JPS6256731B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power on/off device for turning on/off a commercial frequency power supply to electrical equipment such as a computer system.

BACKGROUND ART Momentary power outages (hereinafter referred to as instantaneous power outages) of half a cycle to several cycles may occur intermittently in commercial frequency power supplies that supply computer systems and the like. Conventionally, few countermeasures have been taken against such instantaneous power outages, but the central processing unit of a computer is equipped with a function to detect instantaneous power outages, and if a momentary power outage occurs in the power supply line, the calculation operation is temporarily stopped. Countermeasures have been implemented in which the calculation operation is restarted after waiting for the power supply to stabilize.

Computer systems usually consist of a central processing unit and other input/output processing units, and for the electromagnetic switches that are always used in these devices, the momentary power outage time is close to the opening/closing operation time of the electromagnetic switch. Therefore, there is a drawback that abnormal chattering occurs in the opening/closing operation, or this abnormal chattering occurs intermittently, resulting in an abnormal state in which restarting is not possible.
In addition, input/output devices also have the disadvantage of causing failures due to intermittent mechanical operations.

This invention was made in order to eliminate the above-mentioned drawbacks. When a momentary power outage occurs in the commercial frequency power supply supplied to a computer system, etc., the power supply is automatically cut off and the power supply is returned to a stable state. It is an object of the present invention to provide a power on/off device configured to automatically turn on the power again in anticipation of recovery.

FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which 1 and 2 are resistors that divide the power supply voltage, 3 is a full-wave rectifier, 4 is a capacitor, 5 is a semiconductor switch, 5
1 is a switch that equivalently indicates its opening/closing, and 6 is the first switch.
The coil of the electromagnetic switch is temporarily called the first coil, 61 is a self-holding contact that is closed by the excitation of the first coil 6, and 7 is the coil of the second electromagnetic switch, temporarily called the second coil. 71 is a contact that is opened by the excitation of the second coil 7 and closed after a predetermined time delay when the excitation disappears, and is temporarily referred to as a second contact. Forms an electromagnetic switch. 8 is a coil of a third electromagnetic switch, tentatively referred to as a third coil, and 81 and 82 are contacts operated by the excitation of the third coil 8, respectively.

The voltage of the power supply is divided and dropped by resistors 1 and 2,
This voltage-dropped alternating current is rectified by a full-wave rectifier 3,
The capacitor 4 is charged with this rectified voltage. The semiconductor switch 5 is operated by the terminal voltage of the capacitor 4. The first coil 6 is initially connected to the second coil 7 which is closed when the second coil 7 is not excited.
When the semiconductor switch 5 is in a conductive state, it operates to close the self-holding contact 61, and once the self-holding contact 61 is in the closed state, this Remains closed as long as the condition continues.

When the self-holding contact 61 of the first electromagnetic switch is in the closed state, the second coil 7 is excited through the semiconductor switch 5 which is in conduction with the closed contact, and as long as this state continues, the second contact 71 is opened. Retain state. The third coil 8 is controlled by the opening and closing of the self-holding contact 61 of the first electromagnetic switch to open and close the power supply circuit.

FIG. 2 is a voltage waveform diagram for explaining the operating state of an embodiment of the present invention when a half-cycle instantaneous power outage occurs in the power supply, and (a) shows the voltage waveform of a commercial frequency power supply; (b) shows the voltage waveform of the terminal voltage of the capacitor 4, (c) shows the state of the semiconductor switch 5, (d) shows the state of the second contact 71, and (e) shows the state of the second contact 71.
indicates the state of contacts 82 and 83.

When a half-cycle instantaneous power failure occurs in the commercial frequency power supply as shown in Figure 2a, the waveform portion corresponding to the half-cycle instantaneous power failure occurs in the terminal voltage of the capacitor 4 as shown in Figure 2b. Threshold value (v _t ) for operating the semiconductor switch 5 in the part
A lower portion occurs, and the semiconductor switch 5 causes a one-cycle power outage as shown in FIG. 2c, during which the excitation current of the coils 6, 7, and 8 is cut off. Due to this one cycle of power outage, the excitation of the first coil 6 is extinguished and the self-holding contact 61 is opened. Since the excitation of the second coil 7 disappears, the second contact 71 is closed, but its operation delay time is set to several seconds, and this set time (the time indicated by t ₁ in Fig. 2 d) During this period, the second contact 71 remains open. Therefore, as shown in FIG. 2e, the operation of the third coil 8 is such that the excitation disappears for several seconds during the above-mentioned set time. The computer system is configured to be powered off while the third coil 8 is extinguished.

When the set time of several seconds has elapsed and the second contact 71 is closed, the first coil 6 is operated and brought into a closed state, and the power of the computer system is turned on.

As described above, when a momentary power failure occurs in the power supply of the computer system, the power is automatically cut off once, and the power is automatically turned on again after a set time of several seconds.

In addition, although the case where commercial frequency power is supplied to the computer system has been explained above,
The present invention is not limited to the above example, but can be used as a protection circuit for equipment that becomes abnormal or malfunctions due to a momentary power outage of half a cycle to several cycles when supplying commercial frequency power to electrical equipment. You can also do it.

As explained above, according to the present invention, when an instantaneous power outage occurs in the commercial frequency power supply supplied to a computer system, etc., the power is automatically cut off, the computer system, etc. is temporarily stopped, and the equipment is placed in an abnormal state. The power is automatically turned on again when the power supply returns to a stable state without causing any malfunction or malfunction, eliminating abnormal equipment operation or failure due to instantaneous power outages, and allowing unattended operation of computer systems, etc. It has the effect of greatly contributing to driving.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a voltage waveform diagram for explaining the operating state of the embodiment of the present invention when a half-cycle instantaneous power failure occurs in the power supply. . In the figure, 1 and 2 are resistors, 3 is a full-wave rectifier, and 4
is a capacitor, 5 is a semiconductor switch, 6 is a first coil, 61 is a self-holding contact, 7 is a second coil,
71 is a second contact, and 8 is a third coil.

Claims (1)

[Claims] 1. In a power on/off device that turns on/off commercial frequency power supplied to electrical equipment, a semiconductor switch controlled by a voltage obtained by full-wave rectification of the power source, and a semiconductor switch between both terminals of the power source. An electromagnetic switch connected in series with a switch, the first
a first electromagnetic switch having a self-holding contact connected in series to the first coil and closed by excitation of the first coil;
and a second coil connected in parallel to the self-holding contact, which is opened by excitation of the second coil and closed after a delay of a predetermined time by extinction of excitation of the second coil. a second electromagnetic switch having a second contact point, and a third electromagnetic switch having a third coil connected in parallel to the first coil. Cutting device.