JPH02226683A - Control method for high-frequency heating device - Google Patents

Abstract

PURPOSE:To prevent the automatic oscillation of high frequency output by causing one active signal to be non-active at least once when a door is opened during a cooking setting process or a cooking process. CONSTITUTION:In a cooking process, a signal becomes active at the start O of the (a) port of a microcomputer 10, and a latch circuit 15 is turned on. Also, a main relay signal at the (b) port becomes active. Consequently, a transistor(TR)Q2 is turned on and a main relay coil 28 is excited, thereby causing the operation of a high frequency heat generation source 16. When a door is opened and then closed in that mode, a door switch 19 is turned off and the main relay signal becomes non-active, thereby turning off the transistor TRQ2. ROM 10-3 of the microcomputer 10 is so set that a non-active signal is outputted a few times for the clock interruption of a start OK signal. Transistors TRQ3 and TRQ4, therefore, are turned off and the latch circuit 15 is also turned off, thereby enabling the prevention of the automatic oscillation of high frequency output.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to high frequency heating devices, and in particular to the control of safety devices thereof.

2. Description of the Related Art A recent high-frequency heating device that uses electronic circuits to control heating conditions and display contents will be described with reference to the circuit diagram in FIG. 2 and the perspective view in FIG. 3.

In FIG. 3, a door body 2 that can be opened and closed and an operation panel 3 are provided on the front of the heating device main body 1, and the operation panel 3 includes:
Necessary heating I! ! A cooking menu switch group 4 for setting functions, a start switch 5 for instructing the start of cooking, a cancel switch 6, etc. are provided.

In FIG. 2, a microcomputer (hereinafter referred to as microcomputer) 10 provided on the control circuit side is connected to a cptr (central information processing unit) 10-2 via an I10 section (input/output section) 10-1. A ROM (read-only storage device) 10-3 and a RAM (read-write storage device) 10-4 are coupled to this. Also, connected to the terminals of the microcomputer 10 are a time pulse generation circuit 11 necessary for the microcomputer 10 to measure heating time, a temperature detection element 12 whose analog value changes depending on the temperature, and a timer 13 for setting the heating time. and display device 1
4 is connected. In addition, the terminal of the microcomputer 10 has
The cooking menu switch group 4, start switch 5, cancel switch 6, etc. shown in FIG. 3 are connected.

Furthermore, a high frequency heat source 16 on the main circuit side and other attached heat sources 17 such as a heater are connected to the terminals of the microcomputer 10 via a latch circuit 15.

On the other hand, in the ROM 10-3 of the microcomputer 4, after selecting a desired menu from the cooking menu switch group 4 and setting the heating time and the weight of the food to be substituted for the heating time using the timer 13, the start switch 5 is turned on. When input, this heating function performs a predetermined heating. Furthermore, the ROM section 10-3 of the microcomputer 10 includes a temperature detection element 1.
It has the function of converting the temperature analog signal obtained through the circuit 2 into a digital signal and measuring it, and the function of counting the time signal taken in through the time pulse generation circuit 11 to measure the heating time. In addition, the ROM section 10- of the microcomputer 10
3 has the function of storing the heating function selected from the menu switch group 4 and the heating time value set by the timer 13 in the RAM section 10-4. Further, in the ROM section 10-3 of the microcomputer 10, when the cancel switch 6 is pressed, the contents stored in the RAM section 10-4 are erased, and when the start switch 5 is pressed, the contents are stored in the RAM section 10-4. Based on the heating content, the high-frequency heat source 16 or other attached heat source 17 such as a heater, or a combination thereof is operated to start heating, and the heat is further increased based on the above-mentioned heating temperature and heating time that were measured separately. It has the function of controlling the source.

Furthermore, the ROM section 10-3 of the microcomputer 10 has a function of displaying the progress of the heating contents in progress in the display bags M, 14 by subtracting the progress of the heating contents, for example, along with the elapse of the already set heating time.

Also, on the main circuit side, a door switch 1 is connected to the commercial power supply 18.
9. A main relay contact 20, a high voltage transformer 21, a temperature switch 22, and a fuse 23 are connected in series, a lamp 24 is connected to the power supply side of the door switch 19, and a motor 25 such as a turntable motor or fan motor is connected to the output side of the door switch 19. Each is connected in parallel. In addition, the high frequency heat source 16
is connected to the secondary side of the high voltage transformer 21 via a high voltage capacitor 26 and a high voltage diode 27, and other attached heat generating sources 17 such as a heater are connected in parallel on the output side of the main relay contact 20.

28 is a main relay coil that drives the main relay contact 20, and is connected to the start switch 5 via the transistor Q2.
and the latch circuit 15. Further, this transistor Q2 is connected to a terminal of the microcomputer 10 and controlled.

Next, the operation in such a configuration will be explained. In Fig. 2, VCC of the microcomputer 10 is the power supply of the microcomputer 10, C-1 to C-4 are key scan output ports that output square waves at regular intervals, and d-1 to d-4 are key-powered boats. , one C-1 of the key scan output ports C
is connected via the start switch 5 to the connection point A between the latch circuit and the transistor Q2, and to dl, which is one of the key human power ports d (in this circuit, it is LOW active), and the a port of the microcomputer 10 is This is a start OK signal output port that outputs an active signal when a required cooking switch is selected from the cooking menu switch group 4 and pressed, and is connected to the transistors Q3 . Connected to Q4. The b-board of the microcomputer 10 is configured such that when the cooking switch of the cooking menu switch group 4 is selected and the start switch 5 is input after the cooking time and food weight of the timer 13 are set, that is, the latch circuit 15 is activated. This is the main relay signal output port to which an active signal is output after being turned on (described later), and is connected to B at the base of transistor Q2.
Point B is connected to A of the latch circuit 15 via a resistor.
Connected to the dots.

First, select and press the required cooking switch from the cooking menu switch group 4, and the start OK signal of the active signal (LOW signal) will be sent from the a boat (Figure 1 + b).
The signal is output as shown in (A), and the conditions under which the latch circuit 15 can be turned on are set. After the cooking time and food weight are set, when the start switch 5 is pressed, the latch circuit 15 connected to the start switch 15
The point falls to LOW, the latch circuit 15 turns on, and the point A becomes LOW.
Hold in OW. Further, when the start switch 5 is pressed, a main relay signal of an active signal (HIG to I signal) is outputted from the b boat as shown in (b) of FIG. 1(b). This start OK (logical product of No. 76 and the main relay signal turns on the transistor Q2, the main relay coil 28 is energized, the main relay contact 20 is closed, and a high frequency output is made.

When the door body 2 is opened during this high frequency output, the main relay signal from the b boat is released, the transistor Q2 is turned off, the excitation of the main relay coil 28 is stopped, the main relay contact 20 is opened, and the high frequency output is stopped. be done.

Problem to be Solved by the Invention However, with the above configuration, as shown in FIG. 1(b), when the door is opened during cooking, the start OK signal of boat a remains active, so the transistor Q
1 remains on and therefore the latch circuit 15
remains on.

Here, if the b boat of microcomputer 10 breaks down,
If the GH signal remains active, there is a drawback that automatic oscillation of high frequency output occurs when the door body is closed.

The present invention solves the above problem, and aims to provide a high-frequency heating device that does not cause automatic oscillation of high-frequency output even when the door is opened or closed during cooking settings or cooking.

Means for Solving the Problems In order to solve the above-mentioned problems, the high frequency heating device of the present invention provides a high-frequency heating device that prevents signals from being input to the cooking menu switch group when the door body is opened during cooking settings or during cooking. The start OK signal of one of the active signals is made non-active at least once.

Operation With the above configuration, the intermittent means for intermittent operation of the high frequency generation means is unlatched by one active signal, and even if the b-board of the microcomputer fails and continues to output the other active signal, the high frequency generation means continues to output the active signal. is shut off, preventing automatic oscillation of high frequency output that occurs when the door is opened or closed during cooking settings or during cooking.

Example An embodiment of the present invention will be described below based on the drawings.

FIG. 1(a) is a waveform diagram in a method of controlling a high-frequency heating device according to an embodiment of the present invention. First, in FIGS. 1(a) and 2, during cooking, the start OK signal of boat a of the microcomputer 10 becomes active, the latch circuit 15 is turned on, and the main relay signal of boat b also becomes active. Therefore, transistor Q2 is turned on, main relay coil 28 is excited, and high frequency heat source 1
6 is working. Assume that the door body 2 is opened in this state and then closed again. At this time, the door switch 19 is turned off, the main relay signal also becomes non-active, and the transistor Q2 is turned off, so the high frequency heat source 16, however,
The latch circuit 15 remains on.

Here, when the door body 2 is opened during cooking, the ROM 10-3 of the microcomputer 10 sends the start OK signal to the non-active state about 1 to 3 times during the clock interrupt, as shown in FIG. 1(a) (b). It is set to output a signal. Therefore, when the main relay signal of the b boat becomes non-active and the transistor Q2 is turned off, and then the start OK signal of the a boat becomes non-active, the transistors Q3 and Q4 are turned off, and the latch circuit 15 is turned off.

After this, even if the start OK signal is activated, transistor Q3. Since Q4 is not turned on, the latch circuit 15 is turned off. At this time, even if noise is applied to point B on the base side of transistor Q2, transistor Q2 will not turn on, and even if the b port of microcomputer 10 fails and continues to output an active signal, automatic oscillation of high frequency output will not be performed. .

Effects of the Invention As described above, according to the present invention, it is possible to obtain the effect that automatic oscillation of high frequency output is not performed even if there is a port failure of the microcomputer when the door body is opened and closed during cooking.

[Brief explanation of the drawing]

Figure 1! aHb) is a waveform diagram in a control method for a high-frequency heating device according to an embodiment of the present invention and a conventional waveform diagram, FIG. 2 is a main body and control circuit diagram of the same high-frequency heating device, and FIG. 3 is a perspective view of the main body. 2... Door body, 3... Operation panel, 4... Cooking menu switch group, 5... Start switch, 6...
Cancellation switch, 10...Microcomputer, 10
-1...110 copies, 10-2...CPU, 10-3
...ROM, 10-4...RAM, 11...time pulse generation circuit, 12...temperature detection element, 13...
Timer, 15... Latch circuit, 16... High frequency heat source, 19... Door switch, 20... Main relay contact, 28... Main relay coil.

Claims (1)

[Claims] 1. A heating chamber, a door provided on the front side of the heating chamber, a high-frequency generating means for heating the food, an input means for inputting cooking data consisting of functional information and numerical information, and the above-mentioned high-frequency generating means. an intermittent means for intermittent operation of the means; a microcomputer that receives signals from the cooking menu switch group and a start switch signal of the input means and generates two active signals; An active signal is generated, and a subsequent signal from the start switch enables the above-mentioned intermittent means, and further, by ANDing two active signals, the other active signal generated by the signal from the start switch and the one active signal. and control means for controlling the intermittent means to operate for the first time, and when the door body is opened during cooking setting or cooking, one of the two active signals output from the microcomputer is provided. A method for controlling a high-frequency heating device by deactivating an active signal at least once.