TW201511521A - Power supply apparatus and telephone system - Google Patents

Abstract

A power supply control device comprising a power supply control department(12) and a power supply circuit(11), wherein the power supply control department(12) export a PMW signal which contain duty ratio in responce to the difference between the voltage of DC power supply supply and the predetermined target voltage, the power supply circuit swtich the swtich element based on the PMW signal and convert the external AC power supply input to DC output, the power supply control department(12) export logs that display AC power supply status when the DC power supply noise level has above the predetermined noise level threshold.

Description

Power supply unit and telephone system

The present invention relates to a power supply unit and a telephone system, and more particularly to a power supply unit and a telephone system for generating a DC power source from an AC power source.

Most of the components that make up the electronic device operate on the basis of a DC power source. Therefore, the electronic device has a power supply circuit or an AC adapter that generates a DC power source by supplying an AC power source such as a commercial power supply. However, the DC power generated by the power supply circuit may change in voltage level due to fluctuations in the AC power supply, and thus the device that is operated by the DC power supply may have a problem of malfunction. Thus, Patent Documents 1 and 2 disclose techniques for monitoring an AC power source supplied from the outside.

Patent Documents 1 and 2 disclose a technique for detecting a voltage drop or a momentary interruption of an AC power source and recording the date and time when the failure occurs. [Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 05-027495.

However, even if the log of the voltage drop or instantaneous interruption of the AC power source is obtained, the failure of the system that is operated by the DC power source generated from the AC power source is caused by a power failure, and the determination of the cause is still difficult.

A power supply device according to an embodiment of the present invention includes: a power control unit that outputs a PWM signal having a duty ratio corresponding to a voltage of a DC system power supply and a predetermined target voltage; And a power supply circuit that switches the switching element based on the PWM signal and outputs an AC power source externally supplied to the DC system power supply, wherein the power control unit is adapted to the DC current When the noise level of the system power supply is equal to or higher than the preset noise level threshold value, a log showing the status of the AC power source is output.

An embodiment of the telephone system of the present invention comprises: a power control unit for outputting a PWM signal having a difference between a voltage corresponding to a power supply of the DC system and a predetermined target voltage a duty ratio; a power supply circuit that switches a switching element based on the PWM signal and outputs an AC power source externally supplied to the DC system power supply; and a dedicated switch based on the DC Actuating the system power supply, and performing connection control between the telephone terminal and the station line; wherein the power control unit displays the communication when the noise level of the DC system power supply is higher than a preset noise level threshold value A log of the status of the power supply is output.

With the power supply device and the telephone system of the present invention, it is possible to determine whether the failure of the system is caused by a failure of the power supply.

First Embodiment An embodiment of the embodiment of the present invention will be described below with reference to the drawings. The invention is related to a power supply unit. This power supply unit is particularly effective for use in a telephone system, but a system that can be applied is not limited to a telephone system.

Fig. 1 is a block diagram showing the telephone system 1 of the first embodiment. As shown in Fig. 1, the telephone system 1 of the first embodiment has a power supply unit 10, a private exchange 20, a telephone terminal TM1, TM2, and a system temperature sensor SEN. The system temperature sensor SEN outputs temperature information TSEN indicating the temperature inside the casing of the telephone system 1 (hereinafter referred to as ambient temperature).

The power supply unit 10 converts AC power supplied from an external commercial system power supply into a DC system power supply. In the following description, the voltage of the DC system power supply is indicated as the DC output voltage VOUT. The power supply unit 10 has a power supply circuit 11, a power supply control unit 12, and an insulation circuit 13.

The power supply circuit 11 switches the switching element based on a PWM signal generated by the power supply control unit, and outputs the AC power supplied from the outside to the DC system power supply. The power control unit 12 outputs a PWM signal which is a duty ratio having a voltage (DC output voltage VOUT) corresponding to a DC system power supply and a difference from a preset target voltage. . Further, when the noise level of the DC system power supply is equal to or higher than a predetermined noise level threshold value, the power source control unit 12 outputs a log indicating the state of the AC power source. This log is a memory that is sent to the private branch exchange 20 or stored in the power supply control unit 12. For example, the power supply control unit 12 is an MPU (Micro Processor Unit) that uses various calculations and controls in response to the program. The insulating circuit 13 insulates the voltage observation point OVS of the power supply circuit 11 and the input terminal of the current observation point OCS and the power supply control unit 12, and signals the signal level corresponding to the voltage obtained from each observation point. Output. It is particularly effective to provide the insulating circuit 13 in a state where the voltage observed by each observation point is larger than the input range of the power supply control unit 12. Furthermore, the details of the power supply device 10 will be described later.

The private branch exchange 20 is for performing connection control of the telephone terminals TM1, TM2 and the station line. The private switch 20 is actuated based on a DC system power supply. The private branch exchange 20 includes a system control unit 21, a memory 22, an instant clock generation unit 23, and a interface circuit 24.

The system control unit 21 performs connection control of the telephone terminal TM1 and the station line. For example, the system control unit 21 is used in response to various calculations of the program and control of the MPU (Micro Processor Unit). The memory 22 is an operation program of the system control unit 21 and storage of logs generated by the power supply device 10. The capacity of the memory 22 is larger than the memory capacity of the power supply unit 10 itself. The instantaneous clock generation unit 23 generates an instant clock signal to the system control unit 21. This instant clock signal is used for time detection by the system control unit 21.

For example, the telephone terminals TM1, TM2 are fixed telephones. The telephone terminals TM1, TM2 are connected to the interface circuit 24 of the private exchange 20. The telephone terminals TM1 and TM2 include a display unit (for example, an LCD (Liquid Crystal Display)) that displays various messages such as an incoming call message, and a terminal control unit. For example, the terminal control unit performs various calculations and controls the MPU (Micro Processor Unit) in response to the program.

Next, the contents of the power supply device 10 will be described. Fig. 2 is a detailed block diagram showing the power supply device 10 of the first embodiment. As shown in FIG. 2, the power supply circuit 11 of the power supply device 10 of the second embodiment has a rectification smoothing circuit 31, a drive circuit 32, a transformer 33, a rectification smoothing circuit 34, and a switching element (for example, a driving transistor Tr) current detecting resistor. Rs1, resistor R1, and resistor R2.

The rectifying and smoothing circuit 31 rectifies the AC input voltage given from the AC power source to generate a DC voltage. The drive circuit 32 generates a drive signal in response to the PWM signal given from the power supply control unit 12 to switch the drive transistor Tr.

The transformer 33 has a primary side coil and a secondary side coil. Further, one end of the primary side coil is connected to the positive output terminal of the rectifying and smoothing circuit 31. The other end of the primary side coil is connected to the negative output terminal of the rectifying and smoothing circuit 31 by a drive transistor Tr. Furthermore, the driving transistor Tr is an NMOS transistor. In the drive transistor Tr, a drive signal output from the drive circuit 32 is applied to the gate, a source is connected to the negative output terminal of the rectification smoothing circuit 31, and a drain is connected to the other end of the primary side coil of the transformer 33.

One end of the secondary side coil of the transformer 33 is connected to the positive output terminal of the rectifying and smoothing circuit 34, and the other end is connected to the negative output terminal (for example, a ground node) of the rectifying and smoothing circuit 34. The rectifying and smoothing circuit 34 rectifies the pulse signal generated by the secondary side coil of the transformer 33 to output a DC voltage. The DC voltage output from the rectifying and smoothing circuit 34 becomes a DC system power supply. The voltage of the DC system power supply is the DC output voltage VOUT of the power supply circuit 11.

Further, the positive output terminal of the rectifying and smoothing circuit 34 is connected to the power supply node, and the negative output terminal of the rectifying and smoothing circuit 34 is connected to the ground node. Further, resistors R1 and R2 are connected in series between the power supply node and the ground node. The node to which the resistor R1 and the resistor R2 are connected becomes the voltage observation point OVS. Further, a current detecting resistor Rs1 is inserted in the ground node. Further, the terminal of the current detecting resistor Rs1 on the side of the rectifying and smoothing circuit 34 becomes the current observation point OCS.

The power supply control unit 12 includes an AD conversion circuit 41, a calculation unit 42, a PWM timer 43, a memory 44, and an instant clock generation unit 45.

The AD conversion circuit 41 outputs a digital value corresponding to the voltage value of the current observation point OCS obtained by the insulation circuit 13 and the voltage value of the voltage observation point OVS. Further, the power supply device 10 outputs a digital value corresponding to an AC input voltage value indicating a voltage level of an AC input voltage given from an AC power source. Further, the AD conversion circuit 41 outputs a digital value corresponding to the temperature information TSEN output from the system temperature sensor SEN.

The calculation unit 42 updates the set value of the PWM timer 43 so that the difference between the DC output voltage VOUT generated as the DC system power supply and the preset target voltage value is close to zero. Further, the calculation unit 42 applies a Fourier transform, a Wavelet transform, and the like to the voltage value of the voltage observation point OVS, and applies a digital filter process to the converted value. In this way, the calculation unit 42 is a C message noise, a psophometric noise, a Ripple noise, and a spike noise for the voltage value of the voltage observation point OVS. And at least one of the voltage changes is observed. Further, the calculation unit 42 monitors the abnormality of the DC output voltage VOUT of the power supply device 10 by monitoring the fluctuation of the observed voltage value, and outputs an abnormality detection time point when the DC output voltage VOUT detects an abnormality. Log. This log contains information such as the voltage value of the AC input voltage, the voltage value of the DC output voltage VOUT, the current value of the output current, the abnormality occurrence time, and the type of alarm. Details on this log will be explained below. Further, in the telephone system 1 of the first embodiment, in addition to the log at the time of abnormality detection of the output of the direct-current output voltage VOUT, a periodic log is output.

The PWM timer 43 outputs a PWM signal having a duty ratio corresponding to a set value given from the calculation unit 42. Further, the PWM timer 43 determines the frequency of the PWM signal based on the system clock signal output from the system clock generation unit (not shown).

The memory 44 is a program for storing the operation of the calculation unit 42 and a log output by the calculation unit 42. Further, the memory 44 stores various kinds of information such as intermediate data generated by the calculation unit 42 during the calculation.

The instantaneous clock generation unit 45 generates a real time timing signal. This instant clock signal is used in the calculation unit 42 for acquiring time. Furthermore, the instant clock signal can also be utilized for the instant clock signal generated by the instant clock generating unit 23 of the private exchange 20. In this case, the immediate clock generation unit 45 of the power source control unit 12 becomes unnecessary.

Next, the operation of the telephone system 1 according to the first embodiment will be described. The telephone system 1 has a feature that outputs a log containing the state of the AC power source in an abnormal state condition in which the DC output voltage VOUT generated by the power supply device 10 for the operation of the private branch exchange 20 exceeds the expected range. Next, as a description of the operation of the telephone system 1, the log generated in the telephone system 1 will be described. Although the form of the log generated by the power supply device 10 can be associated with various types, three examples are given to illustrate the log.

Fig. 3 shows a first example of a log generated by the power supply device 10 according to the first embodiment. As shown in Fig. 3, in the first example, information such as an AC input voltage is obtained every 10 seconds. At this time, in the example shown in FIG. 3, at the time when the bottom line is drawn, the power supply device 10 obtains the noise level change because the noise level of the DC output voltage VOUT is above the noise level threshold. The information such as the AC input voltage at a large time point is recorded in the log. In the example shown in Fig. 3, 10:20:33 seconds records the drop in the voltage level of the AC input voltage and the rise in the DC output current. Further, in the example shown in Fig. 3, a momentary interruption of the AC power source (the AC input voltage is 0 V state) is recorded at 10:20:56.

Next, Fig. 4 shows a second example of the log generated by the power supply device 10 according to the first embodiment. In the example shown in FIG. 4, when the DC output voltage VOUT detects an abnormality such as a large noise, the log is acquired in a cycle shorter than the normal log acquisition cycle after the abnormality is detected. Therefore, in the example shown in FIG. 4, after the abnormality of the DC output voltage VOUT is detected at 10:20:24, the DC output voltage VOUT is between 10:20 minutes and 28 seconds from the abnormal state to the returning to the normal state. The log is generated every second. In this way, by obtaining the log in a short period after the abnormal state occurs, the correlation between the power failure and the abnormality of the telephone system 1 can be more clearly understood.

Next, Fig. 5 shows a third example of the log generated by the power supply device 10 according to the first embodiment. In the third example shown in Fig. 5, in the case where the same voltage abnormality as in the first example shown in the third figure occurs, the recorded information is changed. In the third example, as the information recorded in the log, the utilization state of the telephone system 1 such as the AC input voltage, the outgoing call, the incoming call, the capture, and the idle is recorded at the time when the DC output voltage VOUT is abnormal. In place of the circuit information such as the DC output voltage, the use of the telephone system can be more clearly understood by the relationship between the failure of the telephone system 1 and the AC input voltage by recording with the AC input voltage.

Further, in the example of the log shown in the third to fifth figures, the state of the power source or the like is displayed by a specific numerical value, and the memory 44 of the power supply device 10 or the memory 22 of the private branch exchange 20 is used. The recorded logs are retrieved and displayed by a chart, and reference logs can also be referenced. Here, FIG. 6 is a display example showing a log generated by the power supply device according to the first embodiment.

The example shown in Fig. 6 shows the AC input voltage and the system temperature as the acquisition target information. In the example shown in Fig. 6, the AC input voltage and the system temperature are plotted in time series. Further, in the example shown in Fig. 6, the vicinity of 14:5:23 is the voltage value at which the AC input voltage has a normal operating range (the range between the upper limit voltage and the lower limit voltage) from the normal operation of the system.

According to the above description, in the telephone system 1 of the first embodiment, the power supply device 10 detects that the noise level of the DC output voltage VOUT has become an abnormal state exceeding the noise level threshold value, and detects the abnormal state. The information such as the AC input voltage at the time point is output as a log. In this way, according to the telephone system 1 of the first embodiment, the general log acquisition interval is lengthened and set to reduce the log capacity, and the log of the power failure abnormality in which the failure may occur can be surely obtained. .

In particular, the telephone system may have a call noise caused by an abnormal power supply. Therefore, as in the telephone system 1 according to the first embodiment, by acquiring a log of an AC input voltage or the like in response to the occurrence of a power source abnormality, there is a call noise caused by a system side failure, or an external communication occurs. The determination of the call noise caused by the abnormality of the power supply becomes simple.

Further, according to the telephone system 1 of the first embodiment, a calculator that is operated by a program such as an MPU is used in the voltage control of the power supply device 10, and the abnormality of the DC output voltage VOUT is detected by the calculator. Therefore, in the telephone system 1, only the detection noise program is included in the program for defining the operation of the calculator, and the function of obtaining the log can be newly added without adding hardware.

Second Embodiment A second embodiment will be described with respect to another aspect of the power supply device 10 of the first embodiment. Here, Fig. 7 is a block diagram showing the power supply device 50 according to the second embodiment. In the description of the second embodiment, the constituent elements which have been described in the first embodiment are denoted by the same reference numerals as the first embodiment, and the description thereof will be omitted.

As shown in FIG. 7, the power supply device 50 is replaced with the power supply circuit 51 by the power supply circuit 11 of the power supply device 10, and the power supply control unit 12 is replaced with the power supply control unit 52.

The power supply circuit 51 is a PFC circuit (Power Factor Correction) using a circuit that generates a DC output voltage VOUT. The power supply circuit 51 has a rectification smoothing circuit 61, a drive circuit 62, a drive transistor Tr, an inductor L, a diode D, a capacitor C, heat dissipation temperature sensors THSEN1, THSEN2, a current detection resistor Rs1, and resistors R1, R2.

The rectifying and smoothing circuit 61 rectifies the AC input voltage supplied from the AC power source to output a DC voltage. This DC voltage is output to the power supply node to which the positive output terminal of the rectification smoothing circuit is connected, and to the ground node to which the negative output terminal is connected.

An inductor L and a diode D connected in series are inserted into the power supply node. Further, a drive transistor Tr is connected between the node between the inductor L and the diode D and the ground node. A driving signal from the driving circuit 62 is applied to the gate of the driving transistor Tr. The drive circuit 62 generates a drive signal from the PWM signal output from the PWM timer 43 of the power supply control unit 52. Further, in the power supply circuit 51, a heat sink is provided on the driving transistor Tr and the diode D. Further, a heat radiation temperature sensor THSEN1 that detects the temperature of the heat sink is provided in the heat sink provided in the driving transistor Tr. A heat dissipation temperature sensor THSEN2 that detects the temperature of the heat sink is disposed in the heat sink disposed in the diode D. Further, the temperature information detected by the heat radiation temperature sensor THSEN1 and the heat radiation temperature sensor THSEN2 is sent to the AD conversion circuit 71 of the power source control unit 52.

The capacitor C is provided between the terminal on the output side of the power supply circuit 51 among the terminals of the diode D and the ground node. The capacitor C is for smoothing the pulse signal generated by switching between the inductor L and the driving transistor Tr.

Further, similarly to the power supply circuit 11, the power supply circuit 51 is provided with a current detecting resistor Rs1 and resistors R1 and R2.

The power supply control unit 52 is replaced by the AD conversion circuit 41 of the power supply control unit 12 by the AD conversion circuit 71. The AD conversion circuit 71 is a function of converting the temperature information output from the heat radiation temperature sensor THSEN1 and the heat radiation temperature sensor THSEN2 in the AD conversion circuit 41 into a digital value in the AD conversion circuit 41.

In the PFC circuit, when the input AC input voltage fluctuates greatly, the driving transistor Tr and the diode D may be heated. Therefore, in the power supply device 10 according to the second embodiment, in addition to direct observation of the noise of the DC output voltage VOUT, and the temperature information outputted by the heat dissipation temperature sensor THSEN1 and the heat dissipation temperature sensor THSEN2 exceeds a preset The temperature is output when the log is output.

In the power supply device 50 according to the second embodiment, in addition to fluctuations in noise of the DC output voltage VOUT, etc., a log corresponding to the temperature of the switching element or the like for voltage conversion is generated. As a result, in the power supply device 50 according to the second embodiment, the log regarding the larger range factor can be obtained than the power supply device 10 according to the first embodiment, and the accuracy of the failure resolution of the telephone system can be improved.

THIRD EMBODIMENT The third embodiment will be described with respect to a modified example of the power supply device which is implemented in accordance with a larger range of failure causes of the power supply device 10 according to the first embodiment. Here, Fig. 8 is a block diagram showing a power supply device 80 according to the third embodiment. In the description of the third embodiment, the constituent elements which have been described in the first embodiment are designated by the same reference numerals as the first embodiment, and the description thereof is omitted.

As shown in Fig. 8, the power supply device 80 is formed by adding an X capacitor XC and a current detecting portion 82 to the AC power supply line of the power supply device 10 according to the first embodiment. Further, in the power supply device 80, the power supply control unit 81 is provided in addition to the current detecting unit 82, and the power supply control unit 81 includes the newly added self-current detecting unit 82 at the AD conversion circuit 41 of the power supply control unit 12. The AD conversion circuit 83 that converts the current information into a digital value function.

The X capacitor XC is disposed between two wirings that are transmitted from an AC input voltage supplied from an AC power source. The X capacitor XC is for removing the noise component contained in the AC input voltage. The current detecting unit 82 detects a current flowing through the X capacitor XC, and outputs current information corresponding to the detected current value. Furthermore, the current detecting unit 82 can form the PCB pattern as a coil.

Here, an uninterruptible device that outputs a signal having a rectangular wave as an AC power source is connected. When such a rectangular wave as an AC power source is given, the X capacitor XC may be damaged. This is because, in the case of having a rectangular wave input, the current Ic flowing through the X capacitor XC becomes large, and there is a possibility that the X capacitor XC is excessively heated and is damaged.

Therefore, in the power supply device 80 according to the third embodiment, the current Ic flowing through the X capacitor XC is detected by the current detecting portion 82 and the X capacitor XC being arranged in series. In the X capacitor XC, once the current Ic flowing through the unit time becomes large, the amount of heat generated for the internal resistance also increases. This current Ic has a relationship of Mathematical Formula 1 with the amount of heat generated. [Math 1] P[j/s]=Ic2×ESR where P is the amount of heat generation and ESR is the resistance of the internal resistance. In addition, the current Ic can be derived using the following mathematical formulas 2 to 4 [Math 2] Ic=ΔQ/Δt [Math 3] Q=CV [Math 4] Ic=(C×ΔV) where Q is an X capacitor XC The capacity value, V is the voltage applied to the X capacitor XC, and t is time. The current Ic can be derived by calculating the variation of the AC input voltage per unit time by Math. 4).

Next, the calculation unit 42 of the power supply control unit 81 calculates the amount of heat generation of the internal resistance of the X capacitor XC based on Mathematical Formulas 1 and 4. In a situation where the amount of heat generated by the X capacitor XC is greater than the expected external input noise level threshold (for example, the calorific value threshold), the power supply unit 80 determines that the AC power source has an abnormality and generates a log.

As a result, according to the power supply device 80 of the third embodiment, it is possible to record an abnormality of the AC power source which is a cause of failure of the X capacitor XC, which is difficult to determine only by the fluctuation of the DC output voltage VOUT. When the X capacitor XC is destroyed, the noise level of the AC input voltage is increased, and the call noise caused by the noise occurs. In addition, when the uninterruptible power device causing the cause of the failure has been removed at the time of the site investigation, there is a problem that the cause of the failure of the X capacitor XC is difficult to estimate. However, with the power supply device 80 according to the third embodiment, it is possible to estimate the abnormality of the AC power source from the log from the magnitude of the current Ic flowing through the X capacitor XC.

Fourth Embodiment A fourth embodiment will be described with respect to a modified example of the power supply device which is implemented by the power supply device 10 according to the first embodiment with a larger range of failure causes. Here, Fig. 9 is a block diagram showing a power supply device 90 according to the fourth embodiment. In the description of the fourth embodiment, the constituent elements which have been described in the first embodiment are denoted by the same reference numerals as the first embodiment, and the description thereof will be omitted.

As shown in Fig. 9, the power supply unit 90 is a new one in which the surge absorber VA and the current detecting unit 82 are added to the AC power supply line of the power supply unit 10 according to the first embodiment. Further, in the power supply device 90, the power supply control unit 91 is provided in addition to the current detection unit 82, and the power supply control unit 91 includes the newly added self-current detection unit 82 at the AD conversion circuit 41 of the power supply control unit 12. The AD conversion circuit 93 that converts the current information into a digital value function.

The surge absorber VA is a circuit including a varistor. When the varistor is subjected to a surge current such as a lightning surge on the AC power source, the surge current is extracted from the AC power line. The surge absorber VA is disposed between two wires that are transmitted from an AC input voltage supplied from an AC power source. The current detecting unit 82 detects the current flowing through the surge absorber VA, and outputs current information corresponding to the detected current value. Furthermore, the current detecting unit 82 can form the PCB pattern as a coil.

In the case where a general lightning strike is applied to an AC power source, the surge current becomes large in a short time. Therefore, the surge absorber VA has no problem with the operation of a general lightning strike. However, if a surge current smaller than a normal lightning strike is applied for a long period of time, the varistor included in the surge absorber VA is heated, and there is a possibility that problems such as smoke generation and sparking may occur. When the problem occurs, there is a problem that the surge absorber VA is broken and the power quality is problematic. When such a problem occurs, it is particularly difficult to estimate the cause of fluctuations in noise such as the DC output voltage VOUT.

Therefore, in the power supply device 90 according to the fourth embodiment, the current Ic flowing through the surge absorber VA is detected by the current detecting portion 82 being provided in series with the surge absorber VA. Therefore, when the value of the current Ic is abnormal due to an abnormality of the external input noise level threshold (for example, the noise current threshold value), and it is determined that there is a risk of breakage of the surge absorber VA, the exchange of the time point is performed. The status of the power supply or the like is output as a log.

As described above, according to the power supply device 90 of the fourth embodiment, it is possible to record an abnormality of the AC power source which is a cause of failure of the surge absorber VA, which is difficult to determine only by the fluctuation of the DC output voltage VOUT, in the log. When the surge absorber VA is broken, the noise level of the AC input voltage becomes large, and the call noise caused by the noise occurs. In addition, the induced lightning strike caused by the cause of the failure does not occur at the time of the on-site investigation, and there is a problem that the cause of the failure of the surge absorber VA is difficult to be estimated. However, with the power supply device 90 according to the fourth embodiment, the abnormality of the AC power source can be estimated from the log by the magnitude of the current Ic flowing through the surge absorber VA.

The above description and description are only illustrative of the preferred embodiments of the present invention, and those of ordinary skill in the art can make other modifications in accordance with the scope of the invention as defined below and the description above, but such modifications should still be It is within the scope of the invention to the invention of the invention.

(1)‧‧‧Phone system
(10, 50, 80, 90) ‧‧‧Power supply unit
(11, 51) ‧‧‧Power Circuit
(12, 52, 81, 91) ‧‧‧Power Control Department
(13)‧‧‧Insulated circuit
(20) ‧‧‧ Private Switch
(21)‧‧‧System Control Department
(22, 44) ‧ ‧ memory
(23, 45) ‧‧‧ Instant Clock Generation
(24) ‧‧‧Interface circuit
(31, 34, 61) ‧ ‧ rectification smoothing circuit
(32, 62) ‧‧‧ drive circuit
(33)‧‧‧Transformers
(41, 71, 83, 92) ‧‧‧AD conversion circuit
(42) ‧ ‧ Calculation Department
(43)‧‧‧PWM timer
(82) ‧‧‧ Current Detection Department
(OVS)‧‧‧Voltage observation point
(OCS) ‧ ‧ current observation point
(TM1, TM2) ‧ ‧ telephone terminal

1 is a block diagram of a telephone system of a first embodiment; FIG. 2 is a block diagram of a power supply device of the first embodiment; and FIG. 3 is a first example of a log generated by the power supply device of the first embodiment. 4 is a schematic diagram showing a second example of a log generated by the power supply device of the first embodiment; FIG. 5 is a schematic view showing a third example of a log generated by the power supply device of the first embodiment; 6 is a schematic diagram showing a display example of a log generated by the power supply device of the first embodiment; FIG. 7 is a block diagram of the power supply device of the second embodiment; and FIG. 8 is a block diagram of the power supply device of the third embodiment. Figure 9 is a block diagram of a power supply device of a fourth embodiment;

(1)‧‧‧Phone system

(10, 50, 80, 90) ‧‧‧Power supply unit

(11, 51) ‧‧‧Power Circuit

(12, 52, 81, 91) ‧‧‧Power Control Department

(13)‧‧‧Insulated circuit

(20) ‧‧‧ Private Switch

(21)‧‧‧System Control Department

(22, 44) ‧ ‧ memory

(23, 45) ‧‧‧ Instant Clock Generation

(24) ‧‧‧Interface circuit

(TM1, TM2) ‧ ‧ telephone terminal

Claims (5)

A power supply device comprising: a power control unit that outputs a PWM signal having a duty ratio corresponding to a voltage between a DC system power supply and a predetermined target voltage; And the power circuit, the switching element is switched based on the PWM signal, and the AC power source externally given is output as the DC system power; wherein the power control unit is in response to the noise level of the DC system power supply When it is equal to or greater than the preset noise level threshold value, a log showing the status of the AC power source is output. The power supply device of claim 1, wherein the power control unit detects C message noise, psophometric noise, Ripple noise, and peaks of the DC system power supply. At least one of noise noise and voltage fluctuation of the DC system power supply is outputted when the noise level of the detection target is equal to or higher than the noise level threshold value. The power supply device of claim 1 or 2, wherein the power control unit is in addition to the noise level of the DC system power supply, and the noise level of the AC power source is a preset external input noise level threshold The log is output when the value is above. The power supply device of claim 1, wherein the power control unit has a memory, and the memory system stores the log. A telephone system comprising: a power control unit that outputs a PWM signal having a duty ratio corresponding to a voltage between a DC system power supply and a predetermined target voltage; The power circuit converts the switching element based on the PWM signal, and outputs the AC power supplied from the outside to the DC system power supply; and the dedicated switch is activated based on the DC system power supply, and performs the telephone terminal and The connection control of the station line; wherein the power control unit outputs a log indicating the status of the AC power source when the noise level of the DC system power supply is equal to or greater than a preset noise level threshold value.