JP3309798B2 - Transformer for piezoelectric speaker - Google Patents
Transformer for piezoelectric speakerInfo
- Publication number
- JP3309798B2 JP3309798B2 JP08133498A JP8133498A JP3309798B2 JP 3309798 B2 JP3309798 B2 JP 3309798B2 JP 08133498 A JP08133498 A JP 08133498A JP 8133498 A JP8133498 A JP 8133498A JP 3309798 B2 JP3309798 B2 JP 3309798B2
- Authority
- JP
- Japan
- Prior art keywords
- transformer
- piezoelectric speaker
- secondary winding
- piezoelectric
- winding
- 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
- 238000004804 winding Methods 0.000 claims description 91
- 230000008878 coupling Effects 0.000 description 10
- 238000010168 coupling process Methods 0.000 description 10
- 238000005859 coupling reaction Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000005236 sound signal Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F30/00—Fixed transformers not covered by group H01F19/00
- H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
- H01F30/10—Single-phase transformers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
- H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Circuit For Audible Band Transducer (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、圧電スピーカを駆
動するのに最適な圧電スピーカ用トランスに関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric speaker transformer most suitable for driving a piezoelectric speaker.
【０００２】[0002]
【従来の技術】従来の圧電スピーカ用のトランスとし
て、たとえば、実開昭６４−２９９８６号公報に示され
るものがある。これを図４を用いて説明する。トランス
１は、四角い板枠状のトロイダル型の磁心２と、磁心２
の図面上の下側に巻回されて設けられている１次巻線３
と、磁心２の図面上の上側に１次巻線３と分離して巻回
されて設けられている２次巻線４とからなる。そして、
１次巻線３は、スピーカを駆動するためのアンプ（図示
せず）の入力端子５に接続されており、２次巻線４は、
圧電体からなる発音体６に接続されて、圧電スピーカ装
置７は構成されている。2. Description of the Related Art A conventional transformer for a piezoelectric speaker is disclosed, for example, in Japanese Utility Model Laid-Open No. 64-29986. This will be described with reference to FIG. The transformer 1 includes a toroidal magnetic core 2 having a square plate shape and a magnetic core 2.
Primary winding 3 provided to be wound on the lower side of the drawing
And a secondary winding 4 provided separately and wound on the upper side of the magnetic core 2 in the drawing. And
The primary winding 3 is connected to an input terminal 5 of an amplifier (not shown) for driving a speaker.
The piezoelectric speaker device 7 is configured by being connected to the sounding body 6 made of a piezoelectric body.
【０００３】そして、アンプによって増幅された音声信
号が入力端子５から１次巻線３に入力されると、１次巻
線３に磁界が発生し、この磁界により２次巻線４に電力
が誘起され、この電力による電気信号が発音体６に加わ
り、音声の再生が行われる。When the audio signal amplified by the amplifier is input from the input terminal 5 to the primary winding 3, a magnetic field is generated in the primary winding 3, and electric power is applied to the secondary winding 4 by the magnetic field. The induced electric signal is applied to the sounding body 6 by this power, and the sound is reproduced.
【０００４】[0004]
【発明が解決しようとする課題】一般にアンプの出力イ
ンピーダンスはほぼ０Ωであり、アンプに接続されるト
ランスと圧電体からなる発音体との周波数特性は、トラ
ンスの２次巻線側のインダクタンスで決定されるもので
はなく、１次巻線側を短絡したときの２次巻線側のイン
ダクタンスにより決定され、これを漏洩インダクタンス
という。Generally, the output impedance of an amplifier is almost 0Ω, and the frequency characteristics of a transformer connected to the amplifier and a sounding body made of a piezoelectric material are determined by the inductance of the secondary winding of the transformer. It is determined by the inductance of the secondary winding when the primary winding is short-circuited, and this is called leakage inductance.
【０００５】そして、このときの、スピーカ装置の共振
周波数をｆとすると、 ｆ＝（２π（ＬＣ）1/2）-1 という式で表される。ここで、Ｌは漏洩インダクタンス
であり、Ｃは圧電体の容量である。漏洩インダクタンス
は、１次巻線と２次巻線の結合度に依存しており、たと
えば、１次巻線と２次巻線の結合度が高くなると、漏洩
インダクタンスは減少する傾向にある。そして、発音体
に接続したトランスの周波数特性は、図５のような曲線
で表され、縦軸で表されるレスポンスが減少傾向となる
ときの周波数を高域遮断周波数という。ここで、実線で
示す曲線と破線で示す曲線では、破線で示す曲線の方が
漏洩インダクタンスが大きい場合を表している。そし
て、実線の曲線の高域遮断周波数をｆ１とし、破線の曲
線の高域遮断周波数をｆ２とすると、ｆ２＜ｆ１とな
り、漏洩インダクタンスが大きくなると、高域遮断周波
数の値が低下することになる。なお、レスポンスとは、
発音体に入力される信号の能率を示す。[0005] When the resonance frequency of the speaker device at this time is f, it is expressed by the formula f = (2π (LC) 1/2 ) -1 . Here, L is the leakage inductance, and C is the capacitance of the piezoelectric body. The leakage inductance depends on the degree of coupling between the primary winding and the secondary winding. For example, as the degree of coupling between the primary winding and the secondary winding increases, the leakage inductance tends to decrease. The frequency characteristic of the transformer connected to the sounding body is represented by a curve as shown in FIG. 5, and the frequency at which the response represented by the vertical axis tends to decrease is referred to as a high cutoff frequency. Here, of the curve shown by the solid line and the curve shown by the broken line, the curve shown by the broken line represents a case where the leakage inductance is larger. Assuming that the high frequency cutoff frequency of the solid curve is f1 and the high frequency cutoff frequency of the broken curve is f2, f2 <f1, and the value of the high frequency cutoff decreases as the leakage inductance increases. . The response is
It shows the efficiency of the signal input to the sounding body.
【０００６】また、圧電体からなる発音体を一定電圧で
駆動した場合、圧電体からなる発音体が容量性であるこ
とから、低周波ではインピーダンスが高く、高周波では
逆にインピーダンスが低くなるため、発音体の音圧特性
は、図６に示すような曲線で表される。なお、発音体に
トランスは接続されていないものとする。When a sounding body made of a piezoelectric body is driven at a constant voltage, the impedance is high at low frequencies and low at high frequencies because the sounding body made of piezoelectric bodies is capacitive. The sound pressure characteristic of the sounding body is represented by a curve as shown in FIG. It is assumed that no transformer is connected to the sounding body.
【０００７】そして、圧電体からなる発音体に、トラン
スの漏洩インダクタンスを利用することにより、図５と
図６のグラフが重なると考えられ、図７に示すように、
高域遮断周波数ｆ１，ｆ２より高周波領域はフラットな
音圧特性を示す。[0007] By utilizing the leakage inductance of the transformer with a sounding body made of a piezoelectric body, the graphs of FIG. 5 and FIG. 6 are considered to overlap, and as shown in FIG.
Higher frequency ranges than the high cutoff frequencies f1 and f2 show flat sound pressure characteristics.
【０００８】ここで、従来例に示した圧電スピーカ装置
では、トランスをたとえば、２０Ｈｚあたりの低周波帯
域から使用する場合、磁心の鉄損により低周波帯域の特
性が極端に歪み劣化する。これを改善する手段として、
巻数を大幅に増やすことによりコアの鉄損の影響を小さ
くする手段が考えられる。しかし、この場合、先に述べ
た漏洩インダクタンスが増加する。このように漏洩イン
ダクタンスを増加させた場合、図５を用いて説明したよ
うに高域遮断周波数が低下する。つまり、低い周波数で
周波帯域が遮断されるため、図７の破線曲線で示すよう
に、音の再生時に音圧が低下し、高周波帯域の音の伸び
が無くなってしまう。Here, in the piezoelectric speaker device shown in the conventional example, when the transformer is used from a low frequency band of, for example, about 20 Hz, the characteristics of the low frequency band are extremely deteriorated due to the core loss of the magnetic core. As a means to improve this,
Means for reducing the influence of core iron loss by greatly increasing the number of turns can be considered. However, in this case, the above-described leakage inductance increases. When the leakage inductance is increased in this manner, the high-frequency cutoff frequency decreases as described with reference to FIG. That is, since the frequency band is cut off at a low frequency, as shown by the broken line curve in FIG. 7, the sound pressure decreases during sound reproduction, and the sound in the high frequency band does not elongate.
【０００９】そこで、巻数を増やさずに低周波帯域の音
圧特性を改善するには、トランスに用いる磁心の断面積
を拡大すればよいが、その場合、トランス自体が大型化
してしまう。In order to improve the sound pressure characteristics in the low frequency band without increasing the number of windings, the cross-sectional area of the magnetic core used in the transformer may be increased. However, in that case, the size of the transformer itself increases.
【００１０】また、圧電体の容量を減らすことにより、
高周波帯域の音の伸びを改善することはできるが、その
場合、低周波帯域の音が不足するとともに、圧電体に入
力された信号が音に変換される能率が低下してしまう。Also, by reducing the capacitance of the piezoelectric body,
Although the elongation of the sound in the high frequency band can be improved, the sound in the low frequency band is insufficient, and the efficiency of converting the signal input to the piezoelectric body into the sound is reduced.
【００１１】したがって、本発明の目的は、上述の問題
を解消するためになされたもので、トランスの巻線の巻
数を多くして漏洩インダクタンスを増加させても、１次
巻線と２次巻線の結合度を十分に向上させたトランスが
得られ、このトランスを圧電スピーカに用いることによ
り、圧電体の容量を小さくすることなく、低周波帯域か
ら高周波帯域にかけて、十分な音圧特性が得られる圧電
スピーカ用トランスを提供することにある。SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problem. Even if the number of turns of the transformer winding is increased to increase the leakage inductance, the primary winding and the secondary winding are reduced. A transformer with sufficiently improved wire coupling can be obtained, and by using this transformer for a piezoelectric speaker, sufficient sound pressure characteristics can be obtained from low to high frequencies without reducing the capacitance of the piezoelectric body. To provide a transformer for a piezoelectric speaker.
【００１２】[0012]
【課題を解決するための手段】上記目的を達成するため
に、本発明の圧電スピーカ用トランスは、圧電体からな
る発音体を備える圧電スピーカに用いられ、磁心と１次
巻線と２次巻線とを有し、１次巻線の両端は、発音体を
駆動するための駆動信号を入力する入力端子に接続さ
れ、２次巻線の両端は発音体に接続され、２次巻線は２
分割され、磁心に対して、２次巻線の分割された一方の
２次巻線，１次巻線，２次巻線の分割された他方の２次
巻線，の順に重ねて巻回されてなることを特徴としてい
る。To achieve the above object, a piezoelectric speaker transformer according to the present invention is used for a piezoelectric speaker having a sounding body made of a piezoelectric material, and includes a magnetic core, a primary winding and a secondary winding. And both ends of the primary winding are connected to an input terminal for inputting a drive signal for driving the sounding body, both ends of the secondary winding are connected to the sounding body, and the secondary winding is 2
It is divided and wound around the magnetic core in the order of one divided secondary winding of the secondary winding, the primary winding, and the other divided secondary winding of the secondary winding. It is characterized by becoming.
【００１３】これにより、１次巻線と２次巻線の接触面
積が従来のトランスと比較して倍以上となったため、１
次巻線と２次巻線との結合度も向上する。[0013] As a result, the contact area between the primary winding and the secondary winding is twice as large as that of the conventional transformer.
The degree of coupling between the secondary winding and the secondary winding is also improved.
【００１４】また、この圧電スピーカ用トランスを圧電
スピーカに用いることにより、トランスの巻線の巻数を
増加させて漏洩インダクタンスを増加させても、１次巻
線と２次巻線との間で十分な結合度が得られ、加えて、
圧電スピーカの漏洩インダクタンスが従来より小さいた
め、低周波帯域から高周波帯域にかけて、十分な音圧特
性が得られる。Further, by using the transformer for a piezoelectric speaker as a piezoelectric speaker, even if the number of turns of the transformer is increased and the leakage inductance is increased, a sufficient amount of space is required between the primary winding and the secondary winding. High degree of coupling, and in addition,
Since the leakage inductance of the piezoelectric speaker is smaller than the conventional one, sufficient sound pressure characteristics can be obtained from a low frequency band to a high frequency band.
【００１５】[0015]
【発明の実施の形態】以下、本発明の実施の形態を図面
を参照して詳細に説明する。図１に本発明の実施の形態
に係る圧電スピーカ用トランスを示す。圧電スピーカ用
トランス１０は、Ｅ型の磁心１１を含む。磁心１１の軸
部分には、２次巻線１２の巻数の約半分に分割された巻
数に相当する内２次巻線１２ａが巻回される。そして、
内２次巻線１２ａが巻回された状態の磁心１１の軸部分
に、内２次巻線１２ａの上から１次巻線１３が巻回され
る。さらに、内２次巻線１２ａおよび１次巻線１３が巻
回された状態の磁心１１の軸部分に、１次巻線１３の上
から、２次巻線１２の残り半分の巻数に相当する外２次
巻線１２ｂが巻回される。そして、Ｅ型の磁心１１の開
放部にＩ型のコア１６が設けられて、圧電スピーカ用ト
ランス１０はＥＩコア型のトランスとして構成される。Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a piezoelectric speaker transformer according to an embodiment of the present invention. The piezoelectric speaker transformer 10 includes an E-shaped magnetic core 11. A secondary winding 12 a corresponding to the number of turns divided into about half of the number of turns of the secondary winding 12 is wound around the shaft portion of the magnetic core 11. And
The primary winding 13 is wound around the shaft portion of the magnetic core 11 in a state where the inner secondary winding 12a is wound from above the inner secondary winding 12a. Further, the number of turns corresponding to the remaining half of the number of turns of the secondary winding 12 from the top of the primary winding 13 on the shaft portion of the magnetic core 11 in which the inner secondary winding 12a and the primary winding 13 are wound. The outer secondary winding 12b is wound. An I-shaped core 16 is provided at an open portion of the E-shaped magnetic core 11, and the piezoelectric speaker transformer 10 is configured as an EI core-type transformer.
【００１６】このように、圧電スピーカ用トランス１０
は、１次巻線１３が２次巻線１２によりサンドイッチ状
に挟まれる構造となっており、１次巻線１３と２次巻線
１２の接触面積が、従来の圧電スピーカ用トランスと比
較して大きくなり、よって、１次巻線と２次巻線の結合
度も向上する。As described above, the piezoelectric speaker transformer 10
Has a structure in which the primary winding 13 is sandwiched between the secondary windings 12. The contact area between the primary winding 13 and the secondary winding 12 is smaller than that of a conventional piezoelectric speaker transformer. Therefore, the degree of coupling between the primary winding and the secondary winding is also improved.
【００１７】この圧電スピーカ用トランス１０を圧電ス
ピーカに用いた場合の説明図を図２に示す。圧電スピー
カ２０は圧電体からなる発音体１５を含む。そして、圧
電スピーカ用トランス１０の１次巻線１３は、圧電スピ
ーカ２０の発音体１５を駆動するためのアンプ（図示せ
ず）の入力端子１４に接続されており、２次巻線１２
は、圧電スピーカ２０の発音体１５に接続されている。FIG. 2 is an explanatory diagram when the piezoelectric speaker transformer 10 is used for a piezoelectric speaker. The piezoelectric speaker 20 includes a sounding body 15 made of a piezoelectric body. The primary winding 13 of the piezoelectric speaker transformer 10 is connected to an input terminal 14 of an amplifier (not shown) for driving the sounding body 15 of the piezoelectric speaker 20.
Is connected to the sounding body 15 of the piezoelectric speaker 20.
【００１８】そして、アンプによって増幅された音声信
号が入力端子１４から１次巻線１３に入力されると、１
次巻線１３に磁界が発生し、この磁界により２次巻線１
２に電力が誘起され、この電力による電気信号が発音体
１５に加わり、音声の再生が行われる。図２は、２次巻
線１２が、２分割された状態を模式的に表したものであ
り、図面上では、磁心１１に対して、内２次巻線１２
ａ，１次巻線１３，外２次巻線１２ｂが隣り合って配置
されているが、実際は、図１に示すように、磁心１１
に、内２次巻線１２ａが巻回され、その上に１次巻線１
３が巻回され、さらにその上から外２次巻線１２ｂが巻
回されるものである。そして、圧電体からなる発音体１
５の例としては、特に図面では表さないが、半球殻状や
球殻状の圧電セラミックスからなる振動体を有する発音
体や、板状の圧電セラミックスからなる振動体を有する
発音体などが挙げられるもので、圧電体で構成された発
音体であれば、その形状等は特に限定されるものではな
い。When the audio signal amplified by the amplifier is input from the input terminal 14 to the primary winding 13, 1
A magnetic field is generated in the secondary winding 13 and this magnetic field causes the secondary winding 1
2 is induced in the electric power, and an electric signal by the electric power is applied to the sounding body 15 to reproduce the sound. FIG. 2 schematically illustrates a state in which the secondary winding 12 is divided into two parts.
a, the primary winding 13 and the outer secondary winding 12b are arranged adjacent to each other, but actually, as shown in FIG.
, A secondary winding 12a is wound thereon, and the primary winding 1
3 is wound, and an outer secondary winding 12b is further wound thereon. And a sounding body 1 made of a piezoelectric body
Examples of 5 include a sounding body having a vibrating body made of hemispherical or spherical shell-shaped piezoelectric ceramics, and a sounding body having a vibrating body made of plate-shaped piezoelectric ceramics, which are not particularly shown in the drawings. The shape and the like are not particularly limited as long as the sounding body is made of a piezoelectric body.
【００１９】このサンドイッチ巻構造の圧電スピーカ用
トランス１０を使用している圧電スピーカは、圧電スピ
ーカ用トランス１０の１次巻線と２次巻線との結合度が
大きく、漏洩インダクタンスが従来の圧電スピーカと比
較して小さくなる。これにより、圧電スピーカ用トラン
ス１０を２０Ｈｚあたりの低周波帯域から使用する場合
の磁心１１の鉄損により低周波帯域の音圧特性劣化を改
善する手段として、巻数を大幅に増やすことによりコア
の鉄損の影響を小さくした場合、漏洩インダクタンスが
増加するが、１次巻線と２次巻線の結合度がもともと十
分大きいため、漏洩インダクタンスは従来の圧電スピー
カと比較しても十分に小さい。よって、圧電スピーカ２
０の高域遮断周波数は高い値となり、低音域から高音域
まで幅広い音域を、十分な音圧を持って再生可能とした
スピーカとなる。In the piezoelectric speaker using the piezoelectric speaker transformer 10 having the sandwich winding structure, the degree of coupling between the primary winding and the secondary winding of the piezoelectric speaker transformer 10 is large, and the leakage inductance is smaller than that of the conventional piezoelectric speaker. It is smaller than a speaker. As a means for improving the sound pressure characteristic deterioration in the low frequency band due to the iron loss of the magnetic core 11 when the piezoelectric speaker transformer 10 is used from the low frequency band around 20 Hz, the number of turns is greatly increased to reduce the iron in the core. When the effect of the loss is reduced, the leakage inductance increases. However, since the degree of coupling between the primary winding and the secondary winding is sufficiently large, the leakage inductance is sufficiently small as compared with the conventional piezoelectric speaker. Therefore, the piezoelectric speaker 2
The high cutoff frequency of 0 is a high value, and the speaker is capable of reproducing a wide range of sound from a low range to a high range with sufficient sound pressure.
【００２０】また、当然、発音体１５の圧電体の容量を
減らす必要がないため、低音域の音の低下は生じること
もなく、また、発音体に入力された信号が音に変換され
る能率（レスポンス）が低下することもない。Also, since it is not necessary to reduce the capacity of the piezoelectric body of the sounding body 15, the sound in the low frequency range does not decrease, and the efficiency of converting a signal input to the sounding body into sound is reduced. (Response) does not decrease.
【００２１】なお、上記の実施の形態において、２次巻
線は、巻数を約半分ずつに分割されて巻回されていた
が、特に巻数の分け方に制限されることなく、１次巻線
をサンドイッチ状に挟み込むように２次巻線が分割され
て巻回されるものであれば、２次巻線の巻数の分け方は
半分ずつに限定されるものではない。In the above-described embodiment, the secondary winding is wound with the number of turns divided into about half. However, the secondary winding is not particularly limited to the number of turns and the primary winding is not limited. If the secondary winding is divided and wound so as to sandwich it in a sandwich shape, the method of dividing the number of turns of the secondary winding is not limited to half.
【００２２】また、図３に示すように、圧電スピーカ用
トランスと発音体との周波数特性は、高域遮断周波数を
ｆ０とすると、破線で示すような、高域遮断周波数ｆ０
付近で凸状ピークをもつ曲線や、高域遮断周波数ｆ０の
手前からなだらかな減少傾向を示す曲線となる場合があ
る。これは、漏洩インダクタンスと圧電体の容量の共振
による影響で生じるものであるが、この場合、１次巻線
や２次巻線の線径を変えることにより巻線抵抗を変え
て、実線で示すような理想状態の曲線に近づけることが
できる。As shown in FIG. 3, the frequency characteristics of the piezoelectric speaker transformer and the sounding body are such that when the high-frequency cutoff frequency is f0, the high-frequency cutoff frequency f0
There may be a curve having a convex peak in the vicinity, or a curve showing a gentle decreasing tendency from just before the high-frequency cutoff frequency f0. This is caused by the influence of the resonance between the leakage inductance and the capacitance of the piezoelectric body. In this case, the winding resistance is changed by changing the wire diameter of the primary winding and the secondary winding, and is indicated by a solid line. It can be approximated to a curve in an ideal state.
【００２３】[0023]
【発明の効果】以上のように、本発明による圧電スピー
カ用トランスでは、１次巻線が２次巻線によりサンドイ
ッチ状に挟まれる構造となっており、１次巻線と２次巻
線の接触面積が、従来の圧電スピーカ用トランスと比較
して大きくなり、１次巻線と２次巻線の結合度も向上す
る。また、圧電スピーカ用トランスの巻線の巻数を増加
させて漏洩インダクタンスが増加しても、１次巻線と２
次巻線との間で十分な結合度が得られ、加えて、圧電ス
ピーカの漏洩インダクタンスが従来より小さいため、低
周波帯域から高周波帯域にかけて、十分な音圧特性が得
られる。As described above, the transformer for a piezoelectric speaker according to the present invention has a structure in which the primary winding is sandwiched between the secondary windings. The contact area is larger than that of a conventional piezoelectric speaker transformer, and the degree of coupling between the primary winding and the secondary winding is also improved. Also, even if the number of turns of the winding of the piezoelectric speaker transformer is increased to increase the leakage inductance, the primary winding and the
A sufficient degree of coupling with the next winding is obtained, and in addition, since the leakage inductance of the piezoelectric speaker is smaller than in the past, sufficient sound pressure characteristics are obtained from a low frequency band to a high frequency band.
【図１】本発明の一つの実施の形態に圧電スピーカ用ト
ランスの構造を示す断面図である。FIG. 1 is a sectional view showing a structure of a piezoelectric speaker transformer according to one embodiment of the present invention.
【図２】本発明の一つの実施の形態に係る圧電スピーカ
用トランスを圧電スピーカに用いた場合を示す説明図で
ある。FIG. 2 is an explanatory diagram showing a case where a piezoelectric speaker transformer according to one embodiment of the present invention is used for a piezoelectric speaker.
【図３】本発明に係る圧電スピーカ用トランスと発音体
の周波数特性を示す説明図である。FIG. 3 is an explanatory diagram showing frequency characteristics of a piezoelectric speaker transformer and a sounding body according to the present invention.
【図４】従来の圧電スピーカ用トランスを示す説明図で
ある。FIG. 4 is an explanatory view showing a conventional piezoelectric speaker transformer.
【図５】発音体を接続した圧電スピーカ用トランスの周
波数特性を説明する説明図である。FIG. 5 is an explanatory diagram illustrating frequency characteristics of a piezoelectric speaker transformer to which a sounding body is connected.
【図６】圧電スピーカ用トランスが接続されていない状
態における圧電体からなる発音体の音圧特性を説明する
説明図である。FIG. 6 is an explanatory diagram illustrating sound pressure characteristics of a sounding body made of a piezoelectric body in a state where a transformer for a piezoelectric speaker is not connected.
【図７】圧電体からなる発音体に圧電スピーカ用トラン
スの漏洩インダクタンスを利用した場合の音圧特性を説
明する説明図である。FIG. 7 is an explanatory diagram illustrating sound pressure characteristics when a leakage inductance of a piezoelectric speaker transformer is used for a sounding body made of a piezoelectric body.
１０ 圧電スピーカ用トランス １１ 磁心 １２ ２次巻線 １３ １次巻線 １４ 入力端子 １５ 発音体 ２０ 圧電スピーカ Reference Signs List 10 transformer for piezoelectric speaker 11 core 12 secondary winding 13 primary winding 14 input terminal 15 sounding body 20 piezoelectric speaker
Claims (1)
ーカに用いられる圧電スピーカ用トランスであって、、
磁心と１次巻線と２次巻線とを有し、前記１次巻線の両
端は、前記発音体を駆動するための駆動信号を入力する
入力端子に接続され、前記２次巻線の両端は、前記発音
体に接続され、前記２次巻線は２分割され、前記磁心に
対して、前記２次巻線の分割された一方の２次巻線，前
記１次巻線，前記２次巻線の分割された他方の２次巻
線，の順に重ねて巻回されてなることを特徴とする圧電
スピーカ用トランス。1. A piezoelectric speaker transformer used for a piezoelectric speaker having a sounding body made of a piezoelectric body,
It has a magnetic core, a primary winding, and a secondary winding, and both ends of the primary winding are connected to an input terminal for inputting a drive signal for driving the sounding body. Both ends are connected to the sounding body, the secondary winding is divided into two parts, and one of the divided secondary windings of the secondary winding, the primary winding, and the secondary winding are separated from the magnetic core. A transformer for a piezoelectric speaker, which is wound in such a manner as to be wound in the order of the other secondary winding divided from the next winding.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08133498A JP3309798B2 (en) | 1997-06-03 | 1998-03-27 | Transformer for piezoelectric speaker |
| EP98401302A EP0883326A3 (en) | 1997-06-03 | 1998-05-29 | Transformer for piezoelectric speaker and piezoelectric speaker operative with said transformer |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14528097 | 1997-06-03 | ||
| JP9-145280 | 1997-06-03 | ||
| JP08133498A JP3309798B2 (en) | 1997-06-03 | 1998-03-27 | Transformer for piezoelectric speaker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1155783A JPH1155783A (en) | 1999-02-26 |
| JP3309798B2 true JP3309798B2 (en) | 2002-07-29 |
Family
ID=26422355
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08133498A Expired - Lifetime JP3309798B2 (en) | 1997-06-03 | 1998-03-27 | Transformer for piezoelectric speaker |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0883326A3 (en) |
| JP (1) | JP3309798B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3692897B2 (en) * | 1999-06-18 | 2005-09-07 | 株式会社村田製作所 | Speaker device and speaker system |
| JP5421845B2 (en) * | 2010-04-23 | 2014-02-19 | パナソニック株式会社 | Vehicle theft alarm sound drive circuit |
| CN113840217A (en) * | 2021-07-12 | 2021-12-24 | 天津大学 | Piezoelectric MEMS loudspeaker system |
| WO2023283784A1 (en) * | 2021-07-12 | 2023-01-19 | 天津大学 | Piezoelectric mems loudspeaker system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5799899A (en) * | 1980-12-12 | 1982-06-21 | Sanyo Electric Co Ltd | Electro-acoustic converter |
| US5696477A (en) * | 1994-05-30 | 1997-12-09 | Tabuchi Electric Co., Ltd. | Transformer |
| JPH0864432A (en) * | 1994-08-26 | 1996-03-08 | Matsushita Electric Works Ltd | Electromagnetic device |
-
1998
- 1998-03-27 JP JP08133498A patent/JP3309798B2/en not_active Expired - Lifetime
- 1998-05-29 EP EP98401302A patent/EP0883326A3/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0883326A2 (en) | 1998-12-09 |
| EP0883326A3 (en) | 2005-07-13 |
| JPH1155783A (en) | 1999-02-26 |
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