KR950014028B1 - Electronic range - Google Patents

Abstract

The microwave oven load temperature sensing method comprises an initial heating step of performing an initial heating until the load temperature reaches a fermentation temperature; a temperature maintaining step of heating for a predetermined on time if the load temperature remains at the fermentation temperature, reducing the predetermined on time if the load temperature is over the fermentation temperature and increasing the predetermined on time if the load temperature is below the fermentation temperature to maintain a constant fermentation temperature; and fermentation completing step of detecting the fermentation completion time after the temperature maintaining step and if it is completed, stopping the driving of a magnetron to complete the fermentation function.

Description

Load temperature detection method and device of microwave oven

1 is a configuration diagram of a yogurt production system of a conventional microwave oven.

2 is a schematic view showing a yogurt manufacturing process according to FIG.

3 is a graph of temperature control of the load according to FIG.

4 is a waveform diagram of the magnetron control voltage according to FIG. 1, a is a magnetron control voltage waveform diagram in an initial heating stage, and b is a magnetron control voltage waveform diagram in a temperature holding stage.

5 is a view showing a change state of the power supply voltage when driving the magnetron of FIG.

6 is a view showing the temperature change state of the intake port during the magnetron continuous drive of FIG.

7 is a signal flow diagram illustrating the operation of FIG.

8 is a configuration diagram of a load temperature sensing system of the present invention microwave oven.

9 is a view showing the position of the load temperature sensing means of FIG.

10 is a configuration diagram showing in detail the load temperature detecting means of FIG.

11 is a view of the output change of the infrared sensor according to the load temperature of FIG.

12 is a signal flow diagram for the operation description of FIG.

* Explanation of symbols for main parts of the drawings

1: micom 2: first relay

3: second relay 4: third relay

8 magnetron 9 load temperature sensing means

The present invention relates to the yogurt fermentation temperature control in a microwave oven, and in particular, the yogurt fermentation function is controlled by controlling the temperature of the load to an optimal temperature at which lactic acid bacteria are well fermented, regardless of the load capacity and the change in the power supply voltage or the ambient temperature. A method and apparatus for detecting load temperature of a microwave oven to be improved.

The conventional yogurt production system of a microwave oven, as shown in Figure 1 attached, a microcomputer (1) for controlling the overall operation of the microwave system according to the cooking start key or yogurt fermentation key input, and the microcomputer (1) A first relay 2 which separates and drives only the turntable 5 according to a control signal of the second signal, a second relay 3 and a third relay 4 which are switched according to a control signal of the microcomputer 1, and A magnetron 8 which drives according to the switching of the third relay 4 to generate electromagnetic waves in the heating chamber, and a high lamp 6 which illuminates the heating chamber by turning on and off the switching of the second relay 3; The fan motor 7 cools the magnetron 8 by sucking external air according to the switching of the second relay 3.

As such, in the conventional microwave yogurt production system configured, the lactic acid bacteria fermentation should be maintained at 37 ° to 40 ° C or 42 ° to 45 ° C, although it depends on the type of fermentation bacteria.

Therefore, when the yogurt fermentation function key is input from the key input means for fermentation of the lactic acid bacteria, the microcomputer (1) is initially loosened like tofu when the load (milk + yogurt + jam) is shaken during fermentation of the lactic acid bacteria. Since the fermentation does not occur, the rotation of the turntable 5 is stopped through the first relay 2 and the magnetron 8 is driven through the third relay 4 so as not to shake the load.

As shown in FIG. 5 after turning on the magnetron 8, when a predetermined time TA has elapsed, the power supply voltage is read as a digital value through an analog / digital conversion means (not shown) to search for a state of the power supply voltage. Done.

In other words, when the power supply voltage is unstable, the power supply voltage fluctuates like the fifth degree when the magnetron 8 is driven. In this case, the predetermined time TA is in the range of 0 seconds < TA seconds < TB seconds. Magnetron on time at initial heating.)

Subsequently, the on time t1 and the off time t2 of the magnetron 8 are determined according to the searched power voltage value, and initial heating is performed.

At this time, in the initial heating, as shown in FIG. 3, since the load temperature (T1) of the refrigerated storage is low, it should be heated to a temperature (T2) where fermentation is well performed. At this time, the on time (t1) and the off time of the magnetron (8) t2) heats the load through the magnetron 8 with an on / off period three times larger than the usual on / off period (22 seconds), as in a of FIG. This is because lactic acid bacteria can adapt well to temperature changes.

In the above, the off time t2 of the magnetron 8 is about four times the on time t1.

As such, when the on / off time t1 (t2) of the magnetron 8 is determined, the magnetron 8 is periodically turned on / off until the temperature T2 at which the load temperature is well fermented through the third relay 4 is determined. In addition, the load is initially heated for a predetermined time, and the fan motor 7 is turned on through the second relay 3.

After the initial heating is completed before the completion of the fermentation function is performed to check whether a certain time (tc) has elapsed, if the predetermined time (tc) has not elapsed, repeat the above process, if the predetermined time (tc) e The ambient temperature is converted into a digital signal and searched using the intake sensor installed in the intake port of the range.

The temperature maintaining step is performed by determining the on time t3 and the off time t4 of the magnetron 8 with reference to the searched ambient temperature.

That is, the reason for searching for the predetermined time (tc) is because, as shown in FIG. 6, when the microwave oven is continuously operated (when performing another cooking function before yogurt fermentation), the initial intake air temperature is high. This is because if the fan motor 7 is continuously driven, the fan motor 7 has a characteristic of converging to the ambient temperature after a predetermined time.

And when the initial heating is completed in the above, that is, when heated to the temperature (T2) well with the fermentation, the on time (t3) and off time (t4) of the magnetron (8) determined in order to continue to maintain the temperature (T2) The temperature is kept constant by repeating the fermentation completion time.

The on time t3 and the off time t4 of the magnetron 8 in the temperature holding step are on / off about three times the usual on / off cycle (22 seconds), as shown in FIG. With the off period, the off time t4 of the magnetron 8 is 15 to 20 times the on time t3 to repeatedly heat the load.

After the fermentation is completed, the second and third relays 3 and 4 are turned off to stop the driving of the fan motor 7 and the magnetron 8 to complete the fermentation function.

However, the yogurt manufacturing system of the conventional microwave oven is controlled by a simple initial heating and temperature holding step without a device for sensing the temperature of the load, so that the yogurt without flavor can be produced when the initial temperature of the load is high. In addition, yogurt ripening capacity is limited.

In other words, the milk currently on the market has a problem that the capacity varies from 200㏄ to 1000 소비자 when the consumer wants to ferment the yogurt load instead of the fixed dose.

Accordingly, an object of the present invention is to improve the yogurt fermentation function by continuously controlling the temperature of the load to an optimum temperature at which lactic acid bacteria are well fermented regardless of the load capacity and power voltage fluctuations or the ambient temperature change while continuously detecting the temperature of the load. The present invention provides a method and apparatus for detecting load temperature of a microwave oven.

The method for achieving the object of the present invention is to determine the on / off time of the magnetron according to the initial temperature of the load to perform the initial heating process until the temperature of the load reaches the fermentation temperature, and the load of the When the temperature reaches the fermentation temperature, the temperature maintenance process for maintaining the fermentation temperature is constant by varying the preset magnetron on / off time, and after completion of the fermentation completion time after the temperature maintenance process to stop the operation of the magnetron to complete It is achieved by the fermentation process.

Another object of the present invention is the load temperature sensing means for detecting the infrared radiation emitted from the load in the heating chamber as a temperature change at regular intervals, and the temperature of the magnetron at an appropriate fermentation temperature according to the temperature change state of the load obtained from the load temperature sensing means. It is achieved by the microcomputer to vary the on / off period, and will be described in detail below with reference to the accompanying drawings of the present invention.

8 is a configuration diagram of a load temperature sensing system of a microwave oven according to the present invention, and FIG. 9 is a view showing the installation position of the load temperature sensing means. As shown in FIG. (11) load temperature sensing means (9) for detecting infrared rays emitted from the temperature at regular intervals, and ambient temperature sensing means (13) for detecting a change in ambient temperature for output value compensation of the load temperature sensing means (9); And the microcomputer controlling the overall operation of the system by variably determining an on / off cycle of an appropriate fermentation temperature according to the ambient temperature obtained from the ambient temperature sensing means 13 and the load temperature sensing means 9 and the temperature change state of the load. (1), a first relay (2) for driving only the turntable (5) by the control signal of the microcomputer (1), and a second relay (3) switched according to the control signal of the microcomputer (1) With the third relay (4) The magnetron 8 generates electromagnetic waves into the heating chamber 10 by driving according to the switching of the third relay 4, and the heating chamber 10 is turned off by switching on the switching of the second relay 3. It consists of a high internal lamp 6 to illuminate and a fan motor 7 that cools the magnetron 8 by sucking external air according to the switching of the second relay 3.

In the above, the load temperature detecting means 9 is opened and closed by the control signal of the microcomputer 1 to block and pass the infrared ray 12 emitted from the load 11 in the heating chamber 10 at a predetermined cycle. And an infrared sensor 9b that detects and outputs an infrared signal 12b through the lens 9b that concentrates and emits infrared rays that are incident at predetermined intervals according to opening and closing of the chopper 9a. 9c) and the ambient temperature change for compensating the output values of the amplifier 9d and the infrared sensor 9c, which amplify an electric signal corresponding to the infrared light from the infrared sensor 9c to an arbitrary level and input it to the microcomputer 1. It consists of an ambient temperature sensor 9e that detects and inputs it to the microcomputer 1.

Thus, the operation and effect of the present invention configured as described in detail with reference to FIGS. 3 to 12 as follows.

First, when the yogurt fermentation function key from the key input means is input for the fermentation of the lactic acid bacteria, the microcomputer 1 controls the load temperature sensing means 9 at a constant period so that the amplifier 9d of the load temperature sensing means 9 and The infrared sensor 9c senses the initial temperature of the load 11 placed in the heating chamber 10 and the ambient temperature through the ambient temperature sensor 9e.

That is, the load temperature detecting means 9 is opened and closed as shown in a of FIG. 11 by a predetermined period generated from the microcomputer 1, and radiated from the load 11 of the heating chamber 10. The infrared rays incident on the lens 9b are blocked and passed at regular intervals.

The infrared rays 12 emitted from the load 11 as the chopper 9a is opened and closed are input to the infrared sensor 9c through the lens 9b.

The infrared sensor 9c converts the infrared ray 12 incident upon opening and closing of the chopper 9a into an electrical signal identical to the period of opening and closing, as shown in FIG. 11 (b), and inputs it to the amplifier 9d.

That is, as in b of FIG. 11, as the temperature of the load 11 is higher, the output voltage amplitude A of the infrared sensor 9c becomes larger, and as the temperature of the load 11 is lower, the output voltage amplitude B ) Becomes low.

The amplifier 9d of the load temperature sensing means 9 amplifies the electric signal with respect to the temperature from the infrared sensor 9c to a predetermined level and inputs it to the microcomputer 1.

The microcomputer 1 detects the initial temperature of the load 11 by converting the magnitude of the amplitude input from the amplifier 9d and the ambient temperature of the ambient temperature sensor 9e into a digital signal.

After that, the on time t1 and the off time t2 of the magnetron 8 are determined to perform initial heating.

At this time, in the initial heating, as shown in FIG. 3, since the load temperature (T1) of the refrigerated storage is low, it should be heated to a temperature (T2) where fermentation is well performed. At this time, the on time (t1) and the off time of the magnetron (8) t2) heats the load through the magnetron 8 with an on / off period three times larger than the usual on / off period (22 seconds), as in a of FIG. This is because lactic acid bacteria can adapt well to temperature changes.

The on time t1 of the magnetron 8 is set to a maximum value of about 1/4 times the off time t2, and the on time T1 is determined according to the initial temperature of the load 11 detected above. Determine.

In this way, when the on / off time t1 (t2) of the magnetron 8 is determined, the magnetron (3) is reached through the third relay 4 until the temperature of the load 11 reaches a temperature T2 where fermentation is well achieved. 8) periodically turns on / off the load 11 while performing initial heating for a predetermined time and continuously detects the temperature of the load 11 from the load temperature sensing means 9.

After that, when the temperature of the load 11 detected from the load temperature sensing means 9 reaches a temperature T2 well fermented, the initial heating is stopped, and the temperature maintaining step is performed to maintain the temperature T2. The load 11 is heated.

As for the heating method in the temperature holding step, as shown in b of FIG. 4, the on time t3 and the off time t4 of the magnetron 8 are about three times the usual on / off cycle (22 seconds), In the initial heating step, the load 11 is loaded through the magnetron 8 with the off time t4 of the magnetron 8 fixed and the on time t3 being about 1/10 of the off time t4 as the maximum time. While heating, the load temperature sensing means 9 senses the temperature of the load 11.

If the detected temperature of the load 11 does not deviate from the fermentation temperature T2, the load 11 is heated at the on time t3 of the magnetron 8 determined above, and the temperature of the load 11 is the fermentation temperature T2. If the temperature of the load 11 is lower than the fermentation temperature T2, the temperature of the load 11 is decreased by decreasing the on time t3 of the magnetron 8 determined above. The load 11 is heated by increasing the on time t3 of 8).

After the fermentation completion time elapses, the fermentation function is completed by stopping the driving of the magnetron 8 through the third relay 4.

As described in detail above, the present invention controls the output of the magnetron while sensing the temperature of the load, so that the output of the magnetron decreases or rises due to the change in load capacity, small and power voltages, and changes in ambient temperature. By controlling the temperature of the load to the optimum temperature well fermentation, yogurt fermentation function is improved.

Claims (2)

When the on time (t1) of the magnetron sets a maximum value of about 1/4 of the off time (t2) and determines the on time (t1) according to the initial temperature of the load, the temperature of the load reaches the fermentation temperature. The initial heating process to perform the initial heating until the magnetron on time (t3) is about 1/10 of the off time (t4) to the maximum time, when the load temperature maintains the fermentation temperature is heated to a predetermined temperature time (t3) If the temperature of the load is more than the fermentation temperature, the predetermined on time (t3) is reduced, and if the temperature below the predetermined on time (t3) by increasing the heating, maintaining the temperature of the fermentation temperature constant, and after the temperature maintenance process The method of detecting load temperature of a microwave oven, characterized in that the fermentation completion process of completing the fermentation function by stopping the driving of the magnetron when the fermentation completion time is searched for is completed. The chopper 9a opens and closes by the control signal of the microcomputer 1 to block and pass the infrared rays emitted from the load in the heating chamber at a predetermined cycle, and the infrared rays incident at regular intervals according to the opening and closing of the chopper 9a are concentrated. The lens 9b to emit light, the infrared sensor 9c for detecting and outputting infrared rays through the lens 9b, and the electrical signal corresponding to the infrared light from the infrared sensor 9c to an arbitrary level. The amplifier 9d is amplified and input to the microcomputer 1, and the main temperature sensor 9e which detects a change in the ambient temperature with respect to the output value compensation of the infrared sensor 9c and inputs it to the microcomputer 1 is heated. Load temperature sensing means for detecting infrared rays emitted from the load as the temperature change for each passion cycle, and the on / off cycle of the magnetron is varied according to the temperature change state of the load obtained from the load temperature sensing means. And a microcomputer (1) for controlling the driving of the magnetron to be heated to an appropriate fermentation temperature.