JPH04135093U - speaker circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a speaker circuit that improves the low frequency characteristics of a speaker. [Structure] The high frequencies in the detection signal obtained from the detection resistor 10 connected in series to the speaker 9 are cut by the high-cut filter circuit 11 and then input to the input terminal 6 of the main amplifier circuit 5. This is designed to improve the low-frequency characteristics of the system.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention improves the acoustic characteristics of speakers called motional feedback. Related to speaker circuits.

0002

[Conventional technology]

Detects the movement of the speaker's vibration system to improve the speaker's acoustic characteristics. , the detection signal is fed back to the amplifier circuit to control the vibration of the speaker. A speaker circuit called motion feedback has been developed. Is this so? In a speaker circuit, the following is a method for detecting the movement of the speaker's vibration system. , although there are various types, use the bridge circuit disclosed in Utility Model Publication No. 1-29950. Those that did are common.

0003

[Problem that the idea aims to solve]

This is a technology that uses the aforementioned bridge circuit to detect the movement of the speaker's vibration system. has a circuit that amplifies the signal obtained from the bridge circuit, so the circuit configuration is The problem is that it becomes complicated and expensive. This invention improves this point. The purpose of this invention is to provide a speaker circuit with improved performance.

0004

[Means to solve the problem]

The speaker circuit of the present invention has an input terminal into which a signal obtained from a signal source is input. a main amplification circuit which has a main amplifier circuit and a speaker is connected as a load; A detection resistor connected in series to the detector and a detection signal obtained from the detection resistor. It consists of a high-cut filter circuit that cuts high-frequency signals in the ing.

[0005]

[Effect]

This invention uses a detection signal obtained from a detection resistor connected in series to the speaker. is applied to the input terminal of the main amplifier circuit through a high-cut filter circuit. which improves the low-frequency characteristics of the signal emitted from the speaker. It is.

[0006]

【Example】

The illustrated circuit is an embodiment in which the speaker circuit of the present invention is incorporated into a tape recorder. In the figure, 1 is a magnetic head that reproduces signals recorded on a magnetic tape, 2 is a reproduction amplifier circuit to which a reproduction signal reproduced by the magnetic head 1 is input and amplified, and 3 is a reproduction amplifier circuit for amplifying the signal. A variable resistor to which the reproduction signal amplified by the reproduction amplifier circuit 2 is applied and whose level is adjusted; 4 is a buffer amplifier circuit to which the reproduction signal whose level has been adjusted by the variable resistor 3 is input; 5 is the aforementioned buffer amplifier circuit; The main amplifier circuit is equipped with an input terminal 6 to which a reproduced signal, which is the output signal of the buffer amplifier circuit 4, is applied, and a negative feedback terminal 8 which is grounded via a feedback amount setting resistor 7, and which is connected to the output terminal and the ground. A speaker 9 and a detection resistor 10 are connected in series between them. Reference numeral 11 denotes a high-cut filter circuit that cuts a high frequency signal in the detection signal obtained from the detection resistor 10 and applies it to the input terminal 6 of the main amplifier circuit 5. It is configured. The speaker circuit of the present invention is constructed as described above, and the operation of the circuit will now be described.

When a tape recorder is operated for reproduction, the magnetic head 1 comes into contact with the magnetic tape and reproduces signals such as music recorded on the magnetic tape. A reproduction signal reproduced by the magnetic head 1 is input to a reproduction amplifier circuit 2, amplified, and then applied to a variable resistor 3. The reproduction signal applied to the variable resistor 3 is applied to the input terminal 6 of the main amplifier circuit 5 through the buffer amplifier circuit 4 after its level is adjusted. The reproduced signal input to the main amplification circuit 5 is amplified by the main amplification circuit 5 and then applied to the speaker 9 to emit sound. When the speaker 9 emits sound, a signal induced by the voice coil constituting the speaker 9 is derived by the detection resistor 10. The detection signal derived from the connection point A between the speaker 9 and the detection resistor 10 is input to the input terminal 6 of the main amplification circuit 5 after high-frequency signals are cut by a high-cut filter circuit 11 . The detection signal input to the input terminal 6 of the main amplifier circuit 5 has high frequency signals cut off and is in phase with the reproduced signal input to the input terminal 6. Therefore, the reproduced signal outputted to the output terminal of the main amplifier circuit 5 becomes a signal in which the signal level of the low frequency range is increased. Therefore, the low frequency level of the signal emitted from the speaker 9 is increased, and even a small speaker device can obtain good frequency characteristics.

[0008] Although this example describes the case where it is incorporated into a tape recorder, It can also be incorporated into a playback device such as a screen player.

[0009]

[Effect of the idea]

The speaker circuit of this invention uses a detection resistor connected in series with the speaker. The obtained detection signal is passed through a high-cut filter circuit to the input terminal of the main amplifier circuit. Improving the characteristics of the low frequency signal emitted from the speaker by applying As a result, there is no need for an amplifier circuit to amplify the detection signal, and therefore the circuit The path configuration is simplified, and the practical value of the present invention is very high.

[Brief explanation of drawings]

FIG. 1 is an embodiment of a speaker circuit of the present invention.

[Explanation of symbols]

5 Main amplifier circuit 6 Input terminal 9 Speaker 10 Detection resistor 11 High-cut filter circuit

Claims (1)

[Scope of utility model registration request] 1. A main amplifier circuit having an input terminal into which a signal obtained from a signal source is input and to which a speaker is connected as a load, a detection resistor connected in series to the speaker, and the detection resistor. and a high-cut filter circuit that cuts high-frequency signals in the detected signal obtained by the above-mentioned high-cut filter circuit, and the signal passed through the high-cut filter circuit is applied to the input terminal of the main amplifier circuit. speaker circuit.