KR890004322B1 - Interface circuit in dtmf/pulse telephone - Google Patents

Abstract

The circuit includes a line sensor relay (1) for detecting pulse signal of an off-hook/pulse phone, a dial pulse decoder (2) for transmitting decoding signal of an off-hook detecting signal or output pulse signal according to line sensor relay, a transformer (T) for transmitting signal input to a tone network (TN) to a local line (P1, P2), for transmitting DTMF signal to the tone network terminal (TN), and for mutual transmission of vocal signal between local lines and vocal network terminals (V1, V2), and a calling control unit (5) for transmitting calling signals (RI1, RI2) to local line according to calling control signal during the hook-off.

Description

Interface circuit for extension call of DTMF / pulse telephone

The accompanying drawings are diagrams of interface circuits for extension calls of the present invention.

* Explanation of symbols for main parts of the drawings

1: Licensor Relay 2: Dial Pulse Decoder

3: interface circuit 4: call path control unit

5: call control unit T: trans

P ₁ , P ₂ : station V ₁ , V ₂ : voice network terminal

TN: Tone network terminal RI ₁ , RI ₂ : Call signal

The present invention relates to an interface circuit for an extension call that allows subscribers to mutually call and make an extension call within one simple exchange. Particularly, the present invention relates to a DTMF (Dual Tone Mult: Frequency) telephone and a pulsed telephone in common. The present invention relates to an interface circuit for extension calls of DTMF / pulse telephones.

Conventional exchanges cannot directly call the subscriber of the other party to which the subscriber wants to make an extension call, so the subscribers first call the operator of the exchange and talk to the other party's subscriber who wants to talk, and the operator connects the subscriber to the other party. It has to be a lot of trouble to the subscriber and its use was inconvenient.

In view of the above-mentioned deficiencies, the present invention has been devised so that subscribers can directly call a counterpart subscriber who wants to make an extension call and make mutual extension calls using a DTMF-type telephone and a pulse-type telephone in common. Detailed description with reference to the following.

The accompanying drawings are the interface circuit for the extension call of the present invention, as shown therein, coils (L ₁ , L) for detecting the output signal of the off-hook and pulsed telephone of the telephone connected to the extension (P ₁ , P ₂ ) ₂ ) and the line sense relay 1 including the switch SW and the off hook detection signal is output to the output terminal OH according to the off hook detected by the line sensor relay 1, and the output pulse signal Transmits the decoded signal of the off-hook detection signal and the output pulse signal outputted by the dial pulse decoder 2 and the dial pulse decoder 2 outputting the decoded signal to the output terminals DO ₀ -DO ₃ . And an interface circuit (3) for outputting call control signals and call control signals under control of the central processing unit, and outputting a dial tone input to the tone network terminal (TN) to the stations (P ₁ , P ₂ ) and the station (P). ₁ , P ₂ ) of the DTMF telephone A transformer (T) for outputting a DTMF signal to the tone network terminal (TN), mutually transmitting voice signals of the stations (P ₁ , P ₂ ) and the voice network terminals (V ₁ , V ₂ ), and the interface circuit (3). A resistor (R ₁ -R ₈ ) and a transistor (TR ₂ -TR ₆ ) for controlling the voice signal communication paths of the transformer (T) and the voice network terminals (V ₁ , V ₂ ) according to the call control signal of In response to the call control signal of the interface circuit 3, the call signal control unit 4 and the call signals RI ₁ and RI ₂ outputted from the ring generator are output to the stations P ₁ and P ₂ according to the call control signal. It consists of a call control section 5 consisting of an inverter I, an end gate AD, a transistor TR, a diode D ₁ , a relay RY and a relay switch RYS ₁ , RYS ₂ for calling a subscriber. .

In the above, the central processing unit has a program in which the telephones connected to the stations P ₁ and P ₂ are notified of DTMF telephones or pulsed telephones, and according to the program, DTMF signals of the cone network terminal TN and dial pulse decoders 2 Input the decoating signal of) and connect the other party's phone to the voice network terminal (V ₁ , V ₂ ), and output the dial tone to the tone network terminal (TN) according to the off-hook detection signal, and relay The switches RYS ₁ and RYS ₂ are connected to one fixed terminal a ₁ and a ₂ when the relay RY is driven and the other fixed terminal b ₁ and b ₂ when the drive is not driven. In the description of the drawings, reference numerals ZD ₁ and ZD ₂ are constant voltage diodes, Vcc is a power supply terminal, and D ₂ and D ₃ are diodes.

The operation of the present invention configured as described above is divided into a case of a DTMF telephone, a pulse telephone, a call to a subscriber, and a call to each other.

1. If you have a DTMF phone.

) 로 저전위가 입력되므로 다이얼 펄스 디코더(2)는 출력단자(OH)로 고전위의 오프후크 검출신호를 출력하고, 출력한 고전위의 오프후크 검출 신호는 인터페이스회로(3)의 입력단자(PB)로 입력된 후 중앙처리장치로 출력된다.When the DTMF telephone is connected to the stations P ₁ and P ₂ and the handset is lifted off the hook, the internal resistance of the DTMF telephone is lowered. Therefore, the power supply of the power terminal Vcc is connected to the coil of the line sensor relay 1. Flowing through L ₁ , L ₂ , he is driven so that the switch SW is connected, and the dial pulse decoder (

Since the low potential is input to the input signal, the dial pulse decoder 2 outputs a high potential off hook detection signal to the output terminal OH, and the output high potential off hook detection signal is input to the input terminal of the interface circuit 3. PB) and then output to the central processing unit.

Accordingly, the central processing unit determines the off hook of the telephone connected to the stations P ₁ and P ₂ , and outputs a dial tone to the tone network terminal TN, and the dial tone is the secondary coil T ₂₁ of the transformer T. ) Is guided to the primary coil (T ₁ ) and then output through the relay switch (RYS ₁ , RYS ₂ ) to the telephone of the extension (P ₁ , P ₂ ).

In this state, when the subscriber of the extension (P ₁ , P ₂ ) presses the button type dial of the DTMF type telephone and the DTMF signal of the pressed button type dial is input to the extension (P ₁ , P ₂ ), the input DTMF signal is inputted. The central processing unit is applied to the tone network terminal because it is applied to the primary coil T ₁ of the transistor T through the relay switches RYS ₁ and RYS ₂ and guided to the secondary coil T ₂₁ and output to the cone network terminal TN. The DTMF signal outputted by the TN is used to identify and call the other party subscriber who wants to make a call so as to be connected to the voice network terminals V ₁ and V ₂ .

2. For pulsed telephone

When the pulsed telephone is connected to the stations P ₁ and P ₂ and the handset is lifted off the hook, the switch SW of the line sensor relay 1 is connected and the dial pulse decoder 2 is connected as in the DTMF telephone. The central processing unit determines the off-hook by outputting the high-potential off-hook detection signal to the output terminal (OH), and outputs the dial tone to the tone network terminal (TN) and outputs it to the telephones of the stations (P ₁ and P ₂ ). do.

) 로 펄스신호가 입력되므로 다이얼 펄스 디코더(2)는 입력된 펄스 신호를 디코딩하고, 디코딩신호를 출력단자(DO₀-DO₃)로 출력하여 인터페이스 회로(3)의 입력단자(PC₃-PC₇)로 입력된 후 중앙처리장치로 전송되어 중앙처리장치는 펄스신호의 디코딩 신호를 통화를 원하는 상대방의 가입자를 판별하고, 호출하며 음성 네트워크 단자(V₁, V₂)에 연결되게 한다.In such a state, when the subscriber rotates the rotary dial of the pulsed telephone and the number of pulse signals corresponding to the number of the rotary dial is input to the stations P ₁ and P ₂ , the line is in accordance with the input pulse signal. As the coils L ₁ and L ₂ of the sensor relay 1 repeat driving and driving stop, the switch SW repeats connection and opening, and the input terminal of the dial pulse decoder 2 (

Since the pulse signal is input to the input signal, the dial pulse decoder 2 decodes the input pulse signal, and outputs the decoded signal to the output terminals DO ₀ -DO ₃ to output the input signal (PC ₃ -PC) of the interface circuit 3. ₇ ) After inputted to the central processing unit, the central processing unit determines the subscriber of the counterpart who wants to make a call and decodes the pulse signal to be connected to the voice network terminals V ₁ and V ₂ .

3. When calling a subscriber

A switch SW of the line sensor relay 1 is connected by off-hooking the telephone connected to the stations P ₁ and P ₂ , and a high-potential off-hook detection signal is output to the output terminal OH of the dial pulse decoder 2. In the case of outputting the signal, the high potential off-hook detection signal is inverted to the low potential through the inverter I and input to the AND gate AD, so the AND gate AD continues regardless of the output signal of the interface circuit 3. The low potential is output, the transistor TR ₁ is turned off, and the relay RY cannot be driven so that the movable terminals of the relay switches RYS ₁ and RYS ₂ continue to be connected to the other fixed terminals b ₁ and b ₂ . Therefore, the ring generator call signals RI ₁ and RI ₂ are not output to the telephones connected to the stations P ₁ and P ₂ .

Then, the switch SW of the line sensor relay 1 is opened by hooking the telephone connected to the stations P ₁ and P ₂ , and the low potential is output to the output terminal OH of the dial pulse decoder 2. In this case, the output low potential is converted to high potential through the inverter I and applied to the AND gate AD.

In this state, when the interface circuit 3 outputs a high potential call control signal to the output terminal PA _{7 under} the control of the central processing unit, the AND gate AD reverses the high potential in contrast to the above off hook state. Outputs, the transistor TR is turned on, and the relay RY is driven so that the movable terminals of the relay switches RYS ₁ and RYS ₂ are connected to the fixed terminals a ₁ and a ₂ , so that the ring generator call signal ( RI ₁ and RI ₂ are outputted to the telephones of the stations P ₁ and P ₂ through the relay switches RYS ₁ and RYS ₂ to call the subscriber.

4. If you are talking to each other

Normally, when no telephone call is made, the interface circuit 3 outputs the high potential to the output terminal PA _{4 under} the control of the central processing unit, and the transistor TR ₄ is turned on by the high potential. ₂ , TR ₃ , TR ₅ , and TR ₆ ) are all off.

Therefore, since one terminal of the secondary coils T ₂₁ and T ₂₂ of the transformer T cannot be grounded, the current flow of the voice network terminal V ₁ (V ₂ ) is blocked, and the telephone call is blocked.

In this state, when the telephone call condition is completed and the interface circuit 3 outputs the low-potential call control signal to the output terminal PA _{4 under} the control of the central processing unit, the transistor TR ₄ is turned off. The power supply of the terminal (+ Vcc) is applied through the resistor R ₃ to the base of the transistors TR ₅ and TR ₆ so that it is turned on and through the resistor R ₁₂ again, the transistors TR ₂ and TR ₃ are turned on. It is applied to the base and it is turned on. At this time, the transistors TR ₂ and TR ₃ operate in the saturation region, and the transistors TR ₅ and TR ₆ operate in the active region.

Accordingly, since one terminal of the secondary coils T ₂₁ and T ₂₂ of the transformer T is grounded through the resistors R ₁₅ and R ₁₆ and the transistors TR ₂ and TR ₃ , the voice network terminals V ₁ and V ₂ are grounded. ) Current flows to ground through diodes (D ₂ , D ₃ ), secondary coils (T ₂₁ , T ₂₂ ) of transformer (T), resistors (R ₇ , R ₇ ) and transistors (TR ₂ , TR ₃ ) The voice signal of the other subscriber connected through the voice network circuit of the voice network terminals V ₁ and V ₂ is guided to the primary coil T ₁ of the transformer T so that the extension signal is transmitted through the relay switches RYS ₁ and RYS ₂ . P ₁ , P ₂ ), the voice signal of the subscriber connected to the stations (P ₁ , P ₂ ) is applied to the primary coil (T ₁ ) of the transformer (T) through the relay switch (RYS ₁ , RYS ₂ ) After being guided to the secondary coils (T ₂₁ , T ₂₂ ) and output to the voice network terminals (V ₁ , V ₂ ) it is possible to make a telephone call between the subscriber and the other subscriber.

As described in detail above, the present invention allows subscribers to directly call the counterpart subscribers to make an extension call, as well as to use DTMF-type telephones and pulsed telephones in common, and also to allow subscribers and counterpart subscribers to simply talk. Has the effect of.

Claims (1)

The off-hook detection signal and the output pulse according to the operation of the line sensor relay 1 and the line sensor relay 1 for detecting the off-hook of the telephone connected to the stations P ₁ and P ₂ and the output pulse signal of the pulsed telephone. A dial pulse decoder 2 for outputting a decoded signal of a signal, and an interface circuit for transmitting the output signal of the dial pulse decoder 2 to a central processing unit and outputting a call control signal and a call control signal under the control of the central processing unit; (3) and the dial tone input to the tone network terminal (TN) is output to the stations (P ₁ , P ₂ ), and the DTMF signal of the DTMF telephones of the stations (P ₁ , P ₂ ) is transferred to the tone network terminal (TN). A transformer (T) for outputting and mutually transmitting voice signals of the stations (P ₁ , P ₂ ) and voice network terminals (V ₁ , V ₂ ), and the transformer (T) and voice network terminals ( as to crack down to V _1, the speech signal between V ₂₎ call That consists of a call signal (RI _1, RI ₂₎ an extension call control unit 5 for outputting a phone (P _1, P ₂₎ according to the intermittent portion 4 and, off the call control signal when the hook call An extension circuit interface circuit of a DTMF / pulse telephone.

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