JPH036526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply control device for a computer, etc., and in particular, it has a power supply voltage abnormality detection circuit, and is capable of controlling the power supply to a computer or the like in the event of a power supply voltage abnormality such as a power outage, momentary power interruption, or abnormal voltage drop. The present invention relates to a power supply control device that controls power supply to a system that has a function of causing a terminal device to perform a save process.

FIG. 1 shows a block diagram of a conventional example of this type of power supply control device.

When the power switch 2 is turned on, power is supplied to the DC stabilized power supply 3 from an AC power supply (for example, a 100 volt AC commercial power supply). Then, the DC stabilized power supply 3 generates DC that is stabilized at a constant voltage value. The constant DC voltage is supplied to a computer or its terminal 4 (hereinafter simply referred to as a computer or the like).

The power supply voltage abnormality detection circuit 5 detects a power supply voltage abnormality of the AC power supply 1 and transmits the detection signal to a computer or the like 4. When a detection signal is generated, in response, the computer or the like 4 interrupts the work being executed at the time and performs an evacuation process according to a predetermined procedure.

As an evacuation process, for example, various data can be stored in a scheduled memory, and when restarting after a power outage,
This includes making sure that you can resume and continue your current work without any hindrance.

When a power supply voltage abnormality occurs during the operation of a computer etc. 4, the power supply voltage abnormality detection circuit 5
It detects when the voltage of the AC power supply falls below a set value and generates a detection signal. Computer etc. 4 is
When it detects that a detection signal has occurred (changed),
Execute a predetermined save process.

By the way, the computer etc. 4 may operate even at a voltage lower than a set value at which the power supply voltage abnormality detection circuit 5 detects a voltage abnormality.
(However, the operation in this case may become unstable...)

Then, by chance, the power switch 2 is turned on when the voltage of the AC power source 1 is lower than the set value of the power supply voltage abnormality detection circuit 5, and if the voltage below the set value continues for a long time, the computer etc. 4 is turned on. The abnormality detection signal continues to be output from the power supply voltage abnormality detection circuit 5 before the voltage rises.

That is, when the computer etc. 4 starts operating, the detection signal has already been output.In other words, after the computer etc. 4 starts up, the signal of the supply power voltage abnormality detection circuit 5 does not change at all. . Therefore, the computer 4, which detects a change in the signal and executes the evacuation process, continues to operate without performing the evacuation process. Therefore, even if the voltage of the AC power supply 1 further drops below the set value and reaches a voltage at which the computer etc. 4 cannot operate completely, the supply power supply voltage abnormality detection circuit 5 continues to generate a detection signal. For this reason, the computer 4 becomes unable to execute a predetermined saving process, and the process and data become so messed up that it becomes impossible to even restore them.

In addition, in such a system, charges are stored in the capacitors in the DC stabilized power supply 3 to execute the scheduled evacuation process when the power supply voltage drops; however, when the power supply voltage is low, the evacuation process Since sufficient charge is not stored in the capacitor to execute the process, even if a save command is issued in this state, the save process cannot be executed reliably, and the data up to that point will be destroyed. There were also problems.

The object of the present invention is that when a power supply voltage abnormality such as a power outage, instantaneous interruption, or abnormal voltage drop occurs after power is turned on, the detection output of the power supply voltage abnormality detection circuit always changes (rises). It is an object of the present invention to provide a power supply control device that can guarantee that a backup process for a computer, etc. is executed in response.

In order to achieve the above object, the present invention provides a voltage higher than the set voltage of the power supply voltage abnormality detection circuit;
A power supply voltage judgment circuit is installed between the power switch and the AC power supply, and the power supply voltage judgment circuit uses a voltage value that is high enough to guarantee the normal operation of computers, etc. as a discrimination value, and when the power supply voltage is lower than the discrimination value, the DC stabilized power supply is switched on. In addition, the power supply voltage is configured to be prohibited from being applied to the power supply voltage abnormality detection circuit and the like.

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 is a block diagram of one embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts.

The power supply voltage determination circuit 8 energizes the power supply control unit 9 when the voltage of the AC power supply 1 is lower than the determination value,
The AC power source 1 and the power switch 2 are cut off.

In this case, the determination value of the power supply voltage determination circuit 8 is selected to be higher than the set value of the power supply voltage abnormality detection circuit 5, and is selected to be such a value that the normal operation of the computer etc. 4 is guaranteed. For this reason, in this embodiment, when the power switch 2 is turned on, (1) If the voltage of the AC power supply 1 is lower than the judgment value of the power supply voltage judgment circuit 8, the action of the power supply control section 9 is As a result, the power supply to the DC stabilized power supply 3, the power supply voltage abnormality detection circuit 5, etc. is prohibited, so the computer etc. 4 is not started.

(2) On the other hand, if the voltage of the AC power supply 1 is higher than the determination value of the power supply voltage determination circuit 8, the power supply control unit 9
is not energized, so when the power switch 2 is turned on, a predetermined amount of power is supplied to the DC stabilized power supply 3 and the supply power supply voltage abnormality detection circuit 5, and the computer etc. 4 is activated.

That is, under the condition (2) above, the device of this embodiment operates in exactly the same manner as the conventional example shown in FIG. 1, and the supply power voltage abnormality detection circuit 5 also operates normally. Therefore, when a power outage or instantaneous power outage occurs after the system is started, the power supply voltage abnormality detection circuit 5 generates a power outage signal, thereby ensuring that the evacuation process of the computer 4 is executed. Become so.

As is clear from the above description, according to the present invention, when the voltage of the AC power supply is lower than the set value of the supply power supply voltage abnormality detection circuit 5, the power supply voltage determination circuit 8 always operates, thereby Since the DC stabilized power supply 3 is prohibited from supplying power to the computer 4, etc., the computer may become unstable due to operation at a low power supply voltage, and the power supply voltage abnormality detection circuit 5 may generate a detection signal immediately after the power switch is turned on. The drawbacks such as disabling the evacuation operation of the computer etc. 4 due to the continuous generation of this problem are completely eliminated.

Further, according to the present invention, power is allowed to be supplied to the DC stabilized power supply and the supply power supply voltage abnormality detection circuit only when the power supply voltage is equal to or higher than the discrimination value. Necessary charge is secured and reliable evacuation processing becomes possible.

Furthermore, according to the present invention, all of the conventional problems can be solved by simply connecting the power supply voltage determination circuit 8 and the power supply control section 6 to the input stage of the conventional DC stabilized power supply without making any changes to it. can.

In the above embodiment, the output of the power supply voltage determination circuit was configured to cut off the connection between the AC power supply and the power switch. It is clear that the configuration may be configured to prevent this from occurring.

Further, the power supply voltage determination circuit may be any circuit that produces an output when the power supply voltage is less than or equal to the determination value, and may be, for example, a voltage relay or a voltage comparator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional power supply control device, and FIG. 2 is a block diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... AC power supply, 2... Power switch, 3... DC stabilized power supply, 4... Computer etc., 5... Supply power voltage abnormality detection circuit, 8... Power supply voltage determination circuit, 9... Power supply control part.

Claims (1)

[Claims] 1. A DC stabilized power supply connected to an AC power supply via a power switch, a computer, etc. that is supplied with the output of the DC stabilized power supply, and a computer etc. that is supplied with AC voltage on the input side of the DC stabilized power supply, and the supplied power supply voltage is abnormal. A power supply control device is provided with a power supply voltage abnormality detection circuit that detects the voltage of the AC power supply, generates a detection signal, and transmits the detection signal to a computer etc. The method further comprises a power supply voltage determination circuit for prohibiting power supply to the stabilized power supply and the supply power supply voltage abnormality detection circuit, and the determination value is selected to be higher than a supply power supply voltage abnormality detection setting value. power supply control device.