JPH0461818A - Rice cooker - Google Patents

Abstract

PURPOSE:To permit the tasty cooking by the fine control for heating by determining the electric conduction ratio of a heating means from the detection value of a temperature detection circuit, and controlling the operation of the heating means in 0.1sec unit or less on the basis of the electric conduction ratio. CONSTITUTION:A bottom heater 4 electrically conducts through a bidirectional thyristor 5, bidirectional thyristor 6 and a relay 7, and is equipped with a microcomputer 15 as control means. Rice cooking is started by the input of a rice cooking key 12. After the completion of several cooking processes, the microcomputer 13 determines the electric conduction ratio of the bottom heater 4 from the detection value (cooked rice quantity is detected from temperature) of a temperature detecting circuit 11. On the basis of the electric conduction ratio, the microcomputer 13 controls a relay driving circuit 10 in 0.1sec unit and the relay 10 controls the electric conduction of the bottom heater 4 in 0.1sec unit. Accordingly, the calorific heat control and the rice cooking control can be carried out finely by a fine output of the heater, and the more tasty cooking can be realized.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a control circuit for a rice cooker.

Conventional technology In recent years, microcomputer-type jar rice cookers with relay-driven heaters have become mainstream.

Conventionally, after determining the energization ratio of the heating means based on the detected value of the temperature detection circuit, based on the energization ratio, the heater, which is the heating means, is controlled by a relay at a certain period as shown in the graph of Fig. 3. On the other hand, the output of the heater was controlled by changing the energization ratio in units of one second.

Problems to be Solved by the Invention However, in such a control method, as shown in FIG. 3, the output of the heater is only roughly output in a stepwise manner.
The heating may be too weak or too strong, making it impossible to precisely control the heating.Furthermore, cast-in aluminum type heaters have a large heat capacity, so controlling the heater in 1-second increments will not work smoothly. I couldn't change the firepower. Therefore, due to inappropriate firepower,
There was a problem that the food could not be cooked deliciously, such as being undercooked or overcooked.

The present invention solves the above-mentioned problems, and aims to provide a rice cooker that allows delicious cooking through precise and smooth heating control.

Means for Solving the Problems In order to achieve the above object, the present invention includes a heating means, a switching element that energizes the heating means, a drive circuit that drives the switching element, and a method that detects the temperature of the food to be cooked. A temperature detection circuit, and a control means that determines an energization ratio of the heating means based on the detected value of the temperature detection circuit, and controls the operation of the heating means in units of 0.1 seconds or less based on the energization ratio. It is what it is.

Effect: With such a configuration, the present invention determines the energization ratio of the heating means based on the detected value of the temperature detection circuit, and then controls the heating means in units of 0.1 seconds or less based on the energization ratio.
A finely tuned output of the heating means can be obtained. Furthermore, even in the case of an aluminum cast-in type heater with a large heat capacity, the heating power can be smoothly changed by controlling the heater in units of 0.1 seconds or less. These things make it possible to delicately control the firepower, so that it is not too strong immediately.
It's not too weak and provides just the right amount of firepower.

EXAMPLE Hereinafter, an example of the present invention will be described based on attached screens.

FIG. 1 is an electrical configuration diagram of a control circuit of a jar rice cooker according to an embodiment of the present invention. 1 is an AC power supply, 2 is a lid heater, 3 is a body heater, and 4 is a bottom heater, which are energized by a bidirectional thyristor 5, a bidirectional thyristor 6, and a relay 7, respectively.

The bidirectional thyristor 6 is a bidirectional thyristor drive circuit 8
The bidirectional thyristor 6 is driven by a bidirectional thyristor drive circuit 9, and the relay 7 is driven by a relay drive circuit 1o. 11 is a temperature detection circuit that detects the temperature of the food to be cooked;
12 is a rice cooking key for starting rice cooking, and 13 is a microcomputer that is a control means.

Next, the operation of the above configuration will be explained. First, rice cooking key 12
Cooking starts with the input. After completing several rice cooking processes, the microcomputer 13 controls the bottom heater 4 based on the detection value of the temperature detection circuit 11 (the amount of cooked rice is detected based on the temperature).
Determine the energization ratio.

Next, based on the energization ratio, the microcomputer 13 controls the relay drive circuit 10 in units of 0.1 seconds, thereby
Relay 1o controls energization of bottom heater 4 in units of 0.1 seconds.

FIG. 2 is a graph of heater output and energization ratio when the relay is controlled in units of 0.1 seconds. When compared with the dotted line graph in units of 1 second (conventional example), this example is better.
It can be seen that the heater output has become more precise. This precise output of the heater allows for very precise control of heat power and rice cooking.

Further, this embodiment, which allows fine and smooth control of the heating power, can also be applied to rice cooking using fuzzy control that adjusts the output of the heating means according to the amount of rice cooked.

Effects of the Invention As described above, the present invention determines the energization ratio of the heating means based on the detected value of the temperature detection circuit, and then controls the heating means in units of 0.1 seconds or less based on the energization ratio. The output of the heater is obtained, which allows for fine-grained heating control. Furthermore, even with aluminum cast-in type heaters that have a large heat capacity, smooth changes in heating power can be achieved by controlling the heater in units of 0.1 seconds or less. This fine-grained and smooth control of the heat power makes it possible to obtain just the right amount of heat power, making it possible to obtain a rice cooker that can cook in a better manner than conventional rice cookers.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a control circuit for a jar rice cooker according to an embodiment of the present invention, Fig. 2 is a graph showing the relationship between heater output and energization ratio in the same embodiment, and Fig. 3 is a conventional jar rice cooker. 3 is a graph showing the relationship between the output of the heater and the energization ratio in the device. 4...Bottom heater (heating means), 7...
Relay 1o... Relay drive circuit, 11...
...Temperature detection circuit, 13...Microcomputer (control means). Name of agent Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] A heating means, a switching element that energizes the heating means, a drive circuit that drives the switching element, a temperature detection circuit that detects the temperature of the food to be cooked, and energization of the heating means based on the detected value of the temperature detection circuit. determine the ratio,
A rice cooker comprising a control means for controlling the operation of the heating means in units of 0.1 seconds or less based on the energization ratio.