JPH0725650U - Voice amplification circuit for elderly telephone - Google Patents

Abstract

(57) [Summary] [Structure] An audio amplification operational amplifier 2 for amplifying input audio, and an amplification rate changeover switch 3 connected to the (-) input side of the audio amplification operational amplifier for switching the amplification rate of the audio amplification operational amplifier. And the output side of the audio amplification operational amplifier (-)
The high frequency compensating circuit 4 is connected between the input sides, includes capacitors C ₁ and C _2, and reduces the capacitance of the capacitors and includes a normally-closed type frequency characteristic changeover switch 5 that works in conjunction with the amplification factor changeover switch. [Effect] The switching of the amplification factor and the frequency characteristic is interlocked in two stages, and the operability is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice amplifier circuit for an elderly telephone, and more particularly to a voice amplifier circuit for an elderly telephone in which an amplification rate changeover switch and a frequency characteristic changeover switch are interlocked.

[0002]

[Prior art]

The conventional voice amplifier circuit 11 for aged persons is used in an aged telephone EQ ₁₁ in which a cable L ₁₁ to which a local line is connected is connected to a terminal T ₁₁ as shown in FIG. The voice amplification circuit 11 for elderly telephone has a voice amplification operational amplifier 12 and an amplification factor switching switch 13. The (+) input side of the voice amplification operational amplifier 12 is connected to the reference potential point, and the (-) input. side of which is connected to the input terminal 11a of the elderly telephone audio amplifier circuit 11 through a resistor R _7, R ₆ connected in series.

Further, the input terminal 11a is connected to the terminal T ₁₁ of the elderly person's telephone EQ ₁₁ and receives the voice inputted from the office line. Input terminal 11a in series connected resistors R ₆ elderly telephone audio amplifier circuit 11, the amplification factor changing switch 13 of the normally open type between the connection point of the R ₇ are connected, the audio amplifier operational amplifier 12 A resistor R ₈ and a capacitor C ₆ are inserted between the output side and the (−) input side.

The output side of the voice amplification operational amplifier 12 is connected to the speaker 14 via the output terminal 11b of the voice amplification circuit 11 for the elderly telephone. In such an elderly telephone EQ ₁₁ , the amplification factor of the voice amplifying operational amplifier 12 is determined by the resistor R ₈ and the resistors R ₆ and R ₇ , and the cutoff frequency of the voice amplifying operational amplifier 12 is the phase caused by the resistor R ₈ and the capacitor C ₆ . Determined by.

When the amplification factor changeover switch 13 is operated to close the amplification factor changeover switch 13, the resistor R ₆ is short-circuited and the amplification factor of the voice amplification operational amplifier 12 increases. In an actual circuit, a resistor (not shown) on the (+) input side of the audio amplification operational amplifier 12 is inserted between the reference potentials, and a bandpass filter or the like can be configured by adding a capacitor at an appropriate position, and the frequency characteristic of the speaker 14 can be configured. Shows a steep downward slope from point as shown in FIG.

[0006]

[Problems to be solved by the device]

Normally, since the communication member used for the elderly person's telephone EQ ₁₁ is small, it is only necessary that the operation amplifier for voice amplification has an excellent characteristic so that it can be handled easily. Further, it is sufficient to switch the frequency characteristics by about two stages. In general, elderly people who are a little deaf cannot hear the high-frequency component, and if the high-frequency component is extended, the other party's voice becomes easier to hear, and conversely, the high-frequency component is extended to those who have no hearing loss. On the contrary, it is known that there is a phenomenon in which the voice of the other party becomes difficult to hear.

However, there is a drawback that the voice amplification operational amplifier 12 used in the elderly telephone EQ ₁₁ cannot properly meet such a demand.

[0008]

【Purpose】

 The present invention has been made in order to solve the above-mentioned problems, and by switching the amplification factor and the frequency characteristic in two linked stages, the elderly equipped with a voice amplification circuit for the elderly telephone with good operability. The purpose is to provide a person's telephone.

[0009]

[Means for Solving the Problems]

 In order to achieve this object, the voice amplification circuit for the elderly telephone of the present invention is a voice amplification operational amplifier for amplifying the input voice, and the voice amplification operational amplifier connected to the (-) input side of the voice amplification operational amplifier. , Which is a normally-closed type switch that is connected between the output side and (-) input side of the operational amplifier for audio amplification to reduce the capacitance of the capacitor and the capacitor, and that works in conjunction with the amplification factor switch. And a high frequency compensating circuit including a frequency characteristic changeover switch.

[0010]

[Action]

 In this voice amplification circuit for the elderly telephone, the input voice is amplified by the voice amplification opamp. The gain and frequency characteristics are switched by a normally closed type frequency characteristics switch that works in conjunction with the gain switching switch connected to the (-) input side of the audio amplification operational amplifier and the gain switching switch of the high frequency compensation circuit. Switch between 2 steps.

[0011]

【Example】

Hereinafter, a preferred embodiment of a voice amplifier circuit for an elderly telephone according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the voice amplification circuit for the elderly telephone according to the present invention includes a voice amplification operational amplifier 2 for amplifying input voice, and a voice amplification operational amplifier connected to the (−) input side of the voice amplification operational amplifier. The amplification rate changeover switch 3 for changing over the amplification rate is connected between the output side and the (-) input side of the voice amplification operational amplifier to reduce the capacitances of the capacitors C ₁ and C ₂ and the capacitor, and also the amplification rate changeover switch. A high frequency compensating circuit 4 including a normally closed type frequency characteristic changeover switch 5 is provided.

The voice amplification circuit 1 for the elderly telephone is used in the elderly telephone EQ ₁ in which the cable L ₁ to which the office line is connected is connected to the terminal T ₁ as shown in FIG. The voice amplification circuit 1 for elderly telephone has a voice amplification operational amplifier 2, an amplification factor changeover switch 3 and a frequency characteristic changeover switch 5 interlocking with the amplification factor changeover switch 3, and the voice amplification operational amplifier 2 (+) input side is connected to the reference potential point, (-) input being connected to the input terminal 1 a of the elderly telephone audio amplifier circuit 1 via a resistor R _1, R ₂ connected in series.

The input terminal 1a is connected to the terminal T ₁ of the elderly person's telephone EQ ₁ and receives the voice input from the office line. A normally open type amplification factor change-over switch 3 is connected between the input terminal 1a of the voice amplification circuit 1 for the elderly telephone and the connection point of the resistors R ₁ and R ₂ connected in series. and the output side (-) of the resistor R ₃ is inserted between the input side.

The terminal 4 a of the high frequency compensation circuit 4 is connected to the (−) input side of the audio amplification operational amplifier 2, and the terminal 4 b is connected to the output side of the audio amplification operational amplifier 2. Capacitors C ₁ and C ₂ connected in series are inserted between terminals 4a and 4b of the high frequency compensating circuit 4, and a normally closed type frequency characteristic changeover switch 5 is connected to the capacitor C ₁ .

The output side of the voice amplification operational amplifier 2 is connected to the speaker 6 via the output terminal 1b of the voice amplification circuit 1 for elderly telephone. In such an intercom device, when the amplification factor changeover switch 3 is closed, the frequency characteristic changeover switch 5 is opened in conjunction with the amplification factor changeover switch 3. When the amplification factor changeover switch 3 is closed, the resistor ₁ is short-circuited, and the amplification factor becomes high as shown in FIG.

Further, the frequency characteristic is compensated up to a high frequency range as shown by the fact that the normally closed type frequency characteristic changeover switch 5 is opened.

[0017]

【effect】

 As is apparent from the above description, the voice amplification circuit for the elderly telephone according to the present invention has improved operability by the interlocking two-stage switching of the amplification rate and the frequency characteristic.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a voice amplification circuit for an elderly telephone according to the present invention.

FIG. 2 is a characteristic diagram showing the operation of a voice amplification circuit for an elderly telephone according to the present invention.

FIG. 3 is a block diagram of a conventional voice amplification circuit for an elderly telephone.

FIG. 4 is a characteristic diagram showing an operation of a conventional voice amplification circuit for an elderly telephone.

[Explanation of symbols]

2 ・ ・ Op Amp for audio amplification 3 ・ ・ ・ ・ ・ ・ Amplification factor switch 4 ・ ・ ・ ・ High-frequency compensation circuit 5 ・ ・ ・ ・ Frequency characteristic switch C ₁ , C ₂・・ ・ ・ ・ ・ Capacitor

Claims (1)

[Scope of utility model registration request] 1. A voice amplification operational amplifier (2) for amplifying an input voice, and an amplification factor change switch (a) connected to the (-) input side of the voice amplification operational amplifier to switch the amplification factor of the voice amplification operational amplifier ( 3) is connected between the output side of the voice amplification operational amplifier and the (−) input side, reduces the capacitances of the capacitors (C ₁ , C ₂ ) and the capacitor, and works in conjunction with the amplification factor switch. A voice amplification circuit for an elderly telephone, comprising a high frequency compensating circuit (4) including a normally closed type frequency characteristic change-over switch (5).