JPH0476712U - - Google Patents
Info
- Publication number
- JPH0476712U JPH0476712U JP11939390U JP11939390U JPH0476712U JP H0476712 U JPH0476712 U JP H0476712U JP 11939390 U JP11939390 U JP 11939390U JP 11939390 U JP11939390 U JP 11939390U JP H0476712 U JPH0476712 U JP H0476712U
- Authority
- JP
- Japan
- Prior art keywords
- speaker
- fet
- drive circuit
- operational amplifier
- power 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.)
- Pending
Links
- 230000005669 field effect Effects 0.000 claims 1
- 239000003990 capacitor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
Landscapes
- Amplifiers (AREA)
Description
第１図は、本考案の一実施例を示す回路図、第
２図は従来例を示す回路図である。
１，８……コンデンサ、２，３，４，６，１４
……抵抗器、１１……電解コンデンサ、５……Ｆ
ＥＴ、７……演算増幅器、９……低周波電力増幅
器、１０……スイツチ、１２……外部スピーカ、
１３……内部スピーカ。
FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. 1, 8... Capacitor, 2, 3, 4, 6, 14
...Resistor, 11...Electrolytic capacitor, 5...F
ET, 7... operational amplifier, 9... low frequency power amplifier, 10... switch, 12... external speaker,
13...Internal speaker.
Claims (1)
ピーカ駆動回路において、負帰還路に帰還抵抗器
と並列に電界効果トランジスタ（以下ＦＥＴ）と
抵抗器から成る電子スイツチを備えた演算増幅器
と、前記演算増幅器出力を入力としスピーカを駆
動する電力増幅器で構成され、切替スイツチで選
択されたスピーカの印加電圧により、前記ＦＥＴ
の状態を切替え、電力増幅器の入力レベルを制御
することを特徴とするスピーカ駆動回路。 In a speaker drive circuit having a switch for switching a plurality of speakers, an operational amplifier is provided with an electronic switch consisting of a field effect transistor (hereinafter referred to as FET) and a resistor in parallel with a feedback resistor in a negative feedback path, and the output of the operational amplifier is input. It consists of a power amplifier that drives a speaker, and the voltage applied to the speaker selected by the selector switch causes the FET to
A speaker drive circuit characterized in that the state of the speaker is switched and the input level of a power amplifier is controlled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11939390U JPH0476712U (en) | 1990-11-16 | 1990-11-16 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11939390U JPH0476712U (en) | 1990-11-16 | 1990-11-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0476712U true JPH0476712U (en) | 1992-07-03 |
Family
ID=31867353
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11939390U Pending JPH0476712U (en) | 1990-11-16 | 1990-11-16 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0476712U (en) |
-
1990
- 1990-11-16 JP JP11939390U patent/JPH0476712U/ja active Pending
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