JP2004357460A - Power supply unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abnormal output from being delivered to a load due to failure in a power supply unit itself, and to detect some failure in an output supplied to a plurality of loads. <P>SOLUTION: This power supply unit includes a means for maintaining a detection state and stopping supplying of the output to the load if it is detected that an output voltage is out of a prescribed range, or is structured so as to detect the failure in the output, independently of a control system, by converting an inputted power supply into a fixed output voltage, and a stopping means for maintaining a detection status and stopping supply of the output to the load, when at least one of a plurality of output voltages is detected as being of the prescribed range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply device having a stabilized output voltage, and more particularly to a power supply device having a protection circuit for abnormal output.
[0002]
[Prior art]
A power supply that supplies power to electronic equipment such as a computer (hereinafter referred to as a load) is designed to prevent damage to the load, smoke, or fire even if the power supply itself fails or malfunctions. Various measures have been taken. The protection operation when the output voltage is abnormal is also a very important function as one of such measures.
[0003]
The power supply device having such a function always stabilizes the output voltage and constantly monitors the output voltage, and even if the power supply device itself fails or malfunctions and the output voltage becomes abnormal, The output is shut off immediately to prevent damage to the load, smoke or ignition.
[0004]
For example, a circuit for generating a reference voltage of the output voltage and detecting a malfunction of the output voltage and a circuit for detecting an excessive output current are provided. There is known a power supply device which is provided with switch means for switching a plurality of types of threshold values for detecting various output currents and supplies electric power which conforms to a plurality of standards without changing the configuration of the device (Japanese Patent Application Laid-Open No. H11-163,837). ).
[0005]
In addition, as a power supply device that avoids the influence of voltage fluctuations in the power supply voltage, it is determined whether the input power supply voltage is within a rated allowable range and whether the input power supply voltage is within a maximum allowable range. The alarm indicator lights up when it fluctuates and deviates from the rated allowable range, and when it deviates from the maximum allowable range, a warning is displayed to warn that the protection function may be activated before the protection function that stops the drive control of the inverter circuit is activated. There is known a power supply device for preventing an operation such as a welding operation from being suddenly and inadvertently interrupted (Patent Document 2).
[0006]
Further, there is known a power supply circuit protection means that detects an overvoltage of a stabilized power supply output, blows an overcurrent fusing type resistor, and quickly protects a subsequent circuit element against a failure of a main switching element (Patent) Reference 3).
[0007]
[Patent Document 1]
JP-A-2002-51542 (FIG. 1)
[Patent Document 2]
JP 2001-212669 A (FIG. 1)
[Patent Document 3]
JP-A-11-149320 (FIG. 1)
[0008]
[Problems to be solved by the invention]
However, the related art is not configured for the purpose of preventing an abnormal output from being transmitted to a load due to an abnormality of the power supply device itself, that is, a failure of a circuit or the like inside the power supply device. In addition, a technique of a power supply device that detects an abnormality in outputs supplied to a plurality of loads is not disclosed.
[0009]
Therefore, a first object of the present invention is to provide a power supply device that prevents an abnormal output from being sent to a load due to an abnormality in the power supply device itself. A second object of the present invention is to provide a power supply device that detects an abnormality of an output supplied to a plurality of loads.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a power supply device that converts input power to a constant output voltage and supplies the output voltage to a load. This power supply device includes a unit for detecting that the output voltage has deviated from the predetermined range. In addition, there is provided a means for holding a detection state. Further, a means is provided for stopping supply of output to the load when the output voltage is out of the predetermined range.
[0011]
According to a second aspect, as a power supply device according to the present invention, there is provided a power supply device that converts input power to a plurality of constant output voltages and supplies the output voltages to a plurality of loads. In this power supply device, there is provided means for detecting that at least one of the plurality of output voltages is out of a predetermined range. In addition, there is provided a means for holding a detection state. Further, a means is provided for stopping supply of output to the load when the output voltage is out of the predetermined range.
[0012]
Further, according to a third aspect, as a power supply device according to the present invention, there is provided a power supply device that controls a switching pulse width in order to switch an input power supply and supply a constant output voltage to a load. Is done. This power supply device is configured to include a reference voltage generating means for generating a reference voltage for detecting that the output voltage has deviated from a predetermined range, and a comparing means for comparing the output voltage with the reference voltage. In this configuration, when the comparison means outputs that the output voltage has deviated from the predetermined range, the operation of holding the output of the comparison means and stopping the switching operation is performed.
[0013]
According to a fourth aspect of the present invention, there is provided a power supply device for controlling a switching pulse width in order to switch an input power supply and supply a constant output voltage to each of a plurality of loads. An apparatus is provided. In this power supply device, a reference voltage generating means for generating a reference voltage for detecting that a plurality of output voltages deviate from respective predetermined ranges, a plurality of predetermined voltages obtained from the reference voltage and a plurality of output voltages And a plurality of comparing means for respectively comparing. In this configuration, when at least one of the plurality of comparison means outputs that at least one of the plurality of output voltages is out of the predetermined range, the operation of holding the output of the comparison means and stopping the switching operation is performed. I do.
[0014]
In the present invention, preferably, the power supply of the reference voltage generating means may be supplied from an input power supply.
[0015]
According to a fifth aspect, a power supply device according to the present invention includes a rectifier that rectifies an AC power supply. In addition, a switching unit for switching an output of the rectifying unit is provided. Further, there is provided rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means. In addition, the apparatus includes first reference voltage generation means for generating a first reference voltage for setting a voltage output from the rectifying and smoothing means and supplied to an external load to a predetermined value. Further, there is provided an error amplifier for amplifying an error voltage between the voltage supplied to the load and the first reference voltage. Also, a sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means is provided. Further, there is provided first comparing means for comparing the sawtooth wave voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means. Further, a driving means is provided for driving the switching means for switching based on the comparison result of the first comparing means. Further, there is provided second reference voltage generating means for generating a second reference voltage for detecting that the voltage supplied to the load has deviated from the predetermined range. In addition, a second comparison unit that compares the voltage supplied to the load with the second reference voltage is provided. And a holding unit for holding the comparison result of the second comparing unit indicating that the voltage supplied to the load has deviated from the predetermined range. In the power supply device having such a configuration, when the holding unit outputs that the voltage supplied to the load is out of the predetermined range, the driving unit is operated to stop the switching operation of the switching unit. .
[0016]
According to a sixth aspect, the power supply device according to the present invention includes a rectifier that rectifies the AC power. In addition, a switching unit for switching an output of the rectifying unit is provided. Further, a plurality of rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means is provided. A first reference voltage generating means for generating a first reference voltage for setting a voltage output from one of the plurality of rectifying / smoothing means and supplied to an external load to a predetermined value; Is provided. Further, there is provided an error amplifier for amplifying an error voltage between the voltage supplied to the load and the first reference voltage. Also, a sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means is provided. Further, there is provided first comparing means for comparing the sawtooth wave voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means. Further, a driving means is provided for driving the switching means for switching based on the comparison result of the first comparing means. Further, a second reference voltage generating means for generating a second reference voltage for detecting that a plurality of voltages supplied from the plurality of rectifying / smoothing means to a plurality of loads deviate from the respective predetermined ranges. Prepare. Further, a plurality of second comparing means for comparing the plurality of predetermined voltages obtained from the second reference voltage with the plurality of voltages supplied to the plurality of loads are provided. Further, a logical operation is performed on the comparison results output by the plurality of second comparing means, and when at least one of the plurality of voltages supplied to the plurality of loads is out of a predetermined range, the logical operation is output. Means. Further, a holding means for holding an output of the logic operation means is provided. In the power supply device having such a configuration, when the holding unit outputs that the power is out of the predetermined range, the driving unit is operated to stop the switching operation of the switching unit.
[0017]
Furthermore, according to a seventh aspect, the power supply device according to the present invention includes a rectifier that rectifies the AC power. In addition, a switching unit for switching an output of the rectifying unit is provided. Further, a plurality of rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means is provided. A first reference voltage generating means for generating a first reference voltage for setting a voltage output from one of the plurality of rectifying / smoothing means and supplied to an external load to a predetermined value; Is provided. Further, there is provided an error amplifier for amplifying an error voltage between the voltage supplied to the load and the first reference voltage. Also, a sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means is provided. Further, there is provided first comparing means for comparing the sawtooth wave voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means. Further, a driving means is provided for driving the switching means for switching based on the comparison result of the first comparing means. Further, a second reference voltage generator for generating a second reference voltage for detecting that a plurality of voltages or currents supplied from the plurality of rectifying / smoothing means to a plurality of loads respectively deviate from respective predetermined ranges. Means. In addition, a plurality of second comparing means for comparing a plurality of predetermined voltages obtained from the second reference voltage with a plurality of voltages or currents supplied to the plurality of loads are provided. Further, a logical operation is performed on the comparison results output by the plurality of second comparing means, and when at least one of the plurality of voltages or currents supplied to the plurality of loads is out of a predetermined range, the fact that the voltage or current is out of range is output. Logical operation means is provided; Further, a holding means for holding an output of the logic operation means is provided. In the power supply device having such a configuration, when the holding unit outputs that the power is out of the predetermined range, the driving unit is operated to stop the switching operation of the switching unit.
[0018]
In the present invention, preferably, the logical operation means may be configured to perform a logical operation consisting of a wired OR or a wired AND.
[0019]
In the present invention, preferably, the power supplied to the second reference voltage generating means may be obtained by rectifying an AC power.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The power supply device of the present invention converts input power to a constant output voltage and supplies the output voltage to a load. When detecting that the output voltage has deviated from the predetermined range, a means for maintaining the detection state and stopping supply of the output to the load is provided. That is, a configuration is provided in which a means for detecting an output abnormality is independent of a control system for converting an input power supply into a constant output voltage and supplying the output voltage to a load.
[0021]
Further, the power supply device of the present invention converts input power to a plurality of constant output voltages and supplies the same to a plurality of loads, respectively. When at least one of the plurality of output voltages is detected to be out of the predetermined range, a means for maintaining the detection state and stopping the supply of the output to the load is provided. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0022]
【Example】
FIG. 1 is a block diagram showing a power supply device according to a first embodiment of the present invention. In FIG. 1, an unstable AC power is supplied from an input terminal 31. The rectifier 11 rectifies the power supplied from the input terminal 31. The switching unit 12 switches the rectified power output from the rectifying unit 11 according to the output of the driving unit 18. For example, the switching unit 12 includes a switching transistor and a transformer, and controls opening and closing of the switching transistor. The rectified power is interrupted by the open / close control, and an interrupted voltage is induced on the secondary side of the transformer. The smoothing rectifier 13 rectifies and smoothes the intermittent voltage output from the switching unit 12.
The power output from the smoothing rectifier 13 is supplied from an output terminal 32 to a load.
[0023]
On the other hand, the reference voltage generator 14 generates a reference voltage of the power supply voltage supplied from the output terminal 32 to the load. The error amplifier 15 amplifies an error voltage between the power supply voltage supplied from the output terminal 32 to the load and the reference voltage generated by the reference voltage generator 14. The sawtooth wave generating means 16 generates a sawtooth voltage waveform having a predetermined period. The comparing means 17 compares the output voltage of the error amplifying means 15 with the voltage of the sawtooth wave generated by the sawtooth wave generating means 16. The driving unit 18 drives the switching unit 12 based on the comparison result of the comparing unit 17. The power supply device thus forms feedback, stabilizes the unstable power supplied from the input terminal 31, and obtains an output voltage at the output terminal 32 according to the reference voltage generated by the reference voltage generating means 14. Works. It should be noted that various types of power supply devices that perform a switching operation by such feedback control have been known.
[0024]
On the other hand, the rectifier 22 rectifies the power supplied from the input terminal 31 and supplies the power to the reference voltage generator 19. The reference voltage generating means 19 generates a reference voltage for determining whether the power supply voltage supplied from the output terminal 32 to the load is within a predetermined range, and is constituted by, for example, a three-terminal regulator element. You. The comparing means 20 compares the power supply voltage supplied from the output terminal 32 to the load with the reference voltage generated by the reference voltage generating means 19. When the comparing unit 20 outputs that the power supply voltage supplied to the load from the output terminal 32 is out of the predetermined range, the holding unit 21 holds the output state. Note that the holding unit 21 can be realized using a flip-flop circuit or the like. When the output state is out of the predetermined range, the driving unit 18 operates to stop driving the switching unit 12. By stopping the switching operation, the power supply voltage is not supplied to the load from the output terminal 32, so that abnormal output to the load can be prevented.
Note that the supply of the power supply voltage to the load is not limited to controlling the driving unit 18. For example, it is needless to say that the supply of the power supply voltage to the load can be stopped even with another configuration such as stopping the generation of the sawtooth wave.
[0025]
As described above, the power supply device according to the first embodiment of the present invention is configured to stabilize an input unstable power supply and perform feedback control so as to supply a stabilized power supply to a load. Is done. Further, a means for preventing abnormal output from being sent to the load is provided independently of this configuration. Therefore, it is possible to prevent an abnormal output from being output to the load due to an abnormality in the power supply device itself that performs the feedback control.
[0026]
FIG. 2 is a block diagram illustrating a power supply device according to a second embodiment of the present invention. In FIG. 2, an input terminal 31, a rectifying unit 11, a switching unit 12, a reference voltage generating unit 14, an error amplifying unit 15, a sawtooth wave generating unit 16, a comparing unit 17, a driving unit 18, a reference voltage generating unit 19, and a holding unit. 21 and the rectifying means 22 are the same as those in FIG.
[0027]
The smoothing rectifiers 13a,..., 13m, 13n rectify and smooth the intermittent voltage output from the switching means 12, and generate different output voltages. For example, the switching means 12 is provided with transformers having different winding ratios, and different intermittent voltages are generated on the secondary side, rectified, and smoothed. Powers output from the smoothing rectifiers 13a,..., 13m, 13n are supplied to respective loads from output terminals 32a,. Note that some or all of the output voltages may have the same value.
[0028]
The error amplifier 15 amplifies the error voltage between the power supply voltage supplied from the output terminal 32a to the load and the reference voltage generated by the reference voltage generator 14, and performs feedback control similar to that described in the first embodiment. Constitute. By this feedback control, the unstable power supplied from the input terminal 31 is stabilized, and an output voltage according to the reference voltage generated by the reference voltage generating means 14 is obtained at the output terminals 32a, ..., 32m, 32n. Operate.
[0029]
On the other hand, the comparison means 20a,..., 20m, 20n are connected to a power supply voltage supplied to each load from the output terminals 32a, ..., 32m, 32n and a predetermined voltage obtained from the reference voltage generated by the reference voltage generation means 19. To compare. When at least one of the comparing means 20a,..., 20m, 20n outputs that at least one of the power supply voltages supplied to the respective loads from the output terminals 32a,. The logical operation means 23 outputs to the holding means 21 that the data is out of the range. When the output of the holding unit 21 is out of the predetermined range, the driving unit 18 stops driving the switching unit 12. By stopping the switching operation, the power supply voltage is not supplied from the output terminals 32a,..., 32m, and 32n to the respective loads, so that abnormal output to the loads can be prevented.
[0030]
Further, in the above description, the power supply voltage supplied to each load from the output terminals 32a,..., 32m, and 32n is compared with the reference voltage generated by the reference voltage generating means 19. In addition to or partially replacing these comparisons, the power supply current supplied from the output terminals 32a,..., 32m, and 32n to the respective loads is compared with the reference voltage generated by the reference voltage generating means 19. You may comprise. That is, the power supply current is detected by means for detecting the power supply current supplied to the load, for example, inserting a resistor having a small resistance value and detecting the voltage across the resistor. This makes it possible to detect an abnormal output current to the load.
[0031]
As described above, the power supply device according to the second embodiment of the present invention stabilizes an unstable input power and performs feedback control so as to supply the stabilized power to a plurality of loads. Is composed of Further, a means for preventing abnormal output from being sent to the load is provided independently of this configuration. Therefore, it is possible to prevent an abnormal output from being sent to a plurality of loads due to an abnormality in the power supply device itself that performs the feedback control.
[0032]
In FIGS. 1 and 2, the unstable power supplied from the input terminal 31 is described as an AC power, but may be a DC power. In the case of a DC power supply, the rectifiers 11 and 22 can be omitted. Further, the rectifying unit 22 can also be used as the rectifying unit 11. However, in the case where the rectifier 11 is also used, depending on the failure of the rectifier 11, the function of preventing abnormal output from being sent to the load may be impaired.
[0033]
Next, an example of a circuit of the error amplifying unit 15 will be described. FIG. 3 is a circuit diagram showing a configuration example of the error amplifying unit according to the embodiment of the present invention. The power supply voltage V0 supplied to each load from the output terminal 32 or 32a is divided by the resistors R2 and R1, and the voltage V0 · R1 / (R1 + R2) is supplied to the + terminal of the amplifier circuit AMP. The reference voltage Vref1 output from the reference voltage generating means 14 is divided by a resistor R4, a variable resistor RV1, and a resistor R3 and supplied to a negative terminal of the amplifier circuit AMP, and the output voltage E of the amplifier circuit AMP is changed to a resistor R5 Is fed back to the negative terminal of the amplifier circuit AMP. In such a circuit configuration, when the amplification factor of the amplifier circuit AMP is sufficiently large and the input offset voltage and the like are ignored, V0 = Vref1 · R3 / (R3 + R4 + RV1) · (R1 + R2) / R1. Therefore, the power supply voltage V0 can be set to a predetermined value by appropriately setting the value of the resistor.
[0034]
Next, an example of a circuit of the comparing means 20 or the comparing means 20a,..., 20m, and 20n will be described. FIG. 4 is a circuit diagram illustrating a configuration example of the comparison unit according to the embodiment of the present invention. The power supply voltage V0 supplied to each load from the output terminal 32 or the output terminals 32a,..., 32m, and 32n is divided by the resistors R7 and R6, and the voltage V0 · R6 / (R7 + R6) is connected to the minus terminal of the comparison circuit CMP. Supplied. The reference voltage Vref2 output from the reference voltage generating means 19 is divided by the resistors R9 and R8, and the voltage Vref2 · R8 / (R9 + R8) is supplied to the + terminal of the comparison circuit CMP.
When Vref2 · R8 / (R9 + R8) <V0 · R6 / (R7 + R6), the comparison circuit CMP outputs an output signal so that the driving unit 18 stops driving the switching unit 12. That is, when {Vref2 · R8 / (R9 + R8) ≧ V0 · R6 / (R7 + R6)} is within the predetermined range, the drive continuation signal D (high level) is output when the voltage is outside the predetermined range, and {Vref2 When R8 / (R9 + R8) <V0 · R6 / (R7 + R6)}, the driving continuation prohibition signal I (low level) is output and supplied to the driving means 18.
[0035]
Next, an example of a circuit of the logical operation means 23 will be described. FIG. 5 is a circuit diagram showing a configuration example of the logical operation means according to the embodiment of the present invention. , 20m, 20n, the output transistors Qa,..., Qm, Qn of the comparators CMPa,..., CMPm, CMPn are open collectors, and the collector of each transistor is a common load. It is connected to the resistor R0. That is, the transistors of each output are connected by a wired OR. In the circuit having such a configuration, when at least one of the comparison units 20a,..., 20m, and 20n outputs a low level (drive continuation prohibition signal I), the D / I signal becomes low and outputs a drive continuation prohibition signal. It will be. Further, as is well known, it is possible to configure the connection by wired AND by inverting the logic, and it is needless to say that the same configuration can be realized by various logic circuits.
[0036]
【The invention's effect】
As can be understood from the above description, the power supply device of the present invention is independent of a control system that converts an input power supply into a constant output voltage and supplies the load to a load, and includes a unit that detects output abnormality. Is done. Therefore, it is possible to prevent an abnormal output from being sent to the load due to an abnormality in the power supply device itself.
[0037]
In addition, the power supply device of the present invention is configured to convert input power to a plurality of constant output voltages and supply them to a plurality of loads, respectively, and to detect a plurality of output voltages. Therefore, it is possible to detect abnormalities in a plurality of outputs supplied to a plurality of loads.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a power supply device according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a power supply device according to a second embodiment of the present invention.
FIG. 3 is a circuit diagram illustrating a configuration example of an error amplifying unit according to the embodiment of the present invention.
FIG. 4 is a circuit diagram showing a configuration example of a comparison unit according to the embodiment of the present invention.
FIG. 5 is a circuit diagram illustrating a configuration example of a logical operation unit according to the embodiment of the present invention.
[Explanation of symbols]
11, 22 rectifying means 12 switching means 13, 13a, ..., 13m, 13n smoothing rectifying means 14 reference voltage generating means 15 error amplifying means 16 sawtooth wave generating means 17, 20, 20a, ..., 20m, 20n comparing means 18 driving Means 19 Reference voltage generating means 21 Holding means 23 Logical operation means 31 Input terminals 32, 32a, ..., 32m, 32n Output terminals

Claims (10)

A power supply device that converts input power to a constant output voltage and supplies the load to a load,
Means for detecting that the output voltage has deviated from a predetermined range,
Means for holding the detection state,
Means for stopping supply of output to the load when the output voltage is out of a predetermined range. A power supply device that converts input power to a plurality of fixed output voltages and supplies the plurality of loads to respective loads,
Means for detecting that at least one of the plurality of output voltages has deviated from a predetermined range,
Means for holding the detection state,
Means for stopping supply of output to the load when the output voltage is out of a predetermined range. A power supply device for controlling a switching pulse width in order to switch an input power supply and supply a constant output voltage to a load,
Reference voltage generation means for generating a reference voltage for detecting that the output voltage has deviated from a predetermined range,
Comparing means for comparing the output voltage with the reference voltage,
A power supply device, wherein when the comparing means outputs that the output voltage has deviated from a predetermined range, the output of the comparing means is held and the switching operation is stopped. A power supply device that controls a pulse width of switching in order to switch an input power supply and supply a constant output voltage to each of a plurality of loads,
Reference voltage generation means for generating a reference voltage for detecting that the plurality of output voltages are out of their respective predetermined ranges,
A plurality of comparing means for respectively comparing a plurality of predetermined voltages obtained from the reference voltage and a plurality of the output voltages,
When at least one of the plurality of comparing means outputs that at least one of the plurality of output voltages is out of a predetermined range, the output of the comparing means is held and the switching operation is stopped. And power supply. 5. The power supply device according to claim 3, wherein the power supply of the reference voltage generation unit is supplied from the input power supply. Rectifying means for rectifying the AC power,
Switching means for switching the output of the rectifying means;
Rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means,
First reference voltage generating means for generating a first reference voltage for setting a voltage output from the rectifying and smoothing means and supplied to an external load to a predetermined value;
Error amplification means for amplifying an error voltage between the voltage supplied to the load and the first reference voltage;
Sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means,
First comparing means for comparing the sawtooth voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means;
Driving means for driving the switching means for switching based on a comparison result of the first comparing means;
Second reference voltage generating means for generating a second reference voltage for detecting that the voltage supplied to the load has deviated from a predetermined range;
Second comparing means for comparing a voltage supplied to the load with the second reference voltage;
Holding means for holding the comparison result of the second comparing means indicating that the voltage supplied to the load has deviated from a predetermined range,
A power supply device, wherein when the holding unit outputs that the voltage supplied to the load is out of a predetermined range, the driving unit is operated so as to stop the switching operation of the switching unit. Rectifying means for rectifying the AC power,
Switching means for switching the output of the rectifying means;
A plurality of rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means,
First reference voltage generation means for generating a first reference voltage for setting a voltage output from one of the plurality of rectification smoothing means and supplied to an external load to a predetermined value; ,
Error amplification means for amplifying an error voltage between the voltage supplied to the load and the first reference voltage;
Sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means,
First comparing means for comparing the sawtooth voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means;
Driving means for driving the switching means for switching based on a comparison result of the first comparing means;
Second reference voltage generating means for generating a second reference voltage for detecting that a plurality of voltages supplied from the plurality of rectifying and smoothing means to a plurality of loads respectively deviate from respective predetermined ranges;
A plurality of second comparing means for respectively comparing a plurality of predetermined voltages obtained from the second reference voltage and a plurality of voltages supplied to the plurality of loads;
A logical operation of performing a logical operation on the comparison results output by the plurality of second comparing means, and outputting, when at least one of the plurality of voltages supplied to the plurality of loads is out of a predetermined range, an indication that the voltage has deviated. Means,
Holding means for holding the output of the logical operation means,
A power supply device, wherein, when the holding unit outputs the departure from the predetermined range, the driving unit is operated to stop the switching operation of the switching unit. Rectifying means for rectifying the AC power,
Switching means for switching the output of the rectifying means;
A plurality of rectifying and smoothing means for rectifying and smoothing the intermittent voltage output from the switching means,
First reference voltage generation means for generating a first reference voltage for setting a voltage output from one of the plurality of rectification smoothing means and supplied to an external load to a predetermined value; ,
Error amplification means for amplifying an error voltage between the voltage supplied to the load and the first reference voltage;
Sawtooth wave generating means for generating a sawtooth wave of a predetermined period for switching of the switching means,
First comparing means for comparing the sawtooth voltage output from the sawtooth wave generating means with the voltage output from the error amplifying means;
Driving means for driving the switching means for switching based on a comparison result of the first comparing means;
A second reference voltage generating means for generating a second reference voltage for detecting that a plurality of voltages or currents respectively supplied from the plurality of rectifying / smoothing means to a plurality of loads deviate from respective predetermined ranges; When,
A plurality of second comparing means for comparing a plurality of predetermined voltages obtained from the second reference voltage with a plurality of voltages or currents supplied to the plurality of loads, respectively;
A logical operation is performed on the comparison results output by the plurality of second comparing means, and when at least one of the plurality of voltages or currents supplied to the plurality of loads is out of a predetermined range, the fact that the voltage or current is out of range is output. Logical operation means;
Holding means for holding the output of the logical operation means,
A power supply device, wherein, when the holding unit outputs the departure from the predetermined range, the driving unit is operated to stop the switching operation of the switching unit. 9. The power supply device according to claim 7, wherein said logical operation means performs a logical operation consisting of a wired OR or a wired AND. The power supply according to any one of claims 6 to 8, wherein the power supplied to the second reference voltage generator is obtained by rectifying the AC power.

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