JPH0316532A - Controller for jar rice cooker - Google Patents

Abstract

PURPOSE:To reduce the load power source by electrified alternately each bidirectional thyristor driving circuit in a definite duty so that even when a plurality of bidirectional thyristors are used, the circuit is driven only with a single unit of gate electric current. CONSTITUTION:Electrification of a plurality of heaters 10, 11 and 13 is controlled with a plurality of bidirectional thyristors 16 and 17. The bidirectional thyristors 16 and 17 are controlled respectively by driving circuits 18 and 19. In a control means 20 constituted with a microcomputer, the driving circuits 18 and 19 are alternately electrified in a definite duty. As a consequence, only one thyristor is electrified without fail. Thus even when a plurality of bidirectional thyristor are used, the controller can be moved with only one gate current and the load of power source can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heater control device for a jar rice cooker.

Conventional technology A conventional structure will be explained with reference to FIG.

The AC power source 1 heats the trunk heater 2 and bottom heater 3.

When the relay 4 is energized, the bottom heater 3 is heated, and when the bidirectional thyristor 6 is energized, the body heater 2 and the bottom heater 3 are heated simultaneously. The bidirectional thyristor 6 is driven by a bidirectional thyristor drive circuit 6, and the drive circuit 6 is controlled by a microcomputer 7.

As shown in the above structure, the conventional rice cooker controls the energization of the heaters 2 and 3 using one bidirectional thyristor.

Problems to be Solved by the Invention However, recently, people have started using jar rice cookers to cook more delicious rice by heating from more directions than just the bottom heater 3 and body heater 2, or to use the lid to remove dew. There has been a demand for heating the lid to prevent this from happening, and as a result, the number of heaters that must be controlled has increased, and the number of bidirectional thyristors that control the heaters has also increased. It became not just one, but several. Therefore 2
When two or more bidirectional thyristors are energized at the same time, driving the bidirectional thyristors requires a gate current that is many times larger than conventional thyristors, placing a large burden on the power supply circuit.

The present invention solves the above problems, and aims to provide a control device for a jar rice cooker that consumes less gate current.

Means for Solving the Problems In order to achieve the above object, the present invention includes a plurality of heaters,
It consists of a plurality of bidirectional thyristors that control the energization of each of the heaters, each drive circuit that drives each of the bidirectional thyristors, and a control means that alternately energizes each of the drive circuits at a constant duty. It is.

Function: Since the present invention alternately drives the bidirectional thyristors with the above-described structure, only one bidirectional thyristor is energized, and even if a plurality of bidirectional thyristors are used, only one bidirectional thyristor is energized. It can be operated with only one gate current,
The burden on the power source can be reduced.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In FIG. 2, a bottom heater 10 is attached to the main body 8 so as to be in contact with the bottom of the inner pot 9, and a body heater 11 is in contact with the body of the inner pot 9.
is attached. A lid heater 13 is attached to the bottom of the lid 12.

FIG. 1 is a circuit diagram of this embodiment. The bottom heater 10, the body heater 11, and the lid heater 13 are heated by the AC power source 14.

The relay 16 controls the energization of the bottom heater 10, the bidirectional thyristor 16 controls the energization of the bottom heater 1o and the body heater 11, and the bidirectional thyristor 17 controls the energization of the lid heater 13. The drive circuit 18 drives the bidirectional thyristor 1e,
A drive circuit 19 drives each of the bidirectional thyristors 17, and a microcomputer 2o controls the drive circuits 18 and 19.

FIG. 3 is a flowchart of the operation of the microcomputer 20.

t is the time counted by the counter in the microcomputer 20, and T1, T2, and T3 are T1<T2<T3
It is a certain period of time that has the following relationship.

Next, the operation will be explained by clicking on the above-mentioned Kaikai.

Referring to FIG. 3, if the time t is smaller than the predetermined time T1, the drive circuit 19 is operated and the bidirectional thyristor 17 is energized accordingly. At this time, as can be seen from FIG. 3, since the step of operating the drive circuit 18 is not performed, the drive circuit 18 is not operated, and therefore the bidirectional thyristor 18 is not energized either. Next, time t is a constant time T
If it becomes larger than 1, the step of operating the drive circuit 19 will no longer be passed, and the bidirectional thyristor 17 will no longer be energized. Then, when the time value becomes longer than a certain time T2 (T1 + T2), the drive circuit 18 is operated, and thereby the bidirectional thyristor 18 is energized. Next, when the time t becomes longer than the predetermined time T3, the above operation is repeated again at a predetermined period T3. In this way, the bidirectional thyristor drive circuits 18 and 19 can be alternately energized at a constant duty.

Effects of the Invention As described above, the present invention alternately energizes each bidirectional thyristor drive circuit at a constant duty, so only one bidirectional thyristor is energized, and the current consumption is lower than that of the bidirectional thyristor. Even though the number of thyristors has increased, it remains the same as the conventional one.

Therefore, especially when the same power supply circuit is used for each bidirectional thyristor drive circuit, even though there are many bidirectional thyristors, a power supply circuit with a small output can be used, and the transformer etc. can also be small. , it is possible to realize a control circuit for a small and economical jar rice cooker at low cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a control device for a jar rice cooker according to an embodiment of the present invention, FIG. 2 is a sectional view showing the internal structure of a jar rice cooker according to an embodiment of the present invention, and FIG. 3 is a circuit diagram of a control device for a jar rice cooker according to an embodiment of the present invention. FIG. 4 is a flowchart of the operation of the microcomputer of the control device for a jar rice cooker in one embodiment, and FIG. 4 is a circuit diagram of a conventional control device for a jar rice cooker. 1o... Bottom heater, 11... Body heater, 13... Lid heater, 16, 17...
Bidirectional thyristor, 18.19...Bidirectional thyristor drive circuit, 20...Microcomputer (control means).

Claims (1)

[Claims] A plurality of heaters, a plurality of bidirectional thyristors that control energization of each of the heaters, each drive circuit that drives each of the bidirectional thyristors, and control that alternately energizes each of the drive circuits at a constant duty. A control device for a jar rice cooker consisting of means.