KR970000576B1 - A container for keeping heat - Google Patents

Abstract

This is about the electronic food warming cabinet to control the temperature of the cabinet by electronic, give a convenience for use, and increase a warming efficiency. The electronic food warming cabinet consists of the electric source supply division(20) for supplying a proper electric source to a computer(10) and an external circuit of computer(10), a driving division(30), the display and switch inlet division(40) contained a numeric display LED(MTX), an electric source LED(L1), an electric source switch(S4), a temperature setting switch(S3), an increase switch(S1), and a decrease switch(S2), the temperature detecting division(50) for putting in the computer by detecting the cabinet temperature through the first temperature detecting element(TH1), an overheat protection division(60), and the computer.

Description

Electronic warmer

1 is a schematic structural diagram of a warmer according to the present invention.

Figure 2 is an embodiment showing the operation panel of the warmer according to the present invention.

3 is a control circuit diagram of a warm storage according to the invention of the ball.

4 is a control flowchart of the warming storage according to the present invention.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: power supply unit

30: load driving unit 40: display and switch input unit

50: temperature detection unit 60: overheat prevention unit

TH1: first temperature sensing element TH2: second temperature sensing element

M: Motor FAN: Blower Fan

100: Warmer 200: Operation panel

MTX: Number display LED L1: Operation LED

L2: Power LED S1: Increment Switch

S2: Reduction switch S3: Temperature setting switch

S4: Power switch H: Heater

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a warmer for maintaining the inside of a refrigerator at a predetermined room temperature. In particular, the present invention relates to an electronic warmer for providing precise temperature management as well as convenience of operation by realizing temperature control in the refrigerator electronically.

In general, a warmer is a device for maintaining warmth of tableware (bowl), and is a thermostat that is essentially used to warm a large amount of rice in a restaurant. In addition, such a warmer is provided with a heater in the interior of the heater to increase the temperature in the interior of the heat of the heater, using a device such as bimetal (Bimetal) so that the heating of the heater is stopped when the temperature in the interior is above a certain temperature The temperature in the refrigerator has been kept at a constant temperature.

However, such a conventional warmer simply stops the heating of the heater when the temperature in the refrigerator reaches a certain temperature or more, and the heat generation stop point of the heater uses bimetal, and the temperature value is fixed to the rated value of the bimetal. There was a limit to the temperature setting inside the room, and the temperature difference between the place where the heater is installed and the place where the heater was installed is far away, so it is difficult to precisely control the temperature. There was a difficult problem.

The present invention has been made in order to solve the above problems, it is possible to freely set the temperature in the temperature storage, and to maintain a high temperature in accordance with the set temperature and to rotate the blower fan during the heating of the heater so that the heat evenly spread in the interior Accordingly, an object of the present invention is to provide an electronic warmer which provides convenience of operation and thermal insulation efficiency by electronically realizing a control such as preventing local warming and preventing overheating of the warmer by providing a safety device.

The present invention for achieving the above object is provided with a power supply unit for supplying proper power to the peripheral circuit of the microcomputer and the microcomputer, and a motor for driving the heater and the blower fan to increase the temperature in the heater and the blower motor It is equipped with a load driving unit for driving the LED, a number display LED, a power LED, a power switch, a temperature setting switch, an increase switch, and a decrease switch to display a current internal temperature, a set temperature, and a key input for setting a temperature. A display and switch input unit for providing the microcomputer, a temperature sensor for sensing the temperature in the refrigerator and inputting the microcomputer through the first temperature sensor installed in the refrigerator, and a second temperature sensor for sensing overheating of the heater. Detects overheating of the heater through the sensor, detects a defective state of the first temperature sensing element and a defective state of the second temperature sensing element, To stop the operation of the heater and to turn on the operation LED during the heater operation, and to turn on the power LED when the power switch key of the display and the switch input is turned on, and at the same time, make the motor of the load driving part become the rated output. An electronic warmer, comprising: a microcomputer configured to sense an internal temperature input through a temperature sensing unit and control a heater of a load driving unit on and off so as to be equal to a set temperature.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

1 is a schematic structural diagram of a warmer 100 according to the present invention, a plurality of shelves 101 on which the object to be kept warm to maintain the warmth, such as rice bowl is provided is provided, the shelf ( The lower portion of the 101 is provided with a heat sink 102 is fixed to the heater (H), the motor (M) for rotating the blowing fan (FAN) is located on the lower surface of the heater (H).

Therefore, the heat emitted from the heater H by the rotation of the blowing fan (FAN) is circulated evenly in the interior of the warming cabinet 100 to perform the warming operation. In addition, the first and second temperature sensing elements TH1 and TH2 are installed in the refrigerator, and the first temperature sensing device TH1 detects the temperature in the refrigerator and is set by a user (eg, 45 to 85 degrees). ℃) and the driving of the heater (H) is turned on and off so that the temperature in the chamber is the same, and the second temperature sensing element (TH2) detects the overheated state of the heater (H) (for example, 120 ℃) when overheating It is comprised so that the drive of the heater H may be interrupted | blocked.

2 is a view illustrating an operation panel 200 attached to a front side of a warmer 100 according to the present invention, and a numeric display LED (light emitting diode) indicating a current temperature or a set temperature set by a user. (MTX), the power switch (S4) for supplying power to the warming cabinet 100, the temperature setting switch (S3) used to set the temperature, and the temperature setting switch (S3) to set the temperature After that, the increase switch S1 increases and sets the temperature by a predetermined temperature (for example, 1.5 ° C.), the decrease switch S2 sets and decreases the temperature by a predetermined temperature (for example, 1.5 ° C.), and the power switch S4. It consists of a power supply LED L1 which is turned on and an operation LED L2 which is turned on only when the heater H is operated.

3 is a control circuit diagram of the warming apparatus 100 according to the present invention. The microcomputer 10 for controlling the overall operation of the heating apparatus 100, the first voltage switching switch SA1, the power transformer TS, and the bridge are shown in FIG. It consists of a diode (BD), smoothing capacitor (C1), regulator (REG) and a capacitor (C2) for supplying a suitable operating power (V1: DC 12V) (V2: DC 5V) to the microcomputer 10 and its peripheral circuit. The power supply unit 20, the first voltage switching switch SA2, the motor M, the second voltage switching switch SB1 and SB2, the heater H, the triac TC, the relay RRY, and the relay It consists of a switch (RYS), a photo die solution (PD), a resistor (R1 ~ R3), a diode (D1) and a capacitor (C3) (C4) by the control of the microcomputer (10) motor (M) and heater (H). Load driving unit 30 for driving the LED display (MTX), increase switch (S1), decrease switch (S2), temperature setting switch (S3), power switch (S4), power LED (L1), transistor (Q1 to Q3), resistors (R4 to R6) (R25), diodes (D2) (D3) and capacitors The display and switch input unit 40 for applying a predetermined key input (power supply and temperature setting) to the microcomputer 10 and displaying a predetermined display according to the present invention. The constant reference voltage divided by the distribution value of (VR1) + resistor (R9) is connected to the non-inverting terminal of the buffer amplifier (IC1), and the output of the amplifier (IC1) is emitter through the resistor (R7). Is connected to the base of the transistor Q4 to which the voltage V2 is applied, and the collector output of the transistor Q4 is connected to be input to the input terminal PI1 of the microcomputer 10 as a temperature reference voltage value and inverted. The terminal is connected to the inverting terminal of the amplifier IC3 grounded through the capacitor C7, and the predetermined reference voltage is divided by the divided value of the resistor R8 and the variable resistor VR1 + resistor R9. The voltage is connected to the non-inverting terminal of the amplifier IC2 where the non-inverting terminal is grounded through the capacitor C5. The constant voltage output through the amplifier IC2 is divided by the resistance (R10) and the self (sensing) resistance + resistance (R12) of the first temperature sensing element TH1 (for example, negative resistance thermistor), and the divided temperature sensing is performed. The voltage is reduced through the resistor R13 and the variable resistor VR20 to be connected to the inverting terminal of the amplifier IC4, and the output voltage of the amplifier IC2 is divided through the resistor R11 and the resistor R15 and divided into this divided voltage. The voltage is connected to the non-inverting terminal of the amplifier IC4 through the resistor R14, and the output of the amplifier IC4 is connected to the non-inverting terminal of the amplifier IC3 so that the output of the amplifier IC3 is Temperature sensing signal is input to the input terminal PI2 of the microcomputer 10 so that the microcomputer 10 recognizes the current internal temperature by comparing the input signals of the two input terminals PI1 and PI2. The contact point between the unit 50 and the first temperature sensing element TH1 of the temperature sensing unit 50 and the resistor R12 is connected to the amplifier IC5. The divided voltage obtained by connecting to the inverting terminal and dividing the voltage V2 into the resistor R19 and the resistor R20 + resistor R21 is connected to the inverting terminal of the amplifier IC6, and the resistor R19 + resistor R20. ) And the voltage divided by the resistor R21 are connected to the inverting terminal of the amplifier IC7, and the voltage divided by the resistor R19 + resistor R20 and the resistor R21 is connected to the front end of the amplifier IC7. The divided voltage obtained by dividing the voltage V2 into the resistor R17 and the sensing resistor of the second temperature sensing element TH2 and the resistor R18 is connected to the non-inverting terminal of the amplifier IC7 and is connected to the amplifier IC6. The output of IC7 is connected to the base of the transistor Q5, and the collector of the transistor Q5 is connected via the resistor R23 to the light emitting device cathode of the photodiode PD of the load driver 30. It is connected to the resistor (R24) and the operation LED (L2) at the same time, the emitter terminal is connected to the output terminal (PO3) of the microcomputer 10, the inverting terminal of the amplifier (IC5) The inverting terminal of the amplifier IC7 is configured such that the output of the amplifier IC5 is connected to the output of the amplifier IC6 and IC7 so that the overheat state and the first and second temperatures of the second temperature sensing element TH2 are established. The present invention consists of an overheat protection unit 60 for detecting a short circuit of the sensing elements TH1 and TH2 and protecting the set.

Reference numerals R16 and R22 are resistors and C6 is a capacitor.

4 is a flowchart illustrating the control of the warmer 100 according to the present invention. When power is applied and the microcomputer 10 is initialized, the microcomputer 10 displays and inputs the key of the power switch S4 of the switch input unit 40. Detecting the presence of a signal; and turning on the power LED L1 at the time of key input of the power switch S4 (401); and reading the value of the input terminal PI2 to read the first temperature sensing element ( Detecting the temperature in the refrigerator through TH1), outputting a temperature display corresponding to the temperature detected in step 402 to the numeric display LED (MTX), and setting the temperature set by the user. Comparing the current internal temperature with a current temperature to determine whether the set temperature is lower than the current temperature (404); and stopping the driving of the heater (H) when the set temperature is lower than the current temperature (405). When the temperature is higher than the present temperature, driving of the heater H (406) and the first temperature sensing element TH1 are performed. Determining whether or not the temperature in the refrigerator through the overheat prevention temperature of 90 ℃ or more (step 407), and in step 407 blocking the operation of the heater (H) when the temperature in the refrigerator is detected above 90 ℃ (408) And detecting the key input of the temperature setting switch S3 (step 409), and when the increase switch S1 is keyed (step 410) during the key input of the temperature setting switch S3, the set temperature in the refrigerator is increased by 1.5 deg. In step 411, when the reduction switch S2 is keyed in step 412, step 413 for decreasing the set temperature in the refrigerator by 1.5 and the temperature set in steps 411 and 413 are displayed. MTX) and detecting the key re-key input of the temperature setting switch S3 after performing step 414 and performing the key re-key input of the temperature setting switch S3 in step 415. Setting the set temperature (416), detecting the re-input of the power switch (S4) (417), and re-key input of the power switch (S4) Turns off the power LED (L1) and controls the step 418 to stop the driving of the heater (H) and the motor (M) in sequence.

The operation of the present invention configured as described above will be described in detail below.

For example, when the first voltage switch (SA1, SA2) and the second voltage switch (SB1, SB2) is switched to the 220V terminal and the power (AC) 220V is applied, the applied power (AC) is a power supply unit ( Step 20 is stepped down by the first voltage switch (SA1) and the power transformer (TS), rectified through the bridge diode (BD) and generates a DC voltage (V1) of about 12V through the smoothing capacitor (C1), regulator 5V DC voltage V2 is generated through the REG and the capacitor C2 and supplied to the microcomputer 10 and the peripheral circuit, and at the same time, the resistor R1 and the motor M of the load driver 30 are provided. The power source AC is applied through the condenser C4 so that the motor M is driven with a reduced pressure output rather than a rated output, so that the blowing fan FAN rotates.

When the power switch S4 of the display and switch input unit 40 is turned on and off while the power input AC is applied, and the key input is input to the microcomputer 10, the microcomputer 10 outputs the output terminal PO1 ( Transistor Q1 and Q2 are turned on by outputting a predetermined signal to PO2, and transistor Q3 is turned on by turning on the transistors Q1 and Q2 so that the collector becomes low potential and the power LED L1 lights up. At the same time, the relay RRY of the load driving unit 30 is excited and the switch contact RYS is turned on so that the rated current is applied to the motor M, and the motor M operates normally. In addition, the first temperature sensing element TH1 of the temperature sensing unit 50 detects the current internal temperature, and the first temperature sensing element TH1 sensing the temperature in the interior has a variable resistance according to temperature. In this case, the potential input to the inverting terminal of the amplifier IC4 is varied by the variable resistor, which is amplified by a difference from the reference potential on the non-inverting terminal of the amplifier IC4, and the output of the amplified amplifier IC4. Is input to the input terminal PI2 of the microcomputer 10 through the amplifier IC3.

Accordingly, the microcomputer 10 recognizes the current high internal temperature in comparison with a predetermined reference voltage value input to the input terminal PI1 through the collector of the transistor Q4. In addition, a predetermined output is performed by the display and the numeric display LED (MTX) of the switch input unit 40 so that the detected temperature in the refrigerator is displayed.

On the other hand, the microcomputer 10 compares the set temperature set by the user using the temperature setting switch (S3), increase and decrease switches (S2) (S3) (for example, 45 ~ 85 ℃) and the current internal temperature. If the internal temperature of the temperature is lower than the set temperature to output a low signal to the output terminal (PO3) to drive the heater (H). Accordingly, since the transistor Q5 is turned on and the collector end thereof becomes low potential, the photo die solution PD of the load driver 30 is turned on, so that a trigger signal is applied to the gate of the triac TC to generate the triac TC. The power is supplied to the heater H by energizing the triac TC, so that the heater H performs a heat generating function. In addition, when the current high temperature exceeds the set temperature, the transistor Q5 is turned off and the collector terminal is turned off by cutting off the output of the low signal to the output terminal PO3 to stop the driving of the heater H. As a result, the photo die solution PD of the load driving unit 30 is turned off and the triac TC is blocked, so that the heater H stops heating.

On the other hand, when the first temperature sensing element TH1 of the temperature sensing unit 30 detects over 90 ° C., which is an overheating temperature in the refrigerator, the microcomputer 10 which detects this as the input terminal PI2 returns to the output terminal PO3. A high signal is output to cut off the driving of the heater H. At this time, the blower fan FAN is continuously driven, thereby easily cooling the chamber to an appropriate temperature.

In addition, when the overheating temperature (eg, 120 ° C.) or more of the heater H is detected through the second temperature sensing device TH2 installed at the heater H part in the refrigerator and detecting the overheating state of the heater H, the overheating occurs. The potential of the non-inverting terminal of the amplifier IC6 of the protection unit 60 is lowered so that the output of the amplifier IC6 is turned low, thereby turning off the transistor Q5 to block driving of the heater H.

In addition, when the first temperature sensing element TH1 or the second temperature sensing element TH2 causes a short circuit fault, first, when the first temperature sensing element TH1 causes a short circuit fault, the overheat protection unit 60 The voltage applied to the non-inverting terminal of the amplifier IC5 of the amplifier is varied, and the amplifier IC5, which normally outputs a high level signal due to the voltage difference with the inverting terminal, outputs a low signal to turn off the transistor Q5. Shut off the drive of the heater (H). In addition, when the second temperature sensing device TH2 causes a short circuit failure, the voltage applied to the non-inverting terminal of the amplifier IC7 of the overheat protection unit 60 is varied, and a high level signal is normally supplied by the voltage difference between the inverting terminal. The output amplifier IC7 outputs a low signal to turn off the transistor Q5 to block driving of the heater H.

On the other hand, when the power switch S4 is rekeyed, the microcomputer 10 cuts off the outputs to the output terminals PO1 and PO2 and the LED for displaying the number MTX, and the power LED L1, operation LED L2, The numeric display LED (MTX) is turned off, the drive of the heater (H) is cut off, and the drive of the motor (M) is made to rotate at a lower speed than the rated state.

As described above, the present invention can arbitrarily set the temperature in the warmer, so that the user can pursue the precision of temperature control, and prevent the local thermal insulation by rotating the blower fan during the heating of the heater so that the heat is spread evenly in the refrigerator. At the same time, it is a novel and useful invention to increase the convenience of operation and thermal insulation efficiency by electronically realizing a control such as preventing overheating of the warmer by providing a safety device.

Claims (1)

The microcomputer 10 and the peripheral circuit of the microcomputer 10 is provided with a power supply unit 20 for supplying appropriate power, and a motor (M) for driving the heater (H) and the blowing fan (FAN) to the temperature inside the Load driving unit 30 for driving the heater (H) and the blowing motor (M) to raise, LED display (MTX), power LED (L1), power switch (S4), temperature setting switch (S3) And an increase switch S1 and a decrease switch S2 to display the current internal temperature, the set temperature, and display and switch input unit 400 for setting the temperature of the key input to the microcomputer 10 to set the temperature. The temperature sensor 50 detects the temperature of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior, and detects overheating of the heater H. The heater H detects overheating through the TH2 and detects a defective state of the first temperature sensing element TH1 and a defective state of the second temperature sensing element TH2. And the overheat prevention unit 60 which stops the operation of the heater H in the case of the overheating and failure, and lights the operation LED 12 during the operation of the heater, and the power switch of the display and switch input unit 40. S4) Turn on the power LED (L1) at the time of key input, and at the same time to make the motor (M) of the load driving section 30 to the rated output, and detect and set the temperature in the chamber input through the temperature sensing unit (50) Electronic warmer, characterized in that composed of a microcomputer 10 for controlling the heater (H) of the load driving unit 30 to be equal to one temperature.