JPH077540A - Control circuit for device for automatically dealing with automatic answering - Google Patents

Abstract

PURPOSE:To keep insulation high with metal constituting the device and to surely detect the voltage drop of a telephone line by stopping the operation of the device for automatically dealing with automatic answering by detecting the voltage drop of the telephone line with the pickup of a transmitter/receiver while using a photocoupler. CONSTITUTION:Normally, a light emitting diode 11 constituting a photocoupler 12 is turned on corresponding to the DC voltage of a telephone line 1. When the voltage of the telephone line 1 is dropped lower than a prescribed value by using a telephone set 2, the light emitting diode 11 is turned off by a voltage drop detection circuit 10, and a phototransistor 14 is inverted from the conducted state to the non-conducted state. When a signal with the inverting operation is inputted to an operation control circuit 4, the operation of the device for automatically dealing with automatic answering is stopped and changed into a call incoming waiting state by operating a closing circuit 7. Thus, insulation between the telephone line and the exposed metal constituting the device for automatically dealing with automatic answering can be satisfactorily kept, and the voltage drop of the telephone line can be exactly detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an answering machine automatic answering apparatus which is constructed so as to send a response message to a caller after an incoming operation and record the message from the caller on a recording means such as a magnetic tape. Regarding

[0002]

2. Description of the Related Art A telephone line is closed by detecting a call signal coming from a telephone line, and a response message recorded on a magnetic tape or the like is sent to a caller and then a message from the caller is sent. Answering machine automatic answering machines that record on magnetic tape have become popular.

Such an answering machine automatic answering apparatus stops the answering operation of the answering machine automatic answering apparatus when a user answers the calling party by lifting a handset of a telephone while answering a caller. Is configured.

[0004]

The above-described operation, that is, the operation of stopping the answering operation of the automatic answering machine of the answering machine is performed by detecting the voltage drop of the telephone line accompanying the lifting of the handset of the telephone. The circuit that constitutes the automatic answering machine is configured to operate from a power source supplied from a commercial power source, and such a device is provided between a telephone line and an exposed metal, for example, a capstan that constitutes a tape recorder. It is decided to take the insulation of.

In order to detect the voltage drop of the telephone line while observing the insulation standard between the telephone line and the exposed metal, conventionally, the voltage from the telephone line was obtained by obtaining it through a high resistance. There is a problem that the detection operation cannot be performed accurately. The present invention intends to provide a control circuit of an automatic answering machine for an answering machine, which is improved in this respect.

[0006]

The control circuit of the present invention is incorporated in an automatic answering machine for an answering machine and is turned on by a voltage drop detecting circuit which is in an operating state after an incoming call and a power source supplied from a telephone line. It is composed of a light emitting diode whose operation is controlled by the voltage drop detecting circuit, and a phototransistor which constitutes a photocoupler together with the light emitting diode and which is supplied with operating power from a commercial power supply.

[0007]

According to the present invention, the voltage drop of the telephone line is detected by the inversion operation of the light emitting diode which emits light by the power supplied from the telephone line from the lighting state to the non-lighting state.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The circuit shown in FIG. 1 is an embodiment of the control circuit of the present invention. In the figure, reference numeral 1 is a connection terminal for connection with a telephone line, and 2 is a telephone connected to the connection terminal 1. The telephone handset is incorporated and the telephone line is closed by lifting the handset. A hook switch is provided.

Reference numeral 3 is a call signal detection circuit for detecting a call signal coming from the telephone line, and 4 is an operation control circuit for controlling each operation such as answer recording of the answering machine.
It is composed of a microcomputer. Reference numeral 5 denotes a recording / reproducing apparatus such as a tape recorder which performs a response message sending operation and a message recording operation from a caller based on the control operation of the operation control circuit 4.

Reference numeral 6 is a line transformer connecting the recording / reproducing device 5 and a telephone line, and reference numeral 7 is a closing circuit which is brought into an operating state by the control operation of the operation control circuit 4 accompanying the detection operation by the calling signal detection circuit 3. , Has a function of closing the closing switch 8 inserted and connected to the connection line with the telephone line. Reference numeral 9 is a diode bridge circuit that determines the polarity of the voltage supplied from the telephone line when the closing switch 8 is in the closed state, and 10 is a voltage drop that detects a drop in the DC voltage supplied through the diode bridge circuit 9. It is a detection circuit.

Reference numeral 11 denotes a light emitting diode whose operation is controlled by the voltage drop detection circuit 10 and which constitutes a photocoupler 12 , and an anode of which is connected to the diode bridge circuit 9 via a resistor 13. 14
Is a phototransistor that constitutes the photocoupler 12 together with the light emitting diode, the collector is connected to a DC power source obtained from a commercial power source, the emitter is grounded through a resistor 15, and the voltage drop of the operation control circuit 4 It is connected to the detection input terminal 16.

In such a circuit configuration, when the DC voltage of the telephone line is higher than a predetermined voltage, the light emitting diode 11 is in a lighting state, and the use of the telephone 2 causes the DC voltage of the telephone line to drop below the predetermined voltage. Then, the voltage drop detection circuit 10 works so that the light emitting diode 11 is turned off. Then, when the light emitting diode 11 is switched from the lit state to the extinguished state, the phototransistor 14 is inverted from the conducting state to the non-conducting state, but a signal accompanying the inverting operation is input to the voltage drop detection input terminal 16 of the operation control circuit 4. When the input is made, the answering operation by the answering machine automatic answering device is stopped and the operation is switched to the standby state in which the operation for the next incoming call is performed.

The control circuit of the present invention is configured as described above. Next, the operation of such a circuit will be described. When a call signal arrives from the telephone line while the answering machine automatic answering device is in a standby state, the call signal detection circuit 3 performs a detection operation, and the detection signal is input to the operation control circuit 4. As a result, the operation control circuit 4 controls the closing circuit 7 to bring the closing circuit 7 into an operating state, and the closing switch 8 is closed, so that the telephone line is closed.

After such operation is performed, the operation control circuit 4
The control operation of the recording / playback apparatus 5 is started by. When the recording / reproducing device 5 is activated, the response message recorded on the response tape is reproduced by the magnetic head (not shown). Since the response message thus reproduced is sent to the telephone line through the line transformer 6, the caller will hear the message and then speak the message.

The message sent from the caller comes from the telephone line and is input to the recording / reproducing apparatus 5 via the line transformer 6, and as a result, recorded on the recording tape. Then, after a lapse of a predetermined time, the operation of the operation control circuit 4 releases the closing operation of the telephone line,
The automatic answering machine returns to the standby state waiting for the next incoming call.

The answer recording operation of the answering machine automatic answering apparatus is performed in this way. Next, the operation when the handset provided in the telephone 2 is lifted during the answer recording operation will be described. When the answering machine automatic answering device is in the answer recording operation state, the closing switch 8 is closed by the operation of the closing circuit 7 as described above. In such a state, the DC voltage supplied from the telephone line is supplied to the voltage drop detection circuit 10 and the light emitting diode 11 through the diode bridge circuit 9. When the handset of the telephone 2 is not lifted, the cathode of the light emitting diode 11 is grounded because the DC voltage of the telephone line is higher than a predetermined value. Therefore, the light emitting diode 11 is in a lighted state, and the phototransistor 14 irradiated with the light is in a conductive state. Therefore,
An H (high) level signal is input to the voltage drop detection input terminal 16 connected to the emitter of the phototransistor 14.

When in such a state, the user sets the telephone 2
When the handset is lifted, the hook switch provided in the telephone 2 is closed and the telephone circuit incorporated in the telephone 2 is connected to the telephone line. In such a state, the DC voltage of the telephone line drops, but when the voltage value becomes lower than a predetermined value, the voltage drop detection circuit 1
The detection operation by 0 is performed, and the cathode of the light emitting diode 11 is set to the non-grounded state. As a result, the light emitting diode 11 is turned off and the phototransistor 14 is turned off.

When the phototransistor 14 is inverted to the non-conductive state, the input signal of the voltage drop detection input terminal 16 provided in the operation control circuit 4 is inverted to the L (lower) level than the H level. As a result, the operation control circuit 4 can detect that the voltage of the telephone line has dropped due to the use of the telephone. When such a detecting operation is performed, the operation control circuit 4 releases the closing operation of the telephone line, and the automatic answering machine is returned to the standby state waiting for the next incoming call.

As described above, when the user picks up the handset of the telephone 2 while the automatic answering machine is in the answer recording state, the answer recording operation state is released and the waiting state is restored. Then, using the handset of the telephone 2, the user can talk with the caller. Since the power source for turning on the light emitting diode 11 constituting the photocoupler 12 is obtained from the telephone line, and the voltage drop of the telephone line is detected by turning off the light emitting diode 11 when the voltage of the telephone line drops. It is possible to reliably perform the detection operation even when the value drops to a value at which the light emitting diode 11 cannot be turned on or a value at which the voltage drop detection circuit 10 cannot perform the control operation.

[0020]

Since the control circuit of the present invention uses the photocoupler to detect the voltage drop of the telephone line, the insulation characteristic between the telephone line and the exposed metal forming the automatic answering machine for the answering machine is provided. Can be held satisfactorily. Further, according to the present invention, the driving power of the light emitting diode which constitutes the photocoupler is obtained from the telephone line, and when the voltage of the telephone line drops, the light emitting diode is turned off from the lighted state to detect the voltage drop. Therefore, the voltage drop detection operation of the telephone line can be accurately performed.

[Brief description of drawings]

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

[Explanation of symbols]

2 Telephone 3 Call signal detection circuit 4 Operation control circuit 5 Recording / playback device 7 Closing circuit 8 Closing switch 10 Voltage drop detecting circuit 11 Light emitting diode 12 Photo coupler 14 Phototransistor

Claims (1)

[Claims] 1. A call-out operation is performed by detecting a call signal coming from a telephone line, a response message is sent to a caller, and a message from the caller is recorded by a recording means. In the answering machine automatic answering device, a voltage drop detecting circuit incorporated in the answering machine automatic answering device and being in an operating state after receiving a call, and lighting by a power supply supplied from a telephone line and operating by the voltage drop detecting circuit And a phototransistor which constitutes a photocoupler together with the light emitting diode and whose operating power is supplied from a commercial power source. Automatic answering machine for answering machines characterized by detecting voltage drop Control circuit.