JPS6194127A - Protecting device for service interruption mode - Google Patents

Abstract

PURPOSE:To prevent surely a malfunction is a service interruption mode by fetching the voltage of a power supply bus to a service interruption detecting circuit in order to detect the voltage drop early. CONSTITUTION:A voltage is supplied to a control system power supply device 3 from a power supply bus 1 via an input transformer 2. Then the voltage of the bus 1 is led to a service interruption detecting circuit 4, and a service interruption detecting signal is supplied to an interruption terminal 61 of a microcomputer 6. This computer 6 receives the service interruption detecting signal through the terminal 61 and transmits a service interruption detection output 6b to a service interruption detecting gate circuit 8 synchronously with the end timing of the control signal prescribing signal width and then supplies an inhibition command to a control inhibition gate circuit 5. The output of the circuit 8 is connected to a reset terminal 6c of the computer 6. Thus the voltage drop of the bus 1 is detected before the reduction of the output voltage of the device 3. Then the discontinuation of a control action is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power outage protection device that prevents a control system using a microcomputer or the like from malfunctioning during a control power outage.

[Conventional technology]

FIG. 2 shows a conventional power outage protection device of this type.

In the figure, 1 is a power bus, 2 is an input transformer, 3 is a control system power supply device, 4 is a power failure detection circuit (comparator circuit), 5 is a control inhibition gate 1, and 6 is a control device (microphone). 6a is a microcomputer output, and 7 is a controlled device.

In this configuration, when the voltage of the power supply bus 1 drops and the output voltage of the control system power supply 3 drops below a predetermined level, the power failure detection circuit 4 detects this voltage drop and sends the control prohibition gate circuit 5 to detect the power failure. Send a signal. When the control prohibition gate circuit 5 receives the power failure detection signal, the microcomputer 6 cuts off the control signal sent to the controlled device 7 via the control prohibition gate circuit 5.

[Problem that the invention seeks to solve]

In this conventional device, since the voltage output from the control system power supply 3 is input to the power failure detection circuit 4, the generation of the power failure detection signal is delayed from the voltage drop in the voltage of the power supply bus 1, and the generation of the power failure detection signal is delayed. is almost simultaneously with the drop in the output voltage of the control system power supply 3, so an unauthorized control signal may be input to the controlled device 7, and the control signal output from the microcomputer 6 and the above power failure detection signal may be input to the controlled device 7. Since the control signal cannot be synchronized with the control signal, there is a problem in that the control signal being output is cut off in the middle of the specified signal.

This invention was made to solve the above problem.
An object of the present invention is to obtain a power outage protection device that can reliably prevent malfunction of a control device during a power outage.

[Means to solve the problem]

In this invention, the power failure detection circuit is configured to directly take in the power supply bus voltage, and the control device receives the output of the power failure detection circuit as an interrupt signal, and when receiving this, the specified width of the control signal being output is The configuration is such that the output operation continues until the end of the output operation.

[Effect]

In this invention, since the power failure detection information of the power supply bus voltage is given to the microcomputer before the output voltage of the control system power supply device decreases, a protective operation for preventing unauthorized output can be performed during that time.

[Embodiments of the invention]

FIG. 1 is a block diagram showing one embodiment of the present invention, in which the voltage of the power supply bus l is led to the power failure detection circuit 4, and the power failure detection signal output from the power failure detection circuit 4 is sent to the interrupt terminal (non- (mascarafal interrupt terminal) 61. When the microcomputer 6 receives a power failure detection signal at the interrupt terminal 61 during output, it sends a power failure detection bit output 6b to the power failure detection gate circuit 8 in synchronization with the end timing of the control signal regulation signal. is programmed to. The output of the power failure detection circuit 4 is led to the power failure detection gate circuit 8, and this output and the power failure detection bit signal 6
When b is received, the prohibition gate circuit 5 controls the prohibition command (signal).
Enter. Further, the output of the power failure detection gate circuit 8 is coupled to the reset terminal 6C of the microcomputer 6.

In this embodiment, since the power failure detection circuit 4 is configured to receive the voltage of the power supply bus, when the voltage decreases,
Control system power supply device 3 supplied to the microcomputer 6
A voltage drop on the power supply bus 1 is detected before the output voltage of the microcomputer 6 drops, and upon receiving this voltage drop information, the microcomputer 6 waits for the end of the control signal being output and then generates the power failure detection bit signal 5ba. At the same time as the microcomputer 6 is reset, the control inhibition gate circuit 5 performs an inhibition operation, thereby preventing interruption of the control operation.

〔Effect of the invention〕

As explained above, this invention is configured so that the voltage of the power supply bus is taken into the power failure detection circuit, so that a drop in the voltage can be detected earlier than in the past, and it can be synchronized with the delimitation of the control signal. Since the control operation is prohibited and the control device is reset, it is possible to reliably prevent incorrect operation during a power outage.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention, Figure 179, and Figure 2.
The figure is a block diagram showing a conventional power failure protection device. In the figure, 1--power bus, 2--input transformer,
3--control power supply device, 4-power failure detection circuit, 5-control prohibition gate circuit, 6-control device, 8--power failure detection gate circuit I. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A power outage detection circuit that directly detects a voltage drop on the power bus to which the control system power supply is connected via the input transformer, and cuts off the control signal sent by the control device to the controlled equipment after the output of the power outage detection circuit. The output of the power failure detection circuit is guided to the inhibition gate circuit via the power failure detection gate circuit and is also given to the control device as an interrupt signal, and after the interrupt signal is generated, the control device A power failure protection device having a function of inputting a power failure detection bit signal to the power failure detection gate circuit as a gate signal in synchronization with an outputting control signal, and receiving the output of the power failure detection gate circuit as a reset signal. .