CN100479532C - A low-inductance electromagnetic driver for non-exciting magnetic circuit - Google Patents
A low-inductance electromagnetic driver for non-exciting magnetic circuit Download PDFInfo
- Publication number
- CN100479532C CN100479532C CNB200410047985XA CN200410047985A CN100479532C CN 100479532 C CN100479532 C CN 100479532C CN B200410047985X A CNB200410047985X A CN B200410047985XA CN 200410047985 A CN200410047985 A CN 200410047985A CN 100479532 C CN100479532 C CN 100479532C
- Authority
- CN
- China
- Prior art keywords
- coil
- magnetic
- fixed
- fixed coil
- drive coil
- 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 - Fee Related
Links
Images
Landscapes
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
Abstract
The present invention relates to a low-inductance electromagnetic drive without driving magnetic flux circuit, which comprises a magnetic pole, a drive coil, an upper magnetic inductive board, a permanent magnet and a lower magnetic-inductive board. The magnetic pole is integrated with the lower magnetic-inductive board, and the permanent magnet is located between the upper magnetic-inductive board and lower magnetic-inductive board. The drive coil is wrapped around the magnetic pole and is movable in the axial direction. The electromagnetic drive further comprises the fastening coil, and the fastening coil is fastened to a certain proper place of the magnetic flux circuit of the drive coil. Furthermore, the fastening coil is connected with the drive coil in opposite phase. The present invention is characterized in that the drive source applies the excitation to the fastening coil in an equivalent quantity as the drive coil but in opposite phase, so that the excitation energy generated by the current flowing through the speaker for the magnetic flux circuit system is reduced to the minimum, the inductance quantity of the speaker is decreased to the minimum, and the sound distortion of the vibration system connected with the drive coil is decreased.
Description
Technical field
The present invention relates to a kind of electromagnetic driver, concrete be meant a kind of effective low inductance electromagnetic driver that does not encourage magnetic circuit of audio recording and reproducing that makes, this electromagnetic driver can be used in loud speaker, earphone and sonic transducer etc.
Background technology
Audio-visual apparatus has entered people's sphere of life, sound in these audio-visual apparatuss → electricity and electricity → sonic transducer, and commonly used is DYN dynamic loud speaker, earphone and sonic transducer (microphone).They are to utilize magnetic field to the effect realization electricity of current and the power conversion between the sound, form by drive system, vibrational system and support system, what use in drive system is electromagnetic transducer, and these transducers all have drive coil, and drive coil has inductance value.When frequency change, induction reactance also changes thereupon, increase frequency, induction reactance increases, make energy that electromagnetic transduction obtains along with change, cause the variation of actuating force, simultaneously because the existence of inductance, the voltage that adds on the loud speaker can produce phase shift with the electric current that flows through loud speaker, cause bad feedback for the power amplifier that drives loud speaker, and more because the effect of electricity → magnetic and magnetic hysteresis, the energy of supplying with the speaker drive coil can produce excitation to the magnetic circuit of loud speaker, is stored in the magnetic circuit system of loud speaker in the mode of magnetic energy, when voltage-phase changes, again because of the effect of magnetic → electricity, be stored in energy in the magnetic circuit of loudspeaker can be again through the internal resistance of power amplifier and act on drive coil, make loud speaker, earphone and sonic transducer produce frequency response, the problem of aspects such as distortion.
As known to the present inventor, in order to reduce drive coil to the harmful excitation of magnetic circuit system and the inductance value of electromagnetic driver, some product has taked to be inserted at the sensitive position place of drive coil 2 design (referring to Figure 11) of short-circuited conducting sleeve 8, and this short-circuited conducting sleeve is fixed on conducting magnetic column 1 outer placing after generally adopting conductor such as copper to make a closed round ring.But because the effect of short-circuited conducting sleeve only is the passive energy that a part is produced by drive coil that consumes, and this short-circuited conducting sleeve does not electrically connect with drive coil, so can not do the anti-excitation of active and equivalent to offset the harmful excitation of drive coil to magnetic circuit system to magnetic circuit system, effect is very limited, with the present invention basic difference is arranged.
Summary of the invention
Defective at above-mentioned prior art, the purpose of this invention is to provide a kind of low inductance electromagnetic driver that does not encourage magnetic circuit, it is little that induction reactance is changed, the electric energy that electromagnetic transduction obtains changes little with induction reactance, and the phase change that produces is little, has particularly eliminated substantially because of magnetic circuit and has been subjected to encouraging the distortion that causes.
For achieving the above object, the technical solution used in the present invention is as follows:
A kind of low inductance electromagnetic driver that does not encourage magnetic circuit, comprise conducting magnetic column 1, drive coil 2, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, this conducting magnetic column 1 fuses with magnetic conduction lower plate 6, this permanent magnet 5 is between magnetic conduction upper plate 4 and magnetic conduction lower plate 6, this drive coil 2 can be done being enclosed within on the conducting magnetic column 1 of axial motion, this electromagnetic driver also comprises one first fixed coil 3, the inductance value of described first fixed coil 3 is close with drive coil equivalent electric sensibility reciprocal, this first fixed coil 3 is fixed on the magnetic circuit location-appropriate place of drive coil 2, and this first fixed coil 3 connects encouraged by antiphase equivalent with drive coil 2 antiphases.
This first fixed coil 3 is arranged between drive coil 2 and the conducting magnetic column 1 and is fixed on the conducting magnetic column 1, and this first fixed coil 3 and drive coil 2 are that the antiphase of minimum mode connects encouraged by antiphase equivalent as inductance value.
This first fixed coil 3 is fixedly installed on the magnetic conduction upper plate 4, and this first fixed coil 3 and drive coil 2 are that the antiphase of minimum mode connects encouraged by antiphase equivalent as inductance value.
This first fixed coil 3 encourages to be subjected to antiphase equivalent with the serial or parallel connection that drive coil 2 is made antiphase.
Wherein, it is good more that the inductance value of first fixed coil 3 approaches the equivalent inductance dose-effect fruit of drive coil 2 more, but the ratio of the two in 0.5 to 1.5 scope to the promptly existing obvious improvement effect of distortion.
A kind of low inductance electromagnetic driver that does not encourage magnetic circuit, comprise conducting magnetic column 1, drive coil 2, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, this conducting magnetic column 1 fuses with magnetic conduction lower plate 6, this permanent magnet 5 is between magnetic conduction upper plate 4 and magnetic conduction lower plate 6, this drive coil 2 can be done being enclosed within on the conducting magnetic column 1 of axial motion, this electromagnetic driver also comprises first fixed coil 3 and second fixed coil 7, the total inductance amount of described two fixed coils is close with drive coil 2 equivalent electric sensibility reciprocals, this first fixed coil 3 and second fixed coil 7 are fixed on the suitable magnetic circuit position of drive coil 2, and this first fixed coil 3 and second fixed coil 7 connect encouraged by antiphase equivalent with drive coil 2 antiphases.
This first fixed coil 3 and second fixed coil 7 all are fixed on the conducting magnetic column 1, and this first fixed coil 3 and second fixed coil 7 and drive coil 2 are that the antiphase of minimum mode connects encouraged by antiphase equivalent as inductance value.
This first fixed coil 3 and second fixed coil 7 are separately fixed on conducting magnetic column 1 and the magnetic conduction upper plate 4, and this first fixed coil 3 and second fixed coil 7 are that the antiphase of minimum mode connects encouraged by antiphase equivalent with drive coil 2 as inductance value all.
Further, this first fixed coil 3, second fixed coil 7 and drive coil 2 are that the antiphase serial or parallel connection of minimum mode encourages to be subjected to antiphase equivalent as inductance value.
In addition, this first fixed coil 3, second fixed coil 7 can be that the antiphase series and parallel of minimum mode encourages to be subjected to antiphase equivalent as inductance value with drive coil 2 also.
Wherein, it is good more that the total inductance amount of first fixed coil 3 and second fixed coil 7 is approached the equivalent inductance dose-effect fruit of drive coil 2 more, but the ratio of the two in 0.5 to 1.5 scope to the promptly existing obvious improvement effect of distortion.
This first fixed coil 3 also can be made by the magnetic conductive metal as magnetic conductor.
The design of all fixed coil electrical quantitys, the principle of Ying Zunding " the anti-phase excitation energy that is produced by fixed coil approaches the excitation energy that counteracting is produced by drive coil as far as possible " in concrete operations, certainly has multiple choices, but main following a few example is arranged:
When a. all fixed coils and drive coil were made coupled in series, the inductance value of fixed coil approached the equivalent electric sensibility reciprocal of drive coil more, level off to 1 more with the degree of coupling of drive coil, and the characteristic of the more little then loud speaker of D.C. resistance was good more.
When b. all fixed coils and drive coil are done parallel connection, the inductance value of fixed coil approaches the equivalent electric sensibility reciprocal of drive coil more, level off to 1 more with the degree of coupling of drive coil, and total dc resistance of control fixed coil current circuit, so that the anti-phase excitation energy that is produced by fixed coil approaches the excitation energy that counteracting is produced by drive coil as far as possible.
When c. all fixed coils connect as series and parallel with drive coil, fixed coil total inductance amount after the connection is approached the equivalent electric sensibility reciprocal of drive coil more, level off to 1 more with the degree of coupling of drive coil, and total dc resistance of control fixed coil current circuit, so that farthest offset the excitation energy that produces by drive coil by the anti-phase excitation energy of fixed coil generation.
No matter adopt which kind of coupling method,, promptly can obviously improve the distortion of loud speaker as long as the anti-excitation energy that produced by fixed coil has been offset 0.5 to 1.5 degree of excitation energy that drive coil produces.
The invention is characterized in by drive source fixed coil is done with drive coil equivalent but anti-phase active excitation, make the electric current that flows through loud speaker reduce to minimum to the excitation energy that magnetic circuit system produces, it is minimum that the inductance value of loud speaker reduces to, and the vibrational system audio distortions that is connected with drive coil diminishes.
Use beneficial effect of the present invention to be:
Because the present invention has the inductance value fixed coil close with drive coil equivalent electric sensibility reciprocal in the Position Design of drive coil sensitivity, fixed coil connects as antiphase with drive coil, by drive source fixed coil is done with drive coil equivalent but anti-phase excitation, owing to fixed coil and drive coil have produced equivalent but two tunnel anti-phase excitations cause payment simultaneously, the excitation energy that the magnetic circuit system of loud speaker is subjected to is reduced to minimum, the result makes the magnetic field intensity of magnetic circuit system not change with the change of loud speaker FD feed, and the vibrational system audio distortions that is connected with drive coil diminishes.
Because the present invention has designed the fixed coil of doing anti-phase equivalent excitation with drive coil, reduced the inductance value of loud speaker, low inductance value makes loud speaker can obtain the driving energy equably in very wide frequency range, has expanded the frequency range of resetting.
Because its impedance operator of loud speaker according to manufacturing of the present invention extremely approaches pure resistance, make the interface processing of loud speaker and power amplifier become simple.
All these can both improve the quality that audio frequency is recorded, put effectively with very low cost.
Description of drawings
Fig. 1, Fig. 2 are the structural representations that the present invention has a fixed coil;
Fig. 3, Fig. 4 are the structural representations that the present invention has two fixed coils;
To be the present invention make the structural representation that a fixed coil, fixed coil are also made magnetic conductor with magnetic conductive metal to Fig. 5;
Fig. 6 is that the present invention has the fixed coil figure that connects with drive coil;
Fig. 7 is that the present invention has a fixed coil figure in parallel with drive coil;
Fig. 8 is that the present invention has two fixed coils figure that connects with drive coil;
Fig. 9 is that the present invention has two fixed coil figure in parallel with drive coil;
Figure 10 be the present invention have two fixed coils and drive coil also, figure connects;
Figure 11 is the structural representation of existing electromagnetic driver.
The symbol description of figure:
1, conducting magnetic column, 2, drive coil, 3, first fixed coil, 4, the magnetic conduction upper plate, 5, permanent magnet, 6, the magnetic conduction lower plate, 7, second fixed coil, 8, short-circuited conducting sleeve, 9, vibrating diaphragm.
Embodiment
Below by specific embodiment in addition accompanying drawing the present invention is described in detail.
First kind of embodiment of the present invention: as shown in Figure 1, it is to be made of conducting magnetic column 1, drive coil 2, first fixed coil 3, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, conducting magnetic column 1 fuses with magnetic conduction lower plate 6, permanent magnet 5 is connected with magnetic conduction upper plate 4, and also be connected with magnetic conduction lower plate 6, drive coil 2 is arranged on the conducting magnetic column 1, twine and intrinsic first fixed coil 3 of glue on the conducting magnetic column 1, drive coil 2 connects with first fixed coil, 3 antiphases.
Second kind of embodiment: as shown in Figure 2, it is to be made of conducting magnetic column 1, drive coil 2, first fixed coil 3, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, conducting magnetic column 1 fuses with magnetic conduction lower plate 6, permanent magnet 5 is connected with magnetic conduction upper plate 4, and also be connected with magnetic conduction lower plate 6, drive coil 2 is arranged on the conducting magnetic column 1, intrinsic first fixed coil 3 of magnetic conduction upper plate 4 gluings, drive coil 2 connects with first fixed coil, 3 antiphases.
The third embodiment: as shown in Figure 3, it is to be made of conducting magnetic column 1, drive coil 2, first fixed coil 3 and second fixed coil 7, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, conducting magnetic column 1 fuses with magnetic conduction lower plate 6, permanent magnet 5 is connected with magnetic conduction upper plate 4, and also be connected with magnetic conduction lower plate 6, it is connecting of minimum mode with drive coil as inductance value that drive coil 2, first fixed coil 3 and 7, two fixed coils of second fixed coil are arranged on the conducting magnetic column 1.First fixed coil 3 and 7 windings of second fixed coil and glue are solid on conducting magnetic column 1 around here.
The 4th kind of embodiment: as shown in Figure 4, it is to be made of conducting magnetic column 1, drive coil 2, first fixed coil 3 and second fixed coil 7, magnetic conduction upper plate 4, permanent magnet 5, magnetic conduction lower plate 6, conducting magnetic column 1 fuses with magnetic conduction lower plate 6, permanent magnet 5 is connected with magnetic conduction upper plate 4, and also be connected with magnetic conduction lower plate 6, the drive coil 2 and first fixed coil 3 are arranged on the conducting magnetic column 1, second fixed coil 7 is fixed on the magnetic conduction upper plate 4, and two fixed coils are connecting of minimum mode with drive coil as inductance value.3 windings of first fixed coil and glue are solid on conducting magnetic column 1 around here, and second fixed coil 7 is bonded on the magnetic conduction upper plate 4 by bonding agent.
The glue that adopts during above-mentioned glue is solid is the high temperature resistant colloid that uses in the existing electromagnetic driver.
The 5th kind of embodiment: as shown in Figure 5, it is to be made of conducting magnetic column 1, drive coil 2, first fixed coil 3, magnetic conduction upper plate 4, permanent magnet 5, the magnetic conduction lower plate 6 made by magnetic conductive metal, and first fixed coil 3 is connecting of minimum mode with drive coil 2 as inductance value.Its characteristics are that first fixed coil 3 is by pure iron, magnetic conductive metal such as mild steel or iron-nickel alloy is made, it is that spiral helicine cut is made to form coil in the end of the conducting magnetic column 1 that will make with above-mentioned magnetic conductive metal that wherein a kind of makes mode, to make insulation processing through table outside the coil of cutting then, again with this coil and conducting magnetic column 1 then become first fixed coil 3 that has the conducting magnetic column function concurrently after cutting tip is not fixed, and to draw with drive coil 2 be connecting of minimum mode as inductance value or by drive source this fixed coil 3 is made equivalent but anti-phase excitation by two ends with this first fixed coil 3 shown in Figure 5.
During use, above-mentioned first kind, second kind embodiment placed on the loud speaker, first fixed coil 3 connects in the opposite direction with drive coil 2, and induction reactance reduces, the alternating current phases variation is also little, and drive coil 2 drives vibrational systems, and audio distortions is diminished.Or the third, the 4th kind of embodiment place on the loud speaker, drive coil 2 two ends respectively have first fixed coil 3 and second fixed coil 7, and drive coil 2 is connecting of minimum mode with first fixed coil 3 and second fixed coil 7 as inductance value.
The 5th kind of embodiment placed on the loud speaker, and effect is also good.
According to formula: Leq=L
1+ L
2-2M and Leq=L
1L
2-M
2/ L
1+ L
2+ 2M, promptly coupling coefficient is 1, and its induction reactance was zero when two groups of inductance that inductance value equates were done the antiphase connection, and its impedance is the dc impedance of two inductance.Because the present invention has designed the fixed coil of tightly coupled one or several total inductance amounts inductance value close with drive coil equivalent electric sensibility reciprocal near the drive coil that has than big inductance quantity, and fixed coil done connecting fixed coil is done the excitation of anti-phase equivalent of antiphase with lead and drive coil, therefore, just can make whole loud speaker present very characteristic near pure resistance as long as control the inductance value and the resistance value of fixed coil well.
With the loud speaker that embodiment 1 is installed is example, when speaker operation, drive source (as audio-frequency power amplifier) has also been given 3 feed-ins of first fixed coil when giving the drive coil 2 feed-in electric energy of the loud speaker opposite electric energy of direction, so the bad excitation that 2 pairs of magnetic circuits of loudspeaker of speaker drive coil are done has been offset in the antiphase excitation that 3 pairs of magnetic circuits of loudspeaker of first fixed coil are done, reach the main purpose that the present invention " does not encourage magnetic circuit " thus, solved the problem of loud speaker, earphone and aspects such as sonic transducer generation frequency response, distortion.
The present invention is not limited to above-mentioned each example, wants that various distortion are certainly arranged in the point range not departing from the present invention, as the earphone that the present invention is used for electromagnetic type, sonic transducer, dynamic planar loudspeakers, material shaking device etc.
Claims (12)
1. low inductance electromagnetic driver that does not encourage magnetic circuit, comprise conducting magnetic column (1), drive coil (2), magnetic conduction upper plate (3), permanent magnet (5), magnetic conduction lower plate (6), this conducting magnetic column (1) fuses with magnetic conduction lower plate (6), this permanent magnet (5) is positioned between magnetic conduction upper plate (4) and the magnetic conduction lower plate (6), this drive coil (2) can be done being enclosed within on the conducting magnetic column (1) of axial motion, it is characterized in that: this electromagnetic driver also comprises first fixed coil (3), the equivalent electric sensibility reciprocal of the inductance value of described first fixed coil (3) and drive coil (2) is close, this first fixed coil (3) is fixed on the magnetic circuit location-appropriate place of drive coil (2), and this first fixed coil (3) connects encouraged by antiphase equivalent with drive coil (2) antiphase.
2. electromagnetic driver according to claim 1, it is characterized in that: this first fixed coil (3) is arranged between drive coil (2) and the conducting magnetic column (1) and is fixed on the conducting magnetic column (1), and this first fixed coil (3) and drive coil (2) are that the antiphase of minimum mode connects encouraged by antiphase equivalent as inductance value.
3. electromagnetic driver according to claim 1, it is characterized in that: this first fixed coil (3) is fixedly installed on the magnetic conduction upper plate (4), and this first fixed coil (3) and drive coil (2) are that the antiphase of minimum mode is connected encouraged by antiphase equivalent as inductance value.
4. according to claim 1,2 or 3 described electromagnetic drivers, it is characterized in that: this first fixed coil (3) is made by the magnetic conductive metal as magnetic conductor.
5. according to claim 2 or 3 described electromagnetic drivers, it is characterized in that: this first fixed coil (3) encourages to be subjected to antiphase equivalent with the serial or parallel connection that drive coil (2) is made antiphase.
6. electromagnetic driver according to claim 5 is characterized in that: this first fixed coil (3) is made by the magnetic conductive metal as magnetic conductor.
7. low inductance electromagnetic driver that does not encourage magnetic circuit, comprise conducting magnetic column (1), drive coil (2), magnetic conduction upper plate (3), permanent magnet (5), magnetic conduction lower plate (6), this conducting magnetic column (1) fuses with magnetic conduction lower plate (6), this permanent magnet (5) is positioned between magnetic conduction upper plate (4) and the magnetic conduction lower plate (6), this drive coil (2) can be done being enclosed within on the conducting magnetic column (1) of axial motion, it is characterized in that: this electromagnetic driver also comprises first fixed coil (3) and second fixed coil (7), the total inductance amount of described two fixed coils is close with drive coil (2) equivalent electric sensibility reciprocal, this first fixed coil (3) and second fixed coil (7) are fixed on the magnetic circuit location-appropriate place of drive coil (2), and this first fixed coil (3) and second fixed coil (7) connect encouraged by antiphase equivalent with drive coil (2) antiphase.
8. electromagnetic driver according to claim 7, it is characterized in that: this first fixed coil (3) and second fixed coil (7) all are fixed on the conducting magnetic column (1), and this first fixed coil (3) and second fixed coil (7) and drive coil (2) are that the antiphase of minimum mode connects encouraged by antiphase equivalent as inductance value.
9. electromagnetic driver according to claim 7, it is characterized in that: this first fixed coil (3) and second fixed coil (7) are separately fixed on conducting magnetic column (1) and the magnetic conduction upper plate (4), and this first fixed coil (3) and second fixed coil (7) are that the antiphase of minimum mode connects encouraged by antiphase equivalent with drive coil (2) as inductance value all.
10. according to claim 7,8 or 9 described electromagnetic drivers, it is characterized in that: this first fixed coil (3) is made by the magnetic conductive metal as magnetic conductor.
11. according to Claim 8 or 9 described electromagnetic drivers, it is characterized in that: this first fixed coil (3), second fixed coil (7) and drive coil (2) are that the antiphase serial or parallel connection of minimum mode encourages to be subjected to antiphase equivalent as inductance value.
12. electromagnetic driver according to claim 11 is characterized in that: this first fixed coil (3) is made by the magnetic conductive metal as magnetic conductor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200410047985XA CN100479532C (en) | 2003-06-18 | 2004-06-14 | A low-inductance electromagnetic driver for non-exciting magnetic circuit |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN03149226.6 | 2003-06-18 | ||
| CN03149226 | 2003-06-18 | ||
| CNB200410047985XA CN100479532C (en) | 2003-06-18 | 2004-06-14 | A low-inductance electromagnetic driver for non-exciting magnetic circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1575029A CN1575029A (en) | 2005-02-02 |
| CN100479532C true CN100479532C (en) | 2009-04-15 |
Family
ID=34523666
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB200410047985XA Expired - Fee Related CN100479532C (en) | 2003-06-18 | 2004-06-14 | A low-inductance electromagnetic driver for non-exciting magnetic circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100479532C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106878888B (en) * | 2017-04-10 | 2019-07-30 | 南京俏声波动科技有限公司 | Induct dynamic speaker |
| CN109358472A (en) * | 2018-09-18 | 2019-02-19 | 中国医学科学院生物医学工程研究所 | Magnetoacoustic signals production method and device based on modulated excitation |
-
2004
- 2004-06-14 CN CNB200410047985XA patent/CN100479532C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1575029A (en) | 2005-02-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101415136B (en) | High efficient miniature electro-acoustic transducer with reduced dimensions | |
| CA1141856A (en) | Multi-filar moving coil loudspeaker | |
| EP2480008B1 (en) | Voice coil and smt micro speaker using same | |
| WO2018170945A1 (en) | Moving magnet loudspeaker | |
| CN111464899B (en) | Moving-iron earphone, and damping short-circuit ring of inductor and transformer | |
| US20060078152A1 (en) | Ribbon microphone incorporating a special-purpose transformer and/or other transducer-output circuitry | |
| US20060078135A1 (en) | Ribbon-microphone transducer | |
| US8692635B2 (en) | Sound generating apparatus | |
| CN100479532C (en) | A low-inductance electromagnetic driver for non-exciting magnetic circuit | |
| EP1641315B1 (en) | A low-inductance electromagnetic drive without driving the magnetic flux circuit | |
| CN209462600U (en) | Loudspeaker and earphone | |
| CN206602654U (en) | A kind of multitone ring electro-acoustic product | |
| CN104682587B (en) | Stator for motor | |
| CN210629847U (en) | Bone conduction massage loudspeaker | |
| CN209017296U (en) | Loudspeaker | |
| CN209283490U (en) | Sounding device | |
| CN206196042U (en) | Moving -coil loudspeaker | |
| CN206136273U (en) | Moving -coil loudspeaker | |
| US11611831B1 (en) | Electrodynamic actuator for acoustic oscillations | |
| JP4974690B2 (en) | Ribbon microphone unit and ribbon microphone | |
| CN110933572A (en) | Bone conduction massage loudspeaker and installation method thereof | |
| CN105376681A (en) | Planar coil driven film loudspeaker | |
| US1741226A (en) | of east orange | |
| CN215734823U (en) | A kind of loudspeaker | |
| CN102790936A (en) | Hysteresis-free electrodynamic transducer with motional impedance rectifying return circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: YUYAO TEMPERATURE INSTRUMENT FACTORY CO., LTD. Assignor: Wu Qijun Contract record no.: 2011330000911 Denomination of invention: A low-inductance electromagnetic driver for non-exciting magnetic circuit Granted publication date: 20090415 License type: Exclusive License Open date: 20050202 Record date: 20110707 |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090415 Termination date: 20180614 |