US1822465A - Electrical vibratory device such, for example, as a loud speaker - Google Patents
Electrical vibratory device such, for example, as a loud speaker Download PDFInfo
- Publication number
- US1822465A US1822465A US384212A US38421229A US1822465A US 1822465 A US1822465 A US 1822465A US 384212 A US384212 A US 384212A US 38421229 A US38421229 A US 38421229A US 1822465 A US1822465 A US 1822465A
- Authority
- US
- United States
- Prior art keywords
- coil
- oscillations
- electrical
- corrective
- amplifier
- 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
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers
- H04R3/002—Damping circuit arrangements for transducers, e.g. motional feedback circuits
Definitions
- the present invention relates to electrical vibratory devices such for example as loud.
- aloud speaker is re- Figure 1 shows an arrangement in which corrective electrical oscillations are derived with the aid of a freely movable auxiliary coil
- Figure 2 shows an arrangement in which correction is effected purely electrically.
- one of the output terminals of a wireless receiver 1 or other source of electrical oscillations to be converted into sound is connected to earth and the other terminal is connected to the grid of the valve V and to the grid of the valve V the grids being connected to earth through a grid leak resistance 2 and through a source of grid bias potential 3.
- the anodes of the valves V and V are connected through the chokes 4: and 5 respectively to the positive terminal of a source of high tension supply 30, 31.
- the anode of the valve V is also connected, through acondenser 6 and through the output circuit (which may for example be the secondary winding of a transformer) of an amplifier represented diagrammatically by the rectangle 7, to one terminal of the moving coil 8 of a loudspeaker.
- This coil 8 is mounted, in known manner, for vibration in the annular air gap of a magnet (represented in dotted lines at 40) and is secured to a conical diaphragm 9 which is also mounted in known manner.
- the detail arrangement of the loud speaker is not illustrated since it is well known.
- the other terminal of the coil 8 is connected to earth.
- the anode of the valve V is connected through a condenser 10 to one terminal of a second moving coil 11, the other terminal of which is earthed.
- the coil ll' is also mounted for vibration in dotted lines at 41) and is suspended, for
- Parts of the coils 8 and 11, (which may if desired be wound on metal formers) or metallic projections therefrom are arranged to vibrate within and close to the fixed c lindrical electrodes 13 and 14 respectively which are connected together and to one of the input terminals of the amplifier 7, the other input terminal of the amplifier 7 being earthed.
- the amplifier 7 is of the known type suitable for use with a so-called condenser microphone. That is to say variations in the capacity shunted across the input terminals of the amplifier give rise to elec-- trical oscillations in the output circuit of the amplifier.
- the coils 8 and 11 are so connected that they vibrate in phase opposition.
- coil 11 Since coil 11 is called upon to do a negligible amount of work and since it is light and has very little elastic restraint, its vibrations may correspond more closely to the input electrical oscillations than the vibrations of the coil 8 and the corrective electrical efi'ect above described, therefore tends to cause the coil 8 to follow the input electrical oscillations more closely than it would without such corrective effect.
- the circuit of the amplifier 7 is of course such as to produce negligible phase shift in the oscillations passing through it or at least a phase shift, of known amount or of an amount which is substantially constant for all frequencies concerned so that the phase shift can be corrected in known manner.
- Sui-table phase adjusting means may be included in the circuit for this urpose.
- the coil 11 may, if desired, e provided with damping but if so, the damping should preferably be non-reactive.
- Eddy current damping may, for example, be used and in that case the cylindrical electrode 14 may be in the form of a continuous ring. If minimum damping is desired the electrode should be split.
- any desired number of stages of amplification may of course be used in the amplifiers represented by the valves V and V and v0 umecontrolling means may be provided for the amplifier 2 to permit of adjustment of the amplitude of vibration of the idler coil 11.
- the air space between the electrode 14 and the coil 11 may be made smaller than the air space between the electrode 13 and the coil 8 in order that a. smaller displacement of the former is required to produce a given change in capacity than in the latter.
- the wave form of its movement may be made to correspond very closely with that of vibration of the idler coil in the small air' space betwen the magnet poles, the idler coil and its magnet may, if desired, be placed in vacuo.
- FIG. 2 A further form oftheinvention isillustrated in Fig. 2 wherein like components are given the same references as in Fig. 1.
- the source of oscillations 1 is shunted by a potentiometer 15, a tapping point of which is connected to the grid of the valve V
- the output of the valve V is connected to one primary winding 16 of a transformer 17.
- the output of the valve V is connected to the coil 8 of the loud speaker through the secondary winding of a transformer 18.
- the capacity of the condenser formed by the coil 8 and the fixed electrode 13 is connected across the input of the amplifier 7, the output of which is connected to a second primary winding 19 of the transformer 17
- the secondary winding of the transformer 17 is connected to the input of an amplifier 20, the output of which is connected to the primary winding of the transformer 18.
- connections are so arranged that when the electrical oscillations generated by the condenser 8, 13, amplified by the amplifier 7 and applied to the winding 19 are of the same wave form as the os cillatiQns derived from the potentiometer 15 and fed to the winding 16, no electromotive force is generated in the secondary winding of the transformer 17. ⁇ Vhen, however, there is a difference between these wave forms, a corrective electromotive force is applied to the input of the amplifier 20 and a corrective effort is impressed upon the coil 8 through the transformer 18.
- the corrective oscillations must be prevented from feeding back to the original source of the oscillations.
- the corrective oscillations are effectively localized, in the, arrangement of Fig. 1, by the valve V and in the arrangement of Fig. 2, by the valves V and V
- the corrective effect may of course be derived from some point, on this vibratory system other than the coil or other driving element.
- the capacity between the diaphragm (which is rendered conducting) and a fixed electrode may, for example, be used.
- An electro-mechanical vibratory system comprising a first circuit adapted to be energizedfrom a source of electrical oscillations, a device for converting electrical oscillatory energy into mechanical vibratory energy, a second circuit associated electrically with said first circuit and with said device, means for preventing feed back of electrical oscillatory energy from said second circuit to said firstcircuit, means for deriving corrective electrical oscillations corresponding substantially to the difference between the wave forms of said mechanical vibratory energy and the electrical oscillations in said first circuit, and means for applying said corrective oscillations to said second circuit.
- An electro-acoustic system comprising a sound reproducing device adapted to be actuated from a source of electrical oscillations, a vibratory device which is lightly loaded in comparison with said sound reproducing device and which is adapted to be set in vibration by the electrical oscillations from said source, means for deriving corrective electrical oscillations corresponding substantially to the difference between the mechanical oscillations of said sound reproducingdevice and said vibratory device, and means for applying said corrective oscillations to said sound reproducing device.
- a sound. reproducing system comprising an electrical sound reproducing device, a vibratory device which is slightly loaded compared with said sound reproducing device, and means for actuating said sound reproducing device and said vibratory device from a common source of electrical oscillations.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1822465X | 1928-08-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1822465A true US1822465A (en) | 1931-09-08 |
Family
ID=10891382
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US384212A Expired - Lifetime US1822465A (en) | 1928-08-10 | 1929-08-07 | Electrical vibratory device such, for example, as a loud speaker |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US1822465A (fr) |
| FR (1) | FR679459A (fr) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA982055A (en) * | 1972-09-11 | 1976-01-20 | Toshiyuki Goto | Sound reproducing system |
-
1929
- 1929-07-29 FR FR679459D patent/FR679459A/fr not_active Expired
- 1929-08-07 US US384212A patent/US1822465A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| FR679459A (fr) | 1930-04-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US1822758A (en) | System for transmitting and amplifying vibratory currents and movements | |
| US1535538A (en) | Vibratory system | |
| US3047661A (en) | High fidelity audio system | |
| US2092762A (en) | Variable condenser for modulation | |
| US1906985A (en) | Vibratory frequency standard | |
| US2165510A (en) | Electrical measuring, recording, and control system | |
| US1645282A (en) | Loud-speaking telephone | |
| US1822465A (en) | Electrical vibratory device such, for example, as a loud speaker | |
| US2321285A (en) | Modulation system | |
| US2289183A (en) | Modulation system | |
| US2208091A (en) | Frequency variation response circuit | |
| GB518442A (en) | Electro-mechanical vibration translating systems | |
| US1913331A (en) | Tuning fork drive | |
| US2463533A (en) | Electrical impedance matching apparatus | |
| GB155854A (en) | Improvements in application of thermionic valves to production of alternating currents and in relaying | |
| US2047726A (en) | Modulation system | |
| US1569411A (en) | Dynamic transmitter | |
| US1790636A (en) | Locally controlling radio receiving apparatus | |
| US1933735A (en) | Modulation system | |
| US1702568A (en) | Constant frequency wave source | |
| US1834820A (en) | Electrodynamic sound reproducing system | |
| US1822812A (en) | High frequency stabilizer | |
| US1645305A (en) | Sound-translating device | |
| US2134047A (en) | Method and apparatus for sound transmission and reproduction | |
| US1814051A (en) | Method of and apparatus for controlling alternating current |