JPS6019880B2 - Doorphone control circuit in button telephone device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device in which the number of wires of a connection cord is reduced in a button telephone device for branch-connecting handsets.

Conventionally, in this type of equipment, the central telephone line, internal telephone line, various control lines, power supply lines, etc. are connected independently.
Taking a button telephone device for two central office lines as an example, the number of fibers in the connection cord between the main unit and the slave unit is 2x2 for central line calls, 2x2 for central line control, At least 13 core wires are required: 2 for extension calls, 1 for extension control, and 2 for power supply, and several additional individual call lines for extensions are required, making the connection cord thicker. Another drawback is that the connector is also large.

In order to overcome these drawbacks, button telephone devices with a reduced number of core wires have been proposed, but ``because they serve both the central office line and extension line, The disadvantage is that it cannot be done.

The present invention provides a branch connection type button telephone device in which the connection cord for the n office line is constructed with 12 core wires, so that telephone calls between the central office line and internal telephone calls can be made with a minimum number of core wires. The present invention provides a door intercom control circuit in a key telephone device that can be operated independently.

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

Note that although the embodiment presented here is a button telephone device for two central office lines, embodiments with a different number of central office lines can be easily configured by adding or subtracting the central office line circuit and two essential lines. be.

In the embodiment shown in FIG. 1, 1 is the main device, 2 and 2' are station line circuits, 3 is an arrival detection circuit, 4 is a ring tone generation circuit, 5 is a hold detection circuit, 6 is a multipipeter, and 7 is a High frequency control signal generation circuit, 8 is a monitoring circuit, 9 is a counting circuit, 10 is an individual selection signal tone generation circuit, 11 is a timer circuit, L1,
L2, LI', L2' are central lines, A, R, day, K, K',
×, Y, are relays, al, a2, a3 are contacts of relay A, rl, r2, r3 are contacts of relay R, r2', r3'
are contacts of relay R' (not shown), hl, h2, h3 are contacts of relay day, h3' is contact of relay H' (not shown), kl is contact of relay K, xl, x2 are relay contacts. × contact point, yl is relay Y contact point, B1, B2 are batteries,
10E1, 10E2, 1E1, 1E2 are power supplies for power supplying the handset, TI is a transformer, Trl to Tr6 are transistors, D1 and D2 are diodes, RI to R5 are resistors, CH is a choke coil, C0, CI to C3 are capacitors. Further, 20 is a handset, 21 is a communication circuit, 22 is an amplifier control circuit, 23 is a calling amplifier circuit, 24 is a confidential communication circuit, 25
26 is an extension individual call receiving circuit, 26 is a signal selection circuit, and LKI-
1 to LKI-3, LK2-1 to LK2-3 are the contacts of the office line button, HK1 and HK2 are the contacts of the hold button, SoK is the contact of the interlocking electric key, HS1 and HS2 are the contacts of the hook switch, Ds and Dj are the contacts of the hook switch. Dial contact, AP, PV are relays, a
tl, at2 are contacts of relay AP, tvl, tv2 are contacts of relay PV, SWI is station stopping switch, SW2
is an extension call stop switch, RECT is a double wave rectifier, T2
, T20 is a transformer, AMP is an amplifier, SP is a speaker power, Tr2 0 to Tr2 3 are transistors, S20, S
2 1 is a thyristor, LD1 and LD2 are light emitting diodes, ZD20 and ZD21 are Schenner diodes, D20~
D26 is a diode, R20 to R27 are resistors, C20,
C21 and C22 are capacitors. Further, 30 is another handset connected in parallel with the handset 20, 41 and 41' are central telephone communication lines, and 42-1 and 42-2 are extension telephone lines that also serve as power supply to the handset. . Next, the operation of the circuit of this device will be explained.

(Call) When making a call to a local line, when the handset (not shown) of the handset 20 is raised, contact HSI of the hook switch closes, and when the local line button is further pressed, contact LKI-1 of the local line button closes. , LKI
-2 is switched, the loop of the office line communication line 41 with the main device 1 is closed through the communication circuit 21, and communication current is supplied from the battery BI in the main device 1 to the handset 20.

A relay A is inserted into this loop, and the communication current operates the relay A, and the storm line is captured by the contact point al. At the same time, a current is supplied from battery B2 between the neutral point of the office line communication line 41 and the extension line 42-2 through the contact a2, and this current is passed through the handset 2 to the neutral point of the office line communication line 41 and the extension line 42-2. The current flows through the resistor R20 connected between the extension line 42-2 and the light emitting diode LDI, and the light emitting diode LDI as an indicator lamp lights up, indicating that the central office line is in use on all connected slave units. The following actions are performed. (Answering an incoming call) T Next, we will explain the operation when receiving a call from a central office line.

When a calling signal from the station arrives on the station lines L1 and L2, the signal is guided to the station arrival detection circuit 3, which activates the relay R. The ringing signal is normally sent in an intermittent cycle of 1 second with no signal and 2 seconds with no signal, and while relay R is receiving the ringing signal, it performs the same intermittent operation of 1 second on and 2 seconds off, and the contact rl, current is intermittently supplied from the battery B2 to the neutral point of the office line communication line 41, and the light emitting diode LDI of the handset 20 blinks in synchronization with the ringing signal, making it visible that the incoming call is on the office line. Display is performed. on the other hand,
Between extensions 42-1 and 42-2, in the handset 20, the amplifier control circuit 22, the double-wave rectifier circuit RECT, the hook switch contact HS2, and the relay AP contact atl are connected.
The calling amplifier 0 circuit 23 is connected through the circuit, and the amplifier control circuit 22 is connected to the diode ○22 that conducts current when the extension telephone line 42 has positive polarity → Zener diode aD20 → relay AP → diode D23 → station stopping switch SWI] route and [extension line 42-2
It is composed of a route of extension call stop switch SW2, which conducts current when the polarity is positive, → diode D24, relay AP, Zener diode ZD21, and diode D25. In the standby state, a voltage of 10 EI is applied between the extension communication line 42-1 and the extension communication line 42-20, and EI>Relay AP voltage>EI - voltage V2. Sha......The IJ Ray AP is not operating because it is set to a voltage value that satisfies the relationship {1}. While the relay R is on due to the call signal from the central office line, the transistor T is connected by the contact r2.
1 is turned on to operate relay x, and the voltage of extension line 42-1 is switched from 1EI to 1B2 by contact xl, and the voltage value of +E2 is E2-Tune voltage V2.

Fox > Relay AP’s impressive voltage
. . . . . . ■ As a result, each connected slave device relay AP operates, the contact atl is made, and the calling amplifier circuit 23 becomes operational. Also, contact r3 of relay R allows the ringing tone from the ringing tone generating circuit 4 to be transmitted to the extension telephone line 4 through the transformer TI.
2-1 and is transmitted to each slave unit from the transformer T20 of the calling amplifier circuit 23 of each slave unit to the calling amplifier AM.
After being amplified, the sound is amplified from the speaker SP. When the called party answers the call, the central office line is acquired at the same time as the above-mentioned central office line transmission operation, and a display indicating that the central office line is in use is displayed. Further, since the calling signal is stopped, relay R, relay x, and relay AP are restored, and the calling amplifier circuit 23 also returns to the standby state. Further, in the handset that answers the call by picking up the handset, the ringing amplifier circuit 23 is completely disconnected by the hook switch HS2. (Confidential) Next, the operation of the receiver control will be explained.

The receiving circuit 24 in the handset is connected to the extension telephone line 42- through the double-wave rectifier RECT and the make contact of the hook switch HS2.
1,42-2, and is also connected to the neutral point of the central office line 41 through the make contact LKI-3 of the central office button as a control input. Break contacts W1 and tv2 of the private message relay PV are connected in series to the communication circuit 21, and are configured so that when the confidential message relay PV is turned on, the communication circuit 21 is disconnected and the communication becomes confidential. First, when capturing a station line that is not in use, since the station line is not in use, no current is supplied to the neutral point of the station line communication line 41, and the station line button on the handset 20 is pressed. The transistor Tr20 of the confidential communication circuit 24 is in an OFF state even if the communication is switched off. When the caller picks up the handset, the hook switch HS2 closes.
The contact on the contact side is made, and the extension communication line 42 is
Power is supplied from -1,42-2, but since transistor T and 20 are off, resistor R22 and diode D
A trigger voltage is applied to the gate of thyristor S20 through 21, and thyristor S20 is turned on. Therefore, the transistor Tr21 is off, the secret relay PV does not operate, and when the office line button is pressed, its contacts LKI-1,
LKI-2 is switched, the call loop of the call circuit 21 is closed, and the central office line is captured. When the communication loop is opened, relay A is activated and current is supplied to the neutral point of central communication line 41, and transistor Tr20 of secret communication circuit 24 is turned on, but thyristor S2 is already in the on state. Because it is in
Continue to capture the station line. Next, the operation of the confidential communication when trying to acquire a central office line that is already being used by another handset will be explained.

Since the office line is in use, a voltage is applied to the neutral point of the office line communication line 41. First, we will explain the case where you press the central office line button and then lift the handset.

When the central line button is pressed, contact LKI-3 of the central line button
The current supplied to the neutral point of the central communication line 41 flows through the diode D20 and the resistor R21 to the base of the transistor Tr20, and the peak of the transistor Tr2 is in the on state.Then, when the handset is lifted, the telephone hooks up. When the make contact of the switch HS2 is made and power is supplied to the confidential communication circuit 24, no voltage is applied to the gate of the thyristor S20, and the gate of the thyristor S2 is off, and the resistor R23
, the base voltage is applied to the transistor Tr21 through R24, the transistor Tr21 is turned on, the secret relay PV is operated, the break contacts W1 and tv2 are broken, and the communication circuit 21 is disconnected from the central communication line 41, and the communication circuit 21 is disconnected from the central communication line 41, and the communication circuit 21 is disconnected from the central communication line 41.
Interruptions to central office lines are prohibited. Further, the case where the station line button is pressed after lifting the handset will be explained next. In this case, when the handset is lifted, power is supplied to the confidential communication circuit 24 as described above, but since the transistor Tr20 is off, the confidential communication relay PV is turned on by turning on the thyristor S20 and turning off the transistor Tr21. When the station line button is pressed next time, contact LKI-3
is made, and the voltage appearing at the neutral point of the office line communication line 41 turns on the transistor Tr20 and goes to 0. At the same time, the contact 〆k, which breaks only at the moment the office line button is pressed, breaks, so the thyristor S20 turns off. recovered,
Thereafter, since the transistor Tr21 is on, the thyristor S20 continues to be off, and when the transistor Tr21 is on, the secret relay PV operates, and the communication circuit 2 is also turned on.
1 will be separated and become a secret. (Holding) Next, we will explain the operation when putting the station line on hold.

On the office line in use, relay A operates, and current is supplied to the neutral point of the office line communication line 41 through contact a2, and the current is supplied to the office line indicator lamp LDI of all slave units from IJB2 to resistor R2.
A lamp current is flowing through the slave unit, and the thyristor S20 of the confidential communication circuit 24 is in an on state in the slave unit in use. When the hold button is pressed here, the contact HKI is made, and the break contact LK of the central line button is made.
I-3 → Diode D20 → Hold button contact HKI →
While the hold button is pressed, a hold current flows from the battery B2 through the resistor R2, and the potential difference across the resistor R2 increases. Hold detection circuit 5
is configured to detect that a holding current flows through the resistor R2, and when the holding current flows, the transistor Tr
2 is turned on, the hold relay operates, the contact hl is made, and a DC loop of the station line is formed by the resistor RI. Next, when the hold button is released, the hold button is restored and at the same time the central line button is also restored.
is disconnected, and relay A is restored. Further, since the hold relay is restored slowly and slowly by the capacitor CI, the hold relay date is self-maintained by the contact a3 and the support point h2. The relay K is supplied to the transistor Tr3 by the contact h3, and the relay K is turned on and off by the multipipulator 6 which oscillates at about 1/2 day 2, and the relay K is connected to the central telephone line by the contact h3. Current is intermittently supplied from the battery B2 to the neutral point of the terminal 41, and the office line indicator lamp LDI of each slave unit blinks to indicate the pending state. Next, when you want to cancel the hold and answer again, lift the handset of the handset and press the central line button to acquire the central line.
In addition, while the indicator lamp is on, current is supplied to the neutral point of the central telephone line 41, resulting in the confidential conversation state described above, but when on hold, current is supplied to the neutral point intermittently at a cycle of approximately 1'2 Hz. Therefore, during the period when the supply of this current is cut off, the transistor Tr20 of the privacy circuit 24 is turned off, and in order to turn on the thyristor S20, the privacy relay PV is turned off.
is restored, a call loop is established, and relay A is activated.
The central office line is reacquired. When relay A operates, the self-holding of the relay date is released by contact a3 and restored, contact hl is broken, the hold loop caused by resistor RI is broken, and the state is set to a local line communication state. (Extension) Next, we will explain the operation when making an extension call.

If you lift the handset without pressing the central office line button, the message "
The telephone call circuit 21 has a break contact LKI-1 of the office line button,
It is connected to extension communication lines 42-1 and 42-2 through LK2-1 and LKI-2 and LK2-2, and a communication current is supplied to the communication circuit 21'. Further, a capacitor C20 connected in series with the break contact HK2 of the hold button is also connected to the extension communication lines 42-1 and 42-2. The capacitor C20 has a sufficiently high impedance for signals in the audio frequency band, and has a capacitance value that provides low impedance for high frequency control signals, which will be described later. On the other hand, a high frequency control signal is always superimposed on the extension communication lines 42-1 and 42-2 from a high frequency control signal generation circuit 7 constituted by a tomartino brake, etc., and this control signal is also superimposed on a signal from a monitoring circuit 8. size is being monitored. When no handset is using an extension, the load of the high-frequency control signal is light, and the magnitude of the high-frequency control signal added to the separate monitoring circuit is greater than the detection level of the monitoring circuit 8, so the output of the monitoring circuit 8 is , an alternating current signal switched by a high frequency control signal is output, and the output signal is rectified and smoothed by a diode DI and a capacitor C2, turning on the transistor Tr and turning off the transistor Tr5. Now, when one handset is connected to use the extension as described above, the capacitor C20 is connected as a load to the high frequency control signal generation circuit 7, and since the load has low impedance, it is applied to the monitoring circuit 8. The magnitude of the signal is divided by the resistor B3 and the load capacitor C20, and becomes smaller than the detection level of the monitoring circuit 8, and no alternating current signal is generated at the output of the monitoring circuit 8, and the voltage of the transistor Tr4 is reduced. is the transistor Tr in the off state
5 is turned on, and relay Y operates. Contact yl of relay Y causes the voltage of -EI to be applied to extension line 42-1, current flows through resistor R26 and light emitting diode LD2 in the handset, and the extension indicator lamp lights up.
Also, the extension individual call receiving circuit 26 is connected through the diode D26.
Power is supplied to [Resistor R27 → Flake contact of station line button LK2-3, LKI-3 → Diode D20]
→Resistor R21] A base current flows through the transistor Tr2, turning on the transistor Tr20, and the handset other than the one making the call enters a confidential state in which the extension cannot be picked up. Next, in order to make an individual call to an extension, when the extension caller dials the individual extension number, the shunt contact Ds of the dial is made and acts as a load instead of the capacitor C20, and the dial contact Di corresponds to the number of dials. This load is then intermittent.

Due to the intermittent load, the level of the high-frequency control signal applied to the monitoring circuit 8 changes, and a dial pulse is generated at the output of the monitoring circuit 8 due to the intermittent alternating current signal, and the resistor R6 and diode ○
2. The pulse is corrected to a complete dial pulse by a rectification and time constant circuit including a capacitor C3 and a resistor R7, and is counted by a counting circuit 9. On the other hand, the transistors Tr4 and Tr5 that detect the extension state do not operate when the AC signal is interrupted by the dial due to the time constant of the circuit of resistor R4, diode D1, capacitor C2, and resistor R6, and maintain the extension state. There is. By the output of the counting circuit 9,
A signal tone having a frequency corresponding to the number of dials is generated from the individual selection signal tone generation circuit 10, superimposed on the extension communication line 42-1 through the transformer TI, and sent to the handset. In each handset, a signal selection circuit 2 is installed in the extension individual call reception circuit 25.
6 is provided, and when the received signal tone and the set frequency match, an output is generated from the signal selection circuit 26,
Thyristor S21 is on, transistor Tr22 is off, transistor T23 is on, Schener diode ZD21 is short-circuited, and since EI is set to the condition of formula '1', Schener diode ZD21 is short-circuited. The ToriRay AP operates, the call amplifier circuit 23 is activated by the contact apl, and the caller's voice is transmitted from the call circuit 21 of the calling handset to the extension call lines 42-1, 42-.
2, and also extension lines 42-1 and 42-2.
The signal is amplified by the above-mentioned paging amplifier circuit 23 connected to and amplified by the speaker SP. In addition, in the handset that received the call, the relay AP is operating, and the base current flowing through the transistor Tr2 of the secret circuit 24 is bypassed by the contact ap2, so the secret is released and the call can be answered. Become. Therefore, when the called party raises the transceiver,
The telephone call circuit 21 is connected to extension telephone lines 42-1 and 42-2 in parallel with the telephone circuit 21 of the handset that has made the call, so that extension telephone calls can be made. In addition, the calling amplifier circuit 23 of the called handset
is disconnected by contact HS2 of the hook switch and stops operating. Next, a case where simultaneous calling is performed using an extension will be explained.

The operation of simultaneous calling is the same as the above-mentioned individual calling until the extension line is captured, and when the extension line is captured, the transistor Tr
4 is on, and transistor Tr5 is off. Next, when the simultaneous call button that also serves as the hold button is pressed, the break contact HK2 breaks, the load capacitor C20 is disconnected, and the output of the monitoring circuit 8 becomes the same state as when no handset is connected. The transistor Tr4 is turned on and the transistor Tr5 is turned off. This transistor Tr4
When the voltage changes from off to normal, the collector voltage changes from a high level to a low level, so that a timer circuit 18 such as a monostable multi-circuit whose operating time is set to about 5 seconds is activated, and the transistor Tr6 is turned on. , during which relays X and Y operate, and the extension line 42-
1 is applied with a voltage of -E2. The voltage value of this E2 is
As described above regarding the operation of calling from the central office line, the conditions of formula (2) are set, and the current flows through diode D24, relay AP, Zener diode ZD21, and diode D25 in the amplifier control circuit 22 of all slave units. Then, the relay AP operates, and the paging amplifier circuits 23 of all slave units operate, and a simultaneous paging is performed.
In the embodiment of FIG. 1, the transformer T2 is connected to the central lines L1, L
It is used as a coupling circuit that forms a DC loop for the 2 and the central communication line 41, separates them from each other in terms of DC, and connects them to each other in terms of AC. Since it can be used as this coupling circuit, the coupling circuit shown in FIG. 2a can also be changed as shown in FIG. A DC loop is formed for the communication line 41 by relay A and battery BI, and DC isolation and AC coupling are performed by capacitors C11 and CI2.

FIG. 3 is an embodiment diagram of the present invention showing connection with a doorphone based on the above configuration, in which 50 is a doorphone connection unit, 51 is a doorphone ringing tone generation circuit, 52 is a doorphone handset, and 53 is a hybrid circuit. , D, Z are relays, dl
, d2, zl, z2, z3, y2 are relay contacts, Tr
50, Tr51 is a transistor, C50 is a capacitor,
RECT50G is a double-wave rectifier circuit, MIC is a microphone, SP5 is a speaker, and SW is a switch.

When the switch SW is turned on, the double wave rectifier RECT50
Capacitor C50 and relay D are connected to extensions 42-1 and 42-2 through the capacitor C50 and relay D is operated, and transistor Tr5 is turned on for a certain period of time from contact d, during which switch SW is opened. Relay D continues to operate.

On the other hand, when the load of capacitor C50 is connected, the transistor Tr5 is turned on and the relay Y is operated by the operation described in the explanation of the extension call, and the capacitor C5 is disconnected by the contact y3. relays The call is sent out and is heard from the speakers of each handset that is in simultaneous call mode. To answer a call from the doorbell, the handset that answers the call captures the extension,
When a specific dial number assigned to the doorbell is dialed, the counting circuit 9 counts the number of dials and generates an output, and since the contact y2 is in the on state, the transistor T51 turns on and the relay Z operates. .The relay Z is self-held by the contact zl, and at the same time, the ringing tone is stopped by the contact z2, and the door intercom handset 5 is stopped by the contact z3.
The communication path No. 2 is closed and communication is possible with the responding handset, and the timer circuit 11 which was in the simultaneous paging state by the point z4 is restored and the simultaneous paging state is canceled.
When the call with the doorphone ends and the extension handset goes down, relay Y is restored, relay Z is restored by contact y2, and the doorphone circuit is disconnected and returns to its initial state. As described above, according to the present invention, in the button telephone device in which each of the handsets is branch-connected to the extension lines 42-1 and 42-2, which are also used for supplying power to each handset, the extension lines a signal generator 7 for superimposing a high-frequency signal on the high-frequency signal; a monitoring circuit 8 for identifying the voltage value of the high-frequency signal; a counting means 9 for counting pulses generated in the output of the monitoring circuit when dialing the handset; Ringing tone sending means 51 for sending out sound
and operating means SW for connecting the load exhibiting a low impedance C50 to the high frequency to the extension communication lines 42-1, 42-2; Control means D, d2 for operating the ringing tone sending means, and a connection for connecting a telephone call circuit 53 of a door intercom handset, which is one of the handsets, to the extension telephone line when the output of the counting means indicates a specific number. It is possible to realize a doorbell control circuit in a key telephone device including means Tr51, Z, and z3. As explained above, by using the doorbell control circuit of the present invention, it becomes possible to connect the doorbell to a 12-wire button telephone device that uses high-frequency signals to control extensions.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of a button telephone device to which the present invention is applied, Fig. 2 is a circuit diagram showing a partial modification of the circuit in Fig. 1, and Fig. 3 shows the main part of the present invention. It is a circuit diagram. is 2 figures

[o]

Sai 2 figure [b] figure Six figure Bo

Claims (1)

[Claims] 1. In a button telephone device in which each handset is branch-connected to an extension telephone line that is also used to supply power to each handset,
a signal generator for superimposing a high frequency signal on the extension line; a monitoring circuit for identifying the voltage value of the high frequency signal; and a counting means for counting pulses generated in the output of the monitoring circuit when dialing the handset. , a ringing tone sending means for sending out a ringing tone, an operating means for connecting the load exhibiting low impedance to the high frequency to the extension telephone line, and when the load exhibiting the low impedance is connected by the operating means; a control means for operating the ring tone sending means; and a connection means for connecting a communication circuit of a door intercom handset, which is one of the handsets, to the extension communication path when the output of the counting means indicates a specific number. A doorbell control circuit in a button telephone device.