
US4043109A (en) * 1973-01-11 1977-08-23 Kabushiki Kaisha Suwa Seikosha Electronic timepiece
US5438859A (en) * 1991-09-24 1995-08-08 Murata Manufacturing Co. Ltd. Acceleration sensor having fault diagnosing device
US5517845A (en) * 1991-09-24 1996-05-21 Murata Manufacturing Co., Ltd. Acceleration sensor having fault diagnosing device

Also Published As

Publication number Publication date
BE476550A (enrdf_load_stackoverflow)
GB607398A (en) 1948-08-30
FR947465A (fr) 1949-07-04

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