JP3047992U - Ring tone generator - Google Patents

Abstract

(57) [Summary] To stabilize the ringing tone when the level of an incoming signal is low, and to prevent the volume of the ringing tone from decreasing when the level of the incoming signal is high. A ringing tone signal generating circuit for generating a ringing tone signal using a direct current obtained by rectifying and smoothing an incoming signal led through a public telephone line as an operating power supply.
And a speaker 5 for generating a ringing tone in accordance with a ringing tone signal
And a voltage shifter D1 inserted into the signal path of the speaker 5 and having a constant voltage drop value.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to communication equipment connected to a communication line, such as a telephone or a facsimile machine, and more specifically, operates a direct current obtained by rectifying and smoothing an incoming signal guided through the communication line. The present invention relates to a ring tone generator that generates a ring tone as a power source.

[0002]

[Prior art]

 Telephones that do not require a commercial power supply are configured to perform all operations using power guided through a public telephone line. For this reason, as shown in FIG. 3, the ringing tone generating device for notifying the incoming call uses the DC obtained by rectifying and smoothing the incoming call signal led through the public telephone line 9 as an operating power source to generate a ringing tone. Is generated.

[0003] More specifically, the rectifying and smoothing circuit 61 is a block for sending a DC output obtained by rectifying and smoothing an incoming signal to the ringing circuit 2. The ringing circuit 2 is a block that operates using the DC output sent from the rectifying and smoothing circuit 61 as a power supply. When the voltage of the DC output exceeds a set value, a ringing signal is generated, and 5

The rectifying / smoothing circuit 61 and the ringing tone circuit 2 have the above-described configuration. Therefore, when the level of the incoming signal is sufficient, a large amount of charge is accumulated in the smoothing capacitor, and the terminal voltage is high. Further, a large amount of current is supplied from the rectifying diode. Therefore, even when the ringing circuit 2 starts operating and a current flows through the ringing circuit 2, the voltage supplied to the ringing circuit 2 is maintained at a voltage at which stable operation is possible. However, when the level of the incoming signal is low, the accumulated electric charge is small and the voltage between terminals is low. The current supplied from the rectifying diode is small. Accordingly, when the ringing circuit 2 starts operating when the level of the incoming signal is low, the output voltage of the rectifying and smoothing circuit 61 causes the operation of the ringing circuit 2 to stop due to the effect of the current flowing through the ringing circuit 2. To voltage. As a result, an unstable situation occurs in which the ringing tone, which must continue for 200 to 300 mS, stops halfway, and once the ringing tone starts ringing, it stops halfway.

[0005] The resistor R6 is an element for preventing the above-described problem from occurring. That is, when the resistor R6 is provided, the impedance on the speaker 5 side when viewed from the ringing circuit 2 increases, and the current for driving the speaker 5 decreases. Therefore, the current consumption of the ringing circuit 2 is reduced. When the current consumption of the ringing circuit 2 is reduced, a decrease in the output voltage of the rectifying / smoothing circuit 61 is suppressed even if the level of the incoming signal is low. As a result, even if the level of the incoming signal is low, the ringing circuit 2 can operate continuously, and a stable ringing sound is generated from the speaker 5.

[0006]

[Problems to be solved by the invention]

 However, a problem that occurs when the above configuration is used will be described with reference to FIG. 2 on the assumption that the value of the resistor R6 is equal to the impedance of the speaker 5.

[0007] In FIG. 2, reference numeral 21 denotes a waveform of the ringing tone signal when the level of the incoming call signal is low, and reference numeral 22 denotes a waveform of the ringing tone signal when the level of the incoming call signal is high. The ringing circuit 2 outputs a ringing signal having the above-described waveform corresponding to the level of the incoming signal. However, since the resistor R6 is inserted in the signal path of the speaker 5, the signal level applied to the speaker 5 becomes the level V3 when the level of the incoming signal is low, and becomes the level V8 when the level of the incoming signal is high. .

That is, regardless of the level of the incoming call signal, the level of the ringing tone signal applied to the speaker 5 is half the level of the ringing tone signal output by the ringing tone circuit 2. Therefore, the sound pressure of the ringing tone generated by the speaker 5 becomes 1/4. For this reason, the level of the incoming call signal becomes sufficient, and even when the level of the ringing tone signal output by the ringing tone circuit 2 increases, the volume of the ringing tone generated by the speaker 5 is small. As a result, in an environment where the surrounding noise is loud, for example, even when the level of the incoming signal is sufficient, the volume of the ringing tone does not increase and the ringing tone becomes inaudible.

The present invention has been made to solve the above problems, and an object of the present invention is to insert a voltage shifter having a constant voltage drop value into a signal path of a speaker. Accordingly, it is possible to provide a ringing tone generator capable of stabilizing generation of a ringing tone when the level of an incoming signal is low and preventing a decrease in volume of the ringing tone when the level of the incoming signal is high. It is in.

A fourth object of the present invention is to provide a ringing tone generator which can reduce the cost of the voltage shifter by using a zener diode as the voltage shifter. is there.

[0011]

[Means for Solving the Problems]

 In order to solve the above-mentioned problem, a ringing tone generating device according to the present invention is applied to a communication device connected to a communication line, and rectifies and smoothes an incoming signal guided through the communication line. A ring tone signal generation circuit for generating a ring tone signal using the DC obtained by the above as an operating power source, a speaker for generating a ring tone in accordance with the ring tone signal generated by the ring tone signal generation circuit, and a signal path of the speaker And a voltage shifter having a constant voltage drop value. That is, the voltage shifter is inserted in the signal path of the speaker. Accordingly, the level applied to the speaker is a level obtained by subtracting the voltage drop value of the voltage shifter from the level output by the ringing tone signal generation circuit. Therefore, when the level of the incoming signal is low and the level of the ringing signal from the ringing signal generation circuit is low, the voltage drop value by the voltage shifter has a large ratio to the level of the ringing signal. As a result, the drive current of the speaker decreases at a large rate. Therefore, even when the level of the incoming call signal is low, the ringing tone signal generation circuit outputs a stable ringing tone signal. On the other hand, when the incoming signal level is high and the ringing signal level is high, the voltage drop value by the voltage shifter has a small ratio to the ringing signal level. For this reason, the rate at which the level of the ringing tone signal applied to the speaker decreases is small. Therefore, when the level of the incoming signal is high, a ringing tone of sufficient volume is generated from the speaker.

Further, in the ring tone generating device according to the present invention, in addition to the above configuration, the communication device connected to the communication line is a telephone connected to a public telephone line. For this reason, the ringing tone of the telephone becomes a stable ringing tone even when the level of the incoming signal is low, and becomes sufficient when the level of the incoming signal is high.

[0013] Further, in the ringing tone generating device according to the invention of claim 3, in addition to the above configuration, the communication device is an image communication device. For this reason, the ringing tone of the image communication device becomes a stable ringing tone even when the level of the incoming signal is low, and becomes sufficient when the level of the incoming signal is high.

Further, in the ringing tone generator according to the present invention, the voltage shifter is a Zener diode in addition to the above configuration. That is, the Zener voltage of the Zener diode may be lower than the level of the ringing tone signal output from the ringing tone circuit when the level of the incoming signal is low. Therefore, an inexpensive element having a low Zener voltage can be used for the Zener diode.

[0015]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an electrical configuration of an embodiment of a ringer according to the present invention. Note that the same reference numerals as in FIG. 3 are given to portions having the same configuration as the conventional technology shown in FIG.

In FIG. 1, a ringing tone signal generation circuit 1 generates a direct current by rectifying and smoothing an incoming signal guided through a public telephone line 9, and generates a ringing tone signal using the generated direct current as an operation power source. It is a block to be generated. For this purpose, two capacitors C1 and C2, a resistor R1, a diode bridge 3, a Zener diode D2, and a ringer circuit 2 are provided.

In detail, one of the public telephone lines 9 is connected to the AC of the diode bridge 3 via a capacitor C1 for removing a DC component of the public telephone line 9 and a resistor R1 for matching the line impedance. Connected to one of the inputs. The other end of the public telephone line 9 is connected to the other end of the AC input of the diode bridge 3. The positive output of the diode bridge 3 is connected to one terminal of a capacitor C2 and the cathode of a Zener diode D2. The negative output of the diode bridge 3 is at the ground level, and the other terminal of the capacitor C2 is connected to the anode of the Zener diode D2. The positive output and the negative output of the diode bridge 3 are connected to the ringing circuit 2.

Therefore, when the level of the incoming signal guided through the public telephone line 9 is high, a large amount of electric charge is accumulated in the capacitor C2, and the terminal voltage becomes high. Also, a sufficient value of current is supplied from the diode bridge 3. Therefore, when the capacitor C2 is viewed from the ringing circuit 2, the capacitor C2 is equivalent to a voltage source having a high output voltage and a small internal resistance. Therefore, when the ringing circuit 2 operates, the DC output supplied from the capacitor C2 to the ringing circuit 2 is maintained at a substantially constant voltage at which stable operation is possible. However, when the level of the incoming signal is low, sufficient charge is not accumulated in the capacitor C2, and the terminal voltage is low. Also, a sufficient current is not supplied from the diode bridge 3. Therefore, when the capacitor C2 is viewed from the ringing circuit 2 side, the capacitor C2 is equivalent to a voltage source having a low output voltage and a large internal resistance. Therefore, when the level of the incoming call signal is low and the current consumption of the ringing circuit 2 is large, the voltage supplied to the ringing circuit 2 is greatly reduced. The Zener diode D2 connected in parallel with the capacitor C2 is an element for preventing the voltage between the terminals of the capacitor C2 from exceeding the allowable range of the power supply voltage of the ringing circuit 2.

The ringing circuit 2 is a block that generates a ringing signal using the DC output rectified by the diode bridge 3 and smoothed by the capacitor C2 as an operating power supply. For this purpose, two oscillation circuits 11 and 12 and an amplifier 13 are provided. Specifically, the oscillation circuit 12 is an oscillation circuit that generates a signal of a predetermined frequency within the audible band. The oscillation circuit 11 is an oscillation circuit for interrupting the operation of the oscillation circuit 12 at a predetermined low frequency. The amplifier 13 is a block that amplifies the signal generated by the oscillation circuits 11 and 12 and sends the amplified signal to the outside as a ringing tone signal.

The output of the amplifier 13 of the ringing circuit 2 is connected to the cathode of the Zener diode D1, and the anode of the Zener diode D1 is connected to the c contact of the switch 4 via the resistor R2. I have. The a contact of the switch 4 is connected to one terminal of the speaker 5 via a resistor R3, and the b contact of the switch 4 is directly connected to one terminal of the speaker 5. Further, the other terminal of the speaker 5 is connected to the minus output of the diode bridge 3.

More specifically, the Zener diode D1 is a voltage shifter having a constant voltage drop value. In the present embodiment, the voltage drop value is about 5V. Therefore, an element having a Zener voltage of 5 V is used for the Zener diode D1. The voltage drop value of the zener diode D1 should be any other voltage, such as 4V or 6V, corresponding to the signal level of the ringing signal and the configuration of the ringing circuit 2. Is possible.

The speaker 5 is a sounding body constituted by a piezoelectric element. Therefore, when vibration is applied to the speaker 5 or the like, an electromotive force is generated in the speaker 5. The resistor R <b> 2 is an element for limiting the current value of the electromotive force generated in the speaker 5 flowing into the output terminal of the amplifier 13, and protects the amplifier 13. For this reason, the value of the resistor R2 is set to a value that does not reduce the current flowing through the speaker 5 (for example, several hundred Ω). The switch 4 is a block for switching the volume of the ringing tone according to the user's preference, and the resistor R3 is an element for reducing the volume of the ringing tone. For this reason, the value of the resistor R3 is set to a value (for example, several tens of KΩ) that reduces the current flowing through the speaker 5.

FIG. 2 is an explanatory diagram showing the level of a ringing tone signal, and the operation of the embodiment will be described with reference to the drawing as necessary. In the following description, it is assumed that the c contact of the switch 4 is connected to the b contact.

Now, it is assumed that the level of the incoming signal is a low level of about 40 V, for example. At this time, the output voltage of the diode bridge 3 is low, and the voltage between the terminals of the capacitor C2 is low. Further, the current supplied from the diode bridge 3 to the capacitor C2 is small. That is, for the ringing circuit 2, the capacitor C2 is a voltage source having a low output voltage and a large internal resistance. Therefore, when the current consumption of the ringing circuit 2 is large, the voltage supplied to the ringing circuit 2 is greatly reduced.

However, a zener diode D 1 is inserted in the signal path of the speaker 5. Therefore, when the ringing signal has the waveform shown in FIG. 21 because the level of the incoming signal is as low as about 40 V, the voltage applied to the speaker 5 is changed from the level V1 of the ringing signal to the Zener voltage V2 ( The level V3 (about the same level as the prior art) is obtained by subtracting about 5V. As a result, the driving current of the speaker 5 is reduced, so that the current consumption of the ringing circuit 2 is suppressed to a small value. Therefore, the amount of drop in the voltage between the terminals of the capacitor C2 is reduced, so that the ringing circuit 2 can continuously perform the operation of generating the ringing signal. As a result, a stable ringing tone is generated from the speaker 5 without interruption.

Now, it is assumed that the level of the incoming signal is a high level, for example, 80 to 90V. When the level of the incoming signal is high, sufficient charge is accumulated in the capacitor C2, and the terminal voltage is high. Further, a sufficient current is supplied from the diode bridge 3. Therefore, for the ringing circuit 2, the capacitor C2 serves as a voltage source having a high output voltage and a low internal resistance. Therefore, even when the ringing circuit 2 consumes a large amount of current, the DC output voltage is maintained at a substantially constant voltage. For this reason, the ringing circuit 2 performs a stable operation and transmits a ringing signal having a signal waveform shown in FIG.

The zener diode D 1 is inserted in the signal path of the speaker 5. For this reason, the level applied to the speaker 5 is the level V7 obtained by subtracting the zener voltage V6 of the zener diode D1 (equal to the level V2, about 5 V) from the level V5 of the ringing tone signal. That is, the level applied to the speaker 5 is a level V7 slightly reduced from the level V5 of the ringing tone signal output from the ringing tone circuit 2. This level V7 is almost twice as high as the level V8 when the conventional technique is used. Therefore, the sound pressure of the speaker 5 is about three times as high as that of the prior art, and a ringing tone of a sufficient volume is obtained.

Note that the present invention is not limited to the above embodiment, and the case where the communication line is a public telephone line 9 has been described. However, as other communication lines, for example, a communication line for digital subscribers , Etc. can be similarly applied. Although the description has been given of the case where the communication device is a telephone, the same applies to other communication devices such as an image communication device that performs image communication such as a facsimile device and a videophone device. It is possible to apply.

The voltage shifter has been described as being a Zener diode D1. However, as another configuration, for example, a diode having a forward voltage of about 0.7 V corresponds to a voltage drop value. It is possible to adopt a configuration in which the number is connected in series, or the like.

[0030]

[Effect of the invention]

 The ringing tone generator according to the present invention is applied to a communication device connected to a communication line, and uses a direct current obtained by rectifying and smoothing an incoming signal guided through the communication line as an operation power supply. A ring tone signal generating circuit for generating a ring tone signal; a speaker for generating a ring tone in accordance with the ring tone signal generated by the ring tone signal generating circuit; and a speaker inserted in the signal path of the speaker and having a constant voltage drop value. It has a configuration with a certain voltage shifter. Therefore, when the level of the incoming signal is low, the voltage drop by the voltage shifter has a large ratio to the level of the ringing signal, and the driving current of the speaker decreases at a large ratio. On the other hand, when the level of the incoming signal is high, the voltage drop value by the voltage shifter has a small ratio to the level of the ringing signal. Therefore, it is possible to stabilize the generation of a ringing tone when the level of the incoming signal is low, and to prevent a decrease in the volume of the ringing tone when the level of the incoming signal is high.

Further, in the ring tone generating device according to the present invention, the communication device connected to the communication line is a telephone connected to a public telephone line. Therefore, it is possible to stabilize the generation of the ringing tone of the telephone when the level of the incoming signal is low, and to prevent the volume of the ringing tone from decreasing when the level of the incoming signal is high.

[0032] Further, in the ringing tone generating device according to the invention of claim 3, in addition to the above configuration, the communication device is an image communication device. Therefore, it is possible to stabilize the generation of the ringing tone of the image communication device when the level of the incoming signal is low and to prevent the volume of the ringing tone from decreasing when the level of the incoming signal is high. I have.

In the ringing tone generator according to the invention of claim 4, in addition to the above configuration, the voltage shifter is a Zener diode. That is, the Zener voltage of the Zener diode may be lower than the level of the ringing signal output by the ringing circuit when the level of the incoming signal is low. Therefore, an element having a low Zener voltage can be used for the Zener diode, so that the voltage shifter can be inexpensive.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of a ringer according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a ringing signal level and a level applied to a speaker.

FIG. 3 is a block diagram showing an electric configuration of the related art.

[Explanation of symbols]

 Reference Signs List 1 ringing tone signal generation circuit 2 ringing tone circuit 5 speaker 9 public telephone line as communication line 21 waveform of ringing tone signal when incoming signal level is low 22 waveform of ringing tone signal when incoming signal level is high D1 voltage Zener diode as a shifter

Claims (4)

[Utility model registration claims] A communication device connected to a communication line, wherein a ring tone signal for generating a ring tone signal using a direct current obtained by rectifying and smoothing an incoming signal led through the communication line as an operation power source. A generation circuit; a speaker that generates a ringing tone in accordance with the ringing tone signal generated by the ringing tone signal generation circuit; and a voltage shifter that is inserted into a signal path of the speaker and has a constant voltage drop value. Ringing tone generator. 2. A communication device connected to the communication line,
2. The ring tone generator according to claim 1, wherein the ring tone generator is a telephone connected to a public telephone line. 3. The ringing tone generator according to claim 1, wherein said communication device is an image communication device. 4. The ringing tone generator according to claim 1, wherein said voltage shifter is a Zener diode.