JPS63108276A - Power failure detection system - Google Patents

Abstract

PURPOSE:To put a computer in normal operation even in case of a longer instantaneous interruption of a commercial AC power source when the constitution of the computer is small by detecting the output voltage level of a batch rectifying circuit part by using a comparator and sending out a power failure detection signal. CONSTITUTION:When the commercial AC power source is disconnected to lower the output of the batch rectification part and the voltage at the variable reed A of a variable resistor 14 drops below a division voltage generated by resistances 20 and 21, the output of the comparator 22 falls almost to 0V, a transistor 23 turns off, and the photodiode of a photocoupler 24 turns off, thereby sending out the power failure detection signal. If the load of a voltage converting circuit varies owing to the alternation of the constitution such as an increase or decrease in the memory capacity of the computer and an increase or decrease in the number of channels, the time when the output voltage of the batch rectification part drops at the time of a break of the AC commercial power source varies, so the time for sending out the power failure detection signal also varies at the same time. Therefore, when the computer mechanism is made small, the computer can be put in normal operation even in case of a longer instantaneous break of the commercial AC power source.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a power outage detection method for an information processing device, and more particularly to a power outage detection circuit that detects when an AC power supply is cut off or drops below a certain level.

[Conventional technology]

Conventionally, in a power supply for a computer, a commercial alternating current (AC) power source is converted to direct current using a rectifier circuit, and this direct current is converted to a direct current (DC) voltage necessary for operating a logic circuit, etc. using a DC-DC converter or the like. In general, the value of this smoothing capacitor is determined so that even if the commercial AC power supply is cut off by approximately 20 m5, the maximum configuration computer can operate normally using the energy stored in the smoothing capacitor of the rectifier circuit. ing.

In this case, power outage detection is performed within 10 to 15 ms.
# This is done by a power failure detection circuit with a delay circuit so that it sends out a detection signal when the power continues.

When the configuration of a computer becomes smaller (for example, due to a decrease in memory capacity or a decrease in the number of channels), the load on the computer's power supply becomes lighter, and even if the commercial AC power supply is cut off, the smoothing capacitor of the rectifier circuit remains The stored energy allows the computer to operate normally for a long time.

However, even if the computer configuration becomes smaller, the power outage detection signal is still sent out a certain period of time after the power is turned off, so even though the computer can still operate normally, it still performs processing in response to the power outage. There is a problem in that the processing that has been going on so far is interrupted and the energy stored in the smoothing capacitor is not used effectively.

[Problem that the invention seeks to solve]

The prior art described above consists of a power supply system and circuit shown in FIGS. 2 and 3.

In Fig. 2, 1 is a bulk rectifier circuit that rectifies commercial AC power with a diode, smoothes it with a smoothing chip and a capacitor 2, and supplies the DC output to a voltage conversion circuit 5 consisting of a plurality of DC-DC converters, etc. ing. The voltage conversion circuit 3 measures the high voltage DC 'α pressure supplied from the bulk rectifier circuit section 1! The machine's logic circuit converts it into the voltage necessary for operation and outputs it.

Reference numeral 4 denotes a power outage detection circuit section, which is composed of a power outage detection section 5 and a delay signal sending section 6, and the input of the outage α detection circuit section 4 is connected to a commercial AC '4 source.

The power failure detection section No. 5 is disclosed in, for example, Japanese Utility Model Publication No. 57-47855 and Japanese Patent Publication No. 56-23172. Here, the delay signal sending section 6 will be explained with reference to FIG.

If the commercial AC power supply is cut off, it is detected by the power outage detection unit 5, and a signal is sent to the transistor 370 in FIG. 6 to cut off the transistor 37.
Resistor 58 completes capacitor 59 and resistor 40
When the charging voltage of the capacitor 39 becomes larger than the voltage divided by the voltages 41 and 41, the state of the output of the comparator IC 42 is reversed and a power failure detection signal is output.

In FIG. 2, the capacity of the smoothing capacitor of the bulk rectifier circuit section 1 is such that even if the commercial AC power supply of about 20 m5 is cut off, the voltage conversion circuit 6 Assume that the value is set to a value that can supply energy for normal operation of the logic circuit, etc., which is the load.

At this time, the resistor 38 and capacitor 39 of the delay signal sending circuit shown in FIG.
Each constant is determined so that there is a delay of 5 ms.

The storage energy of the smoothing capacitor is 20ms after the power is turned off.
``Since it is not a 4 hold, 20-15-5ms
During this period, the computer only needs to perform processing corresponding to the power outage.

However, in the case of a commercial AC power cut-off when the computer configuration has become smaller, the load on the computer's power supply becomes lighter (the load on the computer's power supply becomes lighter). Since the resistor 38 and capacitor 39 shown in FIG. 3 are constant, there is a problem in that the time during which the power failure detection signal is sent does not change.

SUMMARY OF THE INVENTION An object of the present invention is to solve this problem and provide a power outage detection method in which the time during which a power outage detection signal is sent out after a power outage changes depending on the load on a computer power supply.

[Means for solving problems]

The above object is achieved by detecting the output voltage level of the collective rectifier circuit section and sending out a power failure detection signal.

In other words, as the computer configuration becomes smaller, the load on the computer source becomes more rapid, and if the commercial AC power supply is cut off, the time it takes for the output voltage of the bulk rectifier to drop to the detection level becomes slower, so the detection signal also increases. This is because it is served rather late.

[Effect]

The output voltage level of the bulk rectifier circuit section drops when the commercial AC power supply is cut off, but the drop is fast if the load capacity of the bulk rectifier circuit section is large (or slow if it is small. Focusing on this point, , this output voltage level is detected using a comparator V-Y, and a power outage is detected.

The detection level may be a voltage repeater that takes into account the time required for the computer to perform processing corresponding to a power outage when the voltage deviates from the output specifications of the voltage conversion circuit.

In this way, the time at which the power failure detection signal is sent after the commercial power supply is cut off will vary depending on the size of the computer configuration, and the energy stored in the smoothing capacitor can be used effectively. In other words, when the configuration of the computer is small, the computer can operate normally even during a longer momentary interruption of the commercial AC power supply.

[Example]

FIG. 1 is a diagram showing an embodiment of the present invention.

In FIG. 1, 1 is a collective rectifier. Reference numeral 3 denotes a voltage conversion circuit, which has the same configuration as that shown in FIG. Reference numeral 29 denotes a power failure detection circuit, which is connected to the output of the collective rectification circuit section 1.

The power failure detection circuit is configured such that it is connected to a Zener diode 19 and a capacitor 18 through a diode 14 and a resistor 17 from the {circle around (2)} side of the bulk rectifier.

Also, the same (resistance 23 from the ■ side. Polyneem 14° resistance 1
5 are connected in series, and the variable lead 2 of the polyneem 14 is connected to one input of the comparator 22. The zener voltage of the zener diode 190 is divided by a resistor 20 and a resistor 21 and connected to another input of a comparator 22. A resistor is connected to the output of the comparator 22, and a transistor 23 is connected to the emitter thereof, and a photodiode of a photocoupler 24 is connected in series.

Now, if the commercial AC power supply is cut off, the output of the bulk rectifier drops, and the voltage of the variable lead ■ of the polyurethane 14 falls below the voltage divided by the resistor 20 and resistor 210, then the comparator output 22
The output becomes approximately EV, the transistor 23 is turned off, the photodiode of the photocoupler 24 is turned off, the phototransistor of the photocoupler 24 is turned off, and a power outage initiation signal is sent.

If the load on the voltage conversion circuit changes due to a change in the configuration due to an increase or decrease in the total memory capacity of Kd or an increase or decrease in the number of channels, the time for the output voltage of the batch rectifier to drop when the commercial AC power is cut off will change, so at the same time, The time taken until the power outage detection signal is sent also changes.

- Therefore, as computer configurations become smaller, normal operation can be achieved even during longer commercial AC power interruptions, and the energy stored in the smoothing capacitor in the bulk rectifier can be used effectively, and even when the load is light. allows the computer to operate normally even after a longer momentary power outage.

〔Effect of the invention〕

According to the present invention, the time from when the commercial power supply is cut off to when the power failure detection signal is sent changes due to a change in the load of the computer power supply, so the energy stored in the smoothing capacitor of the collective rectification section is This has the effect of making it possible to utilize the information effectively.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a configuration example of the present invention, FIG. 2 is a power supply circuit diagram of a conventional example, and FIG. 3 is a delay signal sending circuit diagram of a conventional example. 1... Bulk rectifier circuit section, 2... Smoothing capacitor,
3... Voltage conversion circuit, 4... Power outage detection circuit section, 5...
...Stop α detection section, &...Delay signal sending section, 9...
・Zener diode, 14...Polyneem, 24・
... Photo-12 goo) +, 22.42... Comparator. −・、

Claims (1)

[Claims] 1. A bulk rectifier that rectifies and smoothes commercial AC power to supply DC power, and multiple voltages that take the DC power of the bulk rectifier as input and convert it into the DC voltage necessary for the computer to operate. In a computer power supply system consisting of a converter, a lower voltage power source is created using a Zener diode or the like than the output voltage of the bulk rectifier, and a voltage comparison circuit operated by the power source is used to detect a drop in the output voltage of the bulk rectifier. detect,
When a photocoupler consisting of a photodiode and a phototransistor is connected to the output of the voltage comparator circuit via a transistor, and a drop in the collective rectifier is detected,
A power outage detection method characterized by sending a detection signal by reversing the operation of the phototransistor in the photocoupler.