JPH0789991B2 - Control circuit of electric rice cooker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control circuit for an electric rice cooker, and more particularly to a rice cooker equipped with a plurality of different rice cookers by fully mechanicalizing a mechanical lever-type rice cooker switch unit. It relates to the storage of rice cooking menu information at the time of power failure.

2. Description of the Related Art Most of recent rice cookers are equipped with a microcomputer, and the structure thereof is as shown in FIG. In FIG. 4, 21 is an outer pot, 22 is an inner pot, 23 is a main heater, 24 is a temperature sensor, 25 is a rice cooking switch, 26 is a switch for selecting a menu, 27 is a light emitting diode (hereinafter, LED) for displaying the menu. 28) is a control circuit section by a microcomputer. In such a structure, a small switch or a touch switch is used for the rice cooking switch, so if you accidentally turn off the power during rice cooking or recover due to a power outage while using the kitchen timer, the rice cooking switch
25 will need to be replaced.

Problems to be Solved by the Invention As a general method for solving the above problems, a method of adding a backup function of a power source for a relatively long time or a method shown in FIG. 5 is considered. However, the power source backup method may use a battery or an electric double layer capacitor, but it has a drawback of high cost.

Next, the method shown in FIG. 5 will be described. This figure shows the relationship between the temperature in the pan and the time during cooking of the rice cooker.
Section A in FIG. 5 shows a portion where the temperature inside the pan is rising during rice cooking. Point B indicates a power failure or accidentally turning off the power. Section C is a power outage, and shows the part where the temperature inside the pan is cooling down. When the point where the power failure is restored in this C section where the power failure occurs is point D, the temperature inside the pot is higher than the point E, so in this case, rice cooking is continued again as shown in F, but the power failure is relatively long G In the case of point I in the section, the section H in the initial stage of rice cooking, or when the timer is being set, the temperature inside the pot is below the point E, so there is a drawback that the rice cannot be cooked even after re-energization.

In addition, recently, with the multi-functionalization of rice cookers, a plurality of rice cooking processes have become possible. For example, in addition to the conventional white rice cooking, it is possible to select rice cooking menus such as brown rice, rice with rice, and porridge. In such a multifunctional rice cooker, there is a drawback that the rice cooking process corresponding to multiple rice cooking menus cannot be stored in the judgment after the power failure is restored due to the temperature in the pan as described above, and a special rice cooking process such as porridge In the case of, the cooking time and temperature were different from those of normal white rice cooking, and it was impossible to realize despite the necessity of discrimination.

The present invention solves such a problem, and an object of the present invention is to enable a memory of a rice cooking process corresponding to a plurality of different rice cooking menus to be realized at low cost for a long time.

Means for Solving the Problems In order to solve this problem, the present invention stores the operation of the rice cooking start switch by the potential charged in the capacitor, and the charge of the capacitor is discharged after the cancellation switch is operated to store the memory. A rice cooking process menu that has a rice cooking switch operation memory circuit that is designed to be released, and uses the rice cooking switch operation memory circuit to control the temperature and time in response to multiple different rice cooking menus that can be selected. According to the above, a plurality is provided.

Operation With this configuration, the rice cooking process menu can be stored in 2 ⁿ by combining a plurality of rice cooking switch operation storage circuits.

Example Hereinafter, a control circuit of the electric rice cooker of the present invention will be described with reference to the drawings of FIGS. 1 to 3.

FIG. 1 shows one embodiment of the present invention. In FIG. 1, 1 is a control unit by a microcomputer for controlling the temperature inside the pan of the rice cooker, 2 is a switch for selecting a rice cooking menu, and 3 is selected. Display for displaying the menu, 4 is a switch to start cooking rice, 5 is a reset switch for canceling, 6 is a heater for cooking rice, 7 is a heater for keeping warm, 8 is a temperature measuring unit for detecting the temperature in the pan. is there. The rice cooking menu is selected for this basic function, and a plurality of memories such as the first memory 9 and the second memory 10 are selected and set when the rice cooking is started.

A concrete example is shown in FIG. 1 in FIG. 2 is a control unit for controlling the temperature inside the pan of the rice cooker, 2 is a switch for selecting a rice cooking menu, 4 is a switch for starting rice cooking, and 5
Is a reset switch for canceling, 3a is an LED that indicates that rice is being cooked, 3b is an LED that indicates that rice is being cooked, 3c is an LED that is indicating that heat is being cooked, 6 is a heater for cooking rice, 7 is a heater for retaining heat, and 8 is This is a temperature measurement unit that detects the temperature inside the pan. 9 is the first memory for memorizing that rice cooking with white rice has started, 10
Is a second memory for storing that rice cooking has started. Here, the internal circuit configuration of the first and second memories 9 and 10 and the operation thereof will be described. 13,20 are capacitors that are charged when the rice cooking starts and store the potential, and 14 are capacitors
Current limiting resistor for charging 13,20, 15 for capacitor 1
A backflow prevention diode for preventing the electric charge charged in 3, 20 from discharging, 16 has a reference voltage input (not shown), compares the charging potentials of the capacitors 13, 20 and sends a memory signal to the control unit 1 side. It is a comparator. Reference numeral 17 is a transistor for resetting the memory, and the resistor 18 is for limiting the discharge current of the capacitors 13 and 20. Reference numeral 19 is a base input resistance for inputting a memory release signal from the control unit 1 to the transistor 17. Similarly, the second memory 10 is also charged in the capacitor 20 to form a memory set. The memory release signal is output from the control unit 1 only when the power is turned on or when the reset switch 5 for cancellation is pressed.

Next, we will explain the concrete memory function of the rice cooker in the third section.
It will be described with reference to the drawings. The step 1 in FIG. 3 shows the position where the rice cooker is turned on. The arrow indicates the action for that step. Next, the point where the menu is set to white rice is 2, and when the rice cooking start switch 4 is pressed at 3, the rice cooking heater 6 is turned on, and at the same time, the capacitor 13 of the first memory 9 is charged. This charging is performed in a relatively short time, and serves to remember that the rice cooking with white rice has started. 4 indicates that there was a power outage during rice cooking, and both the white rice display and the rice cooking heater 6 are turned off. If the power outage is relatively short, the power supply can be backed up at a low cost, but a wide range of power outage guarantee of several seconds to several tens of hours cannot be guaranteed. Reference numerals 4 to 5 in FIG. 3 represent the above seconds to tens of hours. When the control unit 1 determines that the potential of the first memory 9 of the point 5 is at a high level (hereinafter referred to as H level) when the power failure is restored, the white rice display is turned on again and the rice cooking heater 6 is operated. When the rice is cooked at 6, the rice cooking heater 6 is cut off, and the heat retention heater 7 is turned on.
The display also changes from white rice display to heat retention display, and the second memory 10
Is set to H level. Even if the power fails again at 7, the first memory 9 at the point is at the H level and the second memory 10 is also at the H level, so that even if the power is restored at 8, the same operation as before the power failure can be executed. When the reset switch 5 for cancellation is pressed at 9, both the heat retention display, the heat retention heater 7, the first memory 9 and the second memory 10 are released,
Low level (hereinafter referred to as L level). Next, when the porridge is selected, the same operation is carried out as 10, 11, 12, but the point different from the above is the set of the memory. In the case of porridge, it is set in the second memory 10 as in 12, and when the porridge display changes from the porridge display to the heat retention display, the first memory 9 is also set and the heat retention is stored. The table of the above memory function is shown in the following table, and four kinds of modes can be stored by two memory functions.

Effects of the Invention As described above, according to the present invention, by providing a plurality of memory functions, as compared with the conventional method of judging by temperature,
With 2 ⁿ , the memory of the rice cooking process menu can be realized inexpensively for a long time. Moreover, the same effect can be obtained in a microcomputer rice cooker with a built-in kitchen timer or digital timer, which is highly practical.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a circuit configuration of a control circuit of an electric rice cooker according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a concrete embodiment thereof, and FIG. 3 is a memory function in the rice cooker. 4 is a sectional view showing an example of the electric rice cooker, and FIG. 5 is an operation timing chart in the conventional control circuit. 1 ... Control unit, 2, 4 ... Switch, 3 ... Indicator, 5 ...
... Reset switch, 6 ... heater for rice cooking, 7 ... heater for keeping heat, 9 ... first memory, 10 ... second memory.

Claims (1)

[Claims] 1. A rice-cooking-switch operation storage circuit for storing the operation of the rice-cooking start switch with the potential charged in the capacitor, and discharging the electric charge of the capacitor after the cancel switch is operated to release the memory. An electric rice cooker characterized in that a plurality of rice cooker switch operation memory circuits are provided in accordance with a rice cooker process menu in which rice is cooked while controlling temperature and time corresponding to a plurality of differently prepared rice cooker menus. Control circuit.