KR930010280B1 - Telephone number extension system - Google Patents

Abstract

This invention concerns a phone number extension system which enables to call directly and receive selectively when a plurality of telephones are connected to one phone number. This invention consists of 3-parts: an extension number setting and recognizing part which consists of an automatic answering circuit, an extension comparing and detecting circuit and aringing signal generating circuit, a interphone part which enables to call and receive each other who is connected to the extension number, and a phone number switching part which enables to use a 7-number unit phone number or an extended phone number selectively or simultaneously.

Description

Phone number extension method and device

1 is a block diagram of a phone number expansion device.

2 is a circuit diagram of a telephone number expansion device.

3 is a detailed circuit diagram of the extension book.

[Purpose of invention]

In the current communication system, the number of telephone numbers is one-to-one proportional to the trunk line capacity of the switchboard, and telephones have been operated by using one or more telephones (when connected in common) to one telephone number (cline and line) as needed. . Therefore, the number of telephones is generally larger than the number of telephone numbers, and this phenomenon is exacerbated by the capacity limit of the alternator and the high cost of facility investment.

However, in a situation where a telephone number is shared by several telephones, that is, several people share a home (home, living room, bunk room, etc.), the caller cannot directly call the calling party. That is, when a call is made, all the connected phones ring, so the receiving side cannot know who the incoming call is looking for. Therefore, the call requester must be changed after receiving one of the connected phones. Due to such inconvenience, it is difficult to make a phone call in a house where an adult is in the middle of the night, so the communication line is installed 24 hours but is rarely used in the middle of the night.

The present invention overcomes these problems and provides one or more different telephone numbers for each telephone under a limited trunk line (telephone number and telephone) capacity so that the caller can directly call the person who wants to call, without investing in a separate exchange facility. We have designed a series of devices that can increase the number of telephone numbers. The general idea of the present invention is to make a caller by connecting a device capable of depositing a telephone number which can be arbitrarily set by a user to existing telephones (commonly connected to one trunk line to which one telephone number is assigned). If you continue to dial a private number after dialing this existing phone number, only the device to which the extension number is deposited will ring, resulting in a remotely selected call from one of the commonly connected phones. Extension method, telephone number extension device commonly connected to one trunk line Intercom method that enables call and call forwarding between each extension line and existing unique phone number (7 digits) and extended phone number (eg 9 digits) It's about how to make that possible.

Therefore, if the device is able to deposit multiple confirmation numbers, one person can have several direct exchange numbers, thus improving the operational efficiency of the current telecommunications network, and directly calling and screening parties (different extension by school, work and friends). If you give the number, you can look at the extension number used to determine where the call came from and decide whether or not to answer the call. The design of the invention is as follows: (1) extension number setting and recognition unit to enable selective calling, (2) interphone unit to enable call and call transfer between number extension devices, and (3) existing 7 It consists of a telephone number converter that allows you to select or simultaneously use a digit telephone number and an extended telephone number (eg 9 digits).

Therefore, when using the present invention, several telephones connected to the trunk line may use the individual extension number and the unique 7-digit telephone number as they are, and the existing 7-digit telephone number is used as the representative telephone number, and the extended telephone number is the telephone. It can be used as a separate phone number and can be mutually called by the extension number of the designed devices, so it can be used as a key point for homes or small businesses, or for border guards of factories or military units, and connect FAX and PC to one trunk line. By designating a unique extension number, it is possible to directly select and perform communication between terminals, and additionally, it can eliminate prank calls that do not know the confirmation number.

[Configuration of Invention]

[Extension Number Setting and Recognition Unit for Selecting Call]

This circuit is divided into (a) telephone answering unit and (b) extension number comparison detecting unit (c) ringing bell signal generation unit as shown in FIG.

The telephone answering unit detects this signal when the switch inputs a ringing signal to ring the telephone through the telephone line and automatically turns off the HOOK switch so that the designed device can answer the call. Once the HOOK switch is activated and the call path is established, the DTMF signal can be sent from the calling side to the track. When using this, the extension number comparison detection unit uses the DTMF decoder to It detects the signal and converts it into a BCD code, and sends an extension number comparison part. If the BCD code matches the code set in advance in the extension number setting switch, it turns on the bell signal generator and rings the bell. Turn off the negative HOOK switch to hang up.

[Interphone unit which enables call and call forwarding between number extension devices]

The automatic answering unit of the extension number recognition circuit is used for the common connection telephones (e.g., A, B, C) in order to mutually designate calls and call forwards in a common connected telephone period in which a device designed using the extension number setting and recognition unit is installed. Either A picks up the phone and presses any number (e.g. 0 seconds) for more than a certain period (e.g. 2 seconds) and detects that the devices connected to A, B and C are in the HOOK OFF state, Make the state received. That is, the answering machine has a function of automatically answering a call not only by a call signal from an exchange but also by a signal of which a certain number lasts for a predetermined time or more. Therefore, when A presses the extension number of B or C by using the keypad of the telephone, this signal is identified by the extension number recognition circuit of (1) and rings the device connected to the telephone. Screening calls can be made with each other, and this process can also be used for call forwarding, since A can call B or C even when a call is received. This interphone function can only be used for about 20 seconds while the exchange detects HOOK OFF and waits for dialing. To extend this period, intercom function users on a call can simultaneously extend the talk time by pressing the HOOK switch to let the exchange detect that the call is disconnected, and then dial an arbitrary number to allow the exchange to wait for dialing again. .

[Phone number conversion unit to select or simultaneously use the existing 7-digit phone number and extended phone number]

The device is designed so that the B and C phones do not ring when the device is attached to A automatically when the phone is called (e.g. A only). I can't answer the phone. In addition, the B and C attached to this device is inconvenient to inform all existing customers and friends of their new extended number, otherwise the call is impossible. Therefore, in the present invention, in order to allow A and B to use a telephone number with an extended number (for example, 9 digits) while C is ringing only the existing telephone number (7 digits), When the same telephone number conversion circuit is designed, and the caller does not press the extension number (DTMF signal transmission) within a certain time (e.g. 2-3 seconds) after the answering machine of the selective calling circuit of (1) receives a call. The caller does not know the extension number or tries to call the existing 7-digit phone number and rings the designed device so that the caller can call the existing phone number (7-digit).

Of course, this circuit can be selected according to the user's purpose by the selection switch, so that the designed device can use the existing telephone number, the extension number, or both the existing number and the extension number, not the extension number.

One Embodiment of the Invention

One embodiment of the present invention will be described with reference to FIG. 2.

(1) The extension number recognition function that enables selective calling is as follows.

JP1 is the telephone line at the top left of the circuit diagram.When the telephone rings, the output is output to the terminals 3 and 4 through the input terminals 2 and 1 of the diode D3, and the output from 4 is the zener diode (D5). DC current is applied to Nos. 3 and 4 of the photo coupler U6 through and D2 to drop the state of the output (No. 7) of the port coupler U6 from H to L. This state is connected to the AND gate (U19), and the output of the normally AND gate is combined with U20, which is L, so it is applied to the one-shot timer U5 to make the output (No. 3) in the H state for 20 seconds. To form.

At this time, the time of the one shot U5 is adjusted by the capacitor C7 and the variable resistor VR1. The output (No. 3) of the one-shot U5 applies the bias voltage of the transistor Q1 for driving the relay via the current driver U18 and U17 via the terminal 1 of JP4 through H11 to make a call. Operate the HOOK control relay K1. When the relay K1 operates, the current loop with the exchanger is formed by the resistor R4 and the transformer T1 through the coils L1 and L2 of the first stage of the first JP1, and the hook is turned off. Receive. When the device answers the call, the voice input message “Press the password”, which is the voice message that was stored in the control input terminal (No. 2) of the voice chip (U4) on the right half of the circuit diagram, is in the “H” state. The DC component is removed and applied to No. 4 of the transformer T1 on the telephone line side through TOUT and guided to No. 1 and No. 2 to the talker. At this time, if the talker presses the extension number through the telephone keypad, tone is applied to the input terminals (1, 2) of DTMF decoder (U1) through C12, R15, and R3. Appears converted. In this case, X1 is a crystal oscillator for operating the DTMF decoder U1, and R18 and C14 are for stabilizing the operating voltage.

A terminal (No. 8) indicating that a signal is being input to the DTMF decoder U1 is input to the register U3 via the H7 via the NAND gate U12 and the NOT gate U21 to act as a clock so that the talker receives the DTMF signal. (The terminals 4 and 5 of register U3 have a binary output indicating the number of times.) The output of the register (terminals 4 and 5) is the hexadecimal BCD switch (SW1) of FIG. 3 via JP5. , SW2) will send the hexadecimal number corresponding to the extension number set in the BCD switch to the switch output. (The diodes D1 to D8 of the switch output section are used to prevent reverse current from being applied to the switch.) The hexadecimal outputs of such switches are applied to the comparator U30 to decode the DTMF signal transmitted by the talker (DTMF decoder outputs A0 to A3) and Comparison is made. The output (No. 6) of the comparator U30 enters the HH state only when the two signals are the same. D-type flip-flops (U31, U32) are used to check whether the input DTMF signals are the same (number of digits of the extension number) sequentially, and the output of the flip-flop (U32) is used when the extension numbers are correct. The LED D13 is emitted to inform the user of the result. In addition, this signal controls the bell drive chip U8 at the lower right of FIG. 2 to generate the bell drive sound, and applies it to the transformer T1 at the upper left of FIG. 2 via R20 to transmit the bell drive sound to the talker. On the other hand, R8 and speaker drive to operate the speaker connected to JP3 through TR (Q3) to inform the user that the call to the extension number has been called. At this time, when the user picks up the receiver, the device is applied to bridge diodes D2 and D3 connected to the telephone cord JP2 and resets the timer U5 through the U6 and AND gates U20. The handset is connected to the telephone and can talk.

(2) A function that enables cross-calling and call forwarding between devised devices

When the device designed for the commonly connected phones A, B, and C is attached, A picks up the handset and presses ＂0＂ for more than 2 seconds and then presses B's extension number to ring only the device attached to B. Designed to enable extension calls, when pressing the telephone keypad # 0, the DTMF signal is applied to the first and second of the transformer T1 to the 5th and 6th times in the telephone jack JP2, and the induced signal Is applied to the DTMF decoder U1 to make the output terminals A1 and A3 in the H state.

A1 and A3 are applied to the comparator U2 (the comparator is set to compare with '0'), and a terminal (No. 8) indicating that the DTMF signal is being input to the DTMF decoder U1 is turned off. The state of H is pressed while pressing 0 ＂, and is maintained while pressing H7 to the state of H through the gates U12 and U21.

Therefore, the comparator U2 determines whether or not the input mutual is 00 and outputs it to output 7 when it is 00. The output signal is induced to C23 through R7, and the time constant of R7 and C23 Delayed for 2 seconds and maintained H state while input 1 of gate (U13) is in H state, and when the telephone keypad key is released in 2, it is in H state, so output 3 of Schmitt trigger (U13) drops to L and is AND Is applied to gate U19.

At this time, as R7 and C23 are discharged, the input of the timer U5 is changed from L to H state to operate the timer U5. When U5's number 3 is output H, it enters the password input standby state. The extension number input standby state is as described above.

Therefore, in this state, when DTMF signal indicating extension number comes in on the telephone line, it is compared (as described in the screening function). Only the designed device with the correct password will work. By pressing ＂0＂ for more than 2 seconds and pressing the confirmation number of B, it is possible to make a call between mutually connected phones.

(3) The operation principle using the existing number is as follows.

If the device is connected to A, B, and C with a common connected phone, A assumes the existing 7-digit phone number and B and C use 9-digit phone numbers with exchange numbers. When the bell signal is applied to the 1 and 2 of the bridge diode D3 at JP1 connected to the JP1, a constant voltage is applied to the 5 and 4 of the photocoupler U6 by the zener diode D5 and R2, and thus the photo coupler. A current is generated in U6, and the seventh time becomes the L state from the H state, and a clock is applied to the fifth time of the timer U7 to operate the timer U7. The operating time of U7 is arbitrarily determined by R25 and C18, but here, for example, about 3 seconds. The output of the timer U7 is in the H state, and the clock is applied to the D flip-flop U9 through the NOT gate U22, and the clock (No. 1) of the D flip-flop U10 is set to H7. Via the output status signal of DTMF decoder U1. If the output status signal of the DTMF decoder is not within 3 seconds during the operation of the timer U7, the output of the timer U7 drops to L, and the output of the D flip-flop U9 (number 3) It flows from H to L and flows into the forward current through the first lower right R22 and the diode D4 via H20 to operate the bell driving chip U8 as described in the former. Therefore, if the telephone number conversion switch (SW-A in the bottom center of the circuit diagram) of the designed device that operates as an extension number is turned ON, the designed device does not wait for the DTMF signal indicating the extension number and detects the bell signal at the exchange to automatically make a call. If no DTMF signal is received within 3 seconds of receiving it, the other party assumes that it does not know the extension number and rings the designed device to make a call with the existing seven-digit phone number.

Claims (4)

A telephone number extension method comprising a circuit for driving a bell by identifying a DTMF signal which is additionally input after an automatic answering of the telephone, and comparing and comparing it with a reserved extension number to enable direct inward dialing from the outside. 2. The method of claim 1 wherein the impedance is reduced by using a port coupler so that multiple number extensions can be used to auto answer the call. The method of claim 1, wherein when a predetermined DTMF signal is input for a predetermined time (e.g., 0 seconds or more, 2 seconds or more), the integrated DTMF signal is detected to detect a screening call signal, and the number expander operates while receiving a call (HOOK OFF). Subsequently, when the extension number is input in the form of DTMF signal, it rings to make the call and call forward between the number extension devices possible. The system of claim 1, wherein when an additional DTMF signal is not input at a certain time after automatically answering the call, the extension number and the extension number are regarded as being unknown and attempted to call the existing number (7 digits). How to make existing numbers available at the same time.