JPS61134905A - Bias oscillating device - Google Patents

Bias oscillating device

Info

Publication number
JPS61134905A
JPS61134905A JP25801684A JP25801684A JPS61134905A JP S61134905 A JPS61134905 A JP S61134905A JP 25801684 A JP25801684 A JP 25801684A JP 25801684 A JP25801684 A JP 25801684A JP S61134905 A JPS61134905 A JP S61134905A
Authority
JP
Japan
Prior art keywords
recording
capacitor
bias
base
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.)
Pending
Application number
JP25801684A
Other languages
Japanese (ja)
Inventor
Toshihiko Hatanaka
俊彦 畑中
Noriyuki Sakamoto
坂本　徳行
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP25801684A priority Critical patent/JPS61134905A/en
Publication of JPS61134905A publication Critical patent/JPS61134905A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G11B5/027—Analogue recording
    • G11B5/03—Biasing

Landscapes

  • Digital Magnetic Recording (AREA)

Abstract

PURPOSE:To prevent foreign sounds for sound recording stop from being sound recorded with an erasing head by grounding the power supply-side end of a resistance, which is used to impress power to the base of a bias oscillating transistor (TR), through a capacitor. CONSTITUTION:A capacitor 10 is added between the earth and the connection point between a recording/reproducing switch 11 and a resistance 9. The supply point of the base voltage of a TR7 is earthed by the capacitor 10 in this manner. Thus, bias oscillation is not immediately stopped when the recording/ reproducing switch 11 is switched to a contact (a), namely, the reproducing state, and the magnetic field of an erasing head 2 is set to zero.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、１つのトランジスタのベースに抵抗を介して
電源を印加することにより動作するように構成したテー
プレコーダのバイアス発振装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tape recorder bias oscillation device configured to operate by applying power to the base of one transistor through a resistor.

従来の技術 従来、テープレコーダのバイアス発振装置は、消去方式
としてのＡＣ消去方式がコスト的に高くなるため、トラ
ンジスタをグツシュプル構成にせず、１石式で構成して
いる。BACKGROUND OF THE INVENTION Conventionally, bias oscillation devices for tape recorders have been constructed with a single transistor instead of using a goose-pull transistor structure, since the AC erasing method increases the cost.

第２図に従来のテープレコーダのバイアス発振装置を示
す。第２図において、録音する場合、録再スイッチ１１
．１６，１７，１８は全てｂ側の状態で、録音入力端子
２ｏから信号が録再ヘッド１に加えられ、そして録音バ
イアスは録再スイッチ１８を介して加えられる。バイア
ス発振袋＃２１は電源端子１２に電圧が印加され、発振
トランス４を介してトランジスタ７に印加される。そし
て、抵抗１３と録再スイッチ１１、抵抗９を介してトラ
ンジスタアにベース電圧が印加され、発振トランス４よ
りトランジスタ７に正帰還がかかり、発振動作をする。FIG. 2 shows a conventional tape recorder bias oscillation device. In Figure 2, when recording, the recording/playback switch 11
．． 16, 17, and 18 are all in the b-side state, a signal is applied to the recording/reproducing head 1 from the recording input terminal 2o, and a recording bias is applied via the recording/reproducing switch 18. A voltage is applied to the power supply terminal 12 of the bias oscillation bag #21, and is applied to the transistor 7 via the oscillation transformer 4. Then, a base voltage is applied to the transistor A via the resistor 13, the recording/reproducing switch 11, and the resistor 9, and positive feedback is applied to the transistor 7 from the oscillation transformer 4, causing an oscillation operation.

発振トランス４の２次側にコンデンサ３と２次側タップ
に消去ヘッド２を接続し、録再スイッチ１８を介して録
再ヘッド１に接続されている。抵抗１４とサーミスタ１
５は温度保証のために抵抗１３と抵抗９の電源側端子と
アースの間に接続している。A capacitor 3 is connected to the secondary side of the oscillation transformer 4, and an erasing head 2 is connected to the secondary side tap, and is connected to the recording/reproducing head 1 via a recording/reproducing switch 18. Resistor 14 and thermistor 1
5 is connected between the power supply side terminals of resistor 13 and resistor 9 and the ground to ensure temperature.

発明が解決しようとする問題点 ところで、従来の構成では、録再スイッチ１１゜１６．
１７，１８の切換えＫよる録音ストップ時にバイアス発
振が急激に止まるため、消去ヘッド２の磁界が零になら
ず、テープに異音が録音されてしまうという問題があっ
た。Problems to be Solved by the Invention By the way, in the conventional configuration, the recording/reproducing switches 11°, 16.
Since the bias oscillation suddenly stops when recording is stopped by switching K of 17 and 18, the magnetic field of the erasing head 2 does not become zero, causing a problem that abnormal noise is recorded on the tape.

本発明は上記従来の問題を解消するもので、録音ストッ
プ時の異音が録音されることのないバイアス発振装置を
提供することを目的とする。The present invention solves the above-mentioned conventional problems, and aims to provide a bias oscillation device that does not record abnormal sounds when recording is stopped.

問題点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バイアス発振装置は
、トランジスタのベースに電源を印加するための抵抗の
電源側端子をコンデンサを介して接地するように構成し
たことを特長とするものである。Means for Solving the Problems In order to achieve the above object, the bias oscillation device of the present invention is configured such that the power supply side terminal of the resistor for applying power to the base of the transistor is grounded via a capacitor. It is characterized by:

作用 本発明は上記の構成によって、録再スイッチの切換え時
点での録音ストップ時のバイアス発振が停止するまでの
時間を長くすることができ、もって消去ヘッドの磁界を
零とすることができる。このため、録再スイッチの切換
時点で異音が消去ヘッドにより録音されることのない利
点を有するものである。According to the above-described structure, the present invention can lengthen the time until the bias oscillation stops when recording is stopped at the time of switching the recording/reproducing switch, thereby making it possible to reduce the magnetic field of the erasing head to zero. Therefore, there is an advantage that no abnormal sound is recorded by the erasing head at the time of switching the recording/reproducing switch.

実施例 第１図は本＝Ｗの一実施例におけるテープレコーダのバ
イアス発振装置の回路図である。第２図において、第１
図と異なるところは録再スイッチ１１と抵抗９の接続点
とアース間にコンデンサ１゜を追加して構成したことで
ある。このようにトランジスタ７のベース電圧の供給点
をコンデンサ１０にてアースすることにより、録再スイ
ッチ１１が再生であるａ状態に切換わった時にバイアス
発振がすぐに停止しなくなり、消去ヘッド２の磁界を零
とすることができる。Embodiment FIG. 1 is a circuit diagram of a bias oscillation device for a tape recorder in one embodiment of the present invention. In Figure 2, the first
The difference from the diagram is that a 1° capacitor is added between the connection point between the recording/reproducing switch 11 and the resistor 9 and the ground. In this way, by grounding the supply point of the base voltage of the transistor 7 with the capacitor 10, the bias oscillation does not stop immediately when the recording/reproducing switch 11 is switched to state a for reproduction, and the magnetic field of the erasing head 2 is reduced. can be set to zero.

発明の効果 以上のように本発明によれば、バイアス発振用のトラン
ジスタのベースに電源を印加するための抵抗の電源側端
をコンデンサを介して接地することにより、録音ストッ
プ時の異音が消去ヘッドで録音されるのを防止し、テー
プレコーダの性能の向上を計ることができ、実用上きわ
めて有利である。Effects of the Invention As described above, according to the present invention, by grounding the power supply side end of the resistor for applying power to the base of the transistor for bias oscillation via a capacitor, abnormal noise when recording is stopped can be eliminated. It is possible to prevent recording by the head and improve the performance of the tape recorder, which is extremely advantageous in practice.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例におけるバイアス発振装置の
回路図、第２図は従来のバイアス発振装置の回路図であ
る。 １・・・・・・録再ヘッド、２・・・・・・消去ヘッド
、３・・・・・・コンデンサ、４・・・・・・発振トラ
ンス、５・・・・・・電源用コンデンサ、８・・・・・
・直流カット用コンデンサ、７・・・・・・発掘用トラ
ンス、８・・・・・・エミッタ抵抗、９・・・・・・ベ
ースバイアス用抵抗、１ｏ・・・・−・バイアス停止遅
延用コンデンサ、１１，１６，１７，１８・旧・・録再
スイッチ、１２・・・・・・電源端子、１３・・・・・
・ベースバイアス用抵抗、１４・・・・・・温度保証用
抵抗、１６・・・・・・サーミスタ、１９・・・・・・
ヘッド出力端子、２゜・・・・・・録音入力端子。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名３・
・・　コンデ゛ンサ ｌθ・　コンデンサ １２・・；を源搗子 ｆ 第２図FIG. 1 is a circuit diagram of a bias oscillation device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional bias oscillation device. 1...Recording/playback head, 2...Erasing head, 3...Capacitor, 4...Oscillation transformer, 5...Power supply capacitor , 8...
・DC cut capacitor, 7: Excavation transformer, 8: Emitter resistor, 9: Base bias resistor, 1o: Bias stop delay Capacitor, 11, 16, 17, 18・Old・・Record/play switch, 12・・・Power terminal, 13・・・・
・Base bias resistor, 14... Temperature guarantee resistor, 16... Thermistor, 19...
Head output terminal, 2゜... Recording input terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person3.
...Capacitor lθ・Capacitor 12...; Source f Figure 2

Claims (1)

【特許請求の範囲】[Claims] 発振トランスの２次側に録音再生ヘッドと消去ヘッドを
接続し、かつ１次側にトランジスタのベースとコレクタ
を接続し、上記トランジスタのベースに抵抗を介して電
源を印加するように構成すると共に、上記トランジスタ
のベースに電源を印加するための上記抵抗の電源側端子
をコンデンサを介して接地したことを特徴とするバイア
ス発振装置。A recording/reproducing head and an erasing head are connected to the secondary side of the oscillation transformer, a base and a collector of a transistor are connected to the primary side, and a power source is applied to the base of the transistor via a resistor. A bias oscillation device characterized in that a power supply side terminal of the resistor for applying power to the base of the transistor is grounded via a capacitor.
JP25801684A 1984-12-06 1984-12-06 Bias oscillating device Pending JPS61134905A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25801684A JPS61134905A (en) 1984-12-06 1984-12-06 Bias oscillating device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25801684A JPS61134905A (en) 1984-12-06 1984-12-06 Bias oscillating device

Publications (1)

Publication Number Publication Date
JPS61134905A true JPS61134905A (en) 1986-06-23

Family

ID=17314355

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25801684A Pending JPS61134905A (en) 1984-12-06 1984-12-06 Bias oscillating device

Country Status (1)

Country Link
JP (1) JPS61134905A (en)

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