JP2001148212A - Electro-magnetic switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-magnetic switch which is enabled to restore automatically to the state immediately before a power failure, after restoration of power supply. SOLUTION: A memory space of rewritable EEPROM is divided, and attribute information and on-off state information are written in the memory space one after another on each occasion of on-off operation. The attribute information is changed and written every time the writing of two kinds of informations make a round.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology of an electromagnetically operated switch that opens when a power failure occurs and automatically returns to a state before the power failure when the power is restored.

[0002]

2. Description of the Related Art As a power switch for a load that is frequently turned on and off, an electromagnetically operated switch that opens and closes a contact by operating an electromagnet having a long switching life is often used. Such a load may be required to automatically return to the state before the power failure when the power is restored after the power failure for safety reasons. It is impossible to fulfill such a demand with a simple electromagnetically operated switch comprising only an electromagnet and a contact.

[0003]

As disclosed in Japanese Patent Application Laid-Open No. 2-136079, a CPU is provided in an electromagnetically operated switch to operate an electromagnet in response to an open / close command. Although there are multifunctional devices that open and close the contacts of the main circuit and provide overcurrent protection, none of them satisfy the above requirements.

In such a switch utilizing a CPU, a rewritable nonvolatile storage means called an EEPROM is provided to always store the open / closed state of the switch.
If the stored contents are rewritten each time an ON operation or OFF operation is performed, if the power is restored after a power failure, the stored contents can be read and the switch can be operated based on the stored contents to easily restore the state before the power failure. Can be returned to.

[0005] However, even though such a switch may be subjected to an extremely large number of switching operations of hundreds of thousands of times, the rewriting life of the EEPROM is about 10,000 times, and the life of both is matched. There was a problem not to do.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electromagnetically operated switch having a large number of switching lifespans that can automatically return to a switching state before a power failure after power recovery.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is directed to an electromagnetically operated switch controlled by an electronic controller that loses power in the event of a power outage and that opens and closes switching contacts. , The controller has a storage means, a writing means, and a comparison means, and the storage means is a rewritable non-volatile storage means. It has a plurality of divided storage spaces which are sequentially written each time the switch is opened and closed, and the writing means sequentially circulates from the first storage space to the last storage space of the storage means in response to a large number of switching operations of the switch. One of two types of attribute information is written to all the spaces until writing to a plurality of storage spaces has been completed, and When the power is restored after a power failure, the comparing means compares the attribute information of the n-th and (n + 1) -th storage spaces written in the storage means, and when the power is restored, The open / close state written in the n-th storage space is read and an operation signal is output to the switch.

With such a configuration, the writing space is different each time the opening / closing operation is performed, so that it is possible to cope with the number of times of opening / closing by multiplying the rewriting life of the storage device by the number of divisions of the storage space. Furthermore, the state before the power failure is such that writing is sequentially performed to a plurality of storage spaces, and attribute information to be written is the same for each space until one cycle, and the attribute information to be written is switched each time the cycle is performed. When the attribute information is sequentially compared from the first storage space, it can be read that the storage content immediately before the attribute information is switched is the state before the power failure.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the embodiments shown in FIGS. Although not shown, the switch includes an open / close contact of a main circuit, an operating electromagnet that turns on the open / close contact only when the switch is energized, and a controller whose configuration is illustrated in FIG.
This controller is used to operate the switch.
FF SW, selection switch for automatically returning to the state before the power failure when power is restored (hereinafter referred to as restart at power recovery), and S for inputting those signals to the CPU.
W input circuit, including an EEPROM, C for processing input signals
PU, M to energize or de-energize the operating electromagnet of the switch
The C control Ry includes a Ry drive circuit for controlling the MC control Ry in accordance with the processing of the CPU.

FIG. 2 is a schematic flow chart of the operation of the controller, in which main functions such as monitoring of an input signal and operation of a switch in response to the input signal, and processing for restarting upon power recovery are performed. Will be

The RAM and the EEPROM store the information of the restart setting at the time of power recovery and the current ON / OFF information of the switch. This EEPROM is provided with first to 40th write spaces for storing ON / OFF states. Each write space can write 1-byte information, half of which is an attribute storage area, and the other half is a state storage area for storing the ON / OFF state of the switch. Two types of bit patterns (for example, 0101 and 1010, which will be described below using this example) are written in the attribute storage area. In addition, ON and OFF are stored in the state storage area.
And two different bit patterns (eg, ON is 000
0, OFF is written as 1111).

Referring to FIG. 3, when the setting of restart at power recovery is added, first, any bit pattern (for example, 0) is stored in the attribute storage area in the first space.
101), the OFF bit pattern (1111) is written in the state storage area. Next, when an ON signal is input, the signal is stored in the RAM, the MC control Ry is excited to turn on the switch, and the EEPRO
The same bit pattern as the bit pattern (0101) of the first space is stored in the attribute storage area of the second space of M, and the bit pattern (000) indicating ON in the state storage area.
0) is written. Next, when the OFF signal is input, the signal is stored in the RAM and the MC control R
The excitation of y is extinguished, the switch is turned off, and EE
The same bit pattern as the bit pattern (0101) of the second space is written in the attribute storage area of the third space of the PROM, and the bit pattern (1111) indicating OFF is written in the state storage area. Similarly, ON / OF
Every time the F signal is input, the attribute and the ON / OFF state are sequentially written in the order of the third space, the fourth space,..., The 39th space, and the 40th space. At this time, the same pattern is written in the attribute storage area up to the 40th space. When the next ON / OFF signal is input after the 40th write, the write space is returned to the first space and the attribute bit pattern is written. Is changed to the other one (1010), and rewriting processing is performed. Then, the pattern is rewritten to the pattern having the same attribute until the 40th writing is performed.

As described above, the latest state is sequentially written by circulating through the first to fortieth spaces, and the attribute is switched every time the cycle is completed. That is, the state storage area is O
The bit pattern corresponding to N · OFF is written, but the bit pattern written to the attribute storage area is one pattern (0101) in the first cycle and the other pattern in the second cycle for all the writing spaces. (1
010) The third round is one pattern (0101), ...
The (m-1) -th cycle is the other pattern (1010), m
In the cycle, different patterns are alternately written such as one pattern (0101),. Therefore,
As shown in FIG. 4, the n-th and (n + 1) -th patterns are different, for example, the pattern of the n-th attribute storage area is (0101) and the (n + 1) -th pattern is (1010). That is, the ON / OFF state stored in the n-th state is the latest state.

In the flowchart shown in FIG. 2, in the initialization processing when the power is restored after the power failure, the state immediately before the power failure is stored in the RAM from the EEPROM, and it is confirmed whether or not the restart at the time of the power recovery is set. When the status is ON, a command to turn ON the switch is issued when the state immediately before the power failure is ON. FIG. 5 shows a flow for reading the state immediately before the power failure. First, the attribute (0101) of the first space is determined, the number of the space is increased by one, and the determination of whether the attribute of the second space is the same as the attribute of the first space is sequentially repeated. . If the attribute (1010) of the (n + 1) th space is different from the attribute of the nth space, the switch is set to n
Since a power failure has occurred when the power is stored in the space stored in the n-th space, the n-th space number, attribute, and ON / OFF state are stored. In addition,
If the attribute does not change from the 1st to the 40th,
Since a power failure has occurred when the space is stored in the 40th space, the space number, attribute, and ON / OFF state of the 40th space are stored.

After such initialization processing, the MC control Ry is excited in the main processing flow to turn on the switch based on the above-mentioned storage. Next, when an OFF signal is input, the same pattern as the n-th bit pattern (0101) is written in the attribute storage area of the space ((n + 1) th) next to the write space (nth) immediately before the previous power failure. In the state storage area, a pattern (1
111) is written. Thereafter, the writing is continued based on the flow of FIG. It should be ON first after power recovery
Then, the ON information may be written in the (n + 1) th space.

By performing the above processing, even if an EEPROM having a writing life of 10,000 times is used, a restart operation after power recovery can be performed for 400,000 opening and closing operations.

The embodiment of the present invention has been described above. However, the embodiment of the present invention disclosed above has the following features.
This is merely an example, and the scope of the present invention is not limited to the above embodiment of the present invention. The scope of the present invention is defined by the appended claims, and is intended to include all modifications within the scope and meaning equivalent to the appended claims.

[0018]

The present invention is embodied in the form described above, and stores the open / closed state of the switch immediately before the occurrence of a power failure, and can automatically operate the switch to the state before the power failure when the power is restored. Therefore, for example, a switch such as a lighting circuit can be automatically turned on after the power is restored, and an effect such that safety can be ensured can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a controller of an embodiment of an electromagnetically operated switch according to the present invention.

FIG. 2 is a schematic operation flowchart of an embodiment.

FIG. 3 is a flowchart of a write operation of the embodiment.

FIG. 4 is a diagram illustrating a state where data is written to an EEPROM according to the embodiment.

FIG. 5 is a flowchart for reading a state before a power failure according to the embodiment.

Claims (2)

[Claims] 1. An electromagnetically operated switch controlled by an electronic controller that loses power when a power failure occurs and that opens and closes contacts, said controller having storage means, writing means and comparison means. The storage means is a rewritable non-volatile storage means, and is divided into a plurality of pieces which are sequentially written each time the switch is opened / closed as a pair of the open / closed state information and the attribute information of the switch. The storage means has a storage space, and the writing means stores one of the storage means in response to a large number of switching operations of the switch.
Writing the two pieces of information by circulating sequentially from the first storage space to the last storage space, wherein there are two types of attribute information for all the spaces until writing to the plurality of storage spaces completes one cycle Is written, and the attribute information is written by switching the attribute information every time the circuit goes round. When the power is restored after the power failure,
The attribute information of the n-th and (n + 1) -th storage spaces written in the storage unit is compared, and if they are different, the open / close state written in the n-th storage space is read and the switch is read by the switch. An electromagnetically operated switch characterized by outputting an operation signal. 2. The electromagnetically operated switch according to claim 1, wherein each of said writing spaces comprises one byte.