KR920002953B1 - Calling tone generator - Google Patents

Abstract

The circuit includes a call signal current generating means (11) which is connected to a power supply means (12) so as to generate call signal currents. A switching circuit (61) is connected to the power supply means (12) and to the call signal generating means (11) to switch over a operation/standby board which is diplexed to generate normal call signals. A zero crossing signal generating circuit (62) generates zero crossing signals, and a warning circuit (63) informs a warning state, while an operation state displaying circuit (64) displays the state of the operation. In the diplexed operation state, the active components show green light through lamps, while inactive components show no such light.

Description

Call signal current generator for exchange

1 is a block diagram showing the configuration of the present invention.

2 is a configuration diagram of a 20 Hz call signal current generator.

3 is a redundant configuration diagram of the present invention.

4 is a schematic diagram of a power amplifier circuit.

5 is a configuration diagram of a zero crossing signal circuit.

6 is an auxiliary circuit unit configuration diagram.

* Explanation of symbols for main parts of the drawings

11: 20Hz call signal current generator 12: power supply

13: auxiliary circuit part 21: 20 Hz sine wave oscillation circuit

22: attenuation hero 23: power amplifier circuit

24: output voltage amplification circuit 25: relay circuit

26: output voltage adjustment circuit

The present invention relates to a call signal current generator for an exchange. In order to generate such a call signal, a circuit configuration is complicated and a substrate assembly technique has to be compounded since it can only operate as a combination of various linear elements. In addition, due to the complexity of the circuit configuration, the product cost is increased, which is uneconomical and has the disadvantage of lowering productivity.

In order to solve the above-mentioned problems, the present invention reduces the cost by a simple circuit configuration using items such as integrated circuits, hybrid integrated circuits, logic circuit components such as NAND / invert / pipper gates, and particularly stabilizes the call signal current generator. The purpose of the present invention is to provide a call signal current generating device.

The present invention is connected to the power supply means, the power supply means is connected to the power supply means, the call signal current generating means for generating a call signal current of the exchange, the power supply means and the call signal current generating means is redundant A switching circuit for switching a redundant operation / standby board so as to generate a normal call signal current using a control signal, and a zero crossing signal connected to the power supply means and the call signal current generating means to generate a zero crossing signal An alarm circuit connected to the circuit, the power supply means and the call signal current generating means to inform an alarm state, and an operation state display connected to the power supply means, the switching circuit and the alarm circuit to display an operation state It consists of a circuit.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a block diagram of the present invention, which is composed of a 20 Hz call signal current generating unit 11, a power supply unit 12, and an auxiliary circuit unit 13. As shown in FIG. 2 is a configuration diagram of a 2 Hz call signal current generation unit according to the present invention, and includes a 20 Hz sine wave oscillation circuit 22, a subtraction circuit 22, a power amplifier circuit 23, an output voltage amplification circuit 24, and a relay circuit 25. And an output voltage adjusting circuit 26, and FIG. 3 shows a redundancy diagram of the present invention, and FIG. 4 is a power amplifier circuit diagram of the present invention. The low frequency power amplifier A and the resistors R1 to R8 are shown in FIG. ), Capacitors C1 to C8, and heat sinks, and FIG. 5 is a zero crossing signal circuit diagram of the present invention, and includes comparators B1 and B2, diodes D, inverters I1 and I2, and NAND gates. ), Buffers E1 to E4, resistors R10 to R14, and capacitors C10 to C14.

In FIG. 1, the power supply unit 12 removes the spike noise, etc. coming into the input, and the spike noise generated in the oscillation circuit and the power amplifier circuit of the 20 Hz call signal current generator 11 affects the input front end. In order to prevent this from happening, a line filter is configured so that -48Vdc is supplied to the power amplifier circuit of the 20Hz call signal current generator 11, and + 12Vdc is supplied to the attenuation circuit and the oscillation circuit. Is supplied by

In addition, when the input power is supplied with reverse voltage, a protection circuit is formed in the circuit to prevent damage to the devices. However, + 5V is supplied to the auxiliary circuit by configuring a DC conversion circuit in the circuit.

In FIG. 2, the 20 Hz sinusoidal oscillator circuit 21 generates a 20 Hz sinusoidal signal using a simple circuit to easily adjust and vary the oscillation frequency by using a sinusoidal oscillator integrated circuit, a resistor, and a capacitor. It is supplied to the input of the attenuation circuit 22 composed of a combination of an integrated circuit, a resistor, and a capacitor to attenuate the signal to produce a small signal, which is configured to be used as an input signal of the power amplifier circuit 23. The power of the input signal is amplified and the power amplified signal is voltage amplified by the output voltage amplifier circuit 24. The output voltage adjusting circuit 26 consists of an electronic attenuator, an output voltage amplifying transformer, and a potentiometer, and puts a resistor and a capacitor on the primary side of the transformer to focus on reducing excessive vibration and spikes on the output side. The rectifier circuit and the feedback resistor are configured so that the voltage regulator adjusts the potentiometer value to return to the attenuation circuit 22 to promote the output voltage, and supplies the call signal current output through the relay circuit 25.

3 is composed of a device that is in operation and a standby device to increase the reliability of the call signal current generation unit, the switching circuit is required as the device is redundantly mounted in the system. If a failure occurs in the component circuit of the device in operation, an alarm signal is generated by the mutual monitoring and transfer signal, and it can be configured to be automatically switched to the waiting device and can also be switched manually.

4 shows a 20 Hz sine wave by constructing a low pass power amplifier (A) which is a hybrid integrated circuit and a region pass filter (R1, C1) having a characteristic that passes a signal of a frequency lower than 20 Hz without attenuation and has a large attenuation to a higher frequency signal. The amplification of the AC signal is achieved so that a gain of 20dB (decibels) can be obtained.In particular, these compensation and DC blocking capacitors (C7) are configured at the rear of the power amplifier so that the output AC signal voltage compensates the gain as the load changes. It was configured to always obtain a constant output voltage. In addition, when a lot of load is applied to the output side, a large amount of heat is generated in the power amplifier hybrid integrated circuit, and a heat sink considering a thermal design is attached to prevent the component from being destroyed.

In addition, it is designed to remove unnecessary harmonics generated in the oscillator and amplifier in order to obtain stable call signal current output characteristics because the harmonics and noises for the fundamental frequency affect noise noise on adjacent subscriber lines or multiple subscriber calls. . Referring to FIG. 5, the zero crossing point is determined using the voltage difference obtained from the input means 51, the comparison means 52, and the output means 53 as the AC signal voltage output from the power amplifier output AC signal voltage. It is configured to connect at the zero crossing time of 20Hz waveform when detecting and connecting the call signal current to the subscriber. The capacitor C10 is used for input and the buffers E1 to E4 and capacitors C11 to C14 are used for output. By removing the noise induced in the subscriber to the subscriber self is configured to supply.

Here, the input means 51 is composed of a resistor (R10, R11), a capacitor (C10), a resistor (R12) and a diode (D), the comparison means are comparators (B1, B2) and resistors (R13, R14). The output means is composed of inverters I1 and I2, NAND gates NAND, buffers E1 to E4, and capacitors C11 to C14. In the auxiliary circuit section shown in FIG. 6, the switching circuit 61, the zero crossing signal circuit 62, and the alarm circuit 63 are connected to the output voltage amplifying circuit 24, respectively, and the switching circuit 61 is It has a characteristic of the structure connected to the relay circuit 25. In addition, an operation state display circuit 64 is provided so that an operator can easily read the presence of an abnormality. In each interconnection operation, the switching circuit 61 is connected to the output voltage amplifying circuit 24 to detect the output voltage and supplies the call signal current output through the relay circuit 25 when the output voltage is normal. When the output voltage is abnormal, it is detected and switched to the waiting device through the relay circuit 25 by the redundant control signal which is a mutual monitoring and switching signal. At this time, the failing device sends an alarm state to the alarm collecting device through the alarm circuit 63 to notify the abnormality.

The zero crossing signal circuit 62 is connected to the output amplifier amplification circuit 24 from the power amplifier output AC signal voltage through a 1: 1 transformer to detect the output alternating voltage to zero crossing with the circuit configuration shown in FIG. Four signals are supplied to the generating subscriber itself, and when there is an error, the signals are switched to the waiting device through the switching circuit by the redundant control signal. At this time, the failed alarm circuit 63 sends an alarm state to the alarm collection device to inform the abnormality. The operation state display circuit 64 shown in FIG. 6 is provided with a light emitting diode on the front panel to read the operation state of the apparatus. The function to display the status is as follows. When the input power (dc _~ 48V) is supplied, the green light emitting diode (power supply status) lights up to indicate the power supply status, and in case of malfunction or overload condition, the red light emitting diode (alarm status) lights up to indicate the alarm status. .

The device in operation in the redundant operation state displays the operation state by turning on the green light emitting diode (operation state), and the standby device indicates the standby state by turning off the green light emitting diode (operation state). When the input power is supplied with the reverse voltage, the red light emitting diode (power alarm state) is turned on to indicate an abnormality.

As described above, the apparatus of the present invention is for the 20 Hz call signal current of the exchanger, its configuration is simple and economical, and its stabilization and reproducibility are improved.

Claims (6)

A power supply means 12, a call signal current generating means 11 connected to the power supply means 12 for generating a call signal current of the exchange, the power supply means 12 and the call signal current generating means ( A switching circuit 61 for switching a redundant operation / standby board so as to generate a normal call signal current by using a redundancy control signal, the power supply means 12 and the call signal current generating means ( 11 is connected to the zero crossing signal circuit 62 for generating a zero crossing signal, and the alarm circuit 63 connected to the power supply means 12 and the call signal current generating means 11 to inform the alarm condition. And an operation state display circuit 64 connected to the power supply means 12, the switching circuit 61, and the alarm circuit 63 to display an operation state. Generation field . 2. The call signal current generator for a switch according to claim 1, wherein the call signal generated from said call signal current generating means (11) is 20 Hz. 3. The power supply means 12 according to claim 1 or 2, wherein the power supply means 12 generates DC voltages of -48Vdc, + 12Vdc, + 5Vdc, and -5Vdc so that the call signal current generating means 12 and the respective circuits 61 are generated. Call signal current generator for the exchange, characterized in that the supply to, 62, 63, 64. The circuit of claim 1 or 2, wherein the call signal current generating means (11) comprises: a sinusoidal wave oscillation circuit (21), an output voltage adjusting circuit (26) of an attenuation circuit (22) connected to the sinusoidal wave oscillation circuit (21), A power amplification circuit 23 connected to the attenuation circuit 22, an output voltage amplifying circuit 24 connected to the power amplifying circuit 23 and an output voltage adjusting circuit 26, and a power amplifying circuit 24 connected to the output voltage amplifying circuit 24. Call signal current generator for a switch, characterized in that consisting of a relay circuit (25). 3. The zero crossing signal circuit (62) according to claim 1 or 2, wherein the zero crossing signal circuit (62) is connected to two comparators (B1, B2) and the comparator (B1), the inverter (I1) and the comparator (B2). And a NAND logic circuit connected to the call signal current generating device for the exchange, wherein the call signal current is connected to the subscriber by detecting a zero crossing point. 5. The power amplifier circuit of claim 4, wherein the power amplifier circuit 23 comprises a low pass power amplifier (A) connected to the low pass filters (R1, C1), the low pass filters (R1, C1), and a direct current capacitor connected to the amplifier (A). (C7), and its output is supplied to the output voltage amplifying circuit 24, and configured to be fed back through the output voltage adjusting circuit 26 and the attenuation circuit 22 to adjust the output voltage. Call signal current generating device for the exchange.

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