JPS5920929B2 - electronically controlled cooker - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electronically controlled cooking appliance. Recently, electronically controlled cookers have appeared, which are controlled by digital technology. As a feature of such a cooking appliance, the operation panel of the cooking appliance is equipped with a keyboard 1 as shown in FIG. 1 and a numerical display section 2 as shown in FIG. As an example of operation using keyboard 1, for example, at a heating output of 20% of the maximum heating output,
To explain the case of cooking for 30 seconds, at this time, on the keyboard 1, select the pressure
Each key operation is performed in the order of 1!7η.Then, on the numerical display section 2, 20 representing the output is first displayed as shown in Figure 2A, and then 1030 representing the cooking time is displayed as the second. When cooking is started by operating the 107η key, the remaining cooking time is displayed on the numerical display section 2.Then, when the remaining cooking time reaches zero, Cooking is finished. The 7 keys are used to cancel the set output and cooking time. However, according to the above-mentioned cooker, you can set any heating output and any heating time. , hence the maximum setting state,
That is, the heating output may be 99% and the heating time may be 99 minutes and 59 seconds. However, in reality, there is no cooking that requires heating at such high output for a long period of time, and rather, such a setting state can be called an erroneous operation. This means that the heating load is light (
For example, even if the amount of food to be cooked is small, if heating is performed at high output and for a long time due to the above-mentioned incorrect operation, the components of the cooker will be strained, resulting in a dangerous accident. It is something. This is because, from a practical standpoint, ordinary cookers are not designed for high output and long heating times under light loads. If the cooker is designed with sufficient margin, there will be no problem even if the above-mentioned erroneous operation is made, but such a design will lead to an increase in costs. The present invention has been made in view of the above-mentioned points, and is designed to ensure safety by overriding the setting state when high output and long-term heating is set due to an erroneous operation. An example in which the present invention is applied to a microwave oven will be described below. The microwave oven of this embodiment is equipped with the same keyboard 1 and numerical display section 2 shown in Figs. 1 and 2, and when the heating output is 90% or more, the heating time is 1 minute or more. It is assumed that this is impossible, and such a setting is treated as an erroneous operation. FIG. 3 shows the overall circuit of the microwave oven of this embodiment,
The configuration and operation of the circuit will be explained below using the above-mentioned key operation example. When the "Ei" key on the keyboard 1 is operated, the key signal processing circuit 3 detects this and generates a gate signal G1 to open the transfer gates 4 and 5. As a result, when the following numerical value 20 is input on the keyboard 1, the key signal processing circuit 3 inputs the numerical value 2 in the BCD code display.
0 is set in the first register 6 via the gate 4. Further, the set value is displayed on the numerical display section 2 via the gate 5. Next, when the Somu = Katana key is operated on the keyboard 1, the key signal processing circuit 3 detects this and outputs a gate signal G.
2 to open transfer gates 7 and 8. Therefore, when the following numerical value 1030 is input on the keyboard 1, the numerical value 1030 in the BCD code display is inputted as the second numerical value.
The set value is set in the register 9 and displayed on the numerical display section 2. Of course, at this time, the gate signal G1 has already disappeared, and gates 4 and 5 are closed. Finally, when the Dση key is operated, the key signal processing circuit 3 eliminates the gate signal G2 and generates a start signal ST, which opens the AND gate 10. On the other hand, the output MO of the erroneous operation detector 11 is input to this gate. The erroneous operation detector 11 checks whether the settings of the first register 6 and the second register 9, that is, the heating output and heating time, are within the permissible limits.The specific circuit is shown in Fig. 4. It is shown. As shown in the figure, the erroneous operation detector 11 includes a first OR gate 12 and a second OR gate 13 that input the information of the first register 6 and the second register 9, respectively, and an AND gate 14 that inputs the output of each OR gate. Contains. That is, the first register 6 has a length of 8 bits to store a 2-digit BCD code, and the bit signals having weights of 1 and 8 of the upper digits enter the first OR gate 12, while the second register 9 It has a length of 16 bits to store a 4-digit BCD code, and all bit signals of the two most significant digits enter the second OR gate 13. Therefore, when the content of the first register 6 is 90 or more and the content of the second register 9 is 100 or more (ie, 1 minute or more), an output MO is generated from the AND gate 14 as an erroneous operation. In this case, the settings in the first and second registers 6 and 9 are within the permissible limits, so the output MO will not occur, but if this is not the case, the output MO will occur, and therefore the start signal When ST occurs, the flip-flop 15, which is initially in the set state, is set by the output of the AND gate 10, and the buzzer 16 is driven by the set output. Such a buzzer alerts the cook to an incorrect operation.
In that case, the cook uses keyboard 1.

[U] After operating the sword key, you will need to set the correct heating output and heating time again. When the self-key is operated, the key signal processing circuit 3 detects this and generates a clear signal CL, which erases the contents of the first and second registers 6 and 9, and also clears the contents of the flip-flop. 15 is reset. The start signal ST passes through the other delay element 17 and then enters the AND gate 18 together with the reset output of the flip-flop 15. The delay element 17 has a flip-flop 15 and an AND gate 1.
By outputting 0, the input of the start signal ST to the AND gate 18 is delayed by the time required for state inversion. Therefore, if the start signal ST is not operated incorrectly, it is AND gate 1.
8, the magnetron control circuit 19 is activated, and in case of an erroneous operation, the circuit is not activated. Upon receiving the start signal ST' output from the AND gate 18, the magnetron control circuit 19 operates the magnetron 20 at a set heating output for a heating time set according to the contents of the first and second registers 6 and 9. A control output MG is generated to drive the . On the other hand, the start signal ST' sets the flip-flop 21, and its set output opens the transfer gate 22. The magnetron control circuit 19 generates a heating remaining time that decreases every moment, and the content of this time is displayed on the numerical display section 2 via the transfer gate 22. When the set heating time has elapsed, the magnetron control circuit 19 eliminates the control output MG and generates an end signal ED, which resets the flip-flop 21. FIG. 5 shows details of the magnetron control circuit 19. When the start signal s'f is input, the signal opens the transfer gates 23 and 24 for a predetermined time, and transfers the contents of the first and second registers 6 and 9 to the third and fourth registers 25 and 26, respectively, through each gate. be forwarded to. The decoder 27 decodes the contents of the third register 25 and outputs the output lines N1 to Nl.
Output to one of OO. That is, the output lines N1 to NlOO are 1 of heating output 0% to 99%.
Corresponding to each stage of 00, the content of the third register 25 is now 20, so an output appears on the output line Nl9. The astable multi 28 generates a pulse MP with a constant period, but its pulse width, that is, the duty, is variable in 100 steps depending on the output state of the decoder 27, and since the output is currently output to the output line Nl9, the pulse width is 20. Pulse MP is generated with a duty of %. On the other hand, the start signal s'f is the third
, a flip-flop 30 is set via a delay element 29 having a delay time necessary for transfer to the fourth registers 25 and 26. The set output of the flip-flop enters the AND gate 31 together with the pulse MP, opens the gate 32, and sends the second pulse SP output from the time signal generator 33 to the fourth register 26. The fourth register 26 has a down counter function for counting time by decimal-sexagesimal counting, and counts down the contents every time it receives the second pulse SP. Therefore, the content of the fourth register 26 decreases moment by moment, and is displayed as the remaining time on the above-described numerical value display section 2. The zero detector 34 is connected to the fourth register 26
When the content of becomes zero, this is detected and an end signal ED is sent.
is generated and the flip-flop 30 is reset. Therefore, the flipflop 30 generates a set output for 10 minutes and 30 seconds after the arrival of the start signal s'f, and during this period, the pulse MP with a duty of 20% is outputted from the AND gate 31 as the control output MG. The control output MG of the magnetron control circuit 19 is then
As shown in the figure, the switching circuit 35 is driven. That is, this circuit transmits the power of the power supply 36 to the high voltage rectifier circuit 37 for driving the magnetron 20 once only when the control output MG is present. Therefore, the magnetron 20 lasts for 10 minutes and 30 seconds.
It will oscillate at 20% of the total output. In the above example, what happens if there is an erroneous operation? Even if the Sekiseigun key was input, the operation of the magnetron was prohibited by the action of the AND gate 18, but the permissible limit values, such as a heating time of 59 seconds and a heating output of 89%, were separately memorized. When an erroneous operation is detected, the magnetron may be operated using the above-mentioned allowable limit value regardless of the value set by the erroneous operation. Further, in the above embodiment, there is only one combination of heating time and heating output that falls within the allowable limit, but the combination is not limited to this.
It is also possible to add a plurality of types, for example, a heating output of 80% and a heating time limit of 2 minutes. As is clear from the above explanation, according to the present invention, in an electronically controlled cooker that can set arbitrary heating output and arbitrary heating time, an unnecessary combination of high output and long cooking time can be set due to erroneous operation. Even if it is, operation will not start, or
Alternatively, it is safe because it is operated within the allowable limit range, and there is no need for unnecessary designs to withstand high output and long cooking times under light loads.

[Brief explanation of the drawing]

1 and 2 are front views showing the keyboard and display section of a typical electronically controlled cooking appliance, respectively, FIG. 3 is a circuit diagram of an embodiment of the present invention, and FIGS. FIG. 2 is a detailed circuit diagram of the main parts of 1...Keyboard, 2...Numeric display section, 11...
Misoperation detector.

Claims (1)

[Claims] 1 Setting means capable of setting arbitrary heating output and arbitrary heating time, mutual tolerance limits are planned between the heating output and heating time, and the heating output and heating time set by the above setting means are set. A detection means is provided for detecting whether the combination of the above is within the allowable limits of the cooking conditions, and based on the output of the detecting means, the heating operation is prohibited or the heating operation is performed within the allowable limits. Electronically controlled cooker.