JPH01252114A - Power source abnormality indicator - Google Patents

Abstract

PURPOSE:To indicate abnormality of power source with high reliability by controlling power supply from a rectifying section to an abnormality, indicating section corresponding to the voltage level of the power source. CONSTITUTION:A rectifier 1 rectifies AC power fed from an external AC power source. An abnormality indicating section 2 is brought into abnormality indicating state corresponding to the power supply state from the rectifying section 1. A switch section 2 is turned ON, OFF corresponding to the source voltage of a power source for an object to be monitored, thus controlling power supply from the rectifying section 1 to an abnormality indicating section 3. The switch section 2 detects abnormality of source voltage, which is indicated on the abnormality indicating section 3. Power is fed to the abnormality indicating section 3 only through the rectifying section 1.

Description

[Detailed Description of the Invention] [Summary] A power supply device that converts power from a commercial AC power supply into stable power having predetermined characteristics such as constant voltage or constant current and supplies it to various devices. Regarding power supply abnormality display devices that detect output abnormalities and display the abnormalities, reliability is increased by receiving power from a more reliable power source than the power supply device that is the target of abnormality detection and display. A rectifying section that rectifies alternating current from an external AC power source, an abnormality display section that displays an abnormal state depending on the state of power supply from the rectifying section, and a power source output from the power source to be monitored. and a switch section that turns on and off depending on the voltage to control the supply of power from the rectifying section to the abnormality display section 3.

[Industrial application field]

The present invention detects abnormalities in the output of a power supply device that converts power from a commercial AC power source into stable power having predetermined characteristics such as constant voltage or constant current and supplies it to various devices. The present invention relates to a power supply abnormality display device that displays the abnormality.

For example, a power supply device such as a DC stabilized power supply device that converts power from a commercial AC power source into stable power with predetermined characteristics such as constant voltage or constant current and supplies it to various devices. Usually, a power supply abnormality display device is provided to detect and display an abnormality in the output.

However, in a power supply abnormality display device included in a conventional power supply device, the power supply device that supplies power to the power supply abnormality display device in order to operate the power supply abnormality display device is a power source that is a target for detecting an abnormality. Although it is installed independently from the equipment, its reliability is not much different from the power supply equipment whose abnormalities are detected.
The reliability of the power supply abnormality display device itself, which receives power from such a power supply device, is not much different from that of the power supply device whose abnormality is to be detected. Therefore, there has been a need for a technology that provides a more reliable power supply abnormality display device. .

[Prior art and problems to be solved by the invention]

FIG. 4 schematically shows a configuration for displaying a power abnormality in a conventional data power supply device.

In FIG. 4, 6 is a transformer for extracting power from a commercial AC power source, 7 is a DC power source for supplying the device, 8 is a DC power source for a power failure indicator, and 1.9 is a power failure indicator. Power for operating a power supply abnormality display unit 9 that detects the output voltage of the device supply DC power supply 7 and displays any abnormality is supplied from a power supply abnormality display unit DC power supply 8.

In the transformer 6, the DC power supply 8 for the power supply abnormality display section includes:
Electric power is taken out from a secondary coil provided independently of the DC power supply 7 for supplying the device. However, the configuration of the DC power supply 8 for the power supply abnormality display section is basically the same as that of the DC power supply 7 for supplying the device, as an example is shown in FIG. 5, for example. The configuration within the broken line 8 in FIG. 5 shows a schematic configuration of a switching power supply, in which a transformer 6 extracts power from a commercial AC power supply, a rectifier 81 rectifies the power, a power supply unit 83 supplies the control unit Under the control of 84, the voltage is converted into a predetermined DC voltage and output. The control section 84 also controls the transformer 6.
It is supplied with power extracted from a commercial AC power source and rectified by a rectifier 82 .

Therefore, the reliability of the conventional DC power supply 8 for the power supply abnormality display section is comparable to that of the DC power supply 7 for supplying the device. Therefore, the reliability of the power supply abnormality display section 9 that receives power from the power supply abnormality display section DC power supply 8 is at most the same as that of the device supply DC power supply 7. That is, there has been a problem in that the reliability of the power supply abnormality display device that detects and displays abnormalities in the power supply apparatus cannot be said to be higher than that of the power supply apparatus that is the object of abnormality detection and display.

The present invention has been made in view of the above problems, and provides a highly reliable power supply abnormality display device that receives power from a more reliable power source than the power supply device that is the target of abnormality detection and display. The purpose is to

[Means to solve the problem]

FIG. 1 is a basic configuration diagram of the present invention. In this figure, l
2 is a rectifier section, 2 is a switch section, and 3 is an abnormality display section.

The rectifier 1 rectifies alternating current from an external alternating current power source.

The abnormality display section 3 enters an abnormality display state depending on the state of power supply from the rectifier 1.

The switch section 2 controls the supply of power from the rectifier section 1 to the abnormality display section 3 by turning on and off in accordance with the power supply voltage output from the power supply to be monitored.

[For production]

The supply of power from the rectifying unit 1, which simply rectifies AC from an external AC power supply, to the abnormality display unit 3 is controlled according to the level of the power supply voltage output from the power supply to be monitored. Displays an abnormality depending on the situation.

Therefore, in the above configuration, the switch unit 2 detects an abnormality in the power supply voltage, and the abnormality display unit 3 displays this abnormality. It is only the rectifying section 1 that supplies power to the abnormality display section 3, and a device that supplies power to a structure that detects and displays an abnormality in the power supply voltage is realized with an extremely simple configuration.

Due to the simple structure, the number of constituent parts is also reduced, which means that there are fewer elements that can cause failures. Therefore, reliability is improved.

〔Example〕

FIG. 2 is a block diagram of a first embodiment of the present invention.

In FIG. 2, 5 is a transformer, 10 and 32 are diodes, 30 is a light emitting diode, 21 and 23 are transistors, and 4, 22, 24, 25 degrees and 31 are resistors.

An alternating current voltage from a commercial alternating current power source is applied to the primary side of the transformer 5. One end of the diode 10 is connected to one end of the secondary coil of the transformer 5, and the other end of the diode 10 is connected to one end of the light emitting diode 30 via the resistor 4. Here, the diode 10 and the light emitting diode 30 are connected to each other in the forward direction. The other end of the light emitting diode 30 is connected to the collector terminal of the transistor 21.

In the example of FIG. 2, one end of a diode 32 consisting of two diodes connected in series is grounded, and the other end is connected to a resistor 31.
It is connected to the one end of the light emitting diode 30 via.

Further, the other end of the diode 32 is connected to the transistor 21.
connected to the base terminal of the

The voltage supplied to other devices from the power supply device (not shown) to be monitored is divided by the series connection of resistors 24 and 25, and the divided voltage is applied to the base terminal of transistor 23. . The supply voltage is also applied to the collector terminal of a transistor 23, and the emitter terminal of the transistor 23, together with the emitter terminal of the transistor 21, is connected to the other end of a resistor 22 whose one end is grounded.

In the above configuration, the diode 10 corresponds to the rectifying section 1 of the configuration shown in FIG. 1 described above, and the light emitting diode 30 realizes the abnormality display section 3 of the configuration shown in FIG.

Further, the series connection of the resistor 31 and the diode 32 applies a constant voltage to the base terminal of the transistor 21 by keeping the connection point between the resistor 31 and the diode 32 at a constant voltage. and transistors 21 and 23
, and the resistor 22 constitute a differential amplifier. Furthermore, the resistor 4 is a current limiting resistor for overcurrent protection.

In the configuration of FIG. 2, the output of the power supply device to be monitored is normal, and the partial voltage of the device supply voltage applied to the base terminal of the transistor 23 depends on the constant voltage from the diode 32. When the voltage is higher than a predetermined voltage determined by
Since the voltage at the emitter terminal of the transistor 21 is high, no current flows between the collector and emitter of the transistor 21. Therefore, no current flows through the light emitting diode 30 connected to the transistor 21, and the light emitting diode 3o does not emit light.

An abnormality occurs in the output of the power supply device to be monitored, and the divided voltage of the device supply voltage applied to the base terminal of the transistor 23 is less than a predetermined voltage determined depending on the constant voltage by the diode 32 described above. When this happens, the voltage at the base terminal and collector terminal of the transistor 23 decreases, so that the current flowing from the power supply device to be monitored to the resistor 22 through the collector-emitter of the transistor 23 decreases. The voltage at the emitter terminal of transistor 21 decreases and the voltage at the emitter terminal of transistor 2
Current flows between the collector and emitter of 1. As a result, the light emitting diode 30 connected to the transistor 21
Current also flows through the light emitting diode 30, and the light emitting diode 30 emits light to indicate the occurrence of an abnormality.

In the configuration shown in FIG. 2, the power supply for operating the abnormality detection and display configuration is essentially performed without using the power supply device 8 which has a large number of parts as in the conventional configuration shown in FIG. Generally, this is done using only the diode 10. Therefore, with this diode 10,
A highly reliable configuration with an extremely small number of parts has been realized as a configuration for supplying power to operate a configuration for detecting and displaying abnormalities. Furthermore, in the configuration shown in FIG. 2, the transistor 2 that drives the light emitting diode 30 is
The base terminal of 1 is kept at a constant voltage, and the light emitting diode 3
0 is driven by a constant current circuit, and the current flowing through the light emitting diode 30 becomes stable.

FIG. 3 is a block diagram of a second embodiment of the present invention.

In Figure 3, 5 is a transformer, 10 is a diode, 2
0 is a transistor, 30 is a light emitting diode, and 4.24 and 25 are resistors.

An alternating current voltage from a commercial alternating current power source is applied to the primary side of the transformer 5. One end of the diode 10 is connected to one end of the secondary coil of the transformer 5, and the other end of the diode 10 is connected to the emitter terminal of the transistor 21 via the resistor 4. Further, the collector terminal of the transistor 20 is connected to the other end of a light emitting diode 30 whose one end is grounded.

Here, the diode 10 and the light emitting diode 30 are connected to each other in the forward direction.

The voltage supplied to other devices from the power supply device (not shown) to be monitored is divided by the series connection of resistors 24 and 25, and the divided voltage is applied to the base terminal of transistor 20. .

In the above configuration, the diode 10 corresponds to the rectifying section 1 of the configuration shown in FIG. 1 described above, and the light emitting diode 30 realizes the abnormality display section 3 of the configuration shown in FIG.

Resistor 4 is a current limiting resistor for overcurrent protection.

In the configuration shown in FIG. 3, the output of the power supply device to be monitored is normal, the partial voltage of the device supply voltage applied to the base terminal of the transistor 23 is high, and the emitter-base voltage of the transistor 20 is high. Therefore, when the value necessary to make the transistor 20 conductive cannot be secured, no current flows between the emitter and collector of the transistor 20. Therefore, no current flows through the light emitting diode 30 connected to the transistor 21, and the light emitting diode 30 does not emit light.

When an abnormality occurs in the output of the monitored power supply device, the partial voltage of the device supply voltage applied to the base terminal of the transistor 20 decreases, and the emitter-base voltage necessary to make the transistor 20 conductive decreases. When the value is realized, a current flows between the emitter and collector of transistor 20. As a result, current also flows through the light emitting diode 30 connected to the transistor 20, and the light emitting diode 30 emits light to indicate the occurrence of an abnormality.

In the configuration shown in FIG. 3 as well, the power supply for operating the configuration for detecting and displaying abnormalities is essentially performed without using the power supply device 8 which has a large number of parts as in the conventional configuration shown in FIG. Generally, this is done using only the diode 10. Therefore, with this diode 10,
A highly reliable configuration with an extremely small number of parts has been realized as a configuration for supplying power to operate a configuration for detecting and displaying abnormalities.

〔Effect of the invention〕

According to the present invention, there is provided a highly reliable power supply abnormality display device that receives power from a power source that is more reliable than the power supply device that is the target of abnormality detection and display.

[Brief explanation of the drawing]

Figure 1 is a basic configuration diagram of the present invention, Figure 2 is a configuration diagram of a first embodiment of the invention, Figure 3 is a configuration diagram of a second embodiment of the invention, and Figure 4 is a conventional power supply. FIG. 5 is a diagram schematically showing the configuration of an abnormality display device, and FIG. 5 is a schematic configuration diagram of the DC power supply device shown in FIG. 4. [Explanation of symbols] 1... Rectifier section, 2... Switch section, 3...
... Abnormality display section, 4.22, 24, 25.31 ... Resistance, 5.6 ...
Transformer, 7.8... DC power supply device, 9... Power supply abnormality detection display unit, 10.32... Diode, 20.21.23... Transistor, 30... Light emitting diode. Basic configuration diagram of the present invention Part 1 Block diagram of the first embodiment of the present invention Part 2 Part 3 A diagram showing an outline of the configuration for displaying a conventional power supply abnormality Diagram showing the schematic configuration Part 5

Claims (1)

[Claims] 1. A rectifier (1) that rectifies alternating current from an external AC power source; and an abnormality display section (3) that displays an abnormal state depending on the state of power supply from the rectifier (1). The rectifying section (
A power supply abnormality display device comprising: a switch section (2) for controlling supply of electric power from the power source 1) to the abnormality display section (3). 2. The switch section (2) both has an emitter terminal connected to the other end of a resistor (22) whose one end is connected to a constant voltage source,
first and second transistors (21, 23) that apply a constant voltage and a voltage corresponding to the power supply voltage output from the power supply to be monitored to their respective base terminals; (21), the rectifier (1)
The power supply abnormality display device according to claim 1, wherein the abnormality display section (3) and the abnormality display section (3) are connected to each other in series. 3. The power supply abnormality display device according to claim 2, wherein a current limiting resistor (4) is connected to the series connection. 4. The switch section (2) applies a voltage corresponding to the power supply voltage output from the power supply to the device to be monitored to the base terminal, and connects the switch section (2) in series with the rectifier section (1) and the abnormality display section (3). The power supply abnormality display device according to claim 1, further comprising a transistor (20) connected to the power supply abnormality display device. 5. The power supply abnormality display device according to claim 4, wherein a current limiting resistor (4) is connected to the series connection.