KR100265621B1 - Apparatus for detecting door open of 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 monitor 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, in which a safety function for load driving is carried out by a monitor switch inversely operating to first and second door switches to be turned on or off by door opening, includes a voltage detection part(11) for detecting a voltage in response to turning on or off of the monitor switch(SW12), and a microcomputer(10) for determining whether the door is opened or not according to the voltage detection result, wherein the voltage detection part is a partial pressure circuit.

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 monitor 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, by reducing the number of parts required by eliminating the separate door detection switch and detecting the open or closed state of the door in the microcomputer through the monitor 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 safety at the time of load driving through the monitor switch inverted operation with the first and second door switch on / off by opening and closing the door A microwave oven for performing a function, the microwave oven comprising: a voltage detector for detecting a voltage according to on / off of the monitor switch; And a microcomputer that determines the open / closed state of the door according to the result detected by the voltage detector.

The voltage detector is a voltage divider circuit.

Therefore, by eliminating the separate door detection switch and detecting the open / closed state of the door through the monitor switch, the number of parts required reduces the production cost, 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 device 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, 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 a magnetron (MGT) is generated to be driven at a high voltage generated to generate microwaves. . 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, a voltage detector 11 detecting a voltage according to on / off of the monitor switch SW12 and a voltage detected from the voltage detector 11 are input to determine an open or closed state of the door, and the door is closed. When opened, the microcomputer 10 for preventing the relay RY10 from operating is provided. The low voltage detector 11 reduces the voltage input through the plurality of resistors R1 and R2 so as to be applied to the microcomputer 10. 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. Accordingly, by operating the relay driver 13 by the microcomputer 10, the relay RY10 is turned on or off to control the overall operation of the microwave oven.

The monitor switch S12 is preferably configured to be turned on when the door is opened to bypass the input voltage and to be turned off when the door is closed to apply the input voltage to the voltage detector 11.

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 so that the lamp L, the fan motor F / M and the high pressure transformer HVT, etc. 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, thereby constituting an electrically closed circuit to bypass the input power source AC.

At this time, the voltage detector 11 detects the voltage according to the on / off of the monitor switch SW12, but the input voltage is not detected when the door is opened as described above. Therefore, the microcomputer 10 determines that the door is opened because there is no voltage detected by the voltage detector 11 so that the relay RY10 does not operate even if a user's operation command is received from the key input unit 12.

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 and a high voltage transformer HVT. Input power (AC) can be supplied to various loads of the. In addition, the monitor switch SW12 is turned off. At this time, the voltage detector 11 detects a voltage generated when the monitor switch SW12 is turned off through a plurality of resistors R1 and R2 and decompresses the microcomputer. Is applied to (10).

Therefore, the microcomputer 10 determines the closed state of the door based on the voltage detected by 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, the load is applied to various loads such as the lamp L, the fan motor F / M and the high voltage transformer HVT. 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 the separate door detection switch and detecting the open or closed state of the door in the microcomputer through the monitor 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 monitor switch, 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 (2)

In the microwave oven to perform a safety function when driving the load through the first and second door switch that is on / off by the opening and closing of the door and the monitor switch inverted operation, A voltage detector detecting a voltage according to the on / off of the monitor switch; And And a microcomputer for determining the open / closed state of the door according to a result detected by the voltage detector. The door open detection device of a microwave oven according to claim 1, wherein said voltage detector is a voltage divider circuit.

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