KR100265635B1 - Apparatus for detecting door opening for microwave oven - Google Patents

Abstract

PURPOSE: A door opening detection device for a microwave oven is provided to detect the door opening by a microcomputer via a door switch instead of removing any additional door sensing switch, thereby simplifying the circuit arrangement and improving the productivity. CONSTITUTION: A door opening detection device for a microwave oven includes a voltage detection part(11) for detecting a voltage change in response to the turning on or off of door switches(SW10,SW11), and a microcomputer(10) for determining the opening or closing of the door according to the voltage detected from the voltage detection part, wherein the voltage detection part is formed of a plurality of partial pressure resistors(R1,R2) which reduce the voltage applied in response to the switching of the door switches by a partial pressure value for applying the reduced voltage to the microcomputer.

Description

Door open detection device of microwave oven

The present invention relates to a microwave oven, and more particularly to a door open detection device of the microwave oven to detect the open or closed state of the door in the microcomputer through the door switch.

In general, microwaves supply high-pressure power to the magnetron to emit microwaves, and the microwaves are supplied to the cooking chamber to vibrate moisture contained in food. Therefore, the food is cooked by the molecular frictional heat generated by the vibration of the water molecules.

The microwave oven uses a high voltage transformer to boost a commercial AC voltage of 120/230 V to a high voltage power supply, and supplies the same to a magnetron to generate microwaves of high frequency (2450 MHz). In addition, such microwave and high-voltage power supply is dangerous in use, and in particular, in order to prevent the microwave oven from being operated while the door is open, the microwave oven can detect an open state of the door according to safety standards. The function is essential.

Referring to FIG. 1, the circuit configuration of the door open detection device of the conventional microwave oven is that when the door (not shown) of the microwave oven is closed, the first and second door switches SW1 and SW2 are turned on. As the relay RY1 is turned on in the state, the power source AC is applied to various loads such as the lamp L, the fan motor F / M, and the high voltage transformer HVT. Here, the first and second door switches (SW1) (SW2) is always kept off when the door is opened to the lamp (L), fan motor (F / M) and high voltage transformer (HVT). Do not allow power.

In addition, the monitor switch SW3 is turned off when the door is closed and turned on when the door is opened, thereby bypassing the input voltage by configuring an electrical closed loop circuit. Therefore, the safety function is performed together with the first and second door switches SW1 and SW2.

In addition, the high voltage transformer (H.V.T) is provided with a high voltage capacitor (H.V.C) and a high voltage diode (H.V.D) for doubling the input voltage, and a magnetron (MGT) for driving microwaves to generate microwaves. In addition, a microcomputer 3 driven by receiving power from a low voltage transformer LVT of one end of the power source is provided, and the microcomputer 3 controls the operation of the relay driver 4 according to the operation of the key input unit 2. do.

Therefore, the relay driver 4 is operated by the microcomputer 3 to turn the relay RY1 on or off. Accordingly, the input power is supplied or cut off to various loads to control the overall cooking operation of the microwave oven. Here, the microcomputer 3 detects an open or closed state of the microwave oven door through a separate door detection switch SW4 so that the relay RY1 does not operate when the door is opened.

However, the door open detection device of the conventional microwave oven, in addition to performing a safety function through the first and second door switch and the monitor switch, a separate door detection switch for detecting the open or closed state of the door in the microcomputer is provided. There is a problem in that the production cost is increased by the consumption of a large number of parts.

In addition, there is another problem that productivity is lowered due to the complicated circuit configuration.

An object of the present invention is to solve the problems of the prior art as described above, the production cost is reduced by eliminating the separate door detection switch and detecting the open or closed state of the door in the microcomputer through the door switch The present invention provides a door open detection device of a microwave oven, which has been reduced.

Another object of the present invention is to provide a door opening detection apparatus for a microwave oven, in which a circuit configuration is simplified to improve productivity.

1 is a circuit configuration diagram showing a door open detection device of a conventional microwave oven;

2 is a circuit diagram showing a preferred embodiment of the door open detection device of the microwave oven according to the present invention.

Explanation of symbols on the main parts of the drawings

10: microcomputer 11: voltage detector

12: key input unit 13: relay drive unit

SW10: first door switch SW11: second door switch

SW12: Monitor switch RY10: Relay

R1, R2: resistance

The door opening detection device of the microwave oven according to the present invention for achieving the above object is, the electronic to perform the safety function when driving the load through the door switch and the monitor switch that is on / off according to the opening or closing of the door In the range, Voltage detection unit for detecting a voltage change according to the on / off of the door switch; And a microcomputer that determines the open or closed state of the door by inputting the voltage detected by the voltage detector.

Preferably, the voltage detector includes a plurality of voltage divider resistors for reducing the voltage applied according to the switching of the door switch according to the voltage divider value and applying the voltage to the microcomputer.

The apparatus may further include a key input unit which is operated by a user and inputs an operation command to the microcomputer, and a relay driving unit which drives the load by turning on / off the relay by the microcomputer.

Therefore, by eliminating the separate door detection switch and detecting the open or closed state of the door through the door switch to reduce the number of parts required, the production cost is reduced, and the circuit configuration is simplified to improve productivity.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the door opening detection apparatus of the microwave oven according to the present invention.

2 is a circuit diagram showing a preferred embodiment of the door open detection device of the microwave oven according to the present invention.

According to FIG. 2, the first and second door switches SW10 and SW11 are turned on when the door (not shown) of the microwave oven is closed, and always remain off when the door of the microwave oven is opened. Input power (AC) is prevented from being supplied to various loads such as fan motor (F / M) and high voltage transformer (HVT).

The monitor switch SW12 is turned off when the door is closed and turned on when the door is opened to configure the electrical closed loop circuit to bypass the input power source AC. Therefore, the safety function is performed together with the first and second door switches SW10 and SW11.

In addition, according to the same drawing, a high voltage capacitor (HVC) and a high voltage diode (HVD) are provided to double the voltage input to the high voltage transformer (HVT), and the magnetron driving the high voltage generated in this way to generate a microwave ( MGT) is provided. Accordingly, as the relay RY10 is turned on, power is applied to various loads such as the lamp L, the fan motor F / M, and the high voltage transformer H.V.T, and the magnetron MTG is driven.

In addition, according to the same figure, the voltage detection unit 11 is provided with a voltage change according to the switching on / off of the first door switch (SW10), the voltage detection unit 11 is the first and second voltage divider resistance (R1) and (R2) are provided.

The voltage detector 11 has a first voltage divider R1 connected to one end of the first door switch SW10 and a second voltage divider resistor R1 connected to a ground terminal. The connection terminal between R1) and the second voltage dividing resistor R2 is connected to the microcomputer 10.

In addition, in the same figure, a microcomputer 10 for inputting a voltage detected by the voltage detector 11 to determine an open or closed state of the door and controlling the relay RY10 not to operate when the door is opened is provided. do.

The first and second voltage dividing resistors R1 and R2 are output to the microcomputer 10 by reducing the voltage applied according to the switching of the first door switch SW10 according to the voltage dividing value.

Here, the first or second door switch (SW10) (SW11) is configured to be turned off when the door is opened, turned on when the door is closed to apply an input voltage to the voltage detector (11).

In addition, the voltage detector 11 is configured to detect a voltage according to the on / off of the first door switch SW10 according to the present embodiment, but as another embodiment not illustrated in the drawings, the second door switch SW10 is not illustrated. It is also preferable to configure to detect the voltage according to the on / off.

In addition, the microcomputer 10 is driven by receiving power from a low voltage transformer (L.V.T) of one end of the input power source AC, and controls the operation of the relay driver 13 according to the operation of the key input unit 12. Therefore, the relay driver 13 is operated by the microcomputer 10 to control the overall operation of the microwave oven by turning on or off the relay RY10.

Referring to the operation of the present invention configured in this way in more detail as follows.

First, when the door is opened to feed food into the microwave oven, the first and second door switches SW10 and SW11 are turned off, such as a lamp L, a fan motor F / M, and a high voltage transformer HVT. Do not allow input power (AC) to be supplied to various loads of In addition, the monitor switch SW12 is turned on when the door is opened in this way to configure the electrically closed loop circuit to bypass the input power source AC.

At this time, the voltage detector 11 detects a voltage according to the on / off of the first door switch SW10, but when the door is opened as described above, the first door switch SW10 is turned off. , Input voltage is not detected. Since the microcomputer 10 does not have a voltage detected by the voltage detector 11, the microcomputer 10 determines the open state of the door so that the relay RY10 does not operate even if a user operation command is received from the key input unit 12. do.

On the other hand, when the door is closed after food is put into the microwave, the first and second door switches SW10 and SW11 are turned on, such as a lamp L, a fan motor F / M, a high voltage transformer HVT, and the like. Input power (AC) can be supplied to various loads of the. At this time, the voltage detector 11 detects the voltage generated when the first door switch SW10 is turned on through the plurality of first and second voltage divider resistors R1 and R2, and decompresses the voltage. 10).

Therefore, the microcomputer 10 determines the closed state of the door based on the voltage detected from the voltage detector 11. Therefore, when a user's operation command is generated from the key input unit 12, the microcomputer turns on the relay RY10, and accordingly various loads such as the lamp L, the fan motor F / M and the high voltage transformer HVT are applied. Power is applied to allow the overall cooking operation of the microwave.

As described above, according to the door open detection device of the microwave oven according to the present invention, by eliminating a separate door detection switch and detecting the open or closed state of the door through the door switch to reduce the number of parts required to reduce the production cost It is effective to let.

In addition, by removing the separate door detection switch and detecting the open or closed state of the door in the microcomputer through the door switch, there is another effect that the circuit configuration is simplified to improve productivity.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (3)

In the microwave oven to perform a safety function when driving the load through the door switch and the monitor switch that is on / off according to the opening or closing of the door, A voltage detector detecting a voltage change according to on / off of the door switch; And And a microcomputer for inputting the voltage detected by the voltage detector to determine an open or closed state of the door. The apparatus of claim 1, wherein the voltage detector comprises a plurality of voltage divider resistors configured to reduce the voltage applied according to the switching of the door switch according to the divided voltage and apply the divided voltage to the microcomputer. . The apparatus of claim 1, further comprising: a key input unit operated by a user to input an operation command to the microcomputer; And And a relay driving unit configured to turn on / off the relay by the micom to drive a load.

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