KR890005373B1 - Direct calling circuit of internal numbers which make use of dial pulses - Google Patents

Abstract

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Description

Extension call circuit using dial pulse detection

1 is a block diagram according to the present invention.

2 is a detailed circuit diagram of the hook on / off sensing and dial pulse counter circuit 50 of FIG. 1 according to the present invention.

3 is a detailed circuit diagram of the hybrid and balancing circuit 30 of FIG. 1 according to the present invention.

4 is an operation timing diagram of the codec circuit 40 of FIG. 1 according to the present invention.

5 is a detailed circuit diagram of FIG. 1 according to the present invention.

6 is an operation timing diagram of FIG. 5 according to the present invention.

The present invention relates to a circuit in which a local subscriber can call a private exchange subscriber at a local exchange and a private exchange interface. In particular, the private exchange interface can directly call a private exchange subscriber without going through a relay station using a dial pulse counter. The present invention relates to an extension direct calling circuit using a dial pulse detection.

In the related art, there is a inconvenience in that a subscriber station of a national exchange has to go directly to a relay station when calling a private exchange subscriber.

Accordingly, an object of the present invention is to provide a circuit capable of directly calling a subscriber of a private exchange without using a dial pulse counter when calling a private exchange subscriber in order to solve the conventional problems.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram according to an embodiment of the present invention, a polarity reverse signal transmitting circuit 10 inverting and transmitting polarity of an input / output signal at input and output terminals 11 and 12, which are a tip and a ring terminal, Balancing and hybrid network for converting high frequency (more than 3400Hz) and AC component and transformer 20, impedance matching between transformer 20 and rear end, and converting 2-wire to 4-wire (Hybird Net Work) circuit 30, a Combo-Codec circuit 40 for converting a voice analog signal to PCM data or a PCM data to an analog signal, a hook on / off sensing signal and Hook on / off detection and counter circuit 50 for counting dial pulses, first buffer 60 for buffering transmitted PCM data, second buffer 70 for buffering received PCM data, and hook on / off A third buffer (80) for buffering the off-sensing and output of the counter circuit (50) and the extreme inversion A relay drive circuit 90 for driving the outgoing relay of the call sending circuit 10 and an address latch circuit 100 for latching the drive value of the relay drive circuit 90 to the next value.

Referring to the functional names of reference numerals 11-20, which are not described above, 11 is a tip line, 12 is a ring, and two terminals of a telephone line or a trunk line, 13 is a transmission PCM data line, and 14 Is the receiving PCM data line, 15 is the combo-codec's input clock line (2.048 MHz), 16 is the signal line enabling the codec, and 17 is the data line read data with hook on / off detection and dial pulse counter values. 18 is a read enable signal line, 19 is a write enable signal line, and 20 is a data line for writing a PRS data value when the inversion signal PRS value is decreased.

Therefore, when an embodiment of the present invention is described in detail with reference to FIG. 1, when a local exchange subscriber tries to directly call a private exchange user through a trunk, the local exchange subscriber forms a loop with a private exchange width. When the loop is formed between the (11, 12) and the local exchange connection, the hook on / off detection and the counter circuit 50 is recognized as a hook off state. At this time, the central purifier (not shown) periodically sends a read enable signal to the terminal 18 and scans the input state of the terminal 17. The hook-off reads through the terminal 17 to prepare a dial pulse counter. At this time, when the user of the local exchange turns the extension number, the ring on / off detection and the dial pulse counter of the counter circuit 50 check the extension number and transmit a ring signal to the extension subscriber.

When the write enable signal is sent to the terminal 19 after the hook-off state, the inverted signal data is inputted through the address latch 100 through the terminal 20 to the relay drive circuit 90 to drive the relay. Since the polarity is inverted by inputting this signal to the inversion signal transmitting circuit 10, the polarity of the tips and ring terminals 11 and 12 of the trunk line is inverted.

Then, when the enable signal is applied to the codec circuit 40 through the terminal 16, a call path is formed. The voice signal passes only the voice component through the transformer 20. In the balancing and hybrid network circuit 30, The receiving part is separated and the transmitted voice signal is converted into the PCM data value in the codec circuit 40 and passed through the first buffer 60 and the terminal 13 through a time switch and then delivered to the private exchange user.

The voice signal of the private exchange user is buffered in the second buffer 70 via the terminal 14 through the time switch, and the codec circuit 40 converts the voice analog signal. The converted signal is transmitted to the trunk lines 11 and 12 through the transformer 20 through the balancing and hybrid network 30.

The release of the call is performed by returning to the inverted signal transmitting circuit 10 when the private exchange user hooks up. And by continuing hook on / off detection, hooking up from the outside restores the inverted signal.

2 is a detailed circuit diagram of the hook on / off sensing and dial pulse counter circuit 50 according to the present invention. In FIG. 2, BD is a bridge diode, T ₁ -T ₄ is a transistor, R ₁ -R ₁₃ is a resistor, and D ₁ The silver diodes and LEDs are light emitting diodes, and reference numerals 11, 12, and 17 not described above are the same as those in FIG.

The trunk line 11, 12 input terminal Ring is connected to the base of the transistor T ₂ through the bridge diode BD and the resistor R ₂ , and the input terminal Tip is connected to the bridge diode BD. (R ₁₎ is connected to the base of the transistor (T ₁₎ through the emitter of the transistor (T ₁₎ is connected through the emitter and a resistor (R ₆₎ of the transistor (T ₂₎ transistor (T ₂₎ The collector of is connected to the base of the transistor T ₁ . The resistor R ₅ is connected to the collector of the transistor T ₁ so that the resistor R ₈ and the diode D ₁ are connected in parallel with the ground, and the resistor R ₉ is connected to the diode D ₁ cathode side. Capacitor (C ₁ ) is grounded from the resistor (R ●) and connected via resistor (R ₁₂ ) at the collector of transistor (T ₃ ) through resistor (P ₁₀ ) and from resistor (R ₉ ). through a resistor (R ₁₁₎ is connected to the base of the transistor (RT ₃₎ the transistor (T ₃₎ and from the collector connected to a resistor (R ₁₄₎ transistor connected to the base of (T ₄₎ and the transistor (T ₄₎ It is configured by connecting the cathode side of the light emitting diode (LED) via a resistor (R ₁₃ ) to the collector of.

An embodiment with the above-described configuration will be described with reference to FIG.

In the idle state, that is, the hook-on state, the tip line 11 is grounded at the -48V ring line 12 so that the transistor T ₁ is turned off and the transistor T ₂ is turned on and the + 5V The transistor T ₃ is turned on and the transistor T ₄ is turned off by the bias voltage, and the line 17 is turned low.

When a hook-off state current flows into tipseon 11 in ringseon 12 wherein timseon 11 takes a higher voltage than the voltage is -48V voltage ringseon 12 may take a voltage lower than the ground transistor (T ₁₎ Is turned on and the transistor T ₂ is turned off. At this time, since the transistor T ₁ is turned on, the voltage applied to the resistor R ₈ becomes a (−) voltage. Thus, the transistor T ₃ is turned off and the transistor T ₄ is turned on.

As the transistor T ₃ is turned off and the transistor T ₄ is turned on, the line 17 is turned high by the voltage applied to the resistor R ₁₄ and the light emitting diode LED is turned on.

The hook on state is the same as the dormant state, and the dial pulse is a repetition of the hook on / off. Therefore, the hook on state is checked according to the hook off state checking method described above. That is, in the dial pulse check state, the line 17 repeats high and low by the dial pulse.

FIG. 3 is a detailed circuit diagram of the hybrid and balancing circuit 30 of FIG. 1 according to the present invention, in which RR is a resistor, FIG. The resistors R _a -R _C and impedance Z i are composed of bridges, and the output gain is adjusted by the resistors R _g and R _g .

Referring to FIG. 3, the balance and line conversion will be described in detail. Therefore, the codec 40 should have a function such that the analog signal outputted from the output terminal is not induced back to the input terminal, that is, there is no crosstalk. 40, an analog output signal is output through the output terminals 32 and 33.

In this case, the gain is adjusted by the resistors R _l and R _h and the analog output signal is zero at the input terminal 31 of the codec 40. At this time it eliminates the cross-talk by the impedance matching with the impedance as viewed in FIG. 1 a transformer (20) (Zi) and a resistor _{(R a, R b, R} c). Here, the resistors R _f and R _g are for adjusting the input gain of the codec 40.

4 is an operation waveform diagram of the codec 40 of FIG. 1 according to the present invention. FIG. 4 (4a) is a frame synchronization signal waveform diagram. FIG. 4 (4b) is a clock pulse waveform diagram. The frequency of the pulse is 2.048 MHz. 4 (4c) is a signal capable of enabling 32 channels, 4 (4d) is a high way enable signal, and 4 (4e) is a data output to the output terminal of the codec 40. This is an example of a waveform.

Referring to FIG. 4, an embodiment of the present invention will be described. In the configuration combo codec 40 of the present invention, 8KHz sampling is performed, and 32 (4c) signals of FIG. 32 comes out. That is, one subscriber can share 32 subscribers, and each subscriber needs to assign a channel.

As shown in Fig. 4, during the time slot in which the signal is received (4c), the signal (4d) enables the highway buffer, and during this time (4e) data comes out.

FIG. 5 is a detailed circuit diagram of FIG. 1 according to the present invention, which has been described in detail with reference to FIGS. 2-4, and FIG. 6 is an operational waveform diagram of FIG.

(6a) is the trunk line on / off detection signal, (6b) is the old width idle state signal, (6c) the trunk line is the write signal, and (6d) is the station hook on / off detection signal, ( 6e) is an extension signal.

Referring to FIG. 5 to FIG. 6, a specific embodiment will be described. The relay switch K ₁ is driven to transmit a polarity inversion signal, which is similar to the waveforms of FIGS. 6C and 6E while being written. The line 19 is in the "high" state, and the output of the operational amplifier OP ₁ drives the relay RY to reverse the polarity of the polarity inversion signal, that is, the trunk lines 11 and 12.

As described above, it is possible to call a private exchange subscriber using a dial pulse counter without using a relay, thereby eliminating hassles and reducing system cost.

Claims (1)

In a circuit in which a CO line subscriber can call a private switch subscriber, a polarity inverted signal transmitting circuit (10) for inverting and transmitting the polarity of an input / output signal at the input / output terminals (11, 12), which are tip and ring ends, and a high frequency and AC component A transformer 20 having a function of blocking the signal, a balancing and hybrid network circuit 30 for converting the impedance between the transformer 20 and the rear end and converting two wires into four wires, and a voice analog signal A codec circuit 40 for converting or converting PCM data into an analog signal, a hook on / off sensing and counter circuit 50 for counting a hook on / off sensing signal and a dial pulse, and buffering transmission PCM data A first buffer 60, a second buffering 70 buffering received PCM data, a third buffer 80 buffering the output of the hook on / off sensing and counter circuit 50, and the extreme inversion. Transmission relay of the signal transmission circuit 10 An internal direct call circuit using dial pulse detection, comprising: a relay drive circuit 90 for driving a; and an address latch circuit 100 for latching a drive value of the relay drive circuit 90 to a next value .

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