JPH0662155A - Telephone device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a telephone device in which circuit constants can be easily determined by a low cost and simple configuration without using a dedicated IC as a communication circuit. [Structure] The call circuit 2 sends a transmission signal and receives a reception signal, the call circuit 2 and the telephone line 1 are connected via a transformer, and power is supplied from a power supply circuit 5 separate from the telephone line 1. Therefore, it is possible to configure the circuit without the restrictions imposed when the power is obtained from the telephone line 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone device connected to a telephone line.

[0002]

2. Description of the Related Art A conventional general telephone device is shown in FIG.
The configuration shown in is known. Hereinafter, description will be made with reference to FIG. The telephone device includes a microphone 38 that converts voice into a voice signal, a call circuit 31 that sends a voice signal to a telephone line and receives a voice signal from the telephone line, and a call circuit 31 that converts voice into a voice signal. Microphone 3 to input to
8 and a handset 32 having a speaker 39 for reproducing and outputting a voice signal from the call circuit 31, and a dial key 3
A dialer circuit 34 for converting the dial input of 3 into a signal,
It has a ringer circuit 36 for turning on the buzzer 35 when receiving a call signal of 16 Hz from a telephone line (exchange), and by connecting this telephone device to a telephone line 37, it is possible to talk with another telephone device. Has become.

The call circuit 31 and the handset 32 have a call function, the key 33 and the dialer circuit 34 have a dial function, and the buzzer 35 and the ringer circuit 36 have a call bell function.

In the telephone device having the above-mentioned configuration, each circuit (call circuit 31, dialer circuit 34, ringer circuit 36, etc.) for functioning as a telephone is directly connected to the telephone line 37, and is connected from the telephone line 37. Although it is configured to be driven by the current supplied from the exchange, the telephone line 3 is usually provided in the telephone circuit 31 which is a circuit that performs a telephone function.
In order to cope with the fluctuation of the supply current from the telephone line 37 which changes depending on the connection state of the speech network 7,
A dedicated IC called C is used, and its characteristics are determined by a resistor or a capacitor.

The constants such as the resistance and the capacitor around the speech network IC are the telephone line 3 together with the conditions for the buzzer 35, the key 33 and the handset 32.
It is determined to some extent by a recommended circuit that serves as an example of a device connected to 7.

[0006]

However, in the call function of the conventional telephone device, the handset 32 is not necessarily required to have the acoustic performance, etc., depending on its design (outer shape), microphone, speaker performance, and the like. Good circuit conditions may not always be obtained with the recommended circuit,
It is necessary to review the circuit constant according to the conditions.

Further, conditions such as a transmission characteristic, a reception characteristic, a side tone (a sound input from a microphone of a receiver goes around a speaker) characteristic, an impedance characteristic required for a call function, and the like are obtained from a telephone line 37. It is not easy to determine the circuit configuration and the circuit constants that satisfy the current fluctuations by using the speech network IC which is a dedicated IC, because the usage conditions are limited to some extent.

Further, the use of a speech network IC, which is a dedicated IC, for the communication circuit 31 is a bottleneck for cost reduction, so it may be possible to replace it with a cheaper general-purpose IC, but fluctuations in supply current, etc. It was difficult to deal with the above, and it was even more difficult to set circuit constants.

The present invention solves the above-mentioned problems, and a speech network I which is a dedicated IC for a speech circuit.
An object of the present invention is to provide a telephone device which can easily determine the circuit constants by using an inexpensive general-purpose IC without using C and by using an analog circuit or the like, and can reduce the cost with a simple configuration.

[0010]

In order to achieve the above object, the present invention comprises a voice converting means connected to a telephone line for converting a voice into a voice signal, and a voice reproducing means for reproducing a voice signal into a voice. In a telephone device provided with a call circuit for transmitting a voice signal to a telephone line and receiving a voice signal from the telephone line, a power supply circuit for supplying power to the call circuit and a circuit between the call circuit and the telephone line And a transformer for separating the electrical coupling.

[0011]

According to the above construction, the speech circuit is supplied with power from the power supply circuit and the transformer electrically separates from the telephone line. The speech signal input from the speech converting means is the speech circuit. The audio signal transmitted from the telephone line to the telephone line via the transformer and received from the telephone line via the transformer and the communication circuit is reproduced as voice by the voice reproducing means.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a telephone device. To the telephone line 1, a call circuit 2 that modulates a voice in the telephone device into a transmission signal and demodulates a reception signal into a voice is connected via a transformer 3. Power is supplied to the call circuit 2 from a power supply circuit 5 on the telephone device side. Further, the call circuit 2 converts voice into a voice signal and then calls the call circuit 2
A handset 4 having a microphone 11 to be input to and a speaker 16 to reproduce and output a voice signal from the communication circuit 2 is connected.

Also, the primary side of the transformer 3, that is, the telephone line 1, is connected to a dialer circuit 6 for converting a key input of the dial key 80 into a signal and a ringer circuit 7 for turning on a buzzer 81 when the signal is received. , Power is supplied from the telephone line 1.

It is possible to connect the dialer circuit 6 and the ringer circuit 7 to the secondary side of the transformer 3, but these do not require particularly complicated circuit constant determination, and even if they are on the primary side, they are The ease of designing does not change so much even on the secondary side, and a separate CPU such as a microcomputer is required to connect to the secondary side, which is not necessarily advantageous in terms of cost, and is therefore not described here.

As the power supply circuit 5 for supplying power to the communication circuit 2, a known circuit for rectifying an AC power supply to obtain a DC power supply may be used.

Next, FIG. 2 shows a concrete circuit example around the communication circuit of FIG. The telephone line 1 is on the primary side of the transformer 3.
The lines L1 and L2 are connected, and the hook switch 10 that is turned on / off by raising and lowering the handset 4 is connected to the line L1 via the relay 20. Further, in the speech circuit 2 connected to the secondary side, the transmission circuit is a transmission amplifier 12 that amplifies the output of the microphone 11.
And an impedance adjusting circuit 13 for giving the output of the transmission amplifier 12 to the secondary side of the transformer 3 and sending it to the line.
Consists of. As the receiving circuit, a microphone signal cancel circuit 14 to which a received signal is input, a reception amplifier 15 that amplifies the output of the microphone signal cancellation circuit 14, and a speaker 16 driven by the output of the reception amplifier 15.
Consists of.

The microphone signal canceling circuit 14 is also provided with the output of a microphone cancel adjusting circuit 17 for correcting the phase of the sending signal that sneak to the receiving circuit side. The sending amplifier 12 and the microphone signal canceling circuit are also provided. 14,
Power supply _Vcc is supplied from the power supply circuit 5 to each circuit such as the reception amplifier 15.

Here, each circuit will be described in detail. The transmission amplifier 12 is composed of a general inverting amplification circuit with a filter, and makes the voice signal from the microphone 11 have a good frequency characteristic and an amplification factor for the line. The operational amplifier 50, the resistors 51, 53, 54 and the capacitors 52, 5
It consists of 5. Like the transmission amplifier 12, the reception amplifier 15 is also a general inverting amplification circuit with a filter, and outputs a voice signal from a line to a speaker 16 which is a receiver with a good frequency characteristic and amplification factor. Operational amplifier 56, resistors 57, 59, 60 and capacitors 58, 61
Consists of.

The impedance adjusting circuit 13 is for satisfying the impedance condition required for a general telephone in accordance with the standards and the like, but the output impedance of the transmitting amplifier 12 is considerably low, and the microphone signal canceling circuit 14 is provided.
Since the input impedance of is extremely high, the impedance condition can be satisfied by setting only the resistance value of the resistor 62 of the impedance adjusting circuit 13. For example, in a telephone line system whose impedance condition is 600Ω, the standard can be almost satisfied only by using a DC resistance of 600Ω for the resistor 62 of the impedance adjusting circuit 13.

The microphone signal cancel circuit 14 is a general differential amplifier circuit, and a point indicated by A in FIG. 2 is provided so that the transmission signal from the microphone 11 does not appear in the speaker 16 which is the receiver at an excessive level. The level of the transmission signal input to the reception amplifier 15 at the next stage by subtracting the transmission signal measured at the point C in FIG. It is for adjustment and includes an operational amplifier 63 and resistors 64, 65, 66, 67. The side tone characteristic is adjusted by this circuit so that the sound signal that circulates from the microphone 11 does not feel uncomfortable in the sense of hearing.

The microphone cancellation adjusting circuit 17 is a transmission signal measured at a point A in FIG. 2 with respect to a transmission signal output from the transmission amplifier 12 measured at a point B in FIG. Is a voltage level that is divided by the resistance 62 of the impedance adjustment circuit 13 and the apparent impedance including the primary side between the point indicated by A in FIG. It is for correcting phase shift and frequency characteristic change.
2 and 69, a signal equivalent to the transmission signal measured at the point A in FIG. 2 is generated at the point C in FIG.

The handset 4 comprises the above-mentioned microphone 11 and speaker 16, and the microphone 11 is supplied with power _Vcc from the power supply circuit 5 through the resistor 71.

The hook switch 10 has a resistor 73.
Power supply _Vcc is supplied from the power supply circuit 5 via the. Further, the hook switch 10 is in an off state when the handset 4 is lowered in the standby state, and is in an on state (conduction state) when the user picks up the handset 4. The relay 20 and the changeover switch 72 are configured to operate in conjunction with the operation of the hook switch 10. Standby, ie handset 4
When the hook switch 10 is turned off and the hook switch 10 is off, the relay 20 is in a state of disconnecting the loop connection of the telephone line 1, and the changeover switch 72 connects the signal input of the receiving amplifier 15 to GND and outputs the sound to the speaker 16. It is in a state so that it cannot be taken out. On the other hand, when the user picks up the handset 4 and the hook switch 10 is turned on, the relay 20 closes the loop of the telephone line 1 and the changeover switch 72 outputs the signal input of the reception amplifier 15 to the output of the microphone signal cancel circuit 14. To allow the generation of audio signals.

In addition, the condenser 74 is the speaker 16
Is arranged between the speaker 16 and the receiving amplifier 15 in order to cut the direct current to the transformer 3, and the capacitor 75 connects the transformer 3 and the impedance adjusting circuit 13 to cut the direct current from the power supply circuit 5 to the transformer 3. It is located in between.

The operation of the telephone device having the above configuration will be described.

In the case of calling from another telephone device,
First, the ringer circuit 7 receives the 16 Hz signal appearing on the telephone line 1.
Is detected and the buzzer 81 is sounded to call the user.

When the user picks up the handset 4, the hook switch 10 is turned on, the relay 20 is driven to close the telephone line 1, and the changeover switch 72 is changed over to cancel the signal input of the reception amplifier 15 by the microphone signal. Connected to the output of circuit 14 to allow amplification of the calling party's voice signal.

Only the AC component of the calling side voice signal is transmitted to the call circuit 2 side by the transformer 3, and the wraparound from the transmission amplifier 15 is adjusted by the microphone signal canceling circuit 14 and the microphone cancel adjusting circuit 17. After that, it passes through the changeover switch 72, is amplified by the reception amplifier 15, and appears on the speaker 16.

The voice signal of the called side (user of the telephone device) is detected by the microphone 11 and amplified by the transmission amplifier 12, and then the impedance adjusting circuit 13 and the transformer 3 are used.
Only the AC component is transmitted to the telephone line 1 via. Then, the voice signal detected by the microphone 11 wraps around to the receiving amplifier 15 similarly to the voice signal from the calling side, but since the level is adjusted by the microphone signal cancel circuit 14, the voice signal does not feel uncomfortable to the listener. Becomes

When the user of this telephone device calls another telephone device, when the user picks up the handset 4, the hook switch 10 is turned on and the relay 20 is turned on.
Is driven to close the telephone line 1, and the changeover switch 7
2 is switched to connect the signal input of the reception amplifier 15 to the output of the microphone signal cancel circuit 14 to allow amplification of the voice signal of the called side. Then, the user presses the dial key 8
When 0 is operated and the dialer circuit 6 sends out a dial pulse or tone signal corresponding to the dial line 6 to the telephone line 1 and the line connection with the other party is completed, the call becomes possible. Since the subsequent steps are the same as the case where the user of the present telephone device is the called side, description thereof will be omitted.

In addition, between the telephone devices according to the present invention,
Even if the line is not capable of supplying power like a public line, the AC component can be transmitted from the microphones via both transformers as long as the line is connected, so it becomes possible to make a call and make a home phone call. Can also be diverted.

[0032]

As described above, according to the present invention, since the communication circuit is driven by the power supply device on the telephone device side, there is no restriction due to the power supply from the telephone line. In other words, in the past, since the power was obtained from the telephone line in which the voltage fluctuation was relatively large, it was difficult to set the circuit configuration and circuit constants of the call circuit in order to operate at a low voltage, for example. Since the device can supply a constant voltage from a power supply circuit separate from the telephone line, there is an effect that the circuit constant can be easily set.

Further, since the power supply of the communication circuit is stable,
Since the call circuit used for this is also stable, it is sufficient to determine the circuit constant of the call circuit in consideration of only the conditions of the handset, and the call circuit can be easily designed without using the dedicated speech network IC. As such, an analog circuit, for example, an inexpensive operational amplifier can be used, and the circuit configuration can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a telephone device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram around a call circuit of the telephone device of the present embodiment.

FIG. 3 is a block diagram of a conventional telephone device.

[Explanation of symbols]

 1 Telephone line 2 Call circuit 3 Transformer 4 Handset 5 Power circuit

Claims (2)

[Claims] 1. A voice conversion means connected to a telephone line for converting a voice into a voice signal, a voice reproducing means for reproducing a voice signal into a voice, and a voice signal sent from the telephone line to the voice line. A telephone device including a call circuit for receiving a call, comprising: a power supply circuit that supplies power to the call circuit; and a transformer that separates electrical connection between the call circuit and the telephone line. Telephone equipment. 2. The telephone device according to claim 1, wherein the communication circuit is composed of general-purpose current amplification means.