JPS5821257Y2 - Remote control signal detection circuit for answering machine - Google Patents

Description

[Detailed Description of the Invention] The present invention provides an inexpensive detection circuit for determining the intermittence of a remote control signal without malfunction in an answering machine that allows the recorded messages of a caller to be heard from a remote location. The purpose is to

An embodiment of the present invention will be described below based on the drawings.

A bell signal arriving at the telephone office line 1 is guided to an incoming call control circuit 3 through a terminal 2.

When the bell signal is input, the incoming call control circuit 3 is activated, closes the central office line, and at the same time operates the response message tape section of the magnetic tape running device 4 to send out the reproduced signal to the telephone central office line 1.

When the transmission of the response message is completed, the completion is detected and the business recording tape section of the magnetic tape running device 4 is operated to record the caller's business.

Next, when the caller sends a remote control signal from a remote location, the remote control signal is applied to the amplifier 6 through the incoming call control circuit 3 and the filter 5.

The filter 5 has a steep waveband characteristic and is designed not to pass not only busy tones but also remote control signals other than designated frequencies, so that a third party cannot perform remote control.

The remote control signal amplified by the amplifier 6 passes through a first diode 7 and a resistor 8 to charge a first capacitor 9, and simultaneously passes through the first diode 7 and charges a second capacitor 1.
Charge 0.

The first capacitor 9 reaches a voltage at which the voltage detection circuit 11 operates about 1 second after it starts being charged.

The operation of the voltage detection circuit 11 triggers the control circuit 12, which operates to switch the magnetic tape running device 4 and rewind the recording tape.

When the remote control signal is interrupted, the charge stored in the second capacitor 10 is discharged through the resistor 13, and the charge stored in the second capacitor 10 is discharged through the resistor 13.
Since the charge stored in the capacitor 9 is also discharged through the second diode 14 and the resistor 13, the operation of the voltage detection circuit 11 is stopped, but the control circuit 12 maintains the rewinding operation.

Note that the value of the resistor 13 is selected so that the discharge time constant of the first capacitor 9 and the second capacitor 10 is a fraction of a second.

Subsequently, the remote control signal is sent again, and when it arrives, the control circuit 12 is triggered, performing the same operation as described above.

The second operation of the control circuit 12 causes the magnetic tape running device 4 to operate to reproduce the business recording tape.

By electrically setting the operating order of the control circuit 12, for example, rewinding and reproduction can be performed even with the same signal from the voltage detection circuit 11.

This allows the caller to listen to the content recorded on the business recording tape at a remote location.

When the reproduction of the business recording tape is finished and the signal is received again, the magnetic tape running device 4 is put into a non-operating state by the operation of the control circuit 12 and returned to a standby state.

If you want to remotely listen to the contents of the business recording tape again, you can listen to it again even if you are using the same operations and operations as above.

Here, the reason why the time from the arrival of the remote control signal to the activation of the voltage detection circuit 11 is set to about 1 second by the first capacitor is to prevent malfunction due to noise etc. The reason why the discharge time constant of the capacitor is small is because during remote listening, if you want to rewind a little bit and listen again, the operation of sending and disconnecting the remote control signal is performed continuously. This is to ensure a quick recovery.

Here, since the time constant for charging and discharging the second capacitor 10 is smaller than the time constant for charging and discharging the first capacitor 9, the voltage of the second capacitor 10 rises quickly during charging, and therefore the diode 14 Since the cathode potential of is higher than the anode potential, the diode 14 is non-conducting.

Therefore, the voltage detection circuit 1 by charging the first capacitor 9
1 can be set to about 1 second by changing the value of the resistor 8 as described above.

On the other hand, when the remote control signal is no longer input, the charge in the second capacitor with a small time constant is discharged through the resistor 13, so the potential at the cathode of the diode 14 decreases, and the diode 14 becomes conductive.

Therefore, the charge on the first capacitor 9 is transferred to the diode 14.
, is discharged through the resistor 13.

That is, since a discharge path (diode 14, resistor 13) with a small time constant can be formed by the capacitor 10 with a small time constant, it is possible to cut off the input to the voltage control circuit 11 in a fraction of the discharging time required for charging. This is the result.

As described above, according to the present invention, with an extremely simple circuit configuration, it is possible to determine whether or not a remote control signal from a remote location is interrupted or interrupted by the action of the first capacitor and the second capacitor without malfunction. Sex is big.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. 1...Telephone office line, 3...Incoming call control circuit, 4...Magnetic tape running device, 7, 14...
...Diode, 8.13...Resistance, 9,1
0... Capacitor.

Claims (1)

[Scope of utility model registration request] A call arrives when a bell signal arrives, and after a response message is sent to the caller, the caller's business is recorded, and when a remote control signal arrives, the caller's business is rewound on the recording tape. In an answering machine that can be regenerated after a remote control signal, a series circuit including a first diode for rectifying a remote control signal, a first resistor and a first capacitor connected to the output terminal of the first diode, and a second a capacitor; and the first
The anode was connected to the connection point of the resistor and the first capacitor, and the cathode was connected to the connection point of the first diode and the second capacitor, and the second diode was connected to both ends of the second capacitor. a second resistor;
The discharging time constant of the second capacitor is set smaller than the charging time constant of the capacitor 11, and the value of the second resistor is set so that the discharging time of the second capacitor is equal to the charging time of the first capacitor. A remote control signal detection circuit for an answering machine, wherein the remote control signal detection circuit for an answering machine is configured such that the value is set to a small value so as to be smaller, and the presence or absence of the remote control signal is determined based on the level of voltage across the first capacitor.