US3846792A - Electric sound-producing device - Google Patents

Electric sound-producing device Download PDF

Info

Publication number
US3846792A
US3846792A US00196032A US19603271A US3846792A US 3846792 A US3846792 A US 3846792A US 00196032 A US00196032 A US 00196032A US 19603271 A US19603271 A US 19603271A US 3846792 A US3846792 A US 3846792A
Authority
US
United States
Prior art keywords
diaphragm
electromagnet
oscillator
transistor
resistor
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
US00196032A
Other languages
English (en)
Inventor
R Haigh
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.)
Individual
Original Assignee
Individual
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
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3846792A publication Critical patent/US3846792A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
    • G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
    • G10K9/13—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using electromagnetic driving means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/0207—Driving circuits
    • B06B1/0223—Driving circuits for generating signals continuous in time
    • B06B1/0269—Driving circuits for generating signals continuous in time for generating multiple frequencies
    • B06B1/0284—Driving circuits for generating signals continuous in time for generating multiple frequencies with consecutive, i.e. sequential generation, e.g. with frequency sweep
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B3/00—Audible signalling systems; Audible personal calling systems
    • G08B3/10—Audible signalling systems; Audible personal calling systems using electric transmission; using electromagnetic transmission
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
    • B06B2201/50—Application to a particular transducer type
    • B06B2201/52—Electrodynamic transducer
    • B06B2201/53—Electrodynamic transducer with vibrating magnet or coil

Definitions

  • An electric sound producing device includes a ferro- Apr. 20, 1971 Great Britain ..l0310/71 magnetic diaphragm, an electromagnet for deforming [52] U.S. Cl. 340/384 E, 340/388 the diaphragm and an oscillator for repeatedly supply- [51] Int. Cl. G08b 3/10 ing short duration current pulses to the electromag- [58] Field of Search 340/384 E, 388 nets.
  • the oscillator may be driven by a multivibrator to produce intermittent sound pulses or by a saw-tooth [56] References Cited pulse generator to produce sound with an apparently UNITED STATES PATENTS cycllcally s 8 q y- 3,l25,752 3/1964 Burns 340/388 R 24 Claims, 8 Drawing Figures PATENTEDHUV 5 29m SHEET 2 0F 3 FIGG.
  • This invention relates to an electric sound producing device and has as an object to provide such a device in a convenient form.
  • An electric sound-producing device in accordance with the invention comprises a resilient diaphragm of ferromagnetic material, an electromagnet whereby said diaphragm is deformed when current is supplied to said electromagnet, and an oscillator for repeatedly supplying current to said electromagnet in short duration pulses.
  • FIG. I is a section through an example of a device in accordance withthe invention.
  • FIG. 2 is a fragmentary section on line 22 in FIG.
  • the device shown in FIGS. 1 and 2 includes a body formed of a synthetic resin material in two parts, namely a base and a cap 11.
  • the base 10 and the cap 11 are fitted together with mating cylindrical surfaces so that the cap can be turned relative to the base 10.
  • a plurality of abutments 12 on the base 10 coact with a series of inclined ramp faces 13 in the cap to determine the relative axial positions of the cap and base.
  • An adhesive 14 is used to secure the two parts together after adjustment as will be explained hereinafter.
  • a diaphragm member 15 is carried by the cap 11.
  • This diaphragm member is formed from thin steel sheet andhas a flat portion 16, a rim 17, a cylindrical marginal portion 18 having an external rib l9 thereon and a lip 20 around its free edge.
  • the rib 19 is a snap fit in an internal groove in the cap.
  • the flat portion 16 of the diaphragm is free to vibrate in a direction perpendicular to its plane and by making its diameter 1 inch and its thickness 0.0] inch. a natural frequency of approximately 3,000 Hz can be obtained. This is a frequency to which the normal human ear is particularly sensitive.
  • the base 10 has an integral spigot 21 therein extending perpendicularly to the plane of the flat portion 16 of the diaphragm member 15.
  • a mild steel electromagnet core 22 of longitudinally split tubular form.
  • a coil 23 is mounted on this core 22.
  • a shallow cup-shaped steel member 24 is fitted on the base part 10 with the core 22 in contact with it around a hole in the member 24 surrounding the spigot 21. The edge of the member 24 receives the lip 20 of the diaphragm member 15, so that the diaphragm member 15, the core 22 and the member 24 form a magnetic circuit with an air-gap between the core 22 and the centre of the flat portion 16 of the diaphragm member 15.
  • the drive circuit for the coil 23 has its components supported on an annular insulation member 25 itself carried by wires 26 extending through holes in the member 24 and the base 10 and connected to power input terminals 27.
  • One of the wires 26 is insulated to prevent the terminals 27 being short-circuited by the member 24.
  • the coil 23 has two windings 28 and 29.
  • the winding 28 has one end connected to a positive input terminal 27 and its other end is connected to the collector of an n-p-n transistor 30.
  • This transistor 30 has its emitter connected to the other terminal 27.
  • a resistor R is connected between the collector of the transistor 30 and the anode of a diode 31 which has its cathode connected to the positive terminal 27.
  • the other winding 29 is connected at one end to the base of the transistor 30 and at the other end to one electrode of a capacitor C and one end of a resistor R
  • the other electrode of the capacitor C is connected to the negative terminal 27 and the other end of the resistor R is connected to the positive terminal 27.
  • the circuit described forms an oscillator which operates to produce a trainof pulses in the coil 23.
  • the capacitor C charges up through the resistor R until current starts to flow to the base of the transistor 30.
  • the resulting collector current through the winding 28 induces a voltage in the winding 29 which drives the transistor 30 into a fully conducting condition.
  • the current in winding 28 increases until the electro-magnet is saturated when the induced voltage falls and the transistor becomes nonconductive.
  • the current in winding 28 then flows through the resistor R and the diode 31 and decays. Meanwhile, the capacitor C has been partially discharged and this then recharges to initiate another pulse.
  • the pulse repetition frequency can be varied by varying the values of the resistor R and the capacitor C, and this frequency is chosen so as to be substantially less than the natural frequency of the diaphragm.
  • the resistor R is chosen so that the pulse length is approximately equal to half the natural period of the diaphragm.
  • the device thus produces a train of pulses of high frequency sound.
  • the quality of the sound can be varied by a suitable choice of the natural frequency of the diaghragm, and the pulse repetition rate.
  • the device canbe inexpensively produced and can produce a relatively loud noise for a small power consumption. It has the advantage over conventional electromechanical devices incorporating contact breakers that there are no wearing parts and dirt and corrosion will not significantly affect the operation of the device.
  • a diode 32 is introduced between the positive terminal 27 and the resistor R to protect the transistor from damage caused by reverse voltages resulting from inadvertently connecting the terminals 27 to the incorrect terminals of the battery or other supply.
  • the device may be arranged to operate intermittently either by connecting the terminals 27 to the supply via a thermal-type flasher unit or as shown in FIG. 6.
  • the circuit 33 which corresponds to the circuit of FIG. with two exceptions operates as before to supply pulses to the winding 28.
  • the capacitor C is, however, shown in an alternative position between the cathode of the diode 32 and the negative terminal 27. In this position it still provides suppression of electrical interference, but safeguards the transistor 30 against high peak transient voltages to a lesser extent.
  • the other modification is the disconnection of the winding 29 from the cathode of the diode 32 and its connection instead to the output terminal 35 of a multivibrator 34.
  • This multivibrator is of conventional form including two n-p-n transistors 36, 37 with their collectors connected via resistors 38, 39 respectively to the cathode of diode 32 and their emitters connected to the negative terminal 27.
  • the bases of the transistors are connected via resistors 40, 41 respectively to the cathode of the diode 32.
  • a capacitor 42 connects the base of the transistor 37 to the collector ofthc transistor 36.
  • a capacitor 43 is connected between the base of the transistor 36 and the anode of a diode 44 having its cathode connected to the collector of the transistor 37.
  • a resistor 45 is connected between the anode of the diode 44 and the cathode of the diode 32.
  • the output terminal 35 is connected to the collector of the transistor 37.
  • the multivibrator produces an intermittent output.
  • the circuit 33 will operate only when an output is received from circuit 34, i.e. during these periods when the transistor 37 is non-conductive.
  • the cap 11 is replaced by a resonator 46 which fits on to the base like the cap 11 and has an internal groove to receive the rib 19 on the diaphragm member.
  • the resonator 46 has tubular portion 47 connected at one end to an annular wall portion 48 adjacent the diaphragm member.
  • the other end of the portion 47 has an end wall 49 which is perforated so that the tubular portion 47 is effectively and acoustically open at both ends.
  • the length of the portion 47 is chosen so that its fundamental frequency is approximately equal to the natural frequency of the diaphragm.
  • the internal diameter of the tubular portion 47 is less than the diameter of the flat portion 16 of the diaphragm member. This too has an effect on the quality of sound produced by the device.
  • the tubular portion 47 has a diameter equal to or greater than the diameter of the diaphragm the acoustic loading on the diaphragm is low and the diaphragm/resonator combination would tend to ring at a relatively low volume after initiation of vibration of the diaphragm. With a reduced diameter resonator tubular portion 47 the acoustic loading is increased so that a shorter and more intense wave train is produced.
  • sealing of the body could be effected by ultrasonic welding after adjustment of the gap.
  • Adjustment of the airgap to the minimum is of some importance in obtaining maximum efficiency from the device.
  • the pulse length is arranged to be approximately equal to one half of the natural vibration of the diaphragm.
  • the diaphragm reaches a rest position and, ideally it is at this point that the pulse to the electromagnet terminates. Clearly, therefore, the total displacement of the diaphragm will increase with reduction of the air gap for the same power consumption.
  • the cap 11 or resonator 46 is replaced by an exponential horn 50.
  • the narrow end of this horn is of smaller diameter than that of the diaphragm to place a high acoustic load on the diaphragm. A high intensity sound can thus be obtained.
  • the circuit of FIG. 8 utilises an oscillator 33 as before, with a saw-tooth pulse generator circuit 59 including a capacitor 51 connecting the resistor R to the negative terminal 28 and a further resistor 52 connecting it to the positive terminal 27. Also connected to the resistor R is the emitter of a p-n-p transistor 53 the collector of which is connected to the negative terminal via a resistor 54. The base of the transistor 53 is connected via a resistor 55 to the negative terminal and via a resistor 56 to the base of another -p-n-p transistor 57, the collector of which is connected to the base of the transistor 53. A capacitor 58 connects the base of the transistor 57 to the collector of the transistor 53.
  • emitter of the transistor 57 is connected to the positive terminal.
  • the cycle of operation of the circuit may be regarded as commencing with the capacitor 51 uncharged and the transistor 53 non-conductive.
  • the capacitor 51 charges up so that initially the voltage on the resistor R is at the negative terminal voltage but this rises as the capacitor 51 charges, progressively increasing the pulse repetition frequency of the oscillator.
  • the voltage across the capacitor 51 exceeds the bias applied to the base of the transistor 53, the latter starts to conduct and the changing voltage at its collector, caused by current flow through the resistor 54, is applied to the base of the transistor 57 via the capacitor 58.
  • This causes the bias on the base of the transistor 53 to be reduced and the regenerative action causes transistor 53 to switch fully on and discharge the capacitor 51 extremely rapidly.
  • the cycle then restarts.
  • the device emits pulses of sound at the resonant frequency of the diaphragm, which ispreferably as mentioned above, in the region of 3,000 Hz.
  • the pulse repetition frequency varies cyclically from a low frequency rising to a high frequency and then commencing at the low frequency again.
  • the total effect is a sound of which the apparent frequency follows this pattern, although in fact all the sound emitted is at or near the aforementioned resonant frequency.
  • an additional transistor may be introduced between the resistor R and the capacitor 51 to allow the magnitude of the current handled by the timebase" circuit to be reduced.
  • the additional transistor may be connected to the base of the transistor 30. In each case the additional transistor would be connected as an emitter follower.
  • the horn of FIG. 7 may also be used in conjunction with any of the circuits shown in FIGS. 4, 5 and 6.
  • An electrical sound-producing device comprising a resilient diaphragm of ferromagnetic material having a substantially flat portion, an electromagnet including a tubular core having one end adjacent said flat portion of the diaphragm and spaced therefrom by an air gap, the other end thereof being mounted on a spigot, whereby said diaphragm is deformed when current is supplied to said electromagnet, and an oscillator for repeatedly supplying current in short duration pulses to said electromagnet.
  • An electrical sound producing device comprising a resilient diaphragm of ferromagnetic material, an electromagnet whereby said diaphragm is deformed when current is supplied to said electromagnet, said electromagnet including a core having one end adjacent said diaphragm, a coil comprising a pair of windings on said core and an oscillator of which said core and windings form an essential part for repeatedly supplying current to the windings in short duration pulses.
  • said oscillator comprises first and second terminals, an n-p-n transistor with its collector connected via one winding of said coil to the first terminal and its emitter connected to the second terminal, a first resistor and a diode in series circuit bridging said first winding, a capacitor connected in a circuit with the second winding of the coil connecting the second terminal to the base of the transistor and a charging circuit for said capacitor including a second resistor.
  • a device as claimed'in claim 4 in which said charging circuit consists of said second resistor connected between the end of the second winding which is connected to the capacitor and the first terminal.
  • said charging circuit comprises a further resistor connecting the second resistor to the first terminal, a further transistor with its collector/emitter path connecting the interconnection of the second and further resistors to said second terminal and means for applying a signal to the base of said further transistor.
  • a device as claimed in claim 6 in which said further resistor and said further transistor form part of a multivibrator whereby the charging circuit is energized intermittently so that the device produces sound intermittently.
  • a device as claimed in claim 4 further comprising a further diode with its anode connected to the first terminal to prevent reverse voltages being applied to the first mentioned transistor.
  • a device as claimed in claim 4 in which the anode of the diode is connected to the collector of the transistor and its cathode is connected to the first resistor, and further comprising a further capacitor connecting the cathode of said diode to the emitter of the transistor.
  • a device as claimed in claim 4 further comprising a further capacitor interconnecting the first and second terminals.
  • a device as claimed in claim 4 further comprising a third resistor connecting said capacitor to the second winding.
  • An electrical sound producing device comprising a body formed in two parts, a flexible resilient diaphragm of ferromagnetic material supported by one body part, an electromagnet supported by the other body part whereby the diaphragm is deformed when current is supplied to the electromagnet, means for adjusting the position of said two parts relative to one another during assembly of the device to vary the air gap between the electromagnet and the diaphragm, sealing means joining the body parts together in an adjusted relationship and an oscillator contained within said body for repeatedly supplying current to the electromagnet in short duration pulses.
  • a device as claimed in claim 13 in which said parts have mating cylindrical surfaces and are rotatable relative to one another about the common axis of said surfaces during assembly, said parts having interengaging means for displacing the two parts axially relative to one another on turning of one part relative to the other.
  • a device as claimed in claim 14, in which said interengaging means comprises a plurality of abutments on one part and a plurality of inclined ramps on the other part.
  • the electromagnet further comprises a cup-shaped member, having a hole fitted on said spigot and engaged by the core, forming a magnetic connection between the core and the periphery of the diaphragm, an air gap being defined between the core and the center of the diaphragm.
  • An electrical sound-producing device comprising a body, a flexible resilient diaphragm mounted in said body, a tubular acoustic resonator on the body tuned to the natural frequency of the diaphragm and whose axis is perpendicular to the plane of the diaphragm, an electromagnet in the body for deforming the diaphragm when current is supplied thereto and an oscillator contained in the body for repeatedly supplying current to the electromagnet in short duration pulses of lengths approximately equal to half the period of the natural vibration of the diaphragm, and wherein the internal diameter of the resonator is less than the diameter of the diaphragm.
  • An electrical sound-producing device comprising a body, a diaphragm within the body dividing the interior of the body into two chambers, a horn on the body opening into one chamber and of increasing crosssectional area in a direction away from said one chamher, an electromagnet having a pair of windings in the other chamber for deforming the diaphragm when the current is supplied to the electromagnet, and an oscillator circuit including said pair of windings within said other chamber for repeatedly supplying current to the electromagnet in short duration pulses.
  • said pulse rate control circuit is a saw-tooth pulse generator circuit whereby the pulse repetition frequency of the oscillator is caused to commence each cycle at a low frequency and rise continuously to a high frequency

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • General Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Reciprocating Pumps (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US00196032A 1970-11-07 1971-11-05 Electric sound-producing device Expired - Lifetime US3846792A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB5308770 1970-11-07
GB1031071*[A GB1376433A (en) 1970-11-07 1971-04-20 Electric sound-producing device

Publications (1)

Publication Number Publication Date
US3846792A true US3846792A (en) 1974-11-05

Family

ID=26247442

Family Applications (1)

Application Number Title Priority Date Filing Date
US00196032A Expired - Lifetime US3846792A (en) 1970-11-07 1971-11-05 Electric sound-producing device

Country Status (8)

Country Link
US (1) US3846792A (de)
CA (1) CA986754A (de)
DE (1) DE2155472C3 (de)
FR (1) FR2113679A5 (de)
GB (1) GB1376433A (de)
IT (1) IT944816B (de)
NL (1) NL7115306A (de)
SE (1) SE390462B (de)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938142A (en) * 1973-06-12 1976-02-10 International Standard Electric Corporation Ultrasonic transmitter for the remote control of radio and television receivers
US3945004A (en) * 1974-07-11 1976-03-16 Projects Unlimited, Inc. High efficiency buzzer
US4003043A (en) * 1976-01-26 1977-01-11 Stewart-Warner Corporation Timed buzzer
USRE29701E (en) * 1976-01-26 1978-07-11 Stewart-Warner Corporation Timed buzzer
US4251807A (en) * 1979-03-08 1981-02-17 Pickering & Company Miniature buzzer
US4297538A (en) * 1979-07-23 1981-10-27 The Stoneleigh Trust Resonant electroacoustic transducer with increased band width response
US4335418A (en) * 1980-10-27 1982-06-15 General Signal Corporation Electronic interrupter
US4534661A (en) * 1977-08-25 1985-08-13 Kabushiki Kaisha Suwa Seikosha Electric alarm wristwatch including cylindrical sound tube for transmitting sound
US4689609A (en) * 1985-12-04 1987-08-25 Ko Clyde M A Electronic horn with spiral deflecting walls coupled to a truncated cone structure
WO1991006942A1 (en) * 1989-11-03 1991-05-16 Sparton Corporation Electric horn with solid state driver
US5160913A (en) * 1987-10-19 1992-11-03 Sparton Corporation Electric horn with solid state driver
US5596477A (en) * 1993-05-03 1997-01-21 Faraday, Inc. Contactless signaling device
US5659288A (en) * 1995-07-28 1997-08-19 Ford Motor Company Method for setting horn air gap
US20040120885A1 (en) * 2002-12-20 2004-06-24 Sumitomo Chemical Company, Limited Method for producing titanium oxide
US20040246110A1 (en) * 2001-12-28 2004-12-09 Corrado Di Giovanni Electropneumatic horn
US20090065291A1 (en) * 2007-09-06 2009-03-12 Stanley Solow Electropneumatic horn system
US20090090292A1 (en) * 2007-09-06 2009-04-09 Stanley Solow Electropneumatic horn with air venting channels
US20140009272A1 (en) * 2012-07-03 2014-01-09 Fisa Italia S.R.L Electro-pneumatic sound alarm
US8687835B2 (en) 2011-11-16 2014-04-01 Wolo Mfg. Corp. Diaphragm for an electropneumatic horn system
US10425732B1 (en) * 2018-04-05 2019-09-24 xMEMS Labs, Inc. Sound producing device
US10609474B2 (en) 2017-10-18 2020-03-31 xMEMS Labs, Inc. Air pulse generating element and manufacturing method thereof

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2647439C2 (de) * 1976-10-21 1982-10-21 Westfälische Metall Industrie KG Hueck & Co, 4780 Lippstadt Schallsignalgeber, insbesondere für Kraftfahrzeuge
DE3442483A1 (de) * 1984-11-22 1986-05-22 Robert Bosch Gmbh, 7000 Stuttgart Verfahren zum kontaktlosen steuern der aufschlagfrequenz des schwingankers eines elektromagnetischen signalhorns
US4967871A (en) * 1986-10-16 1990-11-06 Pioneer Electronic Corporation Body-sensible acoustic device

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3125752A (en) * 1964-03-17 burns
US3137846A (en) * 1958-12-10 1964-06-16 Kenneth Tower Electronic sirens
US3432849A (en) * 1966-04-29 1969-03-11 Leonard E Earling Sound generator
US3440648A (en) * 1968-05-09 1969-04-22 Mallory & Co Inc P R Integrated-circuit amplifier and oscillator
US3456254A (en) * 1964-08-28 1969-07-15 Lucas Industries Ltd Electromagnetic horns
US3516088A (en) * 1966-06-27 1970-06-02 Lucas Industries Ltd Electromagnetic horns

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH409715A (fr) * 1964-01-28 1966-03-15 Micheloud Andre Générateur électro-acoustique
CH1080564A4 (de) * 1964-08-18 1966-05-14

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3125752A (en) * 1964-03-17 burns
US3137846A (en) * 1958-12-10 1964-06-16 Kenneth Tower Electronic sirens
US3456254A (en) * 1964-08-28 1969-07-15 Lucas Industries Ltd Electromagnetic horns
US3432849A (en) * 1966-04-29 1969-03-11 Leonard E Earling Sound generator
US3516088A (en) * 1966-06-27 1970-06-02 Lucas Industries Ltd Electromagnetic horns
US3440648A (en) * 1968-05-09 1969-04-22 Mallory & Co Inc P R Integrated-circuit amplifier and oscillator

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938142A (en) * 1973-06-12 1976-02-10 International Standard Electric Corporation Ultrasonic transmitter for the remote control of radio and television receivers
US3945004A (en) * 1974-07-11 1976-03-16 Projects Unlimited, Inc. High efficiency buzzer
US4003043A (en) * 1976-01-26 1977-01-11 Stewart-Warner Corporation Timed buzzer
USRE29701E (en) * 1976-01-26 1978-07-11 Stewart-Warner Corporation Timed buzzer
US4534661A (en) * 1977-08-25 1985-08-13 Kabushiki Kaisha Suwa Seikosha Electric alarm wristwatch including cylindrical sound tube for transmitting sound
US4251807A (en) * 1979-03-08 1981-02-17 Pickering & Company Miniature buzzer
US4297538A (en) * 1979-07-23 1981-10-27 The Stoneleigh Trust Resonant electroacoustic transducer with increased band width response
US4335418A (en) * 1980-10-27 1982-06-15 General Signal Corporation Electronic interrupter
US4689609A (en) * 1985-12-04 1987-08-25 Ko Clyde M A Electronic horn with spiral deflecting walls coupled to a truncated cone structure
US5049853A (en) * 1987-10-19 1991-09-17 Sparton Corporation Electric horn with solid state driver
US5160913A (en) * 1987-10-19 1992-11-03 Sparton Corporation Electric horn with solid state driver
WO1991006942A1 (en) * 1989-11-03 1991-05-16 Sparton Corporation Electric horn with solid state driver
US5596477A (en) * 1993-05-03 1997-01-21 Faraday, Inc. Contactless signaling device
US5659288A (en) * 1995-07-28 1997-08-19 Ford Motor Company Method for setting horn air gap
US7038576B2 (en) * 2001-12-28 2006-05-02 Stebel Spa Electropneumatic horn
US20040246110A1 (en) * 2001-12-28 2004-12-09 Corrado Di Giovanni Electropneumatic horn
US20040120885A1 (en) * 2002-12-20 2004-06-24 Sumitomo Chemical Company, Limited Method for producing titanium oxide
US20090065291A1 (en) * 2007-09-06 2009-03-12 Stanley Solow Electropneumatic horn system
US20090090292A1 (en) * 2007-09-06 2009-04-09 Stanley Solow Electropneumatic horn with air venting channels
US7712430B2 (en) 2007-09-06 2010-05-11 Wolo Mfg. Corp. Electropneumatic horn with air venting channels
US7802535B2 (en) 2007-09-06 2010-09-28 Wolo Mfg. Corp. Electropneumatic horn system
US7938078B2 (en) 2007-09-06 2011-05-10 Wolo Mfg. Corp. Electropneumatic horn with air venting channels
US8687835B2 (en) 2011-11-16 2014-04-01 Wolo Mfg. Corp. Diaphragm for an electropneumatic horn system
US20140009272A1 (en) * 2012-07-03 2014-01-09 Fisa Italia S.R.L Electro-pneumatic sound alarm
US9024736B2 (en) * 2012-07-03 2015-05-05 Fisa Italia S.R.L. Electro-pneumatic sound alarm
US10609474B2 (en) 2017-10-18 2020-03-31 xMEMS Labs, Inc. Air pulse generating element and manufacturing method thereof
US10425732B1 (en) * 2018-04-05 2019-09-24 xMEMS Labs, Inc. Sound producing device
US20190313189A1 (en) * 2018-04-05 2019-10-10 xMEMS Labs, Inc. Sound Producing Device
US10979808B2 (en) * 2018-04-05 2021-04-13 xMEMS Labs, Inc. Sound producing device

Also Published As

Publication number Publication date
IT944816B (it) 1973-04-20
NL7115306A (de) 1972-05-09
DE2155472A1 (de) 1972-05-10
GB1376433A (en) 1974-12-04
DE2155472C3 (de) 1981-05-07
FR2113679A5 (de) 1972-06-23
SE390462B (sv) 1976-12-20
DE2155472B2 (de) 1980-07-03
CA986754A (en) 1976-04-06

Similar Documents

Publication Publication Date Title
US3846792A (en) Electric sound-producing device
US5293149A (en) Vehicle horn with electronic solid state energizing circuit
KR19980062729U (ko) 핸드폰/무선호출기용 진동 및 호출음 발생장치
US3219969A (en) Electroacoustic transducer and driving circuit therefor
JP3366507B2 (ja) 振動発生装置
GB1330750A (en) Sound generating device
US3912952A (en) Piezoelectric acoustic multiple tone generator
US3940919A (en) Electronic wristwatch with electronic sound emitter device
US4159472A (en) Electronic buzzer
US3480808A (en) Power generator
GB2031204A (en) Audiodetector alarm
JPS6246178Y2 (de)
US3931549A (en) Control circuit for electromagnetic transducer
CA1074003A (en) Acoustic transducer with a dual purpose piezoelectric element
US4310833A (en) Electrically-energized horn
US7880592B2 (en) Arrival alerting device, arrival alerting method, and mobile terminal
US3447151A (en) Alerting device having oscillations of negative resistance circuit controlled by mechanical resonance of transducer
US6166624A (en) Piezoelectric horn, particularly for vehicles
SU396702A1 (ru) УСТРОЙСТВО дл ПРЕДУПРЕДИТЕЛЬНОЙ ЗВУКОВОЙ СИГНАЛИЗАЦИИ
JPS604240Y2 (ja) 電子音発生回路
JPS5946356B2 (ja) ブザ−付電子時計
JPS6235119Y2 (de)
KR820001824Y1 (ko) 압전소자의 구동회로
JPH09130892A (ja) 電気音響変換装置
JP2781126B2 (ja) 電気音響変換器