JPS5868356A - Secretary magneto telephone device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mutual communication device that performs communication between a plurality of terminals connected to a common line.

Conventionally, mutual communication devices generally have one base unit and multiple slave units connected in a one-to-one relationship with the base unit as the center, and only have the selection switching function (i.e. switching function) at the base unit. Ta. For this reason, it was not possible to freely call another child device from any child device without going through the parent interface.

In addition, there are cases where multiple terminals are installed on a common line,
In this case, each terminal is often called by a type of Morse code, which is a combination of long and short ring tones, and when a call is in progress between the terminals, a third party cannot access the call. It did not have a so-called secret function to prevent interruptions or eavesdropping. Although general subscriber telephones have a confidential call function, they do not notify the caller that a third party is waiting for a call in a confidential state.

This invention was made in view of the above circumstances.

Its purpose is to allow multiple terminals connected to a common line to respond to each other's calls, and to have a privacy function.Furthermore, if a third party picks up the handset during a call, the caller can To provide a mutual communication device capable of greatly increasing the utilization of a line by knowing that a person is waiting for a call.

Hereinafter, one embodiment of the present invention will be described with reference to the inner surface.

s1 shows the configuration when using this device. In the same figure, a plurality of terminal devices 1, for example, one master device L and two slave devices 21*2@, are connected to a transmission line 3, which is composed of three conductors.
4.5' is shared. fi machine l and slave machine J'1121
The difference is that the main unit L has the power of the entire device, and the ACloo
DCI 2V is sent out from the commercial power source of V to operate the unit Wlv, whereas the slave unit 2Hml works by receiving power from the parent $1. Therefore, except for the power supply line, the parent Psl is also connected to the slave 2. .

2= has the same configuration. The functions of the three transmission lines 1 to I are as follows. That is, the transmission line 1 supplies power (DC 12V) and transmits a call code signal.

The transmission line 4 transmits speech signals, control signals, and ringing signals, and the transmission line 5 is a ground GND line.

The second factor shows the circuit configuration focusing on the control mechanism of the parent Ill. In the same figure, S is 6, Actoovt
'll style 1. , DC12V'i', and the output voltage of this circuit 6 is applied to the transmission line 1 via a filter 1v. Contact point Sl#'6 of # company transmitting speaker 9, receiving speaker 10, and relay 11
, low frequency amplifier circuit 12 #) This is a transmitting/receiving circuit consisting of a lance T, a transistor Q1, etc. tS is the inversion circuit 14
．． AND circuit 15. Delay circuit 16. Holding circuit 11. This circuit 13 is a calling control circuit consisting of transistors Q+-Q and diode D. When the receiver picks up the handset, it opens its own telephone line, outputs a ringing signal to call the other party's terminal, and also outputs a ringing prevention signal to prevent calls from a third party's terminal. In other words, it applies a control voltage to the telephone line.

18 is a call code transmitter 19, a call button zO...
・A call code transmission circuit consisting of an OR circuit 1821 and a resistor R...

This circuit 18 generates a calling code signal corresponding to the area number of the other party. Reference numeral 22 denotes a ringing tone generation circuit consisting of a ringing tone generator z3 and diodes D, , D, and this circuit 22 generates a ringing tone signal of an audible frequency when making and receiving calls. If the call is in progress, a ring tone signal is generated to indicate that the line is waiting, superimposed on the call tone. 24 is a call code receiver 15 and a holding circuit z
This circuit z4 receives the sent calling code signal l, and if this signal matches its own code, outputs a control signal for opening the telephone line. Reference numeral 11 denotes a speech line control circuit consisting of an analog switch F-28 and an OR circuit I#. , operates to open a call line. Also,,? 17
is diode D.

81m"* is a hook switch that switches the movable contact C to the fixed contact side when the handset is picked up, 37 is a monostable multivibrator, 32 is a filter, 11 is a Noah circuit, and 14 is a telephone line voltage detection circuit consisting of: This is a reception standby switching circuit consisting of transistors Qm-Qh.

Note that the configuration of the child a@ie2g is the same as that of the parent device 1 except that the DC power supply circuit is removed.

Based on the above configuration, the operation of each function will be explained below. (1) First, we will explain the case of making a call.
In the case of a call, when the handset is picked up, the movable contacts C of the hook switches 81 and 81 switch from the fixed contact side to the 1 side, respectively.

As a result, the voltage applied from the DC power supply circuit 6 to the hook switch S1 via the filter 1v is as follows.

It is applied to one input terminal of an AND circuit 16 connected to the call control circuit 13. Here, when the voltage of the transmission line 4 is below the threshold value of the inverting circuit 14 at the front stage of the AND circuit tS, this low level voltage is inverted by the inverting circuit 14 and becomes a high level, and the other side of the AND circuit 15 is applied to the input terminal of Therefore, the output of the AND circuit 15 becomes high level. The output of this AND circuit 15 is delayed by a delay circuit 16 and further held by a holding circuit 17. The output of this holding circuit 11 is sent to a switching circuit of transistors Q and -Qs. -10,000, transistor Q
The lozenge from the contact heat of the hook switch 8s is applied to the emitter of Q, and this voltage is obtained on the collector side of Q by the above switching operation. This voltage is then applied to the diode DI for backflow prevention and the filter sty.
The signal is applied to the transmission line 4 as a calling signal via the signal.

At this point, the inverting circuit 11 detects the voltage, and the inverted output changes the output condition of the AND circuit 16.
Delay first! Since the holding circuit 1r is in operation, the holding state does not change even if the output of the AND circuit 15 changes.

On the other hand, the output voltage of the diode D is further applied to the low frequency amplifier circuit 11 of the transmitting/receiving circuit 8 by the switching circuit of the trough 1F 9-Qs via the diode D.
and is applied to the transistor Qs, thereby putting the transmitting/receiving circuit 8 into an operating state.

In addition, the output voltage of the transistor ( ) suppresses the analog switch 28 via the OR circuit 79g applied to the communication line control circuit 21. That is, the output voltage of the OR circuit 2# is applied to the control terminal of the analog switch IS. When the analog switch z8 becomes conductive, this I
1) The transmitting/receiving circuit 8 is connected to the external transmission line 4.

When transmitting a call from the base unit l, the transmission signal from the transmitting speaker g is amplified by the low frequency amplifier circuit 11, then sent to the hook switch 8 via the transformer TI, and then sent to the hook switch 8 via the analog switch ? It is sent out to the transmission line 4 via the jllV. In this case, the relay 11 linked to the hook switch 81
Contact point 8. and 8. Each movable contact C is a fixed contact a.
Q) signal from the transmitting speaker IO is amplified.

Furthermore, the output voltage of transistor Q is applied to a calling code oscillator 19. in this case.

When the call button 20 corresponding to the slave unit of the person to be called, for example, the slave allj*c, is pressed, these (=corresponding call code signals) are generated and sent to the transmission line 3 via the signal power t filter 1.

Incidentally, since a power source for operating the present device, that is, DCI 2V, is applied in advance to the transmission line 3, the above-mentioned call code signal is superimposed on DC12.

In addition, the call button 20v and the transistor Q,
The output of is directly divided from the OR circuit 21 to the diode D,! The ring generator RAV driver 22 generates a ring signal at an audible frequency. This ringing tone signal is sent to the transmission line 14 via the conductive analog switch 1# and the filter Jzt. Note that the ringing tone signal is transmitted by the hook switch 8. The signal is sent to the transmitting/receiving circuit 8 via Y, and the receiving speaker 10 is thereby sounded. Therefore, it is possible to monitor whether a call is being made from the handset.

(2!1 Next, the case of reception will be explained. When the child II 1 t receives an i call, a voltage of 12 V DC is applied to the transmission line 4 from the base unit l.

This voltage is the voltage of slave unit 2. filter 32 and diode 1)
, 't' are applied to the calling code receiver 2I and the low frequency amplifier circuit 12 for transmitting/receiving by a switching circuit 14 consisting of the telephone number 1 and number 9 -Qm. Subsequently, a calling code signal is transmitted from the transmission line 1 and a ringing tone signal is transmitted from the transmission line 4, respectively. If the calling codes match, an output is obtained from the calling code receiver 15. The output of this receiver 25 holds the holding circuit 26, and the output of this holding circuit 1g is the OR circuit 29v.
The analog switch JJIv is controlled via the analog switch JJIv. As a result, the transmitting/receiving circuit 8 of the slave I111m and the transmission line 4 are electrically connected, and the ringing tone is amplified.

That is, if the handset is left in place, the Fog Switch f8t・8. is pressed, and its movable contact C
are fixed contacts b@l: present, and contact 8. of relay 11 activated by SI. ．． The 8° movable contact C is also on the b side.

Therefore, the ringing signal from the transmission line 4 is.

The signal is sent to the transmitter/receiver circuit 8 via the analog signal input 9281 and amplified by the low frequency amplification circuit 12, whereby a ring tone is generated from the transmitter speaker 9.

Next, handset 2. When the handset is picked up, the movable contacts C of the hook switches 8s * s@ are switched to the fixed contact port side, and accordingly the movable contacts C of the contacts S, , S, of the relay 11 are also switched to the 1 side, respectively. You can make a call using the .

When the call ends, hang up the handset and switch the hook switch 8. ．． 8. switches again from the 1st side of the fixed contact to the 1st side, and at this point a single pulse generated by the monostable multivibrator SL provided on the 1st side of the fixed contact 81 is applied to the holding circuit IF.

Therefore, the analog switch ZX returns to the non-conducting state again.

(3) Next, we will explain the case where one line is in a busy state and the third line picks up the number of SVs for transmission and reception.

When the line is busy, a voltage of DC 12V is applied to the transmission line 4, and when a third party picks up the handset V, the hook switch 8. The movable contact C of , S switches from the b side of the fixed contact to the 1 side, but since it is in the AND circuit 15 and the input of the inverting circuit 14 in the previous stage is higher than the threshold value,
The output of the inverting circuit 14 becomes zero, and the output of the AND circuit is also becomes zero. Therefore, as a result, the collector voltage that is the output of the transistor Ql becomes zero, and the analog switch f28
f cannot be made conductive.

Furthermore, since the transistor Qt is off, the power to the calling code transmitter 19 is also turned off, making it impossible to make a call.

In this case, since the output of the inverting circuit 14, the output of the transistor Qt, and the output of the holding circuit j6 are all zero, an output is obtained from the NOR circuit SS having these three outputs as inputs. The output of this NOR circuit 1j is the diode Dst
Through the ring tone generator 21'' Ik: Drive T. Therefore, a third party can hear the dial tone with his own handset and confirm that the line is busy. The transmission line 4 is connected to the transmission line 4 via an attenuator ATT and a filter Mlv.
is sent, thereby informing the already called party that a third party is waiting for the call.

As described above, according to the present invention, it is possible to answer calls between terminals, and it has a secret function, and furthermore, if a third party picks up the call during a call, the busy sound is superimposed on the call sound. , the caller can know that a third party is waiting for a call, and the utilization of one line is greatly improved.

[Brief explanation of the drawing]

W! Figure I1 is an overall configuration diagram of an intercommunication device according to an embodiment of the present invention. Figure J2 is a circuit configuration diagram of a terminal device that is left behind in the above communication device. l...Main unit, 16m2g...Slave unit, 1 to 5...Transmission line, 6...DC power supply circuit, 8...Talking/receiving circuit.

Claims (1)

[Claims] In an intercommunication device that performs communication between a plurality of terminal devices connected to a common line, the terminal device has a transmitting/receiving circuit, and when making a call, opens its own communication line and makes a call to the terminal device of the other party. Call signal to hang! a call control circuit that outputs a call prevention signal to prevent calls from a third party's terminal; a call code generation circuit that generates a call code signal corresponding to the area number of the other party; a ringing tone generating circuit which generates a ringing tone signal and also generates a ringing tone signal indicating that the line is waiting by superimposing it on the communication line when the communication line between other terminal devices is in use; Control 1 for receiving a calling code signal sent from a terminal and opening a call line if this signal matches its own code (a calling code receiving circuit that outputs an M number, and the above-mentioned calling control circuit) and a call line control circuit that opens a call line in response to a call signal output from the call code receiving circuit or a control signal output from the call code receiving circuit.