JPH0362108A - Power unit with overload detecting function - Google Patents

Abstract

PURPOSE:To inform abnormality occurrence to the outside by detecting an overload state which exceeds a 2nd overload reference value held by a holding means. CONSTITUTION:When an object object current value from a displayed output current value is judged, a user operates an overcurrent value setting input part 23 to input an overcurrent value and then the value is held by a setting holding part 26 and converted by a D/A converting circuit 27 into an analog value. The overcurrent value which is converted into the analog value is supplied as the 2nd reference value to a comparing circuit 20 in an overload protecting circuit 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a power supply device having an overload detection function.

(Conventional technology) Generally, the rated current of a power supply device is determined.

In such a power supply device, when a current exceeding a certain level (i.e., overcurrent) flows relative to the rated current, the overcurrent protection circuit (overload protection circuit) is activated, and the power cutoff mechanism is activated to cut off the power supply. This was designed to protect the equipment.

For computer systems, etc., even if the system configuration is small-scale, the rated capacity of the power supply is sufficiently larger than the load required by the current system, assuming that functions will be expanded by adding hardware in the future. A power supply with a power supply is often used. In the current system, such a power supply device has sufficient power supply capacity, so even if a redundancy occurs in the load, the current does not exceed a certain level compared to the rated current, and overcurrent detection (overcurrent detection) is performed. There was a risk that load detection) would not be performed.

(Problems to be Solved by the Invention) As mentioned above, in conventional power supply devices, overcurrent detection (overload detection) is performed based on the rated current specific to the power supply rated capacity of the device. If you are using a power supply with sufficient capacity for future function expansion, etc., the overload protection circuit will not activate even if an abnormality occurs in the load. Therefore, there were problems in that the system could not be protected and the occurrence of an abnormality could not be recognized.

This invention was made in view of the above circumstances, and its purpose is to set any overload reference value (overcurrent value or overvoltage fil).
The overload can be set independently of the equipment's rated current, and if the set value is exceeded, it can be detected as an abnormal state even if it is below the equipment's overload reference value corresponding to the rated current. An object of the present invention is to provide a power supply device with a detection function.

Another object of the present invention is to provide a power supply device with an overload detection function that can easily determine an overload reference value suitable for an applied system by visually outputting the actually consumed current value or voltage value. It is about providing.

[Structure of the Invention ec1 (Means for Solving the Problems) This invention provides a first system for detecting an overload state exceeding a preset first overload reference value and cutting off the source of supply 'a1 to the load. input means for setting and inputting an arbitrary second overload reference value smaller than the first overload reference value into the power supply device with an overload detection function equipped with the overload detection means; holding means for holding a second overload reference value inputted by the input means; and a second overload state for detecting an overload state exceeding the second overload reference value held in the holding means as an abnormal state. The present invention is characterized in that a load detection means is provided. Further, the present invention is characterized in that it further includes an output means for visually outputting a load current value or load voltage value indicating the state of the load.

(Function) According to the above configuration, the means for inputting the second overload reference value smaller than the first overload reference value set in advance, that is, the first overload reference value corresponding to the rated current. This can be arbitrarily set from the outside using the overload reference value, and if an overload condition that exceeds the set second overload reference value occurs, even if the overload condition exceeds the first overload weight value. Even if this is not the case, the occurrence of an abnormal condition is detected by the second overload 6I detection means. Further, according to the above configuration, the load current value indicating the negative Gj state or the negative Q
Since the M pressure value is output in a visible manner by the output means, the user can recognize the load current value or load voltage value in the steady state of the current system from the output result of this output means, and based on the recognition result. A second overload reference value can be determined that is compatible with the current system load.

(Embodiment) FIG. 1 shows a block configuration of a DC'r4 source device according to an embodiment of the present invention. In the figure, 11 is a rectifier circuit that rectifies, smoothes, and converts alternating current into direct current, and 12 is an output control circuit 1 to be described later for the direct current power from the rectifier circuit 11.
This is a stabilizing circuit that performs voltage control according to the control signal 16 from 5 to stabilize the DC output voltage. This stabilizing circuit I2 also has a cutoff function of prohibiting voltage output in response to a power cutoff signal 18 from an overload protection circuit 17, which will be described later. 13 is a cutoff circuit that cuts off the power supply from the stabilizing circuit 12 in response to a power cutoff signal 18 from the overload protection circuit 17; 14 is an output current (load current) supplied from the cutoff circuit 13 to a load (not shown); ) and a detection circuit 15 that includes a plurality of sensors (not shown) that independently detect the output voltage, and 15 compares the output voltage value detected by the detection circuit 14 with a reference voltage value set internally in advance. , is an output control circuit that feeds back the comparison result to the stabilizing circuit 12 using a control signal 16 to keep the output voltage constant.

l7 is a first reference value (first overload reference value, first overcurrent reference value) corresponding to the rated current for which the output current value detected by the detection circuit 14 is preset internally, or a first reference value (first overload reference value, first overcurrent reference value), which will be described later. An overcurrent circuit that outputs a power cutoff signal 18 for power cutoff control when the second reference value (second overload reference value, second overcurrent reference value) set by the overload setting circuit 25 is exceeded. It is a load protection circuit. The overload protection circuit 17 also outputs a power cutoff signal 18 when the output voltage value detected by the detection circuit 14 exceeds a third reference value (overvoltage reference value) that is preset internally. It has become.

The overload protection circuit 17 includes a comparison circuit 19 that compares the output current value detected by the detection circuit 14 with the first reference value, and a comparison circuit that compares the output current value with the second reference value. 20, a comparison circuit 21 that compares the output voltage value with the third reference value, and an OR gate 22 that ORs the output signals of the comparison circuits 19 to 21 to generate the power cutoff signal 18. Contains. Reference numeral 23 indicates an overcurrent value setting input section including, for example, a key switch, for inputting a digital value of an overcurrent value to be subject to overload protection, and 24 indicates an output current value and overcurrent detected by the detection circuit 14. An indicator 25 has a display circuit for displaying the overcurrent value set and input from the value setting input section z3, and 25 is the second standard corresponding to the overcurrent value set and input from the overcurrent value setting input section 23. This is an overload setting circuit for setting a value in the comparison circuit 20 in the overload protection circuit 17. The overload setting circuit 25 includes a set value holding section 26, such as a rewritable nonvolatile memory, which holds the overcurrent value set and inputted from the overcurrent value setting input section 23, and a set value holding section 26 that holds the overcurrent value set and inputted from the overcurrent value setting input section 23. A D/A (digital/analog) conversion circuit (D/A) that converts the overcurrent value into an analog value and generates the second reference value.
DAC) 27 and an A/D (analog/digital) conversion circuit (ADC) that converts the output current value detected by the detection circuit 14 into a digital value for display on the display 24.
Contains 2g.

Next, the operation of one embodiment of the present invention will be explained.

First, the output voltage and output current of the DC power supply supplied to the load from the DC power supply device shown in FIG. 1 are detected by the detection circuit 14. The output current value detected by the detection circuit 14 is sent to the A/D conversion circuit (ADC) of the overcurrent value setting input section 23.
) 2g and is converted into a digital value by the same circuit 28. The output current value converted into a digital value is supplied to the display 24, and the value is displayed in real time by the display circuit of the display 24. That is, according to this embodiment, the current value consumed by the load is displayed on the display 24 in real time. Therefore, a user of a system (for example, a computer system) including the power supply device shown in FIG. load)
This makes it possible to correctly determine the overcurrent value (degree of overload) that is appropriate for the condition. This overcurrent value will be smaller than the rated current of the fixed H device in the case where the power supply rated capacity of the electric R device shown in FIG. 1 has sufficient margin for the load of the current system.

When the user determines the overcurrent value that should be subject to overload protection in the current system from the output current value displayed on the display 24, the user operates the overcurrent value setting input section 23 to set the overcurrent value. Enter the settings.

The overcurrent value set and input from the overcurrent value setting input section 23 is held in the set value holding section 2B in the overload setting circuit 25. The overcurrent value held in the set value holding section 26 is displayed on the display 24.
The display circuit of the display 24 displays its value (
Externally set overcurrent value) is displayed.

Thereby, the user can visually confirm the overcurrent value set and inputted by the user by operating the overcurrent value setting input section 23 on the display 24.

The overcurrent value held in the set value holding section 26 is also supplied to the D/A conversion circuit 27. The D/A conversion circuit 27 converts the overcurrent value held in the set value holding section 2B into an analog value. This overcurrent value converted into an analog value is supplied to the comparison circuit 20 in the overload protection circuit 17 as a second reference value (second overload reference value). The comparator circuit 20 is also supplied with the output current value detected by the detection circuit 14 . Further, the comparison circuit 19 in the overload protection circuit 17 is supplied with the output current value and the first reference value (first overload reference value), and the comparison circuit 21 is supplied with the output current value detected by the detection circuit 14. The output voltage value and the third reference value (overvoltage reference value) are supplied. The output voltage value is also supplied to the output control circuit 15.

The output control circuit 15 compares the output voltage value detected by the detection circuit 14 with a reference voltage value set internally in advance,
The comparison result is fed back to the stabilizing circuit 12 using a control signal 16 to perform well-known output control to keep the output voltage constant. Further, a comparison circuit 19 in the overload protection circuit 17 compares the output current value detected by the detection circuit 14 with the above-mentioned first reference value (corresponding to the rated current) preset inside the overload protection circuit 17. and outputs an active signal when the output current value exceeds the first reference value. Similarly, the comparison circuit 20 in the overload protection circuit 17 is
Compare the output current value detected by the detection circuit 14 with the second reference value (corresponding to the externally set overcurrent value) output from the overload setting circuit 25 (D/A conversion circuit 27). However, when the output current value exceeds the second reference value, an active signal is output.

Further, the comparison circuit 21 in the overload protection circuit 17 compares the output voltage value detected by the detection circuit 14 with the third reference value (overvoltage reference value) set in advance inside the overload protection circuit 17. However, when the output voltage value exceeds the reference value of the brush 3, an active signal is output. Comparison circuit 19-2
The output signal 1 is ORed by an OR gate 22 and supplied as a power cutoff signal 18 to the stabilization circuit 12 and the cutoff circuit 13. As a result, when the power cutoff signal 18 is active, that is, when any of the output signals of the comparison circuits 19 to 21 is active, the voltage output from the stabilizing circuit 12 is prohibited, and the power supply is turned off in the cutoff circuit 13. will be cut off. Note that when using the power supply devices shown in FIG. 1 in duplicate, the power cutoff signal 18 of each power supply device is output to the stabilization circuit 12 and cutoff circuit 13 of the other power supply device, and both power supply devices are It is also possible to cut off the voltage.

Now, in a power supply device that has sufficient capacity for the load of the current system, the second reference value will be smaller than the first base/$ value corresponding to the rated current as described above.

Therefore, in the power supply device shown in Figure 1, if the output current value (load current value) exceeds the second reference value, the power is cut off even if it does not exceed the first reference value corresponding to the rated current. be able to. In other words, according to this embodiment, even if the output current value would not cause the power supply to be cut off because the power supply device had sufficient capacity compared to the load of the applied system, the current value in the steady state of the applied system In the event of an abnormality in which the output current value becomes significantly larger than the second reference value, the power supply can be shut off to protect the system.

In the above embodiment, the power supply is cut off even when the output current value exceeds the second reference value, but overload (overcurrent) is detected as long as the output current value does not exceed the first reference value. It is sufficient to simply issue an abnormality notification indicating that. In this case, the output signal of the comparison circuit 20 may not be supplied to the OR gate 22, but may be used as a drive signal for an abnormality notification circuit (alarm circuit) such as an alarm or a warning light. It is also possible to perform both power cutoff and abnormality notification.

Further, in the embodiment described above, the value of the current flowing through the load (output current 1ffl) is displayed on the display 24, but block output or printer output is also possible. Furthermore, in the previous embodiment, an arbitrary overcurrent value is set externally, and when the output current exceeds this externally set overcurrent value, it is treated as abnormal, but the present invention It is also possible to set the overvoltage value externally and treat the output voltage as abnormal if it exceeds the externally set overvoltage value.

[Effects of the Invention] As detailed above, according to the power supply device with an overload detection function of the present invention, any overload reference value (overcurrent value or overvoltage value) can be set independently of the rated current of H in the device. If the set value is exceeded, it will be detected that an overload has occurred even if it is less than the overload standard value specific to the device corresponding to the rated current, so depending on the detection result. It is possible to activate the power cutoff mechanism or notify the outside of the occurrence of an abnormality, especially when the rated power capacity of this device has sufficient margin for the load of the system to which this device is applied. is extremely useful.

Further, according to the present invention, since the configuration is such that the actually consumed load status (load current value or load voltage value) is output in a visible manner, from this load status output result, the overload Standard values can be easily determined.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a DC power supply device showing an embodiment of the present invention. 12... Stabilization circuit, 13... Cutoff circuit, 14...
・Detection circuit, 15... Output control circuit, 17... Overload protection circuit, I9... Comparison circuit (first overload detection means), 20... Comparison circuit (second overload detection means) means),
23... Overcurrent value setting input section, 24... Display, 2
5... Overload setting circuit, 2B... Set value holding section, 2
7...D/A conversion circuit (DAC), 2g...A/D
Conversion circuit (ADC).

Claims (2)

[Claims] (1) A first overload detection means is provided for detecting an overload state exceeding a first overload reference value set in advance, and supply to the load is provided according to the detection result of the first overload detection means. A power supply device with an overload detection function that cuts off the power supply includes an input means for setting and inputting an arbitrary second overload reference value smaller than the first overload reference value; holding means for holding the second overload reference value held in the holding means; and second overload detection means for detecting an overload state exceeding the second overload reference value held in the holding means as an abnormal state. A power supply device with an overload detection function, comprising: and. (2) The power supply device with an overload detection function according to claim 1, further comprising an output means for visually outputting a load current value or load voltage value indicating the state of the load.