JPS59178851A - Telephone set circuit - Google Patents

Abstract

PURPOSE:To prevent the transmission of an unnecessary signal and accompanied ringing by operating a DC voltage detecting circuit of a wire telephone line only as required, and inhibiting the outgoing or incoming operation when a detected DC voltage is a prescribed range. CONSTITUTION:When a master device 100 of a cordless telephone set receives an incoming call from a mobile device (telephone set), a control circuit closes a relay contact 11 and a DC voltage detecting circuit 12 detects a voltage between telephone lines L1 and L2. When a telephone set 5 provided in parallel is busy in this case, contacts 2, 4 are closed and since the L1 and L2 are terminated by a low impedance 3, a DC voltage is low. Further, when the telephone set 5 is not busy but hooks on, since the contact 2 is opened, a DC voltage, 48V applied from an exchange is applied thereto. Thus, when it is discriminated that the voltage between the L1 and L2 is at low level by the detecting circuit 12, the control circuit makes the relay contact 6 open and even if a dial signal comes from the mobile set, no dial impulse is transmitted because of the switching of the relay contact 6.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a wired telephone line (hereinafter referred to as a telephone line).
This field relates to a telephone circuit in equipment that uses two or more telephones installed in parallel; or a telephone line.

[Technical background of the invention]

Conventionally, when an attached telephone, such as a cordless telephone, is installed in parallel with the main telephone, the equivalent circuit configuration has been as shown in FIG.

L, L2 is a wired telephone port? IM (telephone line), 2 indicates the hook switch contact, and 3 indicates the equivalent impedance of the telephone circuit network. In the telephone used for fM, t″L is 50 to 220Ω. 4 is the dial contact point,
The telephone set 5 is configured as a whole.

On the other hand, the parent device 10 of the cordless telephone device installed in parallel has a gamma contact 6 that serves as a hook switch contact and a dial contact, and has an impedance equal to the impedance 3, and also has an impedance equal to the impedance 3, and a capacitor 8 for cutting DC. The ringing signal detection circuit 9 is connected to the telephone line.

It is provided between L2.

[Problems with background technology]

Here, the contact state shown in FIG. 1 indicates that the telephone 5 is in the middle of a call and is in standby for the parent device 10 of the cordless device. In this state, if the cordless telephone device makes a call and performs dial operation 2 without checking the DT (dial tone) tone sent from the exchange, the relay contact 6 opens and closes in response to the dial impulse, so the telephone
! 21 line 1. ．． A large impulsive noise occurred on the telephone, making the telephone 50 calls extremely unpleasant,
In extreme cases (for example, if you are close to a telephone office and the line loss is small), it can hurt your ears.

In addition, as shown in Fig. 1, the constant contact state is 1"!, telephone 5b is off-hook, and the situation is the same as yesterday. When dialing is performed at such a time, dial contact 4 is 10 pps or 1 is 20 pps. Since it opens and closes at such a high speed, the discharge signal detection circuit 9 (circuit for detecting a 16 Hz ringing signal) in the parent device 10 of the cordless telephone device erroneously detects this and performs the ringing operation in the same way as when a call is received. This is called accompaniment to the V-knee crotch, and should be completely prevented.)
It's impossible.

[Purpose of the invention]

The present invention has been made with attention to the above-mentioned circumstances, and when the parallel telephones or 91 devices are on a call or are in the process of communicating, the alarm, call origination (transmission) tr, -'vZ layer. Call (
The purpose of this system is to prevent the sending of unnecessary signals and to prevent accompaniment by prohibiting the operation of ``incoming calls''.

[Summary of the invention]

Therefore, the present invention provides a detection handle for detecting the DC voltage of the wired telephone line, operates this only when necessary, and when the detected DC voltage is within a predetermined range, a call is made (outgoing) or a call is received (incoming). ) The above objective was achieved by restricting the movement of

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings.

FIG. 2 is an equivalent circuit configuration diagram of an embodiment of the present invention,
The same main parts as in FIG. 1 are given the same reference numerals, and their explanations are omitted. When the parent device 100 of the cordless telephone device receives a call from a mobile device (telephone) (not shown), a control circuit (not shown) causes the relay contact 11 to be closed/closed f#f, the voltage calculation circuit 12 to connect the telephone line, . Detect voltage.

At this time, if the parallel telephones 5 are in use, the contact 2.4μ is closed as shown in Fig. 2, and the telephone line is connected to L2.
Since there is a low impedance of 3 in between, the DC voltage is 11 low.Also, if you are on-hook and not on a call, contact 2 is open, so the 48V supplied from the exchange DC voltage is applied.
It is assumed that the input DC impedance of the DC voltage detection circuit 12 is sufficiently thicker than the impedance 3.

Therefore, the direct current voltage detection circuit 12 detects the telephone lines L1 and L2.
1' when the voltage of 1Vj is determined to be low level! This is read by a control circuit (not shown), and this control circuit opens the relay contacts 6 and also controls the relay contacts 6 to open and close so that no dial impulse signal is sent even if a dial signal is received from the mobile device.

In addition, the DC voltage detection circuit 12 is always connected to the
If it is connected to 2, is it inside? When used for fM power supply etc., it is a police engineer, but when used for public telephone line, standby is sometimes @taki impedance 2s O between telephone line L1 and L2.
Since it is necessary to make it MΩ or more, it is better to separate the telephone (b) wires, , and L at the contact point 11.

Further, after the DC voltage is detected, the Schley contact 11 is opened. Further, in FIG. 2, since the bell of the telephone 5 rings when a call is received, the calling signal detection circuit 9F shown in FIG. 1 is not necessarily required in the parent device 10 of the cordless telephone device, so it is omitted.

FIG. 3 is an equivalent circuit configuration diagram of another embodiment of the present invention,
This is an example of application to prevention of accompaniment. In the same figure, the second
The same reference numerals are given to the same main parts as those in the figures, and the explanation thereof will be omitted. When the calling signal detection circuit 9 of the parent device 200 of the cordless telephone device detects a calling signal and outputs a detection output a, the control circuit J3 determines that there is a callout based on this detection output a, and drives the relay circuit 14'& Output signal C to close relay contact 11i. In contrast to this, the DC voltage detection circuit 12 operates. When the control circuit i3t'z determines that the DC voltage is higher than a predetermined value (48V) based on the detection output of this DC voltage detection circuit 12, it determines that there is an incoming call, performs the call incoming operation, and moves. Controls the ringer of the machine to sound. At this time, when the mobile device goes off-hook, the control circuit 134 detects this by reading the on-hook information sent through the wireless line (2), and outputs a signal d that drives the relay circuit 15. The relay contact 6 is closed to establish a talking state.

On the other hand, if a dial impulse is sent out by the dial impulse 5 arranged in parallel, the ejection signal detection circuit 9 may erroneously detect this as a call double number, as described above. (However, since the impulse waveform changes depending on various line conditions, it is not necessarily a false detection and should not be ignored.) If a false detection is detected, the DC voltage is determined to be low in the same way as when a call arrives, and the I! The 2nd circuit 11 call operation is not performed. Therefore, accompaniment can be prevented.

FIG. 4 (shows an example of the "L call signal detection circuit 9").The discharge signal appearing at the telephone line terminal LI/L2 pair is sent to the detection circuit 9 via the bridge rectifier circuit DK via the capacitors C, , C, The signal is rectified by the rectifier circuit, smoothed by a circuit including a capacitor C3Y, and the level after smoothing is determined by the gate circuit 0 to obtain a detection output.

Also, FIG. 5) is a circuit diagram showing the configuration of an embodiment of the DC voltage detection circuit 12. The rectified outputs of the detection circuit 12 and the rectifier circuit 49 are guided to the light emitting diode 32 through the current limiting resistor 31, and the light emitting diode 32 is operated to emit light. The light emitting output of the light emitting diode 320 is received by the phototransistor 33 and converted into a voltage with a gain determined by the resistor 34. This voltage is averaged by the integrating circuit 35, and then introduced into the comparator 36 to output the reference power source 37. Comparing with voltage. Then, only when the average output level of the phototransistor 33 exceeds the reference voltage level, a detection output is generated because it is assumed that there is a possibility that an ejection signal has arrived.

FIG. 6 is a circuit configuration diagram showing another embodiment of the DC voltage detection circuit 12, in which the same parts as in FIG. 5 are designated by the same reference numerals. In the figure, the difference in configuration 2 from FIG. 4 is that a constant voltage element 3 is connected in series to the light emitting diode 32
8 is connected so that the light emitting diode 32 is driven to emit light only when the rectified output of the rectifier circuit 49 is equal to or higher than the level corresponding to discharge deviation monitoring (for example, 48■), and the phototransistor 33 is averaged by an integrating circuit 35, and then outputted as a detection output via an inverter circuit 39.

FIG. 7 is a circuit diagram showing another embodiment of the DC voltage detection circuit 12, and the same parts as in FIG. 6 of MiJ are given the same numbers. The same detection circuit 12 (engineering, constant voltage element 38,
The DC output obtained by the light emitting diode 32 and the phototransistor 33 is converted to, for example, a TTL level by an in/(-ta I!2 circuit 40).

Then, the gate circuit 41 is controlled by this conversion output AS, and the gate circuit 43 is controlled by the conversion output A8 whose logic is inverted by the inverter circuit 42, thereby controlling the passage of the constant clock oscillator 44.
S and C8i are supplied to the first and second counter circuits 45 and 46, respectively. These first and second counter circuits 45 and 46 pass through the respective gate circuits 41 and 43, count the clock signals BS and C, and output an output every time the counted value reaches a predetermined number. The flip-flop circuit 47 is set and reset by each of these outputs, and outputted as the output D8'lt detection output.

With such a configuration, since the conversion output AS of H level is always outputted in the standby state, the first counter circuit 45 repeatedly performs counting operation, and as a result, the flip-flop circuit 47 is reset. Hold on to your sadness
Outputs level detection output.

It should be noted that the above-mentioned embodiment is a description of a cordless telephone device, but any device that can be installed in parallel with a cable can also be applied to cables, wired cables, data communication equipment, etc. For example, in the case of a data transmission device, it can be applied to prevent data transmission while other devices installed in parallel are using the line.

〔Effect of the invention〕

As explained above, depending on the invention, the standby mode seen from the wired telephone line does not lower the DC impedance of the equipment at the time, and is unnecessary when the T-phone equipment installed in parallel is using the line. It is also impossible to send out a loud signal. Also, it is impossible to prevent accompaniment.

[Brief explanation of drawings]

Fig. 1 shows a conventional telephone circuit; Fig. 2 shows a second embodiment of the present invention; Fig. 3 shows another embodiment of the present invention; Fig. 4 shows a conventional telephone circuit. No. detection circuit 90 circuit configuration diagram,
FIGS. 5 to 7 are circuit configuration diagrams of the μ DC tortoise pressure detection leap circuit. Mu

Claims (3)

[Claims] (1) A detection means for detecting the DC voltage between the telephone line terminals, a first connection opening/closing means provided in series with the detection means, and driving and controlling the first connection opening/closing means, and a A control means for prohibiting call origination or call reception when the constant DC voltage detected by the operator is within a specified range? A telephone circuit characterized by comprising: (2) A patent claim characterized in that the control means is provided between the telephone line terminals (has a ring signal detection means, and drives and controls the second connection opening/closing means based on the detection result of the ring signal detection means) A telephone circuit according to item 111. (3) The telephone circuit according to claim 11 or (2), wherein the control means is a telephone line network between the telephone line terminals.