JP4993777B2 - AC adapter misconnection prevention device and prevention method in VoIP adapter - Google Patents

Description

  The present invention relates to a technique for preventing AC adapter erroneous connection in, for example, a VoIP adapter.

In the VoIP adapter, hum noise generated in the telephone line is closely related to the AC adapter to be used. For example, if the AC adapter used for the VoIP adapter is not the AC adapter attached to the VoIP adapter, that is, if it is a non-standard AC adapter or an AC adapter different from the genuine product, this AC adapter Even when the voltage of the adapter is the same as the rated voltage of the standard AC adapter, the power line noise generated between the DC input and the FG may cause a hum noise in the telephone line. . For this reason, when using a VoIP adapter, it is preferable to use an AC adapter attached to the evaluated VoIP adapter.

  However, due to diversification of electronic devices, various AC adapters exist today, and it is considered that other AC adapters are inadvertently connected inadvertently. If the AC adapter is connected incorrectly, if it is severe, not only damage to the device but also a burnout accident will occur.

  Therefore, in order to improve the damage caused by the AC adapter misconnection in the VoIP adapter, it can be considered to change the shape and color of the DC jack.

  Further, in order to improve damage caused by incorrect connection of the AC adapter in the VoIP adapter, it is conceivable to protect the circuit by monitoring the input voltage from the AC adapter.

JP-A-62-2170 JP-A-6-22450 JP-A-8-33188 JP 2003-111437 A JP 2004-32170 A

  However, it has been found that the coping method for changing the shape of the DC jack to prevent erroneous connection of the AC adapter has the following problems. For example, the shape of a commercially available DC jack is standardized by the EIAJ standard or the like, and the manufacturing cost increases if the shape of the DC jack is changed.

  Further, it has been found that the coping method for changing the color of the DC jack to prevent the AC adapter from being erroneously connected has the following problems. For example, even if the color of the DC jack is changed, the erroneous connection can be reduced, but the erroneous connection cannot be completely eliminated. Therefore, the degree of improvement of problems that occur when a connection error occurs is small.

  Moreover, it has been found that the coping method for monitoring the input voltage from the AC adapter to prevent erroneous connection of the AC adapter has the following problems. For example, there are many AC adapters having the same rated voltage in the market. For this reason, although the same rated voltage is used, when an AC adapter other than the attached product (genuine product) is connected, the AC adapter cannot be selected. And even if the output voltage is the same, if an AC adapter with insufficient current capacity is connected, this AC adapter will be abnormally heated and deformed, or if severe, will lead to a burnout accident. Even if the rated voltage is the same, since the power source noise between DC and FG is affected by the ripple noise and input / output impedance of the power source, high noise is generated between the DC and FG. If high noise is generated between the DC and FG, the VoIP adapter causes hum noise in the telephone line.

  Accordingly, the problem to be solved by the present invention is to prevent telephone line noise problems and burnout accidents that occur when an AC adapter other than an attached product (genuine product or standard product) is connected to the VoIP adapter. Is to provide technology.

The above issues are
An apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter,
Input voltage monitoring means;
Noise level monitoring means;
Determining means for determining whether or not the input voltage by the input voltage monitoring means is within a reference value and whether or not the noise level by the noise level monitoring means is within a reference value. And
As a result of determination by the determination means, when both the input voltage and the noise level are not within the reference values, the AC adapter is configured to prevent erroneous connection of the AC adapter. It is solved by an erroneous connection prevention device.

Also, there is a method for preventing erroneous connection of an AC adapter in a VoIP adapter,
An input voltage monitoring step for monitoring the input voltage;
A noise level monitoring step for monitoring the noise level;
A determination step of determining whether or not the input voltage in the input voltage monitoring step is within a reference value and whether or not the noise level in the noise level monitoring step is within a reference value;
A VoIP adapter comprising: an erroneous connection prevention step for preventing an erroneous connection of the AC adapter when both the input voltage and the noise level are not within a reference value as a result of the determination in the determination step; This is solved by the method for preventing erroneous connection of the AC adapter in the above.

  If a non-standard AC adapter is connected to the VoIP adapter, hum noise will be superimposed on the telephone line, causing noise problems, and if it is severe, the device will be overvoltaged, causing device failure or burning accidents. Such a problem is solved.

Schematic of AC adapter misconnection prevention device in VoIP adapter according to the present invention Schematic diagram of an input voltage monitoring circuit used in an AC adapter misconnection prevention device according to the present invention. Schematic diagram of a noise level monitoring circuit used in an AC adapter misconnection prevention device according to the present invention. Schematic of the AC adapter determination circuit used in the AC adapter misconnection prevention device according to the present invention. Schematic diagram of another noise level monitoring circuit Schematic diagram of another noise level monitoring circuit

  The present invention is an AC adapter misconnection prevention device in a VoIP adapter. The apparatus of the present invention comprises input voltage monitoring means, noise level monitoring means, and determination means. The input voltage monitoring means has a function of checking the output voltage level of the connected AC adapter and outputting a high output signal if the voltage level is within a preset value range. This can be configured by using a plurality of comparators, for example. The noise level monitoring means is configured such that the noise level between the DC input of the VoIP adapter (this adapter has a function of shorting FG (Frame Ground) -SG (Signal Ground)) and the FG is set in advance. If it is below the level, it has a function of outputting the output signal High. This can be configured by using a comparator. The determination means determines whether the input voltage by the input voltage monitoring means is within a reference value and whether the noise level by the noise level monitoring means is within a reference value. For example, the output signal of the input voltage monitoring unit and the output signal of the noise level monitoring unit are determined. If the input voltage and the noise level are not within the reference values as a result of the determination by the determination means, for example, if both the output signals are not High, the AC adapter can be prevented from being erroneously connected. . The AC adapter erroneous connection prevention configuration is configured such that, for example, power supply from the AC adapter is cut off. More specifically, the relay circuit is configured to have a means for turning off a relay circuit that is a power switch (disconnecting the switch SW). The configuration for preventing the AC adapter from being erroneously connected may be configured such that a warning is issued instead of the means for cutting off the power supply from the AC adapter. For example, a warning unit may be further provided, and the warning unit may be configured to operate as a configuration for preventing an AC adapter erroneous connection. That is, when the warning is recognized, it is recognized that the AC adapter is out of the standard, and can be replaced. Of course, both of the plurality of means may be provided. If configured as described above, the voltage level and the noise level are detected when the DC jack of the AC adapter is inserted, and it is determined whether the AC adapter is within or out of the standard. it can. As a result, when using a VoIP adapter, if it is a non-standard AC adapter, it will be replaced with a non-standard AC adapter, so that the problem of using a non-standard AC adapter can be solved. Become. For example, when a non-standard AC adapter is used, hum noise is superimposed on the telephone line, causing a noise problem. In severe cases, an overvoltage is applied to the device, causing a device failure or a burnout accident. Such a problem is solved. In particular, since the determination of the AC adapter in the VoIP adapter employs two elements, the input voltage range and the allowable noise level, the determination of the AC adapter is more accurate than the determination by simply monitoring the voltage level. became. Since the noise level between the DC input and the FG is checked when the DC jack is inserted, the hum noise problem in the VoIP adapter is reduced. In addition, when there is a manufacturing defect in the AC adapter used, it can be easily inspected simply by connecting to this apparatus, and it is also possible to facilitate shipping inspection at the factory. Since the noise level between the DC input and the FG is detected, it is particularly effective in a communication apparatus having an FG such as a VoIP adapter and having a telephone line interface that is affected by the noise between the DC input and the FG. It is. The input voltage monitoring means preferably has a chattering prevention circuit. The noise level monitoring means preferably has a chattering prevention circuit. The comparator constituting the noise level monitoring means preferably has a hysteresis function.

  The second aspect of the present invention is a method for preventing erroneous connection of an AC adapter in a VoIP adapter. An input voltage monitoring step for monitoring the input voltage is provided. Further, a noise level monitoring step for monitoring the noise level is provided. And determining whether the input voltage in the input voltage monitoring step is within a reference value and whether the noise level in the noise level monitoring step is within a reference value. To do. In addition, if the input voltage and the noise level are not within the reference values as a result of the determination in the determination step, an erroneous connection prevention step for preventing the erroneous connection of the AC adapter is provided. The erroneous connection prevention step is a warning step for causing the warning means to output a warning signal, for example, when both the input voltage and the noise level are not within the reference values as a result of the determination in the determination step. Alternatively, it is a power supply cutoff step of cutting off power supply from the AC adapter. Alternatively, it is a step of causing the warning means to output a warning signal and cutting off the power supply from the AC adapter.

  This will be described in more detail below.

  1 to 4 show an embodiment of an apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to the present invention. FIG. 1 is a schematic diagram of the whole, FIG. 2 is a schematic diagram of an input voltage monitoring circuit, and FIG. Is a schematic diagram of a noise level monitoring circuit, and FIG. 4 is a schematic diagram of an AC adapter determination circuit.

  An AC adapter 6 is connected to a VoIP adapter having a function of shorting the FG-SG. That is, the AC adapter 6 supplies a DC voltage to the device (VoIP adapter) via a DC jack. The VoIP adapter includes an input voltage monitoring circuit (input voltage monitoring means) 1, a noise level monitoring circuit (noise level monitoring means) 2, an AC adapter determination circuit (determination means) 3, an alarm output control circuit 4 and an LED (warning means). ), And a relay circuit 5.

  The input voltage monitoring circuit 1 is connected to a DC input, monitors the level of the input voltage (output voltage of the AC adapter 6), and outputs an output signal if the voltage level is within a preset value range. Is a circuit having a function of outputting High. This type of voltage monitoring circuit 1 can be configured using a comparator. That is, it can be constituted by two comparators A and B. A specific example is shown in FIG. In FIG. 2, the comparator A monitors the allowable minimum voltage of the input voltage, and the comparator B monitors the allowable maximum voltage of the input voltage. The reference voltage of each comparator can be arbitrarily set by using a resistor and a constant voltage diode according to the output range of the AC adapter 6 to be used. In the comparator A, the reference voltage (− side) is set to the allowable minimum voltage of the AC adapter 6, and when the voltage level is higher than the reference voltage, High is output. The comparator B outputs High when the reference voltage (+ side) is the allowable maximum voltage and the input voltage is a voltage level lower than the reference voltage. By taking the AND of both comparator outputs, the output from the AC adapter 6 is High when the output is within the set range.

  The noise level monitoring circuit 2 monitors the noise level between the DC input of the VoIP adapter having a function of shorting the FG-SG and the FG, and outputs an output signal if the noise level is equal to or lower than a preset noise level. This circuit has a function of outputting High. This kind of noise level monitoring circuit 2 can also be configured using a comparator. That is, it can be constituted by one comparator. A specific example is shown in FIG. In FIG. 3, the comparator sets an allowable noise level determined by measuring in advance by evaluation or the like to the reference voltage (+ side). The noise level to be set can be arbitrarily set with a resistor and a constant voltage diode. The negative input of the comparator is connected to the DC input by inserting a DC component cut capacitor so that noise between the DC input and FG is applied. When the noise level is smaller than the set value, the comparator outputs High.

  When the output signal of the input voltage monitoring circuit 1 and the output signal of the noise level detection circuit 2 are confirmed to be neither High by the AND circuit, the AC adapter determination circuit 3 operates the alarm output control circuit 4 to turn on the LED. (Warning means) is a circuit that has a function of displaying a warning and turning off the power of the relay circuit 5 that is a power switch. Details of the AC adapter determination circuit 3 are shown in FIG. In FIG. 4, a chattering prevention circuit using CR is provided in order to prevent erroneous detection in consideration of fluctuations of the output signal of the input voltage monitoring circuit 1 and the output signal of the noise level monitoring circuit 2. The output signal of the input voltage monitoring circuit 1 and the output signal of the noise level monitoring circuit 2 are input to the AND circuit via the chattering prevention circuit. Note that the chattering prevention circuit can be constituted by a logic circuit such as a flip-flop if the device has a clock source or the like. The output of the AND circuit is output as a relay control signal for driving the relay circuit 5 which is a device internal power switch. At the same time, when the output of the AC adapter determination circuit (AND circuit) 3 is NG (Low level), it is output via the alarm output control circuit 4 as an alarm output signal for lighting an LED or the like. The alarm output control circuit 4 can be easily configured using, for example, a simple buffer circuit that draws the LED current.

  When configured as described above, that is, when the VoIP adapter includes the above circuit, the voltage level and the noise level are detected when the DC jack of the AC adapter 6 is inserted. That is, when it is detected (determined) that the voltage level and noise level are values within the set range, it is found that the AC adapter used is a standard product (genuine product). In this case, since it is determined that the AC adapter used has no problem, the VoIP adapter is turned on. Conversely, if at least one of the voltage level and the noise level is Low, the AC adapter used is determined to have a problem, so the relay circuit 5 is turned off and the VoIP adapter is turned off. To. Also, the alarm output control circuit 4 is activated to display a warning. As a result, the user knows that the AC adapter in use has a problem, and therefore replaces the AC adapter with an appropriate AC adapter. In other words, when a nonstandard AC adapter is connected to the VoIP adapter, hum noise is superimposed on the telephone line, causing noise problems, and in severe cases, overvoltage is applied to the device, causing device failure or burning accidents, etc. However, such a problem is solved.

FIG. 5 is a schematic diagram of another example of the noise level monitoring circuit.
The noise level monitoring circuit of the present embodiment uses a comparator having a hysteresis function as a comparator provided after the DC cut capacitor in order to improve the stability of noise level detection between DC input and FG. Thereby, it is possible to prevent oscillation of the output of the comparator that occurs when there is a noise level near the threshold, and stable noise level detection can be performed.

FIG. 6 is a schematic diagram of another example of the noise level monitoring circuit.
The noise level monitoring circuit of the present embodiment is configured such that the noise level monitored by the noise level monitoring circuit can be confirmed to be within an allowable range in accordance with the noise level when the attached AC adapter is used. In FIG. 6, the comparator C monitors the allowable minimum noise level between the DC input and the FG, and the comparator D monitors the allowable maximum noise level between the DC input and the FG. The reference voltage of each comparator can be arbitrarily set by using a resistor and a constant voltage diode in accordance with a preset noise level. The comparator C sets the reference voltage (− side) as the allowable minimum voltage of the noise level, and outputs High if the noise level is higher than the reference voltage. The comparator D outputs High when the noise level between the DC input and the FG is lower than the reference voltage with the reference voltage (+ side) as the allowable maximum voltage. A circuit that outputs High when the noise level is within the set range is provided by ANDing both comparator outputs. By limiting the range of the noise level in this way, it is possible to select with higher accuracy.

1 Input voltage monitoring circuit (input voltage monitoring means)
2 Noise level monitoring circuit (noise level monitoring means)
3 AC adapter determination circuit (determination means)
4 Alarm output control circuit 5 Relay circuit 6 AC adapter

Claims (10)

An apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter,
Input voltage monitoring means;
Noise level monitoring means;
Judgment comprising an AND circuit for judging whether the input voltage by the input voltage monitoring means is within a reference value and whether the noise level by the noise level monitoring means is within a reference value Means,
As a result of determination by the determination means, when both the input voltage and the noise level are not within the reference values, the AC adapter is configured to prevent erroneous connection of the AC adapter. Incorrect connection prevention device. The apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to claim 1, wherein the structure for preventing erroneous connection of the AC adapter is configured such that power supply from the AC adapter is cut off. Furthermore, it has a warning means,
The apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to claim 1 or 2, wherein the structure for preventing erroneous connection of an AC adapter is configured such that the warning means is activated. The apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to any one of claims 1 to 3, wherein the input voltage monitoring means includes a chattering prevention circuit. The apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to any one of claims 1 to 4, wherein the noise level monitoring means includes a chattering prevention circuit. 6. The apparatus for preventing erroneous connection of an AC adapter in a VoIP adapter according to claim 1, wherein the comparator constituting the noise level monitoring means has a hysteresis function. A method of preventing erroneous connection of an AC adapter in a VoIP adapter,
An input voltage monitoring step for monitoring the input voltage;
A noise level monitoring step for monitoring the noise level;
Judgment means comprising an AND circuit for determining whether or not the input voltage in the input voltage monitoring step is within a reference value and whether or not the noise level in the noise level monitoring step is within a reference value. A determination step for determining;
A VoIP adapter comprising: an erroneous connection prevention step for preventing an erroneous connection of the AC adapter when both the input voltage and the noise level are not within a reference value as a result of the determination in the determination step; A method for preventing erroneous connection of an AC adapter in FIG. 8. The erroneous connection preventing step is a warning step for causing the warning means to output a warning signal when both the input voltage and the noise level are not within the reference values as a result of the determination in the determination step. Method of preventing erroneous connection of AC adapter in VoIP adapters. The erroneous connection prevention step is a power supply cutoff step for cutting off power supply from the AC adapter when both the input voltage and the noise level are not within the reference values as a result of the determination in the determination step. The method for preventing erroneous connection of an AC adapter in the VoIP adapter according to claim 7. The erroneous connection prevention step is a step of causing the warning means to output a warning signal and shutting off the power supply from the AC adapter when both the input voltage and the noise level are not within the reference values as a result of the determination in the determination step. 8. The method for preventing erroneous connection of an AC adapter in a VoIP adapter according to claim 7, wherein:

Images