JPH0422634Y2

JPH0422634Y2 -

Info

Publication number: JPH0422634Y2
Application number: JP9792485U
Authority: JP
Priority date: 1985-06-26
Filing date: 1985-06-26
Publication date: 1992-05-25
Also published as: JPS625793U

Description

【考案の詳細な説明】［産業上の利用分野］本考案は、BTL（Baranced Transformer
Less）接続のステレオ用電力増幅器のためのヘ
ツドホン回路に関する。[Detailed description of the invention] [Industrial application field] This invention is based on BTL (Balanced Transformer).
Less) connection to a headphone circuit for a stereo power amplifier.

［従来の技術］ BTL（Baranced Transformer Less）接続の
ステレオ用電力増幅器１は、第２図に示すよう
に、左チヤンネルの信号を増幅するためのBTL
接続の第１の電力増幅器１Ｌ、右チヤンネルの信
号を増幅するためのBTL接続の第１の電力増幅
器１Ｒからなる。第１の電力増幅器１Ｌは、第１
のアンプ２ａとこの第１のアンプ２ａと逆相で動
作する第２のアンプ２ｂとからなり、両アンプ２
ａ，２ｂの出力端子３ａ，３ｂ間に負荷（スピー
カー）を接続するようにしたものである。第２の
電力増幅器１Ｒも第１の電力増幅器１Ｌと同様に
構成され、図中、５ａ，５ｂは第３，第４のアン
プ、６ａ，６ｂはその出力端子である。[Prior Art] As shown in Fig. 2, a stereo power amplifier 1 connected to a BTL (Balanced Transformer Less) is a BTL (Balanced Transformer Less) connected stereo power amplifier 1 for amplifying a left channel signal.
It consists of a connected first power amplifier 1L and a BTL connected first power amplifier 1R for amplifying the right channel signal. The first power amplifier 1L is a first power amplifier 1L.
and a second amplifier 2b that operates in opposite phase to the first amplifier 2a.
A load (speaker) is connected between output terminals 3a and 3b of output terminals 3a and 2b. The second power amplifier 1R is also configured in the same manner as the first power amplifier 1L, and in the figure, 5a and 5b are third and fourth amplifiers, and 6a and 6b are their output terminals.

なお、図中、符号４Ｌ，４Ｒは第１の電力増幅
器１Ｌ、第２の電力増幅器１Ｒの入力端子であ
る。 Note that in the figure, symbols 4L and 4R are input terminals of the first power amplifier 1L and the second power amplifier 1R.

このようなBTL接続のステレオ用電力増幅器
１にヘツドホン回路を接続することを考える。 Consider connecting a headphone circuit to such a BTL-connected stereo power amplifier 1.

従来のヘツドホン回路のための３端子ヘツドホ
ンジヤツク７は、第２図に示すように、左チヤン
ネルの第１のヘツドホンユニツト９Ｌの正側入力
端子１０ａに接続される左チヤンネルの正側入力
端子８ａ、右チヤンネルの第２のヘツドホンユニ
ツト９Ｒの正側入力端子１１ａに接続される右チ
ヤンネルの正側入力端子８ｂおよび両ヘツドホン
ユニツト９Ｌ，９Ｒの負側入力端子１０ａ，１１
ｂに接続される負側共通端子８ｃとから構成され
ている。したがつて、このような３端子ヘツドホ
ンジヤツク７を上記のBTL接続のステレオ用電
力増幅器１にそのまま適用した場合、同図一点鎖
線で示されるように、第１の電力増幅器１Ｌの第
２のアンプ２ｂ、第２の電力増幅器１Ｒの第４の
アンプ５ｂそれぞれの出力端子３ｂ，６ｂ同志が
共通に接続されることになる。 As shown in FIG. 2, a three-terminal headphone jack 7 for a conventional headphone circuit has a left channel positive input terminal 8a connected to a positive input terminal 10a of a first left channel headphone unit 9L. , the positive side input terminal 8b of the right channel connected to the positive side input terminal 11a of the second headphone unit 9R of the right channel, and the negative side input terminals 10a, 11 of both headphone units 9L, 9R.
and a negative side common terminal 8c connected to the negative side common terminal 8c. Therefore, if such a three-terminal headphone jack 7 is applied as is to the above-mentioned BTL-connected stereo power amplifier 1, as shown by the dashed line in the figure, the second terminal of the first power amplifier 1L The output terminals 3b and 6b of the amplifier 2b and the fourth amplifier 5b of the second power amplifier 1R are connected in common.

［考案が解決しようとする問題点］上記の構成では、第１の電力増幅器１Ｌの第２
のアンプ２ｂ，第２の電力増幅器１Ｒの第４のア
ンプ５ｂそれぞれの出力端子３ｂ，６ｂ同志が共
通に接続されることになるから、第２，第４のア
ンプ２ｂ，５ｂが破壊される、という問題点があ
る。[Problems to be solved by the invention] In the above configuration, the second power amplifier 1L of the first power amplifier 1L
Since the output terminals 3b and 6b of the amplifier 2b and the fourth amplifier 5b of the second power amplifier 1R are connected in common, the second and fourth amplifiers 2b and 5b are destroyed. There is a problem.

［問題点を解決するための手段］考案者は、以下に述べるような思考過程を経
て、本考案の完成に至つた。[Means for solving the problem] The inventor completed the present invention through the thought process described below.

まず、第３図に示すように、第１，第２の電力
増幅器１Ｌ，１Ｒの片側のアンプ、たとえば、第
１、第３のアンプ２ａ，５ａの出力端子３ａ，６
ａを３端子ヘツドホンジヤツク７の左チヤンネル
の正側入力端子８ａ、右チヤンネルの正側入力端
子８ｂにそれぞれ接続し、これらの正側入力端子
８ａ，８ｂを第１、第２のヘツドホンユニツト９
Ｌ，９Ｒの正側入力端子１０ａ，１１ａにそれぞ
れ接続するとともに、第１，第２のヘツドホンユ
ニツト９Ｌ，９Ｒそれぞれの負側入力端子１０
ｂ，１１ｂを共通に接続して３端子ヘツドホンジ
ヤツク７の負側共通端子８ｃに接続し、シヤーシ
へ接地することを考えた。 First, as shown in FIG.
A is connected to the left channel positive input terminal 8a and the right channel positive input terminal 8b of the three-terminal headphone jack 7, respectively, and these positive input terminals 8a and 8b are connected to the first and second headphone units 9.
It is connected to the positive input terminals 10a and 11a of the first and second headphone units 9L and 9R, respectively, and the negative input terminal 10 of each of the first and second headphone units 9L and 9R.
It was considered to connect terminals b and 11b in common to the negative common terminal 8c of the three-terminal headphone jack 7, and to ground the chassis.

このようなヘツドホン回路は、次のような問題
点がある。 Such a headphone circuit has the following problems.

すなわち、第１、第２の電力増幅器１Ｌ，１Ｒ
の片側のアンプの出力のみを第１、第２のヘツド
ホンユニツト９Ｌ，９Ｒに供給する構成であるの
で、電力利用率が低い。 That is, the first and second power amplifiers 1L, 1R
Since the configuration is such that only the output of one side of the amplifier is supplied to the first and second headphone units 9L and 9R, the power utilization rate is low.

また、ステレオ用電力増幅器１が車載用であつ
て、このステレオ用電力増幅器１から遠く離れた
後部座席などにヘツドホンジヤツクを装備する場
合、第１、第３のアンプ２ａ，５ａの共通に接続
したそれぞれの負側入力端子１０ｂ，１１ｂを３
端子ヘツドホンジヤツク７の負側共通端子８ｃ，
直流阻止用コンデンサを介して車のボデイに接地
することは避けなければならない。これは、アー
ス線といえども信号経路であり、かつ、車特有の
ノイズが存在するからである。そのため、このよ
うな構成では、負側入力端子１０ｂ，１１ｂに接
続したアース線１２（図中、１点鎖線で示す）を
他の信号線とともに車内を引き回してステレオ用
電力増幅器１のシヤーシへ接地しなければならな
い。そこで、本考案は以下のような構成にするこ
とにより、種々の問題点を解決したものである。 In addition, if the stereo power amplifier 1 is installed in a vehicle and a headphone jack is installed in a rear seat or the like far away from the stereo power amplifier 1, the first and third amplifiers 2a and 5a may be connected in common. The negative side input terminals 10b and 11b are connected to 3
Negative common terminal 8c of terminal headphone jack 7,
Grounding to the vehicle body via a DC blocking capacitor must be avoided. This is because even the ground wire is a signal path, and there is noise peculiar to cars. Therefore, in such a configuration, the ground wire 12 (indicated by a dashed line in the figure) connected to the negative side input terminals 10b and 11b is routed around the vehicle together with other signal wires and grounded to the chassis of the stereo power amplifier 1. Must. Therefore, the present invention solves various problems by having the following configuration.

本考案は、第１のアンプ２ａと当該第１のアンプ２ａと逆
相で動作する第２のアンプ２ｂとからなり、両ア
ンプ２ａ，２ｂの出力端子３ａ，６ｂ間に負荷
（スピーカー）を接続するようにしたBTL
（Baranced Transformer Less）接続の第１の
電力増幅器１Ｌと、第３のアンプ５ａと当該第３
のアンプ５ａと逆相で動作する第４のアンプ５ｂ
とからなり、両アンプ５ａ，５ｂの出力端子６
ａ，６ｂ間に負荷（スピーカー）を接続するよう
にしたBTL（Baranced Transformer Less）接
続の第２の電力増幅器１Ｒとから構成されている
ステレオ用電力増幅器において、上記第１のアンプ２ａ，第３のアンプ５ａの出
力端子３ａ，６ａを第１、第２のヘツドホンユニ
ツト９Ｌ，９Ｒの一方の入力端子にそれぞれ接続
し、当該第１、第２のヘツドホンユニツト９Ｌ，
９Ｒの他方の入力端子を共通に接続し、当該接続
点を第１、第２の抵抗１３，１４を介して上記第
２のアンプ２ｂ，第４のアンプ５ｂの出力端子３
ａ，６ｂにそれぞれ接続し、上記第１、第２のヘツドホンユニツト９Ｌ，９
Ｒの公称インピーダンスRLと第１、第２の抵抗
１３，１４の抵抗Ｒ１との間に、 RL＝Ｒ１なる関係をもたせたことを特徴とするものであ
る。 The present invention consists of a first amplifier 2a and a second amplifier 2b that operates in opposite phase to the first amplifier 2a, and a load (speaker) is connected between the output terminals 3a and 6b of both amplifiers 2a and 2b. BTL made to be
(Balanced Transformer Less) connection between the first power amplifier 1L, the third amplifier 5a, and the third power amplifier 1L.
A fourth amplifier 5b that operates in reverse phase with the amplifier 5a of
The output terminals 6 of both amplifiers 5a and 5b
In the stereo power amplifier configured with a second power amplifier 1R of BTL (Balanced Transformer Less) connection in which a load (speaker) is connected between the first amplifier 2a and the third amplifier 6b, The output terminals 3a, 6a of the amplifier 5a are connected to one input terminal of the first and second headphone units 9L, 9R, respectively.
9R are connected in common, and the connection point is connected to the output terminal 3 of the second amplifier 2b and the fourth amplifier 5b via the first and second resistors 13 and 14.
a, 6b, respectively, and the first and second headphone units 9L, 9
It is characterized in that the relationship RL=R1 is established between the nominal impedance RL of R and the resistance R1 of the first and second resistors 13 and 14.

［作用］以上の構成いおいて、第１、第２のヘツドホン
ユニツト９Ｌ，９Ｒの両端の出力電圧Ｅ１，Ｅ２
は、 E1＝EL（R1＋3RL）＋ER（RL−R1）／４（R1＋RL） E2＝EL（RL−R1）＋ER（R1＋3RL）／４（R1＋RL ただし、Ｒ１：第１、第２の抵抗の抵抗値 RL：第１、第２のヘツドホンユニツトの公称
インピーダンス EL：第１、第２のアンプの出力端子間の電圧 ER：第３、第４のアンプの出力端子間の電圧となる。[Function] In the above configuration, the output voltages E1 and E2 at both ends of the first and second headphone units 9L and 9R
E1=EL(R1+3RL)+ER(RL-R1)/4(R1+RL) E2=EL(RL-R1)+ER(R1+3RL)/4(R1+RL Where, R1: Resistance value of the first and second resistor RL : Nominal impedance of the first and second headphone units EL: Voltage between the output terminals of the first and second amplifiers ER: Voltage between the output terminals of the third and fourth amplifiers.

今、ER＝０とおいて、チヤンネルセパレーシ
ヨンを計算すると、Ｓ＝20log｛（Ｒ１＋3RL）／（RL−Ｒ１）｝となる。 Now, assuming ER=0 and calculating the channel separation, S=20log {(R1+3RL)/(RL-R1)}.

ここで、RL＝Ｒ１であるから、Ｓ＝∞ となり、理論的に、セパレーシヨンは無限大とな
る。 Here, since RL=R1, S=∞, and theoretically, the separation becomes infinite.

［実施例］第１図において説明すると。図中、第２図の従
来例および第３図の回路例と同等部分については
同一符号を附し、その説明は省略する。[Example] This will be explained with reference to FIG. In the figures, the same reference numerals are given to the same parts as the conventional example of FIG. 2 and the circuit example of FIG. 3, and the explanation thereof will be omitted.

第１のアンプ２ａ、第３のアンプ５ａの出力端
子３ａ，６ａを３端子ヘツドホンジヤツク７の正
側入力端子８ａ，８ｂを介して第１、第２のヘツ
ドホンユニツト９Ｌ，９Ｒの一方の正側入力端子
１０ａ，１１ａにそれぞれ接続し、当該第１、第
２のヘツドホンユニツト９Ｌ，９Ｒの他方の負側
入力端子１０ｂ，１１ｂを共通に接続し、この両
負側入力端子１０ｂ，１１ｂを３端子ヘツドホン
ジヤツク７の負側共通端子８ｃに接続し、この負
側共通端子８ｃを第１、第２の抵抗１３，１４を
介して上記第２のアンプ２ｂ、第４のアンプ５ｂ
の出力端子３ｂ，６ｂにそれぞれ接続し、上記第１、第２のヘツドホンユニツト９Ｌ，９
Ｒの公称インピーダンスRLと第１、第２，抵抗
１３，１４の抵抗値Ｒ１との間に、 RL＝Ｒ１なる関係をもたせる。 The output terminals 3a and 6a of the first amplifier 2a and the third amplifier 5a are connected to the positive input terminals of one of the first and second headphone units 9L and 9R via the positive input terminals 8a and 8b of the three-terminal headphone jack 7, respectively. side input terminals 10a and 11a, and the other negative side input terminals 10b and 11b of the first and second headphone units 9L and 9R are connected in common, and both negative side input terminals 10b and 11b are The terminal is connected to the negative side common terminal 8c of the headphone jack 7, and this negative side common terminal 8c is connected to the second amplifier 2b and the fourth amplifier 5b via the first and second resistors 13 and 14.
are connected to the output terminals 3b and 6b of the first and second headphone units 9L and 9, respectively.
A relationship such as RL=R1 is established between the nominal impedance RL of R and the resistance values R1 of the first, second, and resistors 13 and 14.

［考案の効果］本考案は、 (イ) チヤンネルセパレーシヨンが著しく向上する
（理論的には無限大）。[Effects of the invention] The invention has the following advantages: (a) Channel separation is significantly improved (theoretically infinite).

(ロ) 第１の電力増幅器、第２の電力増幅器を構成
するすべてのアンプの出力を利用できるので、
電力利用率が向上する。(b) Since the outputs of all the amplifiers that make up the first power amplifier and the second power amplifier can be used,
Electricity utilization rate improves.

の効果がある。There is an effect.

[Brief explanation of the drawing]

第１図は本考案のヘツドホン回路の構成を示す
図、第２図はBTL（Baranced Transformer
Less）接続のステレオ用電力増幅器および従来
のヘツドホン回路の構成を示す図、第３図は本考
案の思考過程において案出されたヘツドホン回路
の構成を示す図である。１……ステレオ用電力増幅器、１Ｌ，１Ｒ……
第１、第２の電力増幅器、２ａ，２ｂ，５ａ，５
ｂ……第１、第２、第３、第４のアンプ、３ａ，
３ｂ，６ａ，６ｂ……第１、第２、第３、第４の
アンプの出力端子、４Ｌ，４Ｒ……第１、第２の
電力増幅器の入力端子、９Ｌ，９Ｒ……ヘツドホ
ンユニツト、１０ａ，１０ｂ，１１ａ，１１ｂ…
…ヘツドホンユニツトの入力端子、１３，１４…
…第１、第２の抵抗。 Figure 1 is a diagram showing the configuration of the headphone circuit of the present invention, and Figure 2 is a diagram showing the configuration of the headphone circuit of the present invention.
FIG. 3 is a diagram showing the configuration of a stereo power amplifier and a conventional headphone circuit connected as shown in FIG. 1... Stereo power amplifier, 1L, 1R...
First and second power amplifiers, 2a, 2b, 5a, 5
b...first, second, third, and fourth amplifiers, 3a,
3b, 6a, 6b...Output terminals of the first, second, third, and fourth amplifiers, 4L, 4R...Input terminals of the first and second power amplifiers, 9L, 9R...Headphone unit, 10a , 10b, 11a, 11b...
...Headphone unit input terminals, 13, 14...
...First and second resistance.

Claims

[Claims for Utility Model Registration] Consisting of a first amplifier 2a and a second amplifier 2b that operates in opposite phase to the first amplifier 2a, a load ( BTL for connecting speakers)
(Balanced Transformer Less) connected first power amplifier 1L, a third amplifier 5a that operates in the same phase as the first amplifier 2a, and a fourth amplifier 5b that operates in opposite phase to the third amplifier 5a. A load (speaker) is connected between the output terminals 6a and 6b of both amplifiers 5a and 5b.
In a stereo power amplifier configured from a second power amplifier 1R connected with a BTL (Balanced Transformer Less), the first amplifier 2
a. Connect the output terminals 3a and 6a of the third amplifier 5a to the positive input terminals 10a and 11a of one of the first and second headphone units 9L and 9R, respectively, and Unit 9L,
The other negative side input terminals 10b and 11b of 9R are connected in common, and the connection point is connected to the first and second resistors 13,
14 to the output terminals 3b and 6b of the second amplifier 2b and the fourth amplifier 5b, respectively, and the first and second headphone units 9L,
A headphone circuit characterized in that the relationship RL=R1 is established between the nominal impedance RL of 9R and the resistance value R1 of the first and second resistors 13 and 14.