KR19980039672A - Electric thermostat rice cooker with variable duty rate and its method - Google Patents

Abstract

A power supply unit 10 for supplying power, a key input unit 20 for a user to input a command, a temperature sensing unit 30 for detecting a temperature of rice and converting it into an electrical signal and outputting the same; Control means 40 for outputting the heater driving signal by varying the duty according to the average value of the pulse on time during the previous two reference intervals while sensing the temperature of the rice using the temperature sensor when the command is input from the input unit, The heater driving unit 60 is configured to generate heat by driving the heater according to the heater driving signal input from the control means. When the bob's temperature is lower than the warming set temperature, the driving duty ratio of the heater is considered in consideration of the previous heater driving time. After setting, the heater is driven accordingly to reduce the change in the keeping temperature to a minimum, thereby minimizing discoloration and odor of rice. It provides electrical insulation cooker having a variable function control apparatus and method.

Description

Electric thermostat rice cooker with variable duty rate and its method

The present invention relates to an electric thermal cooker control device having a duty rate variable function and a method thereof, and more specifically, to set the driving duty ratio of the heater in consideration of the previous heater operating time when the temperature of the rice is lower than the heat setting temperature. The present invention relates to an electric warm rice cooker control device having a duty rate variable function capable of minimizing discoloration and odor of rice by minimizing the change of the temperature by minimizing the change in the heat keeping temperature accordingly.

As a kind of home appliances to relieve the housewife's work, the spread of electric insulation rice cooker to cook and keep warm is a common situation.

As a technology related to the control device of the electric insulation rice cooker, "Electric Insulation Rice Cooker" of the Republic of Korea Utility Model Registration Application No. 89-8739 (Date: December 5, 1989 AD), and Publication No. 91 -Insulation electric rice cooker of -4322 (announcement date: June 29, 1991) has been disclosed.

However, the conventional electric warm rice cooker control device including the "electric warm rice cooker" and "heat insulation combined electric rice cooker" to control the temperature of the rice without considering the latent heat of the heater in the process of warming the rice after cooking is finished. Because of the long periods of heat in the state that the moisture of the rice disappears, the change in temperature is increased, the rice is yellowed discoloration (sulphurization phenomenon) and the rest becomes difficult to eat, or in severe cases there is a problem that you have to discard the rice.

An object of the present invention is to solve the conventional problems as described above, in the case that the temperature of the rice is lower than the heat set temperature, after setting the drive duty ratio of the heater in consideration of the previous heater driving time by driving the heater accordingly The present invention provides an electric warm rice cooker control device having a duty rate variable function capable of minimizing discoloration and odor of rice by minimizing the change in the keeping temperature to a minimum, and a method thereof.

1 is a block diagram of an electric heat cooker control device having a duty rate variable function according to an embodiment of the present invention.

2 is a flowchart illustrating an operation of a method of controlling an electric rice cooker having a duty rate variable function according to an embodiment of the present invention.

3 is a waveform diagram illustrating a method of controlling an electric thermal cooker having a duty rate variable function according to an embodiment of the present invention.

Explanation of symbols for main parts of the drawings

10: power supply unit 20: key input unit

30: temperature sensing unit 40: microcontroller

50: display unit 60: heater driving unit

As a means for achieving the above object, the first configuration of the present invention, the power supply unit for supplying power, the key input unit for the user to input a command, after sensing the temperature of the bob and converts it to an electrical signal When the command is input from the output temperature sensing unit and the key input unit, the temperature sensing unit senses the temperature of the rice, calculates an average value of the pulse-on time during the previous two reference intervals, and changes the duty accordingly. Control means for outputting a heater drive signal, and a heater drive unit for generating heat by driving the heater in accordance with the heater drive signal input from the control means.

As a means for achieving the above object, the second configuration of the present invention, the thermal insulation cooker control method, the operation is started when the power is applied to initialize all the memory variables, and the temperature is maintained for the first reference time Driving the heater at a reference duty rate when the temperature falls below the set temperature; driving the heater at the reference duty rate when the temperature falls below the heat storage setting temperature during the second reference time; and the previous two reference times. Obtaining the average value by calculating the cumulative pulse on time in each section, determining whether the cumulative pulse on time in all sections is greater than the cumulative pulse on time in all sections, and the cumulative pulse on time in all sections Setting the duty ratio by increasing the duty rate when the cumulative pulse on time is not greater than the cumulative pulse on time. When the pulse on time is greater than the duty cycle is reduced and set, and the heater is driven for the next reference time according to the set duty ratio.

As a means for achieving the above object, the third configuration of the present invention includes command means for starting operation when the power is applied and initializing all the memory variables, and when the temperature is lowered below the heat insulating preset temperature for the first reference time. Command means for driving the heater at a reference duty rate, a command means for driving the heater at a reference duty rate when the temperature falls below the warming set temperature during the second reference time, and cumulative pulses in the previous two reference time intervals. Command means for determining the average value by calculating the on-time respectively, command means for determining whether the cumulative pulse-on time in all sections is greater than the cumulative pulse-on time in all sections, and the cumulative pulse-on time in all sections The command means for increasing the duty ratio when the pulse on time is not greater than the pulse on time, and the cumulative pulse on time between all lamps And instruction means for setting reduces the cumulative duty factor is greater than the pulse on-time, set in accordance with the duty factor in the command comprises a means for driving the heater in the next reference time.

Hereinafter, the most preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

1 is a block diagram of an electric heat cooker control device having a duty rate variable function according to an embodiment of the present invention.

As shown in FIG. 1, the configuration of the electric thermal cooker control device having a duty rate variable function according to an embodiment of the present invention includes a power supply unit 10 for supplying power, a key input unit 20 for inputting a command, and A temperature controller 30 for sensing the temperature of the rice, a microcontroller 40 having an input terminal connected to an output terminal of the power supply unit 10, the key input unit 20, and the temperature sensing unit 30, and It consists of a display unit 50 and a heater driving unit 60 having an input terminal connected to an output terminal of the microcontroller 40.

The microcontroller 40 uses a built-in analog to digital converter and a memory therein.

2 is an operation flowchart of a method of controlling an electric rice cooker having a duty rate variable function according to an embodiment of the present invention.

As shown in FIG. 2, the configuration of the electric heating cooker control method having the duty rate variable function according to the embodiment of the present invention includes a step of starting operation when power is applied (S10) and initializing all memory variables (S20). ) And driving the heater at a reference duty rate when the temperature falls below the warming set temperature during the first reference time (S30), and when the temperature falls below the warming set temperature during the second reference time. Driving the furnace heater (S40), obtaining cumulative pulse on-times in the previous two reference time intervals, and obtaining an average value (S50); Determining whether it is greater than the on time (S60), and setting and increasing the duty ratio when the cumulative pulse on time in all sections is not greater than the cumulative pulse on time in all sections (S70), and When the cumulative pulse on time is greater than the cumulative pulse on time in all sections, the duty cycle is reduced and set (S80), and the heater is driven for the next reference time according to the set duty ratio (S90).

By the above-described configuration, the operation of the electric thermal cooker control device having a duty rate variable function and the method according to the embodiment of the present invention are as follows.

After the power is applied from the power supply unit 10 and the ON command signal is input from the key input unit 20 by the user, the operation shown in FIG. 2 is programmed and stored in the internal memory of the microcontroller 40. Since the procedure is executed by the microcontroller 40, the operation of the electric thermal cooker control device having a duty rate variable function according to an embodiment of the present invention is started (S10).

When the operation starts, the microcontroller 40 detects the internal temperature of the cooker by reading a signal input from the temperature sensor 30 after initializing all memory variables (S20).

Next, as shown in FIG. 3, the microcontroller 40 outputs a control signal to the heater driver 60 when the temperature rises above the heat setting temperature during the first reference time period Z0. When the heater is turned off and the temperature is lowered below the preset temperature, the heater is generated by generating a pulse signal having a reference duty ratio (S30).

Next, the microcontroller 40 outputs a control signal to the heater driving unit 60 when the temperature rises above the heat setting temperature as shown in FIG. 3 even during the second reference time period Z1. When the heater is turned off and the temperature is lowered below the preset temperature, the heater is generated by generating a pulse signal having a reference duty ratio (S40).

Before the next reference time interval Z2 starts, the microcontroller 40 obtains the cumulative pulse on-times of the two previous reference time intervals Z0 and Z1, respectively, and obtains an average thereof (S50).

Next, the microcontroller 40 determines whether the cumulative pulse-on time in the immediately preceding section Z1 is greater than the cumulative pulse-on time in the previous electric zone Z0 (S60).

When the cumulative pulse on time in all the zones Z1 is not greater than the cumulative pulse on time in the all zones Z0, the microcontroller 40 determines that the temperature is falling and increases the duty ratio to increase the pulse on time. (S70)

The duty rate is experimentally determined according to the average value of the pulse on time, and is mapped and stored in the memory.

On the other hand, when the cumulative pulse on time in all the sections Z1 is greater than the cumulative pulse on time in the entire section Z0, the microcontroller 40 determines that the temperature is rising and decreases the duty ratio so that the pulse on time is increased. It is set to become small (S80).

Next, the microcontroller 40 drives the heater by outputting a control signal to the heater driving unit 60 during the next reference time period Z3 so that the heater may be pulsed and operated according to the set duty ratio (S90).

Of course, even during the above process, the heater is turned off unconditionally when the temperature exceeds the set temperature to keep warm.

As such, when the temperature is lower than the heat setting temperature, if the temperature is controlled for each reference section and the duty rate is changed accordingly to control the heater, the temperature quickly maintains the heat setting temperature and at the same time the temperature change becomes small, thereby discoloring the rice. Rest can be minimized. At this time, the control process is displayed to the outside through the display unit 50.

Claims (5)

A power input unit for supplying power, a key input unit for a user to input a command, a temperature sensing unit for detecting a temperature of Bob and converting the electric signal into an electrical signal, and outputting the electric signal if the command is input from the key input unit. Control means for outputting a heater drive signal by calculating the average value of the pulse on time during the previous two reference intervals while sensing the temperature of the rice by using a temperature sensing unit, and outputs a heater drive signal, Electric heating rice cooker control device having a duty rate variable function characterized in that it comprises a heater driving unit for generating heat by driving the heater in accordance with the heater driving signal. The electric warm rice cooker control device having a duty rate variable function according to claim 1, further comprising a display unit for displaying a control process to the outside. The electric warm rice cooker control device according to claim 1 or 2, wherein the control means comprises a microcontroller having an analog / digital converter and a memory therein. The operation is started when the power is applied to initialize all the memory variables, and when the temperature falls below the warm-up set temperature during the first reference time, driving the heater at the reference duty rate, and the temperature during the second reference time. Driving the heater at the reference duty rate when the temperature falls below the set temperature, calculating the average value by calculating the cumulative pulse on-times in the two previous reference time intervals, and accumulating the pulse-on time in all the periods. Determining whether the cumulative pulse on time is greater than the cumulative pulse on time, and setting the duty ratio by increasing the duty ratio when the cumulative pulse on time is not greater than the cumulative pulse on time in all the sections; If the on time is greater than the cumulative pulse on time in all sections, the step of reducing and setting the duty rate, and the following criteria according to the set duty rate Electrical Insulating cooker control method having a function of changing duty factor comprising the step of driving the heater while the liver. Command means for starting operation when the power is applied to initialize all the memory variables, command means for driving the heater at a reference duty rate when the temperature falls below the warm-up set temperature for the first reference time, and for the second reference time. Command means for driving the heater at a reference duty rate when the temperature falls below the preset thermal insulation temperature; command means for obtaining the average value by calculating cumulative pulse on-times in the two previous reference time intervals; Command means for determining whether the on-time is greater than the cumulative pulse-on time in all the sections, and command means for increasing and setting the duty ratio when the cumulative pulse-on time in all the sections is not greater than the cumulative pulse-on time in all the sections; When the cumulative pulse on time in all sections is greater than the cumulative pulse on time in all sections, the duty ratio is reduced. And command means for driving the heater for the next reference time in accordance with the set duty rate.