JPS6226522A - Service interruption detection and power recovery control system - Google Patents

Abstract

PURPOSE:To prevent a mulfunction from being generated due to an instantaneous cut-off, by monitoring an elapsed time from the time when a service interruption is detected, and inhibiting the output of a power source turn-on signal when recovering the power, until a prescribed time elapses. CONSTITUTION:The power source controlling circuit 10 of a processor 18, etc. operated by an AC input is constituted of a service interruption detecting part 11, a power source on/off part 12 and an initializing part 13. Also, a power recovery restart securing circuit 14 provided with a counter 15 for a timer measuring a prescribed time lapse after a service interruption, the battery support part and power source part 17 of the processor 18 are provided. In this state, when the power source control circuit 10 detects a service interruption by its service interruption detecting part 11, a service interruption detecting signal is sent to the power recovery restart securing circuit 14. By this securing circuit 14, in case of an instantaneous cut-off being shorter than a timer set time, the power source is turned on again to the processor 18 after the timer set time elapsed, and in case of the power recovery after the service interruption being longer than the set time, the power source is turned on again immediately.

Description

[Detailed Description of the Invention] [Summary] In a power supply control method that controls the supply of power to a microprocessor, etc., the time elapsed after a power outage is detected is monitored using an independent power supply that is constantly supported by a battery. However, the output of a power-on signal upon power restoration is suppressed until a predetermined period of time has elapsed after a power outage is detected, thereby preventing malfunctions of microprocessors and the like due to instantaneous power outages.

[Industrial application field]

The present invention relates to a power outage detection/recovery control method, particularly a circuit that controls power to a microprocessor and other logic circuits, and which guarantees restart operations when power is restored after a power outage. It is related to.

[Conventional technology]

A microprocessor or the like sequentially fetches and executes predetermined instructions to perform preprogrammed data processing control. Therefore, if a power outage occurs.

Generally, the operation of microprocessors and the like is not guaranteed, and when power is restored, it is necessary to perform an initial clear and then restart. In addition, if the alternating current (AC) power of the device is cut off due to a power outage, it is necessary to maintain the on state and write down.

Conventionally, in order to maintain the state related to a power outage, for example, the input signal itself has been fixed using a mechanical device such as a switch. In addition, the input signal is in the form of a pulse,
If it disappears due to the AC input being cut off, the state is maintained using a latching relay or the like, for example.

[Problem that the invention seeks to solve]

According to the above-mentioned conventional method, since the state is mechanically maintained when AC power is cut off, reliability is not sufficient, and when power is restored immediately after a power outage, That is, in the case of a momentary power outage, there is a possibility that the microprocessor may malfunction.

[Means for solving problems]

The present invention aims to solve the above-mentioned problems, and uses a power supply that is always supported by a battery to simultaneously maintain a power failure detection state and prevent malfunctions of a microprocessor, etc. in the event of a momentary power failure.

FIG. 1 is a basic configuration block diagram of the present invention.

In FIG. 1, 10 operates with AC input.

A power supply control circuit that controls the power supplied to the processor, etc., 11 a power failure detection unit that detects a power outage based on AC input power, etc., and 12 a power on/off unit that outputs a power supply signal that controls power on/off. .

Reference numeral 13 denotes an initial clear unit that outputs an initial clear signal when the power is restored, and 14 is a power recovery restart guarantee circuit, which operates until a predetermined time elapses after the power failure detection unit 11 detects the power failure. 15 (also a timer counter for measuring the elapse of a predetermined period of time after the power outage, 16)
17 is a battery support unit that supplies direct current (DC) power to the power recovery restart guarantee circuit 14; 17 is a power supply unit that supplies DC to the processor and other logic circuits based on the input signal from the power on/off unit 12; 18 represents a processor that fetches and executes instructions.

The operating power supply of the power recovery restart guarantee circuit 14 is supported by the battery server unit 16 independently of the AC input. When a power failure occurs, the power recovery restart guarantee circuit I4 starts a counting operation using a timer counter 15, and turns off a signal RESTAT indicating a state in which power can be restarted until a predetermined count value is counted. It has become.

[Effect]

A power supply control circuit 10 operates with AC input.

When a power outage is detected by the power outage detection unit 11, the power outage detection sends the numbers (2) and (2) to the power recovery restart guarantee circuit 14 during the moment when the power outage occurs. Since the power recovery restart guarantee circuit 14 is guaranteed an operating power source by the battery nabort section 16, it can recognize and maintain the power failure state.

The power recovery restart guarantee circuit I4 has a timer circuit including a timer counter 15, etc., so that even if the AC input is immediately restored after a momentary power outage, the power recovery restart guarantee circuit I4 will not operate until a predetermined period of time has passed since the power outage. , continues to send a signal to the power on/off unit 12 that prohibits turning on the power again. That is, in the case of a momentary power outage that is shorter than the timer setting time, the power to the processor 18 is turned on again after the timer setting time has elapsed, and when the power is restored after a power outage that is longer than the timer setting time, the power is immediately turned on again.

〔Example〕

FIG. 2 is a circuit diagram of an embodiment of a power recovery restart guarantee circuit according to the present invention, and FIG. 3 is a time chart of an embodiment of the present invention.

In FIG. 2, numerals 14 and 15 correspond to those in FIG. 1, 20 is an OR circuit, and 21 is a flip-flop (FF).
represents.

For example, like the time chart shown in Figure 3.

Assume that a momentary interruption occurs in the AC input. The power failure detection unit 11 shown in FIG. 1 detects a decrease in the intermediate voltage when converting AC to DC.

Immediately send the output signal ■ to the power recovery restart guarantee circuit 14 as “
After dropping the output signal to “°L” level, immediately
The power recovery restart guarantee circuit 14 takes the output signal ■ into the flip-flop 21 shown in FIG. 2 in synchronization with the internal clock signal CLOCK, and the output of the flip-flop 21 goes to the "H" level. Become.

When the output of the flip-flop 21 goes high, the timer counter 15 becomes enabled and starts counting. At the same time, a clear signal is sent to the initial clear section 13 to clear the processor 18. The timer counter 15 counts a predetermined number of clock pulses.

The signal RESTAT for the power on/off unit 12 is set to “H”.
``Level up.

The power on/off unit 12 has a signal RESTAT of “TI”.
When the level is reached, the power on/off signal for the power supply section 17 is set to the 'If' level.

Instructs to turn on the power. As a result, DC output to the processor 18 and the like is started.

〔Effect of the invention〕

As explained above, according to the present invention, the power failure detection state is maintained, and when the power is restored due to a momentary power interruption, the time until the power is turned on is
Extend the specified time after a power outage.

Malfunctions of processors, etc. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration block diagram of the present invention, FIG. 2 is a circuit diagram of an embodiment of a power recovery restart guarantee circuit according to the present invention, and FIG. 3 is a time chart of an embodiment of the present invention. In the figure, 10 is a power supply control circuit, and 11 is a power failure detection section. 12 is a power on/off section, 13 is an initial clear section,
14 is a power recovery restart guarantee circuit, 15 is a timer counter,
Reference numeral 16 represents a battery server unit, 17 represents a power supply unit, and 18 represents a processor. Patent Applicant Panafacom Co., Ltd. Representative Patent Attorney Hiroshi Mori 1) (and 1 other person) Honshaved eyes ← To a certain angler 072B IK 1 Figure 2

Claims (1)

[Claims] A power supply control method for supplying power to a device including a processor (18), comprising a power failure detection unit (18) that detects a power failure regarding an AC input power source.
1), a power on/off unit (12) that controls power on/off of the device including the processor (18), and a power outage detection unit (11) based on output signals from the power outage detection unit (11). , a power recovery restart guarantee circuit (14) that outputs a signal that suppresses output of a power-on signal by the power on/off unit (12) at the time of power recovery until a predetermined time has elapsed;
and a battery support unit (16) that supports a DC power source that operates the power recovery restart guarantee circuit (14) independently of the AC input power source. method.