JPH03245216A - Power failure compensating circuit for electrical equipment - Google Patents

Abstract

PURPOSE:To omit the trouble to start an operation again from the first by writing the operation data on a RAM into a nonvolatile memory at detection of power failure, and restarting the operation based on the data in the memory when the power failure had recovered. CONSTITUTION:A microcomputer 29 detects the occurrence of power failure if the synchronizing pulses Pc are not received from a timer base circuit 31 for two cycles. Then the microcomputer 29 writes the operation data stored in a RAM into a nonvolatile memory 38. When the power failure is recovered and the microcomputer 29 is started, the contents of the operation data stored in the memory 38 are read out to the RAM and the operation is restarted based on the operation data. Thus it is not required to carry out the operation from the first. Furthermore no battery nor capacitor is required since the data are held in the memory 38. Then the cost is reduced and at the same time the operation data can be surely held.

Description

DETAILED DESCRIPTION OF THE INVENTION [Aspects of the Invention] (Field of Industrial Application) The present invention relates to a power failure compensation circuit for electrical equipment whose operation is controlled by a microcomputer.

(Prior Art) Recently, devices equipped with microcomputers, such as microwave ovens, have been provided with bread making functions and rice cooking functions in addition to the original microwave function. Since the control contents of such microwave ovens are complex, they are equipped with a microcomputer to control the operation of each function.

For example, in the range function, a turntable motor and a magnetron are driven and controlled by a microcomputer, and while food placed on the turntable is rotated, microwaves output from the magnetron are irradiated onto the food to heat and cook the food.

In this case, the cooking completion control includes time-limited control based on the user's time setting and state control based on the gas sensor. In this state control, a gas concentration detection signal from a gas sensor is given to a microcomputer, and based on this gas concentration detection signal, the microcomputer sets a time limit for finishing cooking from that point on when the gas concentration change reaches a certain value. It is designed to take control. In addition, in the bread manufacturing function, the bread dough kneading motor is driven and the temperature is controlled by controlling the heater etc. based on the temperature sensor, and the end time is time controlled. In addition to the normal bread manufacturing function that starts bread production immediately at the current point in time, this bread manufacturing function also has a scheduled bread manufacturing function that starts bread manufacturing operation at a later point in time and completes bread manufacturing at the desired time. It has a function. In addition, in the rice cooking function, the magnetron is driven and controlled, and the end time is controlled by a time limit. Regarding this rice cooking function, in addition to the normal rice cooking function that starts the rice cooking operation immediately at the current time, there is also a reservation rice cooking function that starts the rice cooking operation at a later point in time and completes the rice cooking at the desired time. be.

By the way, in this type of microwave oven, when a power outage occurs in the commercial power supply, not only does the operation of the microcomputer stop, but also the operation data stored in the RAM is lost, so that when the power outage returns, the operation cannot be restarted. I need to start over. In particular, if the reserved bread making function or reserved rice cooking function is set and a power outage occurs during the timer operation during standby before rice cooking starts, the timer operation will stop and the bread may not be finished or the rice will not be cooked. This causes problems such as not being able to do so. To prevent this, conventional methods have included providing backup batteries and using large-capacity electrolytic capacitors to prevent the operation of the microcomputer from being reset and to prevent the operational data stored in RAM from being lost. are doing.

(Problem to be Solved by the Invention) However, with the above-mentioned conventional device that uses a backup battery or a large-capacity electrolytic capacitor to hold the operating data of the RAM, it is difficult to resume operation. However, there are disadvantages such as very high cost, and there is a risk that the backup battery will run out during a power outage or that the capacitor will not be able to retain power, so there is a problem that the retention of operational data is not perfect. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power failure compensation circuit for electrical equipment that can reduce costs and reliably retain operating data.

[Structure of the Invention] (Means for Solving the Problems) A first means of the present invention is to provide a power failure compensation circuit for electrical equipment whose operation is controlled by a microcomputer, including a power failure detection means for detecting a power failure, and a nonvolatile memory. a writing means for writing the operating data in the RAM of the microcomputer at this point in time into the nonvolatile memory when a power outage is detected by the power outage detection means; and when the microcomputer is started up after recovering from the power outage. The present invention is characterized in that it comprises an operation control means for restarting operation based on the operation data in the nonvolatile memory.

A second means of the present invention is a power failure compensation circuit for electrical equipment whose operation is controlled by a microcomputer, which includes a power failure detection means for detecting a power failure, a nonvolatile memory, and a power failure when a power failure is detected by the power failure detection means. A writing means for writing the operating data in the RAM of the microcomputer at this point into the nonvolatile memory, and when starting the microcomputer after recovery from a power outage, whether the operation at the time of the power outage is in a sensor-based state control operation mode. and a driving mode determining means for determining whether or not the driving mode is not, and if the judgment result by the driving mode determining means is not the state control driving mode, the driving is resumed based on the driving data in the nonvolatile memory, and if the driving mode is the state controlled driving mode, the driving is resumed. It is characterized in that it comprises an operation control means for stopping restart.

(Operation) According to the first means, when a power outage is detected by the power outage detection means, the operating data in the RAM at that time is written into the nonvolatile memory by the writing means. When the power is restored and the microcomputer starts up, operation resumes based on the operation data stored in the nonvolatile memory. Therefore, when there is a power outage and the power is restored, the operation is resumed using the operating data at the time of the power outage, so there is no need to restart the operation from the beginning.

In addition, since operating data is held in non-volatile memory, costs are lower than in cases where operating data is held in RAM by providing a backup battery or using a large-capacity electrolytic capacitor. Operation data retention is also reliable.

Here, if operation is primarily restarted when the microcomputer is started after recovery from a power outage, the following concerns arise.

That is, when the operation at the time of power outage is in the sensor-based state control operation mode, the state based on sensor information at the time of power outage and the actual state at the time of power restoration may be significantly different from the expected situation. Therefore, in the case of the state control operation mode, when the operation is restarted, the operation may be performed in an inappropriate control state.

However, according to the second means, an operation mode determination means is provided which determines whether or not the operation at the time of power outage is in the sensor-based state control operation mode when starting up the microcomputer, and the determination result by this operation mode determination means is the state control operation mode. Since an operation control means is provided which restarts the operation based on the operation data in the non-volatile memory when the control operation mode is not set, and stops the restart of the operation when the state control operation mode is selected, there is no concern that inappropriate control may occur due to a power outage. Execution of a certain operation can be canceled.

(Example) Hereinafter, a first example in which the present invention is applied to a power failure compensation circuit for a microwave oven will be described with reference to FIGS. 1 to 4.

FIG. 1 shows the electric circuit of a microwave oven with bread making and rice cooking functions. A fuse 2, a thermal switch 3, door switches 4, 5, a relay switch 6, and a primary coil 7 of a high-voltage transformer 7 are connected between one terminal 1a and the other terminal 1b of a power plug 1 connected to a commercial AC power source. a-, fixed contact a of changeover type relay switch 8
and movable contact C are connected. A primary coil 9a of the step-down transformer 9 is connected between the power supply side contact of the door switch 4 and the other terminal 1b of the power plug 1.
A series circuit of a relay switch 10 and an interior light 11 is connected in parallel. Between the power supply side contact of the relay switch 6 and the movable contact C of the relay switch 8, a forward relay switch 12, a reverse relay switch 13, and a cross-wire motor 4 are connected as shown in the figure. A cooling fan motor 6 and a turntable motor 7 are connected as shown.

Moreover, between the power supply side contacts of the relay switch 6 and the fixed contacts of the relay switch 8, a series circuit of the relay switch 18 and the hot air motor 19 and a series circuit of the relay switch 20 and the hot air heater 21 are connected in parallel. It is connected to the. A grill heater 22 is connected between the contact of the relay switch 6 on the anti-mold source side and the fixed contact of the relay switch 8.

Furthermore, a half-wave rectifier voltage doubler circuit 23 and a magnetron 24 are connected to the secondary coil 7b of the high-voltage transformer 7.

On the other hand, the control circuit 25 includes a power failure compensation circuit, and the control circuit 25 will be explained below. A rectifier circuit 26 is connected to the secondary coil 9b of the high voltage transformer 9. A stabilized power supply circuit 28 is connected to the intermediate tap of the secondary coil 9b via a smoothing capacitor 27, and this stabilized power supply circuit 28 supplies the operating power supply voltage Vcc (
+5 V). This operating power supply is the reset circuit 3
The reset signal from the reset circuit 30 is applied to the microcomputer 29. In addition, the timer base circuit 31 waveform-shapes a half-wave signal Sc (see FIG. 2(b)) synchronized with the frequency of a commercial AC input (see FIG. 2(a)), and generates a synchronization pulse Pc (see FIG. 2(c) ) is given to the microcomputer 29. This microcomputer 2
9 receives a switch input from a switch input circuit 32 equipped with various switches, a detection signal from a weight sensor 33, a detection signal from a gas concentration sensor 34, and a detection signal from a temperature sensor 35. The microcomputer 29 controls the operation by controlling the relay drive circuit 36 and the display circuit 37 according to the operation program stored in the ROM, and also controls the writing and reading of the nonvolatile memory 38 as described later. Do this. The relay drive circuit 36 is connected to the microcomputer 2
Each of the aforementioned relay switches 6 based on the control signal from 9
．． 8°10.12, 13, 15, 1.8.20. The non-volatile memory 38 is an EEP
The non-volatile memory 38 is composed of a ROM and can retain stored data even if the operating power supply voltage Vcc becomes O[V].

Broadly speaking, the microwave oven of this embodiment has a microwave oven function, a bread making function, and a rice cooking function. A brief description of each function is given below. In the range function, the turntable motor is controlled by the microcomputer 29.
7 and the magnetron 24, the food placed on a turntable (not shown) is rotated, and microwaves output from the magnetron 24 are irradiated onto the food to heat and cook the food. In this case, the cooking end control includes time-limited control based on the user's time setting and state control based on the detection signal from the gas sensor 34. In this state control, a gas concentration detection signal from the gas sensor 34 is given to two microcomputers, and the two microcomputers start cooking from that point when the gas concentration change value reaches a certain value based on this gas concentration detection signal. It is designed to perform time limit control for termination. In this case, the time limit is also set based on the weight detection signal from the weight sensor 33. In the bread making function, the kneading motor 14 is driven and controlled, and the temperature of the hot air heater 21 and the like is controlled based on the temperature sensor 35, and the end timing is time controlled. In addition to the normal bread manufacturing function that starts bread manufacturing immediately at the current time, this bread manufacturing function has a reservation that starts bread manufacturing at a later point in time and completes bread manufacturing at a desired time. It has a bread making function.

In addition, in the rice cooking function, the magnetron 24 is driven and controlled, and the end timing is time controlled. Regarding this rice cooking function, in addition to the normal rice cooking function that starts the rice cooking operation immediately at the current time, there is also a reservation rice cooking function that starts the rice cooking operation at a later point in time and completes the rice cooking at the desired time. be. Time control in each of the above-mentioned functions is performed by counting synchronization pulses Pc manually input to two microcomputers.

Now, the two microcomputers mentioned above constitute a power failure detection means with their software configuration and the timer base circuit 31, and also constitute a writing means and an operation control sub-stage. This will be explained with reference to the flowchart in FIG.

When the microcomputer 29 is activated after recovery from a power outage, the control contents from step S1 onwards are executed.
In order to facilitate understanding of the content of the present invention, the explanation will be given starting from step S8. In the main routine of step S8, heating cooking is controlled using one of the microwave function, bread making function, and rice cooking function. In step S9, it is determined whether a power outage has occurred. That is, the microcomputer 29 determines whether or not there is the human power for two cycles of the synchronizing pulse Pc given from the timer base circuit 31, and if there is no power, it detects the occurrence of a power outage. If a power outage occurs at time t in FIG. 2, its detection time is t in the same diagram.

When the occurrence of a power outage is detected, the current operating data stored in the RAM (the relationship between RAM addresses and data storage examples is shown in FIG. 4) is written into the nonvolatile memory 38. For example, the current operation type, such as clock display, rice cooking reservation, bread production reservation, or microwave cooking, is stored in RAM number 4 "00". RAM address “0”
1" to "o6" contain clock data, and addresses "07" to rO
The remaining driving time data is stored in Cl at addresses "OD" to "1o".
” stores the desired driving end time data. In particular, check data after a power failure (data for determining whether or not the previous writing to the nonvolatile memory 38 was normal) is stored at address rCFJ.

To write the operating data to the non-volatile memory 38, the RAM address "00" is set in step SIO, and the contents (operating data) of that RAM address are written to the non-volatile memory 38 in step Sll. . Then, in step S12, it is determined whether the RAM@ address is rCFJ (the final address of the data area), and if it is not rCFJ, the RAM address is incremented (step 513).
Then, the contents of the incremented address are stored in a nonvolatile manner.
5 Write to emissive memory 38. In this way, the contents of the operating data in the RAM are sequentially written into the nonvolatile memory 38. When this writing is completed, other power outage processing is executed (step 514), and it is determined whether or not there has been a power outage recovery. The purpose of this judgment is that since it is conceivable that the power outage will return during the writing process, this judgment is made from the viewpoint that in this case it is preferable to continue the operation. This power failure recovery is detected by whether or not the synchronization pulse Pc is input, and if it is determined that the power failure has recovered, the process returns to the main routine. Note that at time t in FIG. When a power outage occurs and the power outage continues, the reset signal output from the reset circuit 30 is stopped (see Fig. 2(e)) and the operating holding voltage decreases (see Fig. 2(d)). The computer 29 spontaneously stops.

Note that the time constant of the reset circuit 30 and the time constant of the stabilizing power supply circuit 28 are set so that the writing is completed between the time the occurrence of a power failure is detected and the output of the reset signal is stopped.

Therefore, at the time of a power outage, the microcombi 6 user 29 is stopped and the contents of the RAM are also erased, but the operating data at the time of the power outage is stored in the nonvolatile memory 38.

After that, when the power is restored, the microcomputer 29
The operating voltage Vcc is applied to start the device (the point in time is shown at t2 in FIG. 2). That is, the microcomputer 29
Control is started by

First, initial processing is executed as shown in step S1, then the RAM address is set to ro 0J in step S2, and the contents (operation data) of the non-volatile memory 38 are read into the RAM in step S3. Then, in step S4, the RAM address is re FJ (the final address of the data area).
If it is not rCFJ, the RAM address is incremented (step S5), and the contents of the nonvolatile memory 38 are read into the contents of the incremented address. In this manner, the operating data contents of the nonvolatile memory 38 are sequentially read into the RAM. When this reading is completed, it is determined whether the data contents of RAM address rCFJ are normal or not, and if normal, 7 (if there is no abnormality in writing at the time of power outage), the process moves to the main routine (step S8). . Note that if it is not normal, the RAM is cleared (step S7). In the main routine described above, operation is restarted based on the operation data in the RAM.

Therefore, according to this embodiment, when there is a power outage and the power is restored, the operation is resumed using the operating data at the time of the power outage, so there is no need to restart the operation from the beginning. In addition, since the operating data is held in the nonvolatile memory 38, the cost is low, unlike cases where operating data is held in RAM by providing a backup battery or using a large-capacity electrolytic capacitor. It also ensures that operational data is retained.

Next, FIG. 5 shows a second embodiment of the present invention, in which the content of the operation control means in the microcomputer 29 is different from the content of the operation control means in the first embodiment, and a new one is added. The provision of the driving mode determining means is light, and specifically, steps Si6 and 17 are different from the first example. That is, up to step S6,
If the reading to the RAM is completed and there is no abnormality in the data, instead of proceeding directly to the main routine (step S8) and restarting the operation, in step S16, the operation at the time of the power outage is changed to the gas concentration sensor 34. , temperature sensor 35
It is determined whether the mode is state control operation mode. Data indicating whether or not the state control operation mode is selected is included in the operation data written at the time of a power outage, and the operation mode can be determined from the operation data. However,
If it is not the state control operation mode, the operation is restarted, but if it is the state control operation mode, after executing the operation interruption process in step S17, the process moves to step S8. In this case, the operation is not restarted in the main routine due to execution of the operation interruption process.

According to the second embodiment, execution of an operation that is likely to result in inappropriate control due to a power outage can be canceled. In other words, if the operation at the time of the power outage is in the sensor-based state control operation mode, one reason is that the state based on the sensor information at the time of the power outage and the actual state at the time of power restoration may be significantly different from the expected state a. be. Therefore, in the case of the state control operation mode, when the operation is restarted, the operation may be performed in an inappropriate control state.

However, according to the second embodiment, the operation is resumed based on the operation data in the non-volatile memory 38 when the mode is not the state control operation mode, and the restart of the operation is stopped when the mode is the state control operation mode. Execution of operations that are likely to result in inappropriate control can be canceled.

In this embodiment as well, since the operating data is held in the nonvolatile memory 38, a backup battery is provided or a large-capacity electrolytic capacitor is used.
Unlike the case of retaining AM operation data, the cost is low and the operation data can be retained reliably.

In each of the above embodiments, when the power is restored after a power outage and the two microcomputers are activated, the contents of the nonvolatile memory 38 are read into the RAM and the operation is performed based on the operating data in the RAM. However, the contents of the non-volatile memory 38 are
The operation may be controlled based on the operation data directly stored in the nonvolatile memory 38 without reading it into M.

In addition, the present invention is not limited to the embodiments described above, and can be implemented with various modifications within the scope of the invention.

[Effects of the Invention] As is clear from the above description, the present invention can provide the following effects.

According to the power outage compensation circuit for electrical equipment according to claim 1, when a power outage occurs and the power is restored, operation is restarted using the operating data at the time of the power outage, thereby eliminating the trouble of restarting the operation from the beginning. Since operating data is held in non-volatile memory, costs can be reduced, unlike cases where operating data is held in RAM by providing a backup battery or using a large-capacity electrolytic capacitor. At the same time, operation data can be maintained reliably.

According to the power failure compensation circuit for electrical equipment according to claim 2, since the operating data is held in a nonvolatile memory, the operating data in the RAM is held by providing a backup battery or using a large-capacity electrolytic capacitor. Unlike the case, it is possible to reduce costs, ensure the retention of operational data, and cancel execution of operations where there is a risk of inappropriate control due to a power outage.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is an electrical configuration diagram, FIG. 2 is a diagram showing waveforms of each part and writing/reading timing of the microcomputer, FIG. 3 is a flowchart showing the control contents of the microcomputer, and FIG. 4 is a diagram showing RAM addresses and data storage examples. FIG. 5 is a diagram corresponding to FIG. 3 showing a second embodiment of the present invention. In the drawing, 24 is a magnetron, 29 is a micro 2 computer (power failure detection means, writing means, operation control means, operation mode judgment means), 31 is a timer base circuit,
33 is a weight sensor, 34 is a gas concentration sensor, 35 is a temperature sensor, and 38 is a nonvolatile memory.

Claims (1)

[Claims] 1. A power outage compensation circuit for electrical equipment whose operation is controlled by a microcomputer, comprising: power outage detection means for detecting a power outage; a nonvolatile memory; a writing means for writing the current operating data in the RAM of the microcomputer into the non-volatile memory; and an operation for restarting operation based on the operating data in the non-volatile memory when the microcomputer is started up after recovery from a power outage. A power outage compensation circuit for electrical equipment, comprising a control means. 2. In a power outage compensation circuit for electrical equipment whose operation is controlled by a microcomputer, it includes a power outage detection means for detecting a power outage, a non-volatile memory, and a power outage detection means for detecting a power outage; a writing means for writing the operating data in RAM into the non-volatile memory; and an operating mode for determining whether or not the operation at the time of the power outage is a sensor-based state control operation mode when the microcomputer is started up after recovery from a power outage. a determination means; and an operation control means for restarting the operation based on the operation data in the nonvolatile memory when the determination result by the operation mode determination means is not the state control operation mode, and canceling the restart of the operation when the operation mode is the state control operation mode. A power outage compensation circuit for electrical equipment, comprising: