KR940010287B1 - Automatic dry system of a range - Google Patents

Abstract

The apparatus and method automatically dries the food by use of the damping ratio difference caused by the dielectric ratio difference between the food having moisture and a dried food. The apparatus comprises a microprocessor (22) controlling the overall function; a driving circuit (23) controlled by the microprocessor (22); a magnetron (40) equipped in a wave transmission tube (40) generating heating microwave; a fan (29) and a fan motor (30) exhausting hot steam and inducing outdoor air; a power/signal processing circuit (33) controlling a microwave vibrator (31) and an output stabilizing circuit (32); the microwave vibrator (31) generating the microwave for sensing the drying state; the output stabilizing circuit (32) discharging the microwave toward a heating chamber(24).

Description

Automatic drying device and drying control method of microwave oven

1 is a circuit diagram showing a drying apparatus of a conventional microwave oven.

2 is a circuit diagram showing an automatic drying apparatus of the present invention microwave oven.

3A is a characteristic diagram showing the microwave attenuation rate of a dry matter in a microwave oven. b is a signal characteristic diagram of the reception antenna for each drying time in the microwave oven of the present invention.

4 is a flowchart showing a drying control method of a microcomputer in the microwave oven of the present invention.

* Explanation of symbols for main parts of the drawings

21: control panel 22: microcomputer

23: drive circuit 24: heating chamber

25: building 26: magnetron

27: inlet port 28: outlet port

30: fan motor 31: microwave oscillator

32: output stabilization circuit 33: power supply / signal processing unit

34 transmitting antenna 35 receiving antenna

36: detector 37: amplifier

The present invention relates to an automatic drying apparatus and a control method of a microwave oven, and in particular, by installing a transmitting and receiving antenna on the side of a heating chamber, drying is automatically performed by using a microwave attenuation rate difference resulting from a difference in dielectric constant between moisture and dry matter in the dry matter. It is to be done.

In the conventional microwave drying apparatus, as shown in FIG. 1, a microcomputer 1 for controlling each function of the microwave oven, a driving circuit 2 driven by a control signal of the microcomputer 1, and the driving circuit ( 2) a magnetron 3 for generating microwaves to heat the building 5 in the heating chamber 4, and a suction port 6 for cooling the hot steam and the magnetron 3 generated in the building 5; Fan 8, which is operated by the drive circuit 2, and the fan motor 9, which drives the air so that external air flows into the heating chamber 4 and is discharged to the outlet 7 through the outlet, and the outlet 7 A / D for digitally converting the temperature / humidity sensor 10 for detecting high temperature steam in the heating chamber 4 discharged to the heating chamber and the signal detected by the temperature / humidity sensor 10 to be input to the microcomputer 1. It is composed of a transducer (11).

In the drying apparatus of the conventional microwave oven configured as described above, as shown in FIG. 1, when the user sets a drying time or presses a drying key to heat and dry the dried object 5 in the heating chamber 4 using the microwave oven. The drive circuit 2 is operated by the microcomputer 1 to operate the magnetron 3 attached to the side of the drying chamber 4 so as to heat the object 5 in the drying chamber 4 to generate microwaves.

At this time, while the fan 8 is rotated by the fan motor 9 to dry the object 5 by heating by microwaves, the outside air flows into the heating chamber 4 through the inlet 6 and the magnetron 3 ) Is discharged to the outlet 7 while the hot steam generated in the dry object 5 is cooled.

Therefore, the high temperature steam discharged to the outlet 7 is detected by the temperature / humidity sensor 10 and the corresponding temperature / humidity value is converted into digital through the A / D converter 11 is input to the microcomputer (1) When the signal corresponding to the drying completion is reached, the magnetron 3 and the fan motor 9 are turned off to terminate the drying.

However, in the conventional microwave drying apparatus, it is difficult for a user to set a drying time arbitrarily, and the temperature / humidity sensor 10 detects a high temperature steam to grasp a relatively dry state. There are a lot of changes in the dry state depending on the environment, such as humidity, the reliability is low and there is a problem of less reproducibility because the operation of the temperature / humidity sensor 10 is incorrect when continuously drying.

In order to solve the conventional problems, the present invention is equipped with a transmitting and receiving antenna on the side of the heating chamber so that drying is automatically performed by using a microwave attenuation rate difference resulting from a difference in dielectric constant between moisture and dry matter in the object to be dried. Referring to the configuration and effect of the present invention by the accompanying drawings as follows.

First, the automatic drying apparatus of the microwave oven of the present invention is driven by a microcomputer 22 for controlling each function of the microwave oven by the operation unit 21 and a control signal of the microcomputer 22, as shown in FIG. The magnetron 26 mounted on the waveguide 40 which generates microwaves so that the driven circuit 23 is heated by the driving circuit 23, and the workpiece 25 in the heating chamber 24 is heated. Fan 29 and the fan motor 30 to discharge the hot air into the heating chamber 24 through the suction port 27 so that the hot steam discharge and the magnetron 26 is cooled by By the control signal of the microcomputer 22, the power source / signal processing unit 33 for controlling the microwave oscillator 31 and the output stabilization circuit 32, and the power source / signal processing unit 33 to generate the microwave for drying detection The microwave oscillator 31 and the microwave oscillator 31 In the output stabilization circuit 32 for emitting microwaves to the heating chamber 24 through the transmission antenna 34, the transmission antenna 34 for transmitting microwaves generated by the microwave oscillator 31, and the transmission antenna 34 A reception antenna 35 mounted opposite to a transmission antenna 34 receiving the attenuated microwaves absorbed and attenuated by the emitted microwave dry object 25 and converting the microwaves received through the reception antenna 35 into electrical signals. A detector 36 for amplifying the converted electrical signal and inputting the amplification unit 37 to a power / signal processor 33 for measuring a microwave attenuation rate. It is a motor.

The control method of the automatic drying apparatus of the microwave oven configured as described above includes a rotary table motor 39 for rotating the rotary table 38 on which the object 25 is placed, as shown in FIG. A first process of driving the fan motor 30 to which the magnet 29 and the fan 29 are connected so as to discharge the high temperature steam generated from the object 25 while cooling the magnetron 26; The second process of receiving the microwaves, which are absorbed and attenuated by the receiving antenna 35 after being transmitted to the heating chamber through the transmitting antenna 34 and the drying sensing microwaves generated by the microwave oscillator 31, and receiving the received microwaves, A third step of measuring the microwave attenuation rate by converting it into an electrical signal, and determining whether the drying is completed by the measured microwave attenuation rate, and ending the heating drying once completed. The process is controlled to 4.

As illustrated in FIG. 2, the user puts the object 25 on the rotary table 38 provided in the heating chamber 24, and the drying operation is performed through the operation unit 21. When the key is pressed, the drive circuit 23 is operated by the control signal of the microcomputer 22 to drive the rotary table motor 39 to rotate the rotary table 38.

At the same time, the microwave (frequency; 2.45 GHz, output; 500-1000 W) generated by the magnetron 26 is operated by the driving circuit 23 when the rotary table 38 on which the object 25 is mounted rotates. It is discharged to the heating chamber 24 through and heat-drys the to-be-dried material 25.

At this time, the fan motor 30 is operated together by the driving circuit 23 to cool the magnetron 26, and the outside air through the suction port 27 by the fan 29 rotated by the fan motor 30. It is introduced into the heating chamber 24 to discharge the high-temperature steam generated in the dry object 25 discharge port (28).

On the other hand, the control signal of the microcomputer 22 is input to the power / signal processing unit 33 so that the drying sensing microwave (frequency; 1-30 GHz, output; 1-100 mW) is supplied through the microwave oscillator 31 and the output stabilization circuit 32. The signal processing microwaves are transmitted into the heating chamber 24 through the transmission antenna 34 which is generated and attached to the heating chamber 24 side.

In this way, the microwaves transmitted into the heating chamber 24 are received by the receiving antenna 35 attached to the side of the heating chamber 24 so that the reduced microwaves are absorbed by the object to be dried 25 and face the transmitting antenna 34. And then converted into an electrical signal through the damping circuit 36.

The microwaves converted by the detection circuit 36 are amplified by the amplifier 37 so that the converted electrical signal values are input to the power / signal processing unit 33.

That is, the power supply / signal processing unit 33 and the microcomputer 22 periodically perform signal exchange to measure the microwave attenuation rate. As shown in FIG. Since the attenuation rate is large due to moisture inside, the microwave received by the receiving antenna 35 is converted into a small electrical signal by the detection circuit 36 and inputted. If the dried object 25 is dried as shown in FIG. The attenuation rate decreases due to moisture evaporation in (25), and the microwaves received by the reception antenna 35 are converted into a large electrical signal by the detection circuit 36 and input.

At this time, the microcomputer 22 analyzes the input signal value and controls the driving circuit 23 by a control signal to automatically turn off the rotary table motor 39, the magnetron 26, and the fan motor 30. In this case, on the other hand, the heating can be completed by driving only the fan motor 30 for a predetermined time after the heating is completed to ensure the precision of drying.

That is, as shown in FIG. 4, when the user presses the operation key to dry the object 25, the object 25 is driven by driving the rotary table motor 39, the magnetron 26 and the fan motor 30. ) Is transmitted into the heating chamber 24 through the drying sensing microwave transmission antenna 34 generated by the microwave oscillator 31 and then absorbed and attenuated by the to-be-dried material 25 to the reception antenna 35. Is received.

In this way, the microwave received by the receiving antenna 35 is converted into an electrical signal by the detection circuit 36 to measure the micro attenuation rate, and then the drying is completed by comparing this value with the reference value Vmax of the drying completion determination. The motor 39, the magnetron 26, and the fan motor 30 are turned off to complete drying.

As described above, the present invention is equipped with a transmitting and receiving antenna on the side of the heating chamber of the microwave oven to automatically dry by using the microwave attenuation rate difference resulting from the difference in moisture and dielectric constant in the object to be improved the reliability of the product There is.

Claims (2)

The microcomputer 22 which controls each function of the microwave oven by the operation part 21, the drive circuit 23 driven by the control signal of the said microcomputer 22, and the heating chamber 24 by the drive circuit 23. The magnetron 26 mounted on the waveguide 40 for generating microwaves to heat the to-be-constructed object 25), the high-temperature steam discharged from the to-be-constructed object 25, and the suction port 27 to cool the magnetron 26. The fan 29 and the fan motor 30 for introducing the outside air into the heating chamber 24 through the discharge port 28 to the discharge port 28 and the microwave oscillator (2) by the control signal of the microcomputer 22. 31) and a power supply / signal processing section 33 for controlling the output stabilization circuit 32, a microwave oscillator 31 for generating a drying sensing microwave by the power supply / signal processing section 33, and the microwave oscillator 31 The emitted microwaves are emitted to the heating chamber 24 through the transmission antenna 34. The power stabilization circuit 32, a transmission antenna 34 for transmitting microwaves generated by the microwave oscillator 31, and a transmission for receiving microwaves absorbed and attenuated by the microwave building 25 emitted from the transmission antenna 34. A receiving antenna 35 mounted opposite to the antenna 34, a detector 36 for converting microwaves received through the receiving antenna 35 into electrical signals, and amplified the changed electrical signals to measure microwave attenuation rates. Automatic drying device of the microwave oven comprising an amplifier 37 for inputting to the power / signal processing unit 33. The rotary table motor 39 which rotates the rotary table 38 on which the object 25 is mounted, the magnetron 26 in which microwaves are generated so that the object 25 is heated, and the magnetron 26 is cooled while being cooled. The first process of driving the fan motor 30 is connected to the fan 29 so that the high-temperature steam generated in the dried product 25 is discharged, and the drying sensing microwave generated by the microwave oscillator 31 is heated through the transmission antenna 34. A second process of receiving the microwaves absorbed and attenuated by the object to be dried and then attenuated by the receiving antenna 35, a third process of converting the received microwaves into electrical signals to measure the microwave attenuation rate, and the measured microwave attenuation rate. And a fourth step of determining whether or not the drying is completed and terminating the heating drying if the drying is completed.