JP2001349553A - High-frequency heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a high-frequency heating apparatus eliminating useless power consumption in nonuse and to exactly know the state of use or nonuse of the apparatus on the occasion. SOLUTION: A control circuit 18 makes a control to set a prescribed timer time on the basis of turning-on of a door switch 16 due to opening of a door, while it starts subtraction of the timer time on the basis of turning-off of the door switch 16 due to closing of the door. When a signal of a key input circuit 23 is not inputted during the subtraction, a relay 17 is turned off on expiration of the timer time so as to stop supply of power to the control circuit 18. When the door is opened after the stop of the supply of power, energization of the control circuit 18 is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device such as a microwave oven controlled by a control circuit having a microcomputer (hereinafter referred to as a microcomputer).

[0002]

2. Description of the Related Art Conventionally, a high-frequency heating device controlled by a control circuit having a microcomputer has been supplied with power to the control circuit even when cooking is not performed (for example, Japanese Utility Model Laid-Open No. 55-1164). )

[0003]

A high-frequency heating device operated by a control circuit provided with a microcomputer can detect a key input or operate a clock even when food is not heated.
Power was always supplied to the control circuit.

[0004] The fact that power is always supplied to the control circuit of the device, which has a very short usage time per day, from the actual use situation, is very wasteful even if the consumed power is small.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a key input circuit for setting operation contents of a heating source for heating food, and a door opening / closing detecting door opening / closing. A control circuit including a detection unit and controlling the operation of the heating source, a power supply circuit serving as a power supply of the control circuit,
A high frequency heating device comprising a door switch interposed between a commercial power supply and a power supply circuit thereof, which is turned on when the door is opened, and turned off when the door is closed. A predetermined timer time is set based on ON, and the timer time is reduced after the door is closed. If no key input signal is input from the key input circuit during that time, the subtraction is terminated. The power supply is stopped, and when the door is opened after the power supply is stopped, the power supply from the power supply circuit is restarted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is constructed as described above, and a control circuit sets a predetermined timer time based on the turning on of a door switch by opening a door, and sets a predetermined timer time after the door is closed. When the timer time decrement is started and the key input signal from the key input circuit is not input during that time, the supply of power to the control circuit is stopped at the end of the subtraction, and after this power supply is stopped, the door is opened. When the power supply circuit is turned on, the power supply circuit restarts the power supply circuit. This determines whether the high-frequency heating device is used or not, and when it is determined that the high-frequency heating device is not used, the power supply to itself is cut off. In this way, the power consumption required when the user keeps functioning is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a control circuit diagram of a microwave oven. 1 is a commercial AC power supply, 2 is a current fuse, and 3 and 4 are main door switches that are turned on / off in response to opening and closing of doors. Reference numeral 5 denotes a door switch which also serves as a monitor switch. The door switch 5 blows the current fuse 2 when a failure occurs in which the main door switches 3 and 4 do not turn off when the door is opened. 6 is an oven lamp for illuminating the heating chamber during cooking, 7 is a table motor for rotating a turntable at the bottom of the heating chamber, 8 is an electric heater of a heating source, a grill heater provided on the ceiling of the heating chamber, and 9 is the same. Is an oven heater provided at the bottom of the heating chamber, 10 is a high frequency generation source composed of a magnetron or the like, and 11 is a fan motor for cooling the high frequency generation source 10. 12, 1
Reference numerals 3 and 14 are relays which are controlled by a control circuit to be described later and connect the electric heaters 8 and 9 and the high frequency generator 10 to a commercial power supply. Reference numeral 15 denotes a relay, which is provided between the commercial power supply 1 and the power load circuit including the oven lamp 6, the table motor 7, the electric heaters 8, 9, the high frequency generation source 10, and the fan motor 11, and is turned on by a control circuit described later.
/ OFF control. Reference numeral 16 denotes a switch that is turned on when the door is opened and turned off when the door is closed, in conjunction with opening and closing of the door. Reference numeral 17 denotes a relay which is connected in parallel with the door switch 16 and serves as power switching means.
N / OFF control is performed. 18 is a control circuit,
Reference numeral 19 denotes a microcomputer which is an information processing device of the control circuit 18. Reference numeral 20 denotes a power supply circuit of the control circuit 18, which is connected to the commercial power supply 1 and generates a DC voltage by the above-described parallel circuit of the door switch 16 and the relay 17. Reference numeral 21 denotes a reset circuit which, when the power supply circuit 20 is connected to the commercial power supply 1 and a DC voltage rises, detects the DC voltage and outputs a reset signal. Reference numeral 22 denotes an Hz signal circuit that detects the frequency of the commercial power supply 1 connected to the power supply circuit 20 and outputs the detection result. Reference numeral 23 denotes a key input circuit for setting operation contents such as selection of a heating source and setting of a heating time. 24 is a quantity sensor circuit for detecting the weight of food, 25 is a finished sensor circuit for detecting the finished temperature of the food, 2
6 is a door switch circuit for detecting the open / closed state of the door, 27
Is the microcomputer 1 in addition to the type of heating source selected by the key input circuit 23, the heating time, and the weight of the detected food.
Reference numeral 28 denotes a display circuit for displaying the calculation result of 9 and a message for the cook, and 28 denotes an output circuit for driving the relays 12, 13, 14, 15 and 17 based on a command from the microcomputer 19.

Next, the operation of the embodiment of the present invention configured as described above will be described.

The contact states of the switches 3, 4, 5, 16 in FIG. 1 are those when the door is closed. When the door is closed, the main door switches 3 and 4 are in the ON state, and the switch 5 contacts the contact point b to connect the load to the commercial power supply 1. Since the door switch 16 is OFF, the supply of power to the control circuit 18 through the door switch 16 is shut off.

Next, when the door is opened, switches 3 and 4
At the same time as the FF, the monitor switch 5 comes into contact with the contact a to disconnect the load from the commercial power supply 1 and the door switch 16 is turned on to supply power to the control circuit 18. When the power is supplied, the power supply circuit 20 generates a DC power supply necessary for the operation of the control circuit 18. Further, when the reset circuit 21 detects the rise of the DC power supply of the power supply circuit 20 and outputs a reset signal to the microcomputer 19,
The program of the microcomputer 19 is initialized.

The operation of the microcomputer 19 after initialization will be described with reference to the general flow of FIG.

This general flow is determined by the ON / OFF state of the relay 17.
Only the control related to the OFF control is shown. When the door is first opened to put food into the heating chamber, the door switch 16 is turned on, and power is supplied to the power supply circuit 20 of the control circuit 18. Then, the reset circuit 21 detects the rise of the power supply of the power supply circuit 20 and outputs a reset signal, so that the program of the microcomputer 19 is initialized. The microcomputer 19 uses the frequency signal input from the Hz signal circuit 22 as a reference signal for time management and the like. Next, the microcomputer 19 turns on the relay 17 and sets a fixed timer time. Then, after the door is closed, the timer time subtraction is started, and if no key input signal from the key input circuit 23 or a door opening / closing signal from the door switch circuit 26 is input during that time, when the remaining time becomes zero, The relay 17 is turned off.

If a signal is input from the key input circuit 23 or the door switch circuit 26 before the remaining time becomes zero, the timer time is reset and the relay 17
N is extended. The time value of this timer is set to a length long enough for the cook to set a cooking menu from the key input circuit 23 while watching the display circuit 27 or to confirm on the display circuit that cooking is completed. Needless to say.

When the cooker starts the heating after the cook puts the food into the heating chamber and closes the door and sets the heating function through the key input circuit 23, the microcomputer 19 moves from the standby state (timer subtraction state). It becomes a cooking state. After the cooking is completed, the microcomputer 19 resets the timer and starts the subtraction. Note that when the door is opened and closed according to the cooking program, it is not determined that the microwave oven has not been used even if the door is opened and then closed again. The relay circuit 17 is turned off only when there is no door opening or closing or key input within a predetermined timer time after the control
8 is cut off.

When the door is opened after the relay 17 is turned off, the power supply to the control circuit 18 is resumed.

In addition, in the case where the clock display is always required,
It goes without saying that the relay 17 can be always turned on continuously by the key input setting.

[0018]

As described above, according to the present invention, the control circuit sets a predetermined timer time based on the turning on of the door switch when the door is opened, and starts subtracting the timer time after the door is closed. When the key input signal from the key input circuit is not input to the control circuit, the supply of power to the control circuit is stopped at the end of the subtraction, and when the door is opened after the supply of power is stopped, the power supply from the power supply circuit is turned off. Since it is restarted, it is possible to provide a high-frequency heating device that does not consume useless electric power by preventing the control circuit from being energized when it is not used as a cooker. In addition, by controlling the operation related to the opening and closing operation of the door, it is possible to accurately grasp the use / non-use state of the high-frequency heating device and perform accurate energy saving control.

When the door is opened, the power supply to the control circuit is resumed, so that a new power switch or the like is not required, and the cook can cook with the same convenience as before.

[Brief description of the drawings]

FIG. 1 is a control circuit diagram of one embodiment of the present invention.

FIG. 2 is a general flow chart of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply 8 Electric heater 9 Electric heater 10 Magnetron 16 Door switch 17 Relay 18 Control circuit 19 Microcomputer 20 Power circuit 21 Reset circuit 23 Key input circuit 26 Door switch circuit

Claims (1)

[Claims] A key input circuit for setting an operation content of a heating source for heating food; a control circuit for controlling an operation of the heating source including a door opening / closing detecting means for detecting opening / closing of a door;
A power supply circuit serving as a power supply for the control circuit, and a power supply circuit interposed between a commercial power supply and the power supply circuit, which are turned on when the door is opened,
In a high-frequency heating device comprising a door switch that is turned OFF when closed, the control circuit sets a predetermined timer time based on ON of the door switch when the door is opened, and sets a timer time after the door is closed. If the key input signal from the key input circuit is not input during that time, the power supply from the power supply circuit is stopped, and after the power supply is stopped, when the door is opened, the power supply circuit A high-frequency heating device wherein power supply is restarted.