JPS6084055A - Automatic answering telephone set - Google Patents

Abstract

PURPOSE:To generate a prescribed sound independently of a volume controller by generating a DC voltage from the oscillation output of an identification sound oscillating circuit, and using the DC voltage as the control voltage of a switching element, allowing the switching element to make the volume controller of a preamplifier ineffective, and injecting an identification sound output to the output side of the switching element. CONSTITUTION:When an identification sound having a waveform as shown in Fig. A is generated from the identification sound generating circuit 6, an electronic switch 3 is opened by a DC high level produced at the output point of a diode 10, i.e., at a control terminal 3b of the electronic switch 3, and the injection level to an output terminal 3c of the electronic switch 3 is kept constant by interrupting the effect of the volume controller 2. That is, a speaker 5 generates a prescribed amplitude of identification sound independently of the position of the volume controller 2. Moreover, the sound quality generated from the speaker reaches a waveform close to the fundamental wave and is improved far remarkably than a rectangular wave.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an answering machine that can generate a beacon sound (generally called a beep tone, etc.) used for control etc., and its purpose is to EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a configuration diagram of the main parts of this embodiment, and FIG. 2 is a waveform diagram of the main parts. In the figure, 1 is a preamplifier, 2 is a volume adjuster, 3 is an electronic switch that takes the output of the volume adjuster 2 as an input and whose opening/closing is controlled by the voltage applied to the control terminal, and 4 is an electronic switch. An audio power amplifier is connected to the output side of 3, and a speaker is connected to 6. These form an audio amplification circuit. 6 is a beacon sound generating circuit whose oscillation waveform is a rectangular wave. This output has high resistance 7, 8. It is connected to the output point 1113c of the electronic switch 3 via a series circuit of a capacitor 9, and on the other hand, it is connected to the control terminal 3b of the electronic switch 30 via a diode 10. Note that the output end of the diode 1o is connected to the connection point of the high resistance A, 8, and is grounded from this point via the capacitor 11. Note that the input impedance of the control terminal 3b of the electronic switch 3 is a high resistance 7,
Suppose it is much higher than 8.

→-P When the rectangular wave as shown in FIG. 2A is generated by the P Tangfutake circuit 6, the capacitor 11 is charged through the diode 10 and discharged through the resistor 7, so that the rectangular wave as shown in FIG. 2B is generated. It becomes a waveform. Next, resistance 8. The DC component is blocked by the capacitor 9, and an AC waveform as shown in FIG. 2C is injected into the input section of the audio power amplifier 40.

Here, the electronic switch 3 opens the input terminal between the volume adjuster 2 and the audio power amplifier 4 when the control terminal 3b is at a high level, and opens the connection between the volume amplifier 2 and the input terminal of the audio power amplifier 4 when the -power control terminal 3b is at a low level. It is possible to short-circuit between the power amplifier 40 input terminal and the power amplifier 40 input terminal. Therefore, when the beacon sound having the waveform shown in FIG. By opening the shimiko switch 3 and cutting off the influence of the volume adjuster 2, the injection level to the output terminal 3C of the electronic switch 3 can be kept constant. The beacon force 5 can generate a beacon sound of a constant volume regardless of the position of the volume adjuster 2.

Furthermore, in this embodiment, the sound quality generated by the speaker with the exact size of a square wave is generally very unpleasant, but compared to this, the sound quality generated by the configuration of this embodiment can be seen from FIG. 2C. The waveform is close to the fundamental wave, and the sound quality is much improved compared to square waves.

As is clear from the above embodiments, according to the present invention, when generating a beacon sound, a DC voltage is generated from the oscillation output of the beacon sound generation circuit, and this DC voltage is used as the control voltage of the switching element. By disabling the volume adjuster of the device amplifier and injecting a beacon output into the output side of this switching element, it is possible to generate a beacon sound at a constant volume regardless of the volume adjuster. be. Furthermore, by using the pulsating portion of the oscillation output as the beacon sound output to be injected, the beacon sound can be of good quality, and a high quality answering machine can be provided.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention, and FIG. 2 is a waveform diagram of the main part. 1...Front audio amplifier, 2...Volume adjuster, 3 Insertion...Electronic switch, 4...Audio power amplifier 1] device, 6. ...sign sound generation circuit, 7,
8...Resistor, 9...Capacitor, 1o
...Diode, 11...Capacitor. Name of agent: Patent attorney Toshio Nakao and 1 other person 1 Figure 2 Figure Q

Claims (1)

[Claims] a beacon sound generation circuit; a rectifier circuit that rectifies the output of the beacon sound generation circuit; an audio amplification circuit to which a pulsating output of the output of the rectification circuit is applied to an input end; a switching element connected to an input end of the circuit, a DC output of the rectifier circuit is connected to a control terminal of the switching element, and the switching element is disconnected when the output of the beacon sound generating circuit is generated. An answering machine characterized in that the voice signal to the voice amplification circuit is cut off and only the pulsating current output is applied.