KR0175379B1 - Handset neglect alarm device using error tone - Google Patents

Abstract

The present invention relates to a handset neglect warning device using an error tone applied to a telephone or the like, comprising: a buffer unit 1 for impedance matching an error tone signal transmitted from a telephone station; A filter unit (2) for separating and smoothing an error tone composite signal and a cadence signal by direct current; A waveform shaping unit 3 for converting the signal smoothed by the filter unit 2 to a logic level; A hook switch state detecting unit 6 connected to the hook switch of the telephone and detecting an on / off state of the hook switch; If the hook switch is off and the error tone signal is applied, the output signal of the waveform shaping section 3 and the output signal of the hook switch state sensing section 6 are alarmed until the hook switch is turned on. It is composed of a logic unit (4) for generating a drive signal, the alarm device is activated in the telephone when the handset is left, and notifies the user of the state of neglect, thereby reducing the power loss of the telephone station and the incoming call due to the transmission of an error tone signal when the handset is left. The present invention relates to a handset neglect alarm device using an error tone signal that can solve a problem of failing to receive a signal.

Description

Handset neglect alarm device using error tone

1 is a block diagram showing the configuration of a handset alarm device using an error tone according to an embodiment of the present invention,

2 is a detailed circuit diagram of the first diagram,

3 is a waveform diagram of each part of FIG. 2.

* Explanation of symbols for main parts of the drawings

1: buffer part 2: filter part

3: waveform shaping part 4: logic part

5: Alarm device 6: Hook switch state detection unit

The present invention relates to a handset neglect warning device, and more particularly, to a handset neglect warning device using an error tone applied to a telephone or the like.

The basic telephone can't receive telephone calls from other people and waste of power due to howler or error tone when the handset is left in place due to user's carelessness or children's mischief. There was a problem.

To solve this problem, the telephone station monitors the subscriber circuit and sends an error tone to the neglected subscriber circuit when one of the subscriber circuits is cut off but the corresponding one of the subscriber circuits is not cut off (the handset is left unattended).

In addition, when the state subscriber is in a call and is left unattended while placing the handset on the telephone, the telephone station sends an error tone to notify the subscriber of the handset neglect.

However, the howler tone or error tone is not easy to be perceived by the user in a loud or noisy space because the sound is small, and the telephone company does not transmit the haulertone or error tone indefinitely, and stops after sending it for a certain time. The problem remains that the incoming call cannot be received.

Therefore, an object of the present invention for solving the above technical problem is to detect whether the error tone is applied and the handset neglect alarm using the error tone to notify the user of the state of the handset through the alarm device until the handset is in place. To provide a device.

The present invention for achieving the above object is a buffer unit for impedance matching the error tone signal sent from the telephone station; A first low pass filter for separating the complex frequency signal of the error tone, a second low pass filter for smoothing the output signal of the first low pass filter with DC, and an agent for separating and smoothing the cadence signal of the error tone with direct current A filter unit composed of three low pass filters; A waveform shaping unit for converting the signal peacefully converted into direct current by the filter unit to a logic level; A hook switch state detecting unit connected to the hook switch of the telephone and detecting an on / off state of the hook switch; A logic unit configured to receive an output signal of the waveform shaping unit and an output signal of the hook switch state sensing unit, and generate an alarm driving signal until the hook switch is turned on when the hook switch is in an off state and an error tone signal is applied. .

The invention further includes an alarm device connected to the logic unit for notifying the outside of the handset in accordance with the alarm drive signal.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

FIG. 1 is a block diagram of a handset neglect warning device using an error tone according to an embodiment of the present invention. FIG. 2 is a detailed circuit diagram of FIG. 1 and FIG. 3 is a waveform diagram of each part of FIG.

First, a handset neglect warning device using an error tone according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, a handset neglect warning device using an error tone according to an embodiment of the present invention includes a buffer unit 1 that receives an error tone signal transmitted from a telephone station, and an output signal of the buffer unit 1. (b, c) a filter unit 2 for receiving input, a waveform shaping unit 3 for receiving the output signals d, e of the filter unit 2, a clock signal CK, and the waveform shaping unit Logic section 4, which receives the output signals f and g of (3), is connected in sequence, and is connected to the hook switch of the telephone to send the output signal i to the logic section. ) Is connected, and the alarm device 5 is connected to the output terminal of the logic unit 4.

In the handset neglect alarm device using an error tone according to the embodiment of the present invention described above, a speaker, a warning lamp, or a similar device may be connected to the alarm device 5, and the technical scope of the present invention includes all of them.

The buffer unit 1 of the handset neglect alarm device using the error tone according to the embodiment of the present invention receives an error tone signal a transmitted from a telephone station and performs an impedance matching operation.

The output signals b and c of the impedance matched buffer unit 1 are input to the filter unit 2, and the cadence which is a complex frequency signal of an error tone and an on / off signal from the input signal by the filter unit 2 After the cadence signal is separated, it is smoothed by direct current.

When the output signals d and e of the smoothed filter part 2 are inputted to the waveform shaping part 3 and converted to a logic level, the output signals f and g of the waveform shaping part 3 become the logic part 4. ) Is entered.

Meanwhile, the hook switch state detecting unit 6 connected to the hook switch of the phone detects the on / off state of the hook switching. For example, when the hook switch is in the on state, the hook switch state detecting unit 6 outputs a high signal through the output terminal i, and when the hook switch is in the off state, the hook switch state detection unit 6 outputs a low signal. Output through When the hook switch is in the on state, it means that the handset is in a normal position. When the hook switch is in the off state, it means that the handset is in a busy state or in an idle state.

The logic section 4 detects whether the handset is left and an error tone is input from the output signal f of the waveform shaping section 3 and the output signal i of the hook switch state sensing section 6, If it is determined that the handset is left and an error tone is input, the alarm device 5 is driven by outputting a high signal.

2 and 3, a handset neglect warning device using an error tone according to an embodiment of the present invention will be described in more detail.

As shown in FIG. 2, the buffer unit 1 of the handset neglect warning device using the error tone according to the embodiment of the present invention is composed of two buffers 11 and 12 for receiving an error tone signal.

The filter unit 2 connected to the buffer unit 1 includes a first low pass filter 21 and second and third low pass filters 22 and 23. A first low pass filter 21 and a second low pass filter 22 are connected to the buffer 11, and a third low pass filter 23 is connected to the buffer 12.

The waveform shaping unit 3 connected to the filter unit 2 includes two operational amplifiers 31 and 32 and a reference voltage generator circuit 33.

An operational amplifier 31 is connected to an output terminal of the second low pass filter 22, an operational amplifier 32 is connected to an output terminal of the third low pass filter 23, and the operational amplifiers 31 and 32 are connected to each other. Each non-inverting input terminal is provided with reference voltages Vref1 and Vref2 generated by the reference voltage generating circuit 33.

The logic section 4 connected to the waveform shaping section 3 and the hook switch state sensing section 6 includes two inversion logic elements 41 and 42, a counter 43, a frequency discrimination circuit 44 and Two latch circuits 45 and 46 and an inverted logic element 47 connected to the output terminals of the two latch circuits 45 and 46.

Inverting logic element 41 receives the output signal (f) of the operational amplifier 31 and the output signal of the hook switch state detection unit 6, the inverted logic element 42 is the output signal of the operational amplifier 32 (g) and the output signal i of the hook switch state detection unit 6 are received.

A counter 43 to which a clock signal CK is applied is connected to an output terminal of the inverted logic element 41, and a frequency discrimination circuit 44 to which a clock signal CK is applied to an output terminal of the inverted logic element 42. Is connected.

Two latch circuits 45 and 46, to which the output signal i of the hook switch state sensing unit 6 is input, are sequentially connected to the output terminal of the counter 43 and the frequency discrimination circuit 44. The latch circuit Each output signal of (45, 46) becomes an input of the inversion logical element 47. An alarm device 5 is connected to the output terminal of the inverted logic element 47.

According to the embodiment of the present invention described above, an RS flip-flop (RS-Flip Flop) is used as the latch circuits 45 and 46, but the technical scope of the present invention is not limited thereto.

The handset neglect alarm device using an error tone according to an embodiment of the present invention measures a first path for determining whether there is a complex frequency component of an error tone signal and a cadence period of the error tone signal to determine whether an error tone is input. It consists of two paths, and the alarm device 5 is driven only when it is determined that the error tone is input through both the first path and the second path, thereby enabling stable operation of the circuit.

3 shows a waveform diagram of each part of FIG. 2. 3A is an error tone signal, d in FIG. 3B is an output waveform of the second low pass filter 22, and Vref1 is a waveform applied to the non-inverting input terminal of the operational amplifier 31. Referring to FIG.

In FIG. 3C, e is an output waveform of the third low pass filter 23, Vref2 is a waveform applied to the non-inverting input terminal of the operational amplifier 32, and g is an output waveform of the operational amplifier 32.

The waveform shown in FIG. 3D is a falling edge detection waveform of waveform g for determining the frequency of the cadence in the frequency discrimination circuit 44.

As shown in FIG. 3a, two sections ① and ② exist in the error tone signal, a section ① is a complex frequency section between 400 and 700 kHz, and a section ② is a no signal section. The lengths of the sections ① and ② are the same at 400 msec.

When the power is applied and the operation of the circuit starts, the error tone signal a is commonly input to the buffers 11 and 12. Each of the buffers 11 and 12 performs impedance matching with respect to the input signal a and transmits the output signal to the first low pass filter 21 and the third low pass filter 23.

First, a first path for determining a complex frequency component will be described.

A signal corresponding to 400 Hz to 700 Hz is filtered by the first low pass filter 21, and the filtered signal is smoothed to DC by the second low pass filter 22.

As shown in FIG. 3B, when the reference voltage Vref1 is set smaller than the signal d smoothed by the second low pass filter 22, the output f of the operational amplifier 31 which operates as a comparator Becomes low during the interval of error tone ①.

Since the handset is in the idle state, the output i of the hook switch state detecting unit 6 is low, so that the output of the inversion logic element 41 becomes high and is applied to the high signal of the inversion logic element 41. The counter 43 releases the reset to perform the counting operation.

Since the reset may be canceled by the noise component, the output of the counter 43 is made high only when the counting continues for more than 10 cycles (8 seconds) of the error tone. The output is low when the counter 43 is reset.

Therefore, the output of the latch circuit 45 before the error tone is input is high, and when it is determined that the error tone is input, the output of the latch circuit 45 becomes low to reset the counter by the hook switch. Unless otherwise specified, the output of the latch circuit 45 is kept low.

Next, a second path for determining an error tone in a cadence period will be described.

The error tone signal smoothed by direct current through the third low pass filter 23 is the same as e shown in FIG. E shown in FIG. 3C is the output of the third low pass filter 23, Vref2 is a reference voltage applied to the non-inverting input terminal of the operational amplifier 32 that operates as a comparator, and g is the operational amplifier 32. Output waveform.

That is, the output period of the operational amplifier 32 is equal to the cadence period of the error tone signal. The detected cadence signal is input to the frequency discrimination circuit 44 and converted into a falling edge detection signal as shown in FIG. 3d. Frequency discrimination is performed only when the 800 msec period of the error tone signal continues for more than 10 cycles (8 seconds). The output of the circuit 44 goes high. When the output of the frequency discrimination circuit 44 is high and the output i of the hook switch state sensing section 6 is low, the latch circuit 46 enters the frequency discrimination circuit 44 or the hookswitch state. The output terminal keeps low until the state of the sensing section 6 changes.

When the output i of the hook switch state detecting unit 6 is high, the output of the frequency discriminating circuit 44 is low.

As described above, when it is determined that the error tone signal a is input and the handset is left unattended, the outputs of the two latch circuits 45 and 46 are all low and the output terminal of the inverted logic element 47 is high. The alarm device 5 can be driven by a high signal.

In addition, when the hook switch is turned on while the alarm device 5 is being driven, that is, the handset is corrected to a normal state, the output of the latch circuits 45 and 46 becomes high, and the inversion logic element 47 The output goes low to stop the driving of the alarm device 5.

As described above, in the embodiment of the present invention, when the handset is left, the alarm device is activated in the telephone to notify the user of the state of neglect, thereby causing the power loss and jamming of the telephone station due to the transmission of an error tone signal or a howling tone signal when the handset is left. The handset neglect alarm device using an error tone signal can solve the problem of not receiving an incoming call.

Claims (5)

A buffer unit 1 for impedance matching the error tone signal transmitted from the telephone station; A first low pass filter 21 for separating an error tone complex frequency signal, a second low pass filter 22 for smoothing the output signal of the first low pass filter 21 to DC, and a cadence of an error tone A filter part 2 composed of a third low pass filter 23 for separating and smoothing the signal by direct current; A waveform shaping unit (3) for converting the signal peacefully converted into direct current by the filter unit (2) to a logic level; A hook switch state detecting unit 6 connected to the hook switch of the telephone and detecting an on / off state of the hook switch; When the hook switch is turned off and an error tone signal is applied, the hooks are inputted with the output signals f and g of the waveform shaping section 3 and the output signal i of the hook switch state sensing section 6. And a logic section 4 for generating an alarm driving signal until the position is turned on. The waveform shaping section 3 includes a reference voltage generating circuit for generating two reference voltages Vref1 and Vref2. 33); An operational amplifier (31) for detecting a complex frequency component of the error tone signal from the output signal (d) of the first low pass filter (22) with the reference voltage (Vref1); Handset neglect alarm device using an error tone signal, characterized in that it comprises an operational amplifier (32) for detecting the cadence period from the output signal (e) of the second low pass filter (23) to the reference voltage (Vref2). The method according to claim 1, further comprising an alarm device (5) connected to the logic unit (4) and driven by an alarm driving signal, the alarm device (5) for notifying the user of the handset neglect state. Handset neglect alarm. The handset neglect alarm device using an error tone signal according to claim 2, wherein the alarm device is a speaker or a warning lamp. The logic unit (4) according to claim 1 or 2, wherein the logic unit (4) is for inverting and logically combining the output signal (f) of the operational amplifier (31) and the output signal (i) of the hook switch state detection unit (6). An inversion logic element 41; An inversion logic element (42) for inverting and logically combining the output signal (g) of the operational amplifier (32) and the output signal (i) of the hook switch state detection unit (6); A counter 43 for performing a counting operation by the high signal of the inverted logic element 41 and outputting a high signal when the error tone continues for a predetermined period or more; A frequency discriminating circuit (44) for converting the output signal of the inverted logic element (42) into an edge detection waveform and outputting a high signal if the cadence period continues for a predetermined period or more; A latch circuit (45) for outputting a low signal when the output signal (i) of the counter (43) is high and the output signal (i) rk off of the hook switch state detection unit (6); The low signal when the output signal of the frequency discrimination circuit 44 is high, the output signal of the hook switch state sensing unit 6 is high, and the output signal i of the hook switch state sensing unit 6 is off. A latch circuit 46 for outputting the same; Handset neglect alarm device using an error tone signal, characterized in that it comprises an inverted logic element (47) for inverting logic of the output of the latch circuit (45, 46). 5. The handset neglect alarm device using an error tone signal according to claim 4, wherein said latch circuit (45, 46) is an RS flip-flop.