JPH0197875A - Apparatus for detecting momentary cutoff of dc power source - Google Patents

Abstract

PURPOSE:To prevent erroneous operation with a simple constitution and to omit maintenance, by comparing a DC output from a delay device with a DC output from a DC power source, detecting the difference in these outputs, and detecting the momentary cutoff of the power source. CONSTITUTION:When momentary cutoff occurs in a DC power source 1 to be monitored, the waveforms of voltages at points A and B on the output side of the DC power source 1 are changed. When the output voltages are imparted to a delay circuit 3, the voltages are delayed with an integrating circuit comprising an inductance 31 and capacitor 32. An output voltage having gentle rise-up and fall-down is generated at the output side of the circuit 3. The voltage is applied to a resistor 41 of a comparator circuit 4. The voltage, which is changed by the momentary cutoff as the output voltage of the DC power source 1, is directly imparted to a point A of the input side of the circuit 4. The voltage is applied to a resistor 42. There is the difference in levels of the voltages, which are compared in the circuit 4. A fuse 51 blows at the time of the output. Thus the momentary cutoff of the DC power source 1 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a DC power supply instantaneous interruption detection device that detects instantaneous interruptions in a DC power supply.

(Prior Art) Conventionally, detection circuits configured with active elements such as transistors and IC chips have been known as devices for detecting instantaneous interruptions in monitored DC power supplies. However, such detection circuits using active elements require a drive power source to drive the circuit itself, and because this power source is obtained from the monitored DC power source, malfunctions may occur due to noise during momentary power interruptions. . Therefore, in order to prevent such inconveniences, it has been considered to include a battery power source, etc., but this not only makes the entire device bulky and expensive, but also requires maintenance and handling. It also had the disadvantage of being troublesome.

(Problems to be Solved by the Invention) In this way, the conventional DC power supply instantaneous interruption detection device that detects instantaneous interruptions in the DC power supply is prone to malfunction due to noise during instantaneous power interruption, and also has problems with battery power supply, etc. Not only is the entire device large-scale and expensive to install and install, but it also requires maintenance and is troublesome to handle.

Therefore, the purpose of this invention is to completely eliminate malfunctions caused by noise, to have a simple configuration and low cost, and to eliminate the need for troublesome maintenance that tends to occur during momentary power interruptions. To provide a detection device.

[Structure of the Invention] (Means for Solving the Problems) ゛ This invention provides a monitored DC power supply, a delay means for delaying the DC output of the two DC power supplies for a predetermined period of time, and a DC output from the delay means. It has a detection means for comparing the DC outputs of the DC power sources and detecting a difference between these outputs, and a momentary power interruption is detected by the comparison difference output from this detection means.

(Function) As a result, there is no need to provide a special drive power source for the detection circuit itself, and malfunctions caused by noise during momentary power interruptions can be completely eliminated. It becomes possible to detect instantaneous power interruption without using a power source battery that requires troublesome maintenance.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the circuit configuration of the same embodiment.

In the figure, 1 is a monitored DC power supply, and this DC type 111
DC output from X1 is supplied to load 2. Further, the DC output from this DC power supply 1 is given to a delay circuit 3. This delay circuit 3 delays the DC output of the DC power supply 1 by a predetermined period of time, and as a concrete example, it is comprised of an integrating circuit comprising an inductance 31 and a capacitor 32, as shown in FIG.

A delayed output delayed for a predetermined time by this delay circuit 3 is given to a comparator circuit 4. This comparator circuit 4 is directly supplied with the DC output from the DC power supply 1, and compares this DC output with the delayed output delayed by the delay means, and calculates the difference between these DC outputs into an instant. It is designed to detect disconnections. In this case, the comparator circuit 4 specifically consists of resistors 41 and 42 connected in series as shown in FIG.
The level difference between the output voltage of the resistor 42 and the output voltage applied to the other resistor 42 is detected, and this level difference is output as an instantaneous interruption detection signal. The output of this comparator circuit 4 is then displayed on a display section 5.
This indicates that there was a momentary power outage. In this case, the display diagram is constituted by a quick-acting fuse 51, as shown in FIG. 4, for example.

Next, the operation of the embodiment configured as described above will be explained.

Now, if the monitored DC power supply 1 is normal, the comparator circuit 4
The output voltage of the delay circuit 3 applied to one resistor 41 and the output voltage applied to the other resistor 42 are equal, and no voltage level difference is detected between them, so the instantaneous interruption detection signal is It is never output.

If there is a momentary interruption in the monitored DC power supply 1 in this state, the voltage waveform at the output side point ASB of the DC power supply 1 changes as shown in FIG. 5(a). When this output voltage is applied to the delay circuit 3, it is delayed by the integrator circuit of the inductance 31 and the capacitor 32 shown in FIG. An output voltage that falls and rises slowly is generated, and this output voltage is applied to the resistor 41 shown in FIG. 5 of the comparator circuit 4.
is applied to On the other hand, the input point A of the comparator circuit 4 is directly given the voltage that has changed due to a momentary interruption as the output voltage of the DC power supply 1, as shown in FIG. 5 (C), and this voltage is shown in FIG. applied to resistor 42. Comparison is then performed by this comparison circuit 4, but in this case, since there is a level difference between the voltages applied to these resistors 41 and 42, the comparison circuit 4 makes a comparison as shown in FIG. A momentary interruption detection signal is now output. This signal voltage causes the display section, that is, the quick-blow fuse 51 shown in FIG.
The instantaneous interruption of the monitored DC power supply 1 is detected by visually observing the melting.

Therefore, by doing this, the output voltage from the monitored DC power supply 1 is delayed by the delay circuit 3 and is applied to the comparison circuit 4, and the output voltage from the monitored DC power supply 1 is directly applied to the comparison circuit 4,゛Since a momentary interruption in the monitored DC power supply 1 is detected based on the presence or absence of a level difference between these output voltages, a drive power supply to drive the circuit itself is not required, unlike a detection circuit composed of conventional active elements. Furthermore, compared to a system in which this power source is obtained from a monitored DC power source, this type of driving power source is not required at all, and malfunctions due to noise or the like during momentary power interruptions can be completely eliminated. In addition, compared to devices equipped with a battery power source that were considered to prevent such inconveniences, this type of battery power source is not required at all, making the configuration simpler and cheaper. At the same time, the need for troublesome maintenance can also be eliminated.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, the delay circuit 3 and comparison circuit 4 of the embodiment described above
These are just examples, and circuits other than these may also be employed.

[Effects of the Invention] According to the present invention, a DC power supply to be monitored, a delay means for delaying the DC output of the DC power supply for a predetermined period of time, and a comparison between the DC output from the delay means and the DC output of the DC power supply, and It has a detection means for detecting a difference between these outputs, and a momentary power interruption is detected by the comparison difference in this detection means.

This eliminates the need for a special drive power source for the detection circuit itself, and eliminates malfunctions caused by noise during momentary power interruptions. Moreover, since instantaneous power interruption can be detected without using a power source battery, the configuration can be simplified and the price can be reduced, and the need for troublesome maintenance can also be eliminated.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention, Fig. 2 is a circuit diagram showing a delay circuit used in the embodiment, and Fig. 3 is a comparison circuit used in the embodiment. FIG. 4 is a display circuit diagram showing the output of the comparison circuit, and FIG. 5 is a waveform diagram for explaining the operation of the same embodiment. DESCRIPTION OF SYMBOLS 1... DC power supply to be monitored, 2... Load, 3... Delay circuit, 31... Inductance, 32... Capacitor, 4... Comparison circuit, 5... Display section. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Compare the DC power supply to be monitored, a delay means for delaying the DC output of this DC power supply for a predetermined period of time, and the delayed output from this delay means and the DC output of the above DC power supply. 1. A direct current power supply instantaneous interruption detection device comprising: detection means for detecting an interruption. (2) Claim 1, characterized in that the delay means comprises an integrating circuit having an inductance and a capacitor.
DC power supply instantaneous interruption device described in Section 1.