KR890004321B1 - Interface circuit in exchange - Google Patents

Abstract

The circuit includes a detecting unit (1) for converting the calling sginal of magnetic telephone to pulse signal utilizing an OP amp (OP1), for charging or discharging a condensor (C1) utilizing the pulse for detecting the calling signal, and for detecting the off- hook of semi battery telephone utilizing voltage variation caused by hook action, an interface circuit (2) for transmitting detector signal to CPU and for transmitting communication and calling control signal of CPU, a switching unit (4) for switching conmunication path, and a calling controller (5) for transmitting ring signals (RI1, RI2) through local line (P1, P2) according to control signal.

Description

Interface circuit for trunk line and trunk line exchange of magnetic / semi-optic telephone

The accompanying drawings is a circuit diagram of the trunk line, trunk line exchange of the present invention.

* Explanation of symbols for main parts of the drawings

1: call signal and off-hook detection unit 2: interface circuit

3: voice transmission unit 4: call path control unit

5: subscriber call control unit P ₁ , P ₂ : trunk line

OP ₁ : Operational Amplifier C ₁ : Condenser

V ₁ , V ₂ : Voice network terminal RI ₁ , RI ₂ : Ring signal

The present invention is the exchange of trunk lines and trunk lines of a magnetic / semi-optic telephone that enables a telephone call between subscribers of a trunk line and a counterpart subscriber's side connected through the voice network of the trunk line through the common use of the magnetic telephone and the semi-static telephone. It relates to an interface circuit.

In general, magnetic telephones are designed so that the internal circuitry does not change even when the handset is picked up. In addition, the semi-revolutionary telephones are configured to change an internal resistance value according to an off hook and an on hook, that is, the handset is lifted or lowered. Therefore, the magnetic telephone is equipped with a generator, and the conventional magnetic exchange for replacing the magnetic telephone detects a call signal of about 20 Hz output as the subscriber rotates the generator of the magnetic telephone, and according to the detected call signal, After making a call with this subscriber, the subscriber manually connects the desired subscriber to make a telephone call with each other.

In addition, the conventional semi-idle exchanger for replacing the semi-idle phone detects off-hook by detecting the voltage change of the closed circuit due to the change in the internal resistance of the semi-idle phone as the subscriber lifts off the handset of the semi-idle phone. According to the determined off-hook, the operator makes a phone call with the subscriber and then manually connects the desired subscriber to the other party. However, when the magnetic switch is connected to a CO line by a semi-idle phone, the operator cannot detect the hook-off even if the handset of the semi-idle phone is hooked off and cannot detect the hook-off. Even when the telephone is connected, the call signal outputted by rotating the generator of the magnetic telephone is not detected. Therefore, the magnetic telephone must be connected to the magnetic exchanger, and the semi-static telephone must also be connected to the semi-static exchanger. Of course, there is a problem in that the configuration of a communication circuit for transmitting voice signals of subscribers and counterpart subscribers is complicated.

The present invention, in view of the above-mentioned conventional problems, a simple configuration to exchange the magnetic phone and the revolving phone as well as to simply call the subscriber, and to make a smooth phone call between the subscriber and the other subscribers. The invention of the interface circuit for trunk line, trunk line exchange is described in detail with reference to the accompanying drawings.

The accompanying drawings are the interface circuit for trunk line, trunk line exchange of the present invention, as shown here, the call signal and the anti-idle type of about 20Hz output by rotating the generator of the magnetic telephone connected to the trunk line (P ₁ , P ₂ ) Call signal and off with resistors (R _1- R ₈ ), diodes (D ₁ , D ₂ ), operational amplifiers (OP ₁ , OP ₂ ) condenser (C ₁ ) and inverter (I) for detecting the off hook of the telephone A hook detection unit (1), an interface circuit (2) for transmitting an output signal of the call signal hook-off detection unit (1) to a central processing unit, and outputting a call, control signal and a call control signal transmitted by the central processing unit; Condenser (C ₁ ), resistor (R ₉ ), constant voltage diode (ZD ₁ ,) for transferring voice signals input through trunk lines (P ₁ , P ₂ ) and voice signals of voice network terminals (V ₁ , V ₂ ) to each other. ZD ₂₎ and trans (T) and a diode (D _3, the audio transfer unit 3 to D _4), the interface circuit (2) According to a call control signal to be output at trunk line (P _1, P ₂₎ and resistance to crack down on the currency of the speech signal between the voice network terminal _{(V 1, V 2) (} R 10 -R 17) and a transistor (TR ₁ - and the intermittent portion 4 in the currency, TR _5), the interface circuit (2) a ring generative rudder ring signal (RI _1, RI ₂₎ in accordance with a call control signal output from the trunk line (P _1, P ₂₎ The subscriber call control unit 5 includes an AND gate (AD), a transistor (TR ₆ ), a relay (RY), a relay switch (RYS ₁ , RYS ₂ ), and a diode (D ₅ ).

In the relay switch (RYS _1, RYS ₂₎ is its relay (RY) has a movable terminal side fixed terminal when being driven when each connected to (a _1, a ₂₎ is not driving the other fixed terminal on (b ₁ , b ₂ ) are respectively connected, and in the description of the drawings, reference numerals + Vcc and -Vcc denote power terminals.

The operation of the present invention configured as described above is divided into a case of calling a magnetic telephone, an off hook semi-electric telephone, a mutual telephone call, and a subscriber telephone.

One . When calling with a magnetic telephone When the magnetic telephone is connected to the trunk lines (P ₁ , P ₂ ), there is no change regardless of whether the handset of the magnetic telephone is lifted or put down. Here, if the potential applied to the inverting input terminal (-) is lower than the voltage applied to the non-inverting input terminal (+) of the operational amplifier (OP ₁ ), the value of the resistor (R _1- R ₆ ), the operational amplifier (OP ₁ ) outputs a high potential, and the output high potential is inverted and amplified to a low potential through an operational amplifier (OP ₂ ), and inverted back to a high potential through an inverter (I) and then, Input to the input terminal (PB) to inform the central processing unit not to call.

In this state, if the subscriber rotates the generator attached to the magnetic telephone and a call signal of about 20 Hz is input through the trunk line (P ₁ ), (P ₂ ), the input call signal of about 20 Hz is relay switch (RYS _1). , RYS ₂ ) is applied to the non-inverting and inverting input terminals (+) and (-) of the operational amplifier OP ₁ through the other fixed terminals b ₁ and b ₂ , so that the operational amplifier OP ₁ is approximately 20 Hz. The pulse signal is output, and when the output pulse signal is at low potential, that is, a negative potential, the capacitor C ₁ is charged, and when it is at a high potential, discharge through the resistor R ₇ is repeated.

Here, when the long time constant set its value through the resistance (R ₃₎ than the charging time constant of the capacitor (C _1), and it is continued to charge the low-voltage capacitor (C _1), the potential of the operational amplifier (OP ₂ ) is inverted and amplified to high potential through the inverter I, and is inverted back to the low potential through the inverter I and then input to the interface circuit 2 to inform the central processing unit that the call signal has been input.

At this time, the call signal of about 20 Hz is also input to the voice transmission unit 3, but the call signal is blocked by a high-frequency pass filter composed of a capacitor (C ₂ ) and a resistor (R ₉ ), and passes through the voice transmission unit (3). You won't be able to.

2. If you off hook the semi-static phone

When the semi-idle phone is connected to the trunk line (P ₁ , P ₂ ) and the hook is turned off, the internal resistance of the semi-idle phone is about 5 KΩ or more, and the internal resistance of 5 KΩ or more is relay switch (RYS ₁ ,). RYS ₂ ) is connected to the connection points of resistors R ₁ , R ₂ and resistors R ₄ , R ₅ .

At this time, if the potential applied to the inverting input terminal (-) thereof is lower than the potential applied to the non-inverting input terminal (+) of the operational amplifier OP ₁ , the value of the resistors R _1- R ₆ is anti-revolutionary. The op amp OP ₁ outputs a high potential at the on-hook of the telephone, and the high potential is inverted and amplified to low potential through the operational amplifier OP ₂ and inverted back to high potential through the inverter I and then the interface circuit. It is inputted as (2) to notify the on-hook to the central processing unit.

In such a state, when the handset of the anti-idle phone is lifted off-hook, the internal resistance of the semi-idle phone is about 1.5 KΩ or less, and the internal resistance of 1.5 Ω or less is transferred through the relay switch RYS ₁ and RYS ₂ . R ₁ , R ₂ ) and resistors R ₄ , R ₅ .

At this time, if the potential input to the inverting input terminal (-) thereof is lower than the potential applied to the non-inverting input terminal (+) of the operational amplifier (OP ₁ ), the value of the resistor (R _1- R ₆ ), the anti-idal expression When the telephone is off hooked, the operational amplifier OP ₁ outputs a low potential, which is inverted to a high potential through the operational amplifier OP ₂ , and inverted to a low potential through the inverter I, and then the interface circuit ( 2) to inform the central processing unit that it is off hook.

That is, a call signal when a magnetic telephone is connected to the trunk lines P ₁ and P ₂ and the generator of the magnetic telephone is not rotated or a semi-idle telephone is connected to the trunk lines P ₁ and P ₂ and on hooked. And the off-hook detection unit 1 does not detect a call signal or off-hook and outputs a high potential, and when a call signal of about 20 Hz is input by rotating the generator of the magnetic telephone, or when the anti-idle phone is off-hook, the call is called. The low potential is output by detecting a signal or off hook.

3. When making a telephone call in normal times, that is, when not making a telephone call, the interface circuit 2 of the central processing unit outputs a high potential to the output terminal PA ₄ , and the transistor (TR) is operated by the high potential. ₃ ) is on, so the transistors TR ₁ , TR ₂ , TR ₄ , TR ₅ are mode off.

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

In this state, when the telephone call condition is completed and the interface circuit 2 outputs the low-potential call control signal to the output terminal PA _{4 under} the control of the central processing unit, the transistor TR ₃ is turned off. The power supply of the terminal (+ Vcc) is applied through the resistor R ₁₁ to the base of the transistors TR ₄ and TR ₅ so that it is turned on and through the resistor R ₁₂ , the transistors TR ₁ and TR ₂ are again turned on. In the saturation region, the transistors TR ₄ and TR ₅ operate in the active region.

Accordingly, since one terminal of the secondary coils T ₂₁ and T ₂₂ of the transformer T ₁ is grounded through the resistors R ₁₃ and R ₁₄ and the transistors TR ₁ and TR ₂ , the voice network terminals V ₁ , V ₂ ) current through diodes (D ₃ , D ₄ ), secondary coils (T ₂₁ , T ₂₂ ) of transformer (TD ₁ ), resistors (R ₁₃ , R ₁₄ ) and transistors (TR ₁ , TR ₂ ) The voice signal of the other subscriber connected to the ground 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 capacitor C ₂ and the relay switch RYS , RYS ₂₎ a trunk line (P _1, P ₂₎ to be output, CO (with the subscriber's voice signal the relay switch (RYS _1, RYS ₂₎ connected to the P _1, P _2), a capacitor (C ₂ through), and It is applied to the primary coil (T ₁ ) of the transformer (T ₁ ) through a high-frequency pass filter made of a resistor (R ₉ ), guided to the secondary coils (T ₂₁ , T ₂₂ ), and then output to the trunk lines (V ₁ , V ₂ ). Between you and the other party You can make a phone call.

4. When calling the subscriber's telephone, rotate the generator of the subscriber's magnetic telephone or turn off the semi-idle telephone and the call signal and the off hook detection unit 1 output low potential. Regardless of the output signal of the output terminal PA ₇ , the end gate AD outputs a low potential, the transistor TR ₆ is turned off, and the relay RY cannot be driven, thereby relaying the switches RYS ₁ and RYS ₂ . Since the movable terminal of is connected to the other fixed terminal (b ₁ , b ₂ ), the ring signals (RI ₁ , RI ₂ ) output from the ring generator are not output to the trunk lines (P ₁ , P ₂ ). It will not be called.

When the generator of the subscriber's magnetic telephone is not rotated or the semi-idle telephone is turned on and the call signal and the off-hook detection unit 1 output the high potential, the interface circuit 2 is controlled by the central processing unit. When the high potential is output to the output terminal PA ₄ , in contrast to the above, the end gate AD outputs the high potential, the transistor TR ₆ is turned on, and the relay RY is driven to relay the switch RYS. _Since the movable terminals of ₁ and RYS ₂ are connected to the fixed terminals a ₁ and a ₂ on one side, the ring signals RI ₁ and RI ₂ are connected to the trunk line P ₁ and P ₂ through the relay switches RYS ₁ and RYS ₂ . ), The bell embedded in the subscriber's phone is driven and called.

As described in detail above, the present invention can be used by connecting a telephone line (P ₁ , P ₂ ), as well as a magnetic phone and a semi-idle phone in common, and also not only the call circuit of the voice signal, but also to simply call the subscriber. It can be effective.

Claims (1)

CO (P _1, P ₂₎ the magnetic ringing signal of a telephone is an operational amplifier (OP ₁₎ in and converted into a pulse signal and detecting a charge and a call to a discharge signal to the capacitor (C ₁₎ off of the half gongjeonsik telephone connected to a hook Call and magneto-optical telephone of the magnetic telephone to the central processing unit in accordance with the call signal and off-hook detection unit 1 to detect the voltage change due to the change of the internal resistance, and the output signal of the call signal and the off hook detection unit 1 The voice signal of the interface circuit (2), the trunk line (P ₁ , P ₂ ) and the voice network terminals (V ₁ , V ₂ ) for notifying the off hook of the signal and outputting the call control signal and the call control signal under the control of the central processing unit. Voice transmission unit (3) for mutually transmitting the call path control unit for interrogating the communication path of the voice signal of the trunk line (P ₁ , P ₂ ) and the voice network terminal (V ₁ , V ₂ ) according to the call control signal (4) and a ring signal RI ₁ in accordance with the call control signal. And a subscriber line control unit (5) which outputs RI ₂ ) to a trunk line (P ₁ , P ₂ ) to call a subscriber.

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