JPS6136360B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a microwave oven, and an object of the present invention is to clarify the switching between cooking means by temperature setting and cooking means by heating time setting even in a microwave oven having a turntable. Conventionally, the cooking performance of microwave ovens has been improved year by year, and microwave ovens have both a means of setting the heating time using a timer and a means of cooking that sets the finished temperature of the food by using a temperature sensor. It has become like this. On the other hand, in order to improve cooking performance, microwave ovens equipped with a turntable that improves temperature distribution have become popular. However, in microwave ovens equipped with this turntable, the food to be cooked rotated with the turntable, so conventional temperature sensors could not be used. It has become possible to use a temperature sensor even in a microwave oven equipped with a table, and it has therefore become possible to cook by setting the finished temperature of the food to be cooked. However, the disadvantage of this rotary jack is that it does not have a switch connected to the attachment/detachment of the temperature sensor, which makes it unclear whether the temperature sensor is used or the timer is used. There were some inconveniences in use, such as using a sensor and cooking on a timer, and users often made mistakes. The present invention eliminates such confusion and is useful in cases where cooking is limited to either using a temperature sensor to set the temperature, or using a timer to set the heating time. The aim is to provide a microwave oven that works as long as possible. Hereinafter, embodiments will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of one embodiment of the present invention, where 1 is the main body of the microwave oven, 2 is a heating chamber, and inside thereof is a magnetron for high frequency oscillation and a turntable on which the food to be cooked is placed. etc. 3
is a timer to set the cooking time, 4 is a switch push button to start cooking, 5 is a knob to control the high frequency output level, 6 is a knob to set the finished temperature of the food to be cooked, 7 is a pilot lamp for high frequency output. It is. FIG. 2 is a circuit diagram of this embodiment. This circuit diagram will be explained below. In FIG. 2, 8 is a fuse, 9a and 9b are power switches, and 13 is a control unit, which includes a high frequency output control unit 14, a temperature sensor control unit 15 that detects the temperature of the food to be cooked, and a temperature sensor that is a feature of the present invention. It is composed of a determination unit 17 and the like that performs switching between sensors and timers. The high frequency output control section 14 includes an output control switch 1
1 is intermittent at an arbitrary period, and the anode current flowing through the magnetron 12 is intermittent, thereby changing the high frequency output level. Furthermore, the temperature sensor control section 15 senses the temperature of the food to be cooked using a temperature sensor probe 16 inserted into the food to be cooked, and when the temperature reaches the set temperature, that is, the desired finished temperature, the power relay switch 10 is turned off to output high frequency output. to stop. The determination unit 17 obtains as input the potential level of point a, "L" and "H", depending on the presence or absence of the temperature sensor probe 16, and the potential level of point b, "L" and "H", depending on the ON/OFF state of the timer contact 19. . The combination of these inputs yields the results shown in the output column of the table.

[Table] To explain the case of the circuit state shown in Figure 2,
There is a temperature sensor probe 16, which works with a temperature setting variable resistor 18, so that the transistor Q1 is
ON, and as a result, the potential at point a is set to the "L" level. Furthermore, since the timer contact 19 is OFF, the potential at point b is set to the "H" level. Therefore, the output of the determination unit 17 corresponds to column B of the table and is at the "L" level. When the output of the determination unit 17 is at “L” level, the transistors Q2 and Q4
are both OFF, and transistors Q3 and Q5
control the power relay 10 according to the signals from the high frequency output control section 14 and the temperature sensor control section 15, respectively.
ON, the output control switch 11 is turned ON to control the high frequency output. Further, when the temperature of the food to be cooked reaches a set value, the power relay switch 10 is turned off to stop the operation of the microwave oven. A table summarizes the above conditions in one table.

[Table] (Note: × indicates non-operation)
In other words, the table shows the presence and absence of a temperature sensor probe,
This table shows whether the microwave oven does not operate, and if it does, whether it is controlled by the temperature sensor or by the timer, depending on the combination of ON and OFF of the timer contacts. The circuit states in FIG. 2 correspond to the columns in the table. In the case of table, i.e. temperature sensor probe 1
6 is absent and the timer contact 19 is ON, the output of the determination unit 17 is the same as in case C in the table, so the microwave oven operates, but in this case, there is no temperature sensor probe 16 and the timer contact 19 is ON. ON
This differs from the case shown above in that the power relay switch 10 is turned off when the heating of the food to be cooked reaches the set time. In the case of table, i.e. temperature sensor probe 1
6 is null and the timer contact 19 is OFF, the output of the determination unit 17 becomes "H" level as shown in the table, turning on the transistors Q2 and Q4 and turning off the transistors Q3 and Q5, so that the power relay switch 10 and , output control switch 11
Turn it off and the microwave will not work. In the case of table, i.e. temperature sensor probe 1
6, and when the timer contact 19 is ON, the inputs of the determination unit 17 both go to "L" level, and the output goes to "H" level as shown in the table. Since transistors Q2 and Q4 are turned ON and transistors Q3 and Q5 are turned OFF, both power relay switch 10 and output control switch 11 are turned OFF, and the microwave oven does not operate. In addition, to show another example, as an output control method, 1
Even when adopting a method in which the next input is interrupted by an SCR, the same effect can be obtained by providing the transistor Q4 at the gate of the SCR. As explained above, according to the present invention, it is clear to the microwave oven user whether to use a cooking means that sets and controls the heating time using a timer, and a cooking method that uses a temperature sensor to set and control the finished temperature of the food to be cooked. This has the effect of preventing mistakes by preventing the microwave oven from operating even if a provisional order is used incorrectly. The present invention is applicable not only to microwave ovens equipped with a turntable, but also to conventional microwave ovens without a turntable. As a result, there is no need for a switch that is linked to the attachment and detachment of the temperature sensor probe, and only the signal from the probe is used. It becomes possible to determine the presence or absence of a probe, and there is no need to worry about malfunctions or breakdowns of switches, etc., and has the effect of increasing reliability. If there is no temperature sensor probe and the timer contacts are OFF, that is, the microwave oven is not ready for use, even if you press the start button carelessly, or if the start button does not return properly, the microwave will not start. It has a positive effect on safety.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of one embodiment of the present invention, and FIG.
The figure is the same circuit diagram. 10...Power relay switch, 11...Output control switch, 12...Magnetron, 14...
High frequency output control section, 15... Temperature sensor control section, 16... Temperature sensor probe, 17... Judgment section, 18... Temperature setting variable resistor, 19...
timer contact.

Claims (1)

[Claims] 1. A temperature sensor probe for detecting the temperature of the food to be cooked, a timer device for setting the heating time of the food to be cooked, a device detection circuit for the temperature sensor probe, and a circuit for detecting whether or not the timer device is set. , only in one of the following cases: when the temperature sensor probe attachment detection circuit detects that the temperature sensor probe is attached, or when the heating time setting detection circuit detects that the timer device is set. , a microwave oven with a control function that enables high-frequency oscillation.