JPS6019879B2 - Call control method for button telephone equipment - 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, including two for extension calls, one for the extension control line, and two for the power supply line.Additionally, an individual extension calling line is required, so the connection cord becomes thicker. There was also a drawback that the connector was large.

In order to overcome these drawbacks, button telephone devices with a reduced number of core wires have been proposed, but since the central telephone line and the extension telephone line are both used, the central telephone line and the extension telephone line are independent. 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 call control method for a key telephone device that can be performed independently.

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

Although the embodiment shown here is a button telephone device for two office lines, embodiments with a different number of office lines can be easily constructed by adding or subtracting the office line circuit and two core wires. 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 ringing tone generation circuit, 5 is a hold detection circuit, 6 is a multipipulator, and 7 8 is a high frequency control signal generation circuit, 8 is a monitoring circuit, 9 is a counting circuit, 1 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 relay H' (not shown) , KI is the contact of relay K, X1, ×2 is the contact of relay Power supply for supply, TI is a transformer, Trl to Tr6 are transistors,
01 and D2 are diodes, RI to R5 are resistors, CH is a choke coil, and C0 and CI to C3 are capacitors.
Further, 20 is a handset, 21 is a telephone call circuit, 22 is an amplifier control circuit, 23 is a calling amplifier circuit, 24 is a confidential circuit, 25 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, HK2 are the contacts of the hold button, SOK is the contact of the interlocking electric key, HS1, HS2 are the contacts of the hook switch, D
s, Di are dial contacts, AP, PV are relays, atl
, at2 are contacts of relay AP, tvl, tv2 are contacts of relay PV, SWI station stop switch, SW2 is extension call stop switch, RECT is double wave rectifier, T2, T2
0 is transformer, AMP is amplifier, SP is speaker power, Tr
20~Tr2 3 is a transistor, S20 and S21 are thyristors, LD1 and LD2 are light emitting diodes, ZD20
, ND21 is a Zener diode, D20 to D26 are diodes, R20 to R27 are resistors, C20, C21, C
22 is a capacitor. Further, 30 is another handset connected in parallel with the handset 20, 41 and 41' are central communication lines, and 4
Reference numerals 2-1 and 42-2 are extension communication lines that also serve as power supply to the slave units. Next, the operation of the circuit of this device will be explained.

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

Relay A is inserted into this loop, and relay A is operated by the communication current, and the office line is captured by contact a1. At the same time, a current from the battery B2 is coupled between the neutral point of the central office telephone line 41 and the extension 42-2 through the contact a2, and this current is applied to the neutral point of the central telephone telephone line 41 and the extension 42-2 in the handset 20. -2, the light flows through the resistor R20 and the light emitting diode LDI connected between the terminal and the light emitting diode LDI, and the light emitting diode LDI as an indicator lamp lights up, indicating that the office line is in use. All connected slave units operate the machine. It will be done. (Response to incoming call) Next, the operation when receiving a call from the central office line will be explained.

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, and the relay R is activated. The calling signal is normally sent in an intermittent cycle with a signal for 1 second and no signal for 12 seconds, and while relay R is receiving the calling signal, it performs the same intermittent operation of 1 second on and 2 seconds off. Contact rl causes a state in which current is intermittently supplied from the battery B2 to the neutral point of the central 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 an incoming central line call is being received. Display is performed. On the other hand, between extensions 42-1 and 42-2, in the handset 21, the amplifier control circuit 22, the double-wave rectifier circuit RECT, the hook male switch contact HS2, and the relay AP contact atl
The calling amplifier circuit 23 is connected through the amplifier control circuit 22.
Route of D20 → Relay AP → Diode 023 → Station call stop switch SW
2→Diode D24→Relay AP→Zener diode ZD21→Diode ○25]. In the standby state, a voltage of 10EI is applied between the extension telephone line 42-- and the extension telephone line 42-2.
EI > Relay AP emotional voltage > EI-ena voltage V blood 2.

... is set to a voltage value that satisfies the relationship of m, and the relay AP is not operating. During the period when relay R is on due to a call signal from the central office line, contact r2
The transistor Trl is turned on to operate the relay ×, and the voltage of the extension line 42-1 is switched from 1EI to 1E2 by the contact ×1, and the voltage value of +E2 is E.
2 x enna voltage V ■ 2o > Relay AP's moving voltage...'21 This has the relationship of '21, and as a result, the IJ relay AP of each connected slave unit operates, the contact atl makes, and the call is made. The amplifier circuit 23 becomes operational.

Further, the contact r3 of the relay R causes the calling charge from the calling charge generating circuit 4 to be superimposed on the extension telephone line 42-1 through the transformer TI and transmitted to each handset, and the transformer T20 of the calling amplifier circuit 23 of each handset The signal is added to the paging amplifier AMP, amplified, and then output from the speaker SP. When the scarlet caller answers the call, the central office line is captured in the same way as the above-mentioned operation for calling the central office line, and a display indicating that the central office line is in use is displayed. Furthermore, 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. (Secret talk) Next, the operation of the secret control will be explained.

The confidential communication circuit 24 in the handset is connected to the extension communication lines 42-1 and 42-2 through the double-wave rectifier RECT and the make contact of the hook switch HS2, and is connected to the extension communication lines 42-1 and 42-2 through the make contact LKI-3 of the office line button as a control input. It is connected to the neutral point of the communication line 41. 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 make side contact of the hook switch HS2 is made, and the extension line 42 is connected to the secret line 24.
Power is supplied from -1,42-2, but since transistor Tr20 is 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. For this reason,
Transistor Tr21 is off, private relay PV does not operate, and when the central line button is pressed, its contact LKI-1
, LKI-2 are switched, the communication loop of the communication 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 the office line communication line 41, and the transistor Tr20 of the secret communication circuit 24 is turned on, but the cylist S20' is already on. Because of the situation, it continues to capture the station line as it is. 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, the contact LKI-3 of the central line button
The current connected to the neutral point of the telephone communication line 41 flows through the diode D20 and the resistor R21 to the base of the transistor Tr20, and the transistor Tr20 is in the on state. When the make contact of the switch HP2 is made and power is supplied to the private communication circuit 24, no voltage is applied to the gate of the thyristor S20, the thyristor S20 is off, and the resistors R23,
The base voltage is applied to the transistor Tr21 through R24, turning on the transistor Tr21 and turning on the secret relay PV.
is activated, the break contacts W1 and tv2 are broken, the communication circuit 21 is disconnected from the office line communication line 41, and interruption to the office line in use is 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 the transistor Tr20
is off, the secret relay PV is in a state of not operating due to the on of the thyristor S20 and the off of the transistor Tr21, and when the central line button is pressed next, the contact LKI-3 is turned off.
The voltage appearing at the neutral point of the central line communication line 41 turns on the transistor Tr20, and at the same time the voltage that appears at the neutral point of the central line communication line 41 causes a break. After the recovery, the transistor Tr20 is on, so the thyristor S
20 remains off, and the private communication relay PV operates by turning on the transistor Tr21, and the communication circuit 21 also operates.
is separated and becomes 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 from point a2, and the current is supplied to the office line indicator lamp LDI of all slave units from battery B2 through resistor R2. A lamp current is flowing, and the thyristor S20 of the confidential communication circuit 24 is in an on state in the handset in use. When the hold button is pressed here, the contact HKI is made, and the break contact LKI of the central line button is
-3 → diode D20 → contact HKI of the hold button → resistor R25 → thyristor S20 → break contact 〆K → double-wave rectifier RECT], while the hold button is pressed, the hold current flows from the battery B2 through the resistor R2,
When the potential difference across 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 call circuit 21 of the handset is disconnected by contacts LKI-1 and LK-2 of the central line button. , relay A is restored. Further, since the pending relay date is slowly restored by the capacitor CI, the pending relay date is self-maintained by the contact a3 and the contact h2. Relay K is connected to transistor Tr3 through contact h3, and relay K is turned on by multipipulator 6, which is oscillating at approximately 1'2 Hz. An intermittent off operation is performed, and current is intermittently supplied from the battery B2 to the neutral point of the office line communication line 41 by the contact KI, and the office line indicator lamp LDI of each handset flashes to indicate the hold state. Next, when canceling the hold and re-answering, the handset of the handset is lifted and the central office line button is pressed to acquire the central office line.
Note that while the indicator lamp is on, current is supplied to the neutral point of the central office 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 this current supply is cut off, the transistor Tr20 of the secret communication circuit 24 is turned off.
"Secret relay PV" to turn on thyristor S20
is restored, the call loop is closed, and relay A is activated.
When the central office line is recaptured and the relay A is operated, the self-holding of the relay date is released by the contact a3 and restored, the contact hl is broken, the holding loop by the resistor RI is broken, and the central office line communication state is established. (Extension) Next, we will explain the operation when making an extension call.

If you lift the handset without pressing the central line button,
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, LK-2, and LK2-2, and a communication current is supplied to the communication circuit 21. Also, the break contact H of the hold button
A capacitor C20 connected in series with KK2 is also connected to the extension 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 pigeon circuit 7 constituted by a multi-pipe rake, etc., and this control signal is transmitted by a monitoring circuit 8. Signal magnitude is monitored. When no handset is using an extension, the load of the high-frequency control signal is light, the magnitude of the high-frequency control signal applied to the monitoring circuit 8 is greater than the detection level of the monitoring circuit 8, and the output of the monitoring circuit 8 is , an AC 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 Tr4 and turning off the transistor TR5. Now, when one slave unit is connected to use the extension as described above, the capacitor C20 is connected as a load of the high frequency control signal generation circuit 7, and since the load is low impedance, it is added to the monitoring circuit 8. The magnitude of the signal is divided by the resistor B3 and the load capacitor C201 and becomes smaller, and becomes below the detection level of the monitoring circuit 8. No AC signal is generated at the output of the monitoring circuit 8, and the transistor Tr4 is turned off. In this state, the transistor Tr5 is turned on, and the relay Y operates. Contact y of relay Y
1, a voltage of -EI is applied to the extension line 42-1, and the resistor R26 light emitting diode LD in the slave unit
2, the extension indicator lamp lights up, power is supplied to the extension individual call receiving circuit 25 through the diode D26, and [resistor R27 → break contacts of the office line button LK2-3, LKI-3 → diode 020 →Resistance R2
1], a base current flows through the transistor Tr20, the transistor Tr20 is turned on, and the handset other than the one making the call enters a confidential state in which the extension cannot be captured. Next, in order to call the extension individually, when the extension caller dials the extension individual number, when dialing, the dial shaft contact D
s makes up and becomes a load instead of capacitor C20.
This load is switched on and off according to the number of dials by the dial contact Di.

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 in 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 the rectification and time constant circuit formed by the capacitor C3 and resistor R7, and then counted by the 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 R5, 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 turned on, transistor Tr22 is turned off, transistor Tr23 is turned on, Zener diode ZD21 is short-circuited, and EI is set to the tl-type condition, so when Zener diode ND21 is short-circuited, The relay AP operates, the call amplifier circuit 23 becomes operational 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 is amplified by the above-mentioned paging amplifier circuit 23, which is also connected to the extension telephone lines 42-1 and 42-2,
The sound is amplified from the speaker SP. In addition, in the handset receiving the call, the relay AP is operating, and the base current flowing through the transistor Tr20 of the privacy circuit 24 is bypassed by the contact ap2, so that the privacy is released and the handset can respond to the call. Therefore, when the called party picks up the handset, the telephone call circuit 21 is connected to the extension telephone lines 42-1 and 42-2 in parallel with the telephone circuit 21 of the handset that has made the call, allowing an extension telephone call to be made. Further, the calling amplifier circuit 23 of the called handset is disconnected by the contact HS2 of the hook switch and stops operating. Next, a case will be described in which simultaneous calling is performed using an extension.

The operation of simultaneous calling is the same as the above-mentioned individual calling until the extension line is captured. When the extension line is captured, the transistor Tr
4 is on. 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 collector voltage changes from off to on, the collector voltage changes from a low level to a low level, and the timer circuit 18, such as a monostable multi-circuit whose operating time is set to about 5 seconds, operates and turns on the transistor Tr6. During this time, 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 mentioned in the operation of calling from the central office line, the conditions of the formula are set, and the current flows through diode D24, relay AP, Zener diode ZD2 1, and diode ○25 in the amplifier control circuit 22 of all slave units. flows to the relay AP, the relay AP operates, and the paging amplifier circuits 23 of all slave units operate, thereby performing simultaneous paging. In the embodiment of FIG. 1, the transformer T2 is connected to the central lines L1 and L2.
It is used as a coupling circuit that forms DC loops for the and central telephone communication lines 41, separates them from each other in terms of DC, and connects them to each other in terms of AC. It can be used as a coupling circuit, so
This coupling circuit shown in FIG. 2a can also be modified as shown in FIG. Relay A and relay BI each form a DC loop, and capacitors C11 and CI2 perform DC separation and AC coupling.

As described above, according to the present invention, each slave unit 20, 30 is branched to the extension communication line 42-1, 42-2, which is also used for power supply to each slave unit, and the office line communication line 41 within the device. In the connected button telephone device, the main device includes an open source switching means X for switching the voltage value and polarity of the voltage applied to the extension communication line;
Y, xl, x2, yl, and control means R4, 01, C2 that controls the power supply initial cut-off means to create mutually distinguishable combinations at the time of receiving a call on a central office line, when calling an individual extension, and when calling all extensions.
, R5. Tr4 and Tr5, each slave unit detects the combination of the voltage value and polarity of the voltage applied to the line communication line, and detects the combination of the voltage value and polarity of the voltage applied to the line communication line, and when the station line call arrives, the extension individual call, and the simultaneous call. and control means apl, ap2 for setting the handset to the respective states of receiving a call from a central office line, calling an individual extension, and calling all extensions in accordance with the identification result of the identifying means. It is possible to realize a call control method in a key telephone device equipped with the following.

The above is an explanation of the entire device, but the feature of the present invention is that the voltage value and gutter characteristics of the DC voltage supplied to the extensions are This is achieved by a combination of these functions, which eliminates the need for control lines that were conventionally used independently to control calling of slave units, and has the effect of reducing the number of core wires.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the invention, and FIG. 2 is a circuit diagram showing a partially modified example of the invention. Outside 2 figures {0) Year 2 figures 'b] Figure dog

Claims (1)

[Claims] 1. In a button telephone device in which each handset is branch-connected to an extension line that is also used to supply power to each handset and a central office line inside the device, the main unit is configured to control the voltage applied to the extension line. A power supply switching means for switching the voltage value and polarity, and a control means for controlling the power supply switching means to create combinations that can be distinguished from each other at the time of receiving a call from a central office line, when calling an individual extension, and when calling all extensions, , an identification means for detecting the combination of the voltage value and polarity of the voltage applied to the extension telephone line to distinguish between the arrival of a call to the central office line, the call for each extension, and the call for all calls; 1. A call control method for a button telephone device, comprising a control means for setting the handset to each state of receiving a call from a central office line, calling an individual extension, and calling all extensions in response to an identification result.