KR20000002676U - Microwave power saving circuit - Google Patents

Abstract

The power saving circuit of the microwave oven is started. The present invention has a pair of commercial exchange lines, one end of which is connected to an input side of a commercial AC power supply, a high voltage transformer connected to the other end via a door switch, a monitor switch, and a power relay, and the pair of commercial AC lines. A microwave oven having a main relay connected to turn on / off a lamp, a fan motor and a driving motor together, the microwave oven comprising: a lamp relay and a lamp relay for turning on or off the lamp independently of the fan motor and the driving motor. It includes a microcomputer to control the on / off operation of. Preferably, the microcomputer counts the lighting time of the lamp, and turns off the lamp when the lighting time of the lamp has elapsed over a preset reference time. Therefore, the lamp for illuminating the inside of the cooking chamber can be arbitrarily turned on / off by the user through the lamp relay, and the lamp is automatically turned off when a predetermined time elapses under the control of the microcomputer, thereby preventing unnecessary power consumption.

Description

Microwave power saving circuit

The present invention relates to a power saving circuit of a microwave oven, and more particularly, to enable a user to arbitrarily turn on / off a lamp that illuminates the inside of a cooking chamber of a microwave oven, and to automatically turn off the lamp after a predetermined time. It relates to a power saving circuit of.

In general, a microwave oven is a device for heating / cooking food using microwaves. The microwave oven is composed of a general high voltage transformer and a magnetron. The high voltage transformer generates a predetermined high voltage to drive the magnetron. The magnetron emits microwaves of high frequency (approximately 2450 MHz) in a confined space where food is stored. Microwaves emitted in this way vibrate the water molecules contained in the food, molecular friction heat is generated in accordance with the vibration of the water molecules is to heat / cook food.

1 is a partially exploded perspective view showing a conventional microwave oven, and FIG. 2 is a circuit diagram of FIG. 1.

According to FIG. 1, the cabinet 20 forming the external shape of the microwave oven is divided into left and right spaces, and on one side thereof, a cooking chamber 22 having an open front is provided, and on the other side thereof, a lamp 2, a fan motor 3, and a magnetron are provided. The apparatus room 23 in which various electric appliances, such as (MGT), a high voltage transformer (HVT), and a high voltage capacitor (HVC), is installed is provided. In addition, an operation panel 25 is provided on the front surface of the apparatus chamber 23 to operate the microwave oven and display the state thereof.

In addition, the door 21 that opens and closes the front of the cooking chamber 22 is rotatably fixed to one side of the cabinet 20, and the rotating dish 24 in which food to be cooked is placed in the bottom surface of the cooking chamber 22. ) Is installed, the rotary dish 24 is rotated by a drive motor and gears not shown in the bottom surface of the cabinet 20 during food cooking to increase the cooking efficiency.

2, one end of the first and second commercial AC lines L1 and L2 is connected to the noise filter 1 on the input side to input a normal commercial AC power supply AC 110V or 220V. The ends are connected to both ends of the high voltage transformer (HVT) primary coil. The noise filter 1 includes first and second fuses FUSE1 and FUSE2, and components such as capacitors C1 to C3, inductor L, resistor R1, and the like, and their functions are conventional. Since it is the same as the noise filter, the detailed description thereof is omitted here.

Meanwhile, the first fuse FUSE1 is connected to the first commercial exchange line L1, and the second fuse FUSE2 is connected between the second commercial exchange line L2 and the monitor switch SW2 to be described later. do.

In addition, a first and a second temperature switch (TCO1) (TCO2), a door switch (SW1) and a monitor switch (SW2) are connected in series to the first commercial AC line (L1), the second commercial AC line The power relay RY3 and the inrush relay RY2 are connected in parallel to L2, respectively.

The first and second temperature switches TCO1 and TCO2 block overheating generated in the magnetron MGT and the microwave cabinet 20, respectively, and the door switch SW1 and the monitor switch SW2 are doors (S). In accordance with the open and closed state of the (not shown) to perform a safety function of the microwave oven.

The power relay RY3 applies a commercial AC power supply to the primary coil of the high voltage transformer HVT, and the inrush relay RY2 is a few seconds before the power relay RY3 is turned on. Operation to remove inrush current.

In addition, a magnetron (MGT), a high voltage capacitor (HVC), and a high voltage diode (HVD) for generating microwaves are provided on the secondary coil side of the high voltage transformer (HVT).

In addition, a lamp 2, a fan motor 3, a driving motor 4, and a low voltage transformer LVT are connected between the first commercial AC line L1 and the second commercial AC line L2. In addition, a main relay RY1 for turning on / off the operation of the lamp 2, the fan motor 3, and the driving motor 4 is connected to one end thereof. Here, the other end of the main relay RY1 is connected to the second commercial AC line L2 through the inrush relay RY2 and the power relay RY3.

In addition, a microcomputer 7 driven by power supplied from the low voltage transformer LVT is provided, and the microcomputer 7 is turned on of the main relay RY1, the inrush relay RY2, and the power relay RY3. Control the on / off operation. In addition, a key input unit 5 for inputting a user's command to the microcomputer 7 and a display unit 6 for displaying various operating states of the microwave under the control of the microcomputer 7 are provided. (7), the key input section 5 and the display section 6 are preferably arranged on the operation panel 25 shown in FIG.

Looking at the operation of the conventional microwave oven configured as described above are as follows.

First, the user opens the door 21 and places the food on the top of the rotating dish 24 inside the cooking chamber 22 through the front of the cabinet 20 in the state in which the cooking chamber 22 is opened. At this time, the lamp 2 illuminating the cooking chamber 22 is turned on in the state in which the door 21 is opened as described above, and is turned off when the door 21 is closed.

That is, the microcomputer 7 determines a state in which the door switch SW1 and the monitor switch SW2 are turned off as the door 21 is opened in a state in which the microcomputer 7 is always operated by the voltage supplied through the low voltage transformer LVT. , Turn on the main relay (RY1). Therefore, the current is cut off to the fan motor 3, the driving motor 4, and other circuits behind the door switch SW1, and only the lamp 2 is supplied with the commercial AC voltage to be turned on. On the other hand, when the door 21 is closed, the microcomputer 7 detects the state in which the door switch SW1 and the monitor switch SW2 are turned on, and accordingly turns off the main relay RY1 to cut off the currents of all the loads. Let's do it.

Subsequently, in the state in which the door 21 is closed, the user sets / inputs cooking time and temperature according to the amount and type of food through the key input unit 5 of the operation panel 25, and the microcomputer 7 detects this. The microwave oven is operated by turning on the power relay RY3.

When the operation of the microwave is started as described above, the commercial AC power inputted through the first and second commercial AC lines L1 and L2 is respectively a door switch SW1, a monitor switch SW2, and a high voltage transformer. The high voltage transformer HVT is driven through the primary coil of the HVT and the power relay RY3 to the input side.

Along with this, a commercial AC power is also supplied to the lamp 2, the fan motor 3 and the driving motor 4 so that the lamp 2 illuminates the inside of the cooking chamber 22, and the fan motor 3 is Various circuit components in the electrical equipment room 23 are cooled, and the driving motor 4 rotates the rotary dish 24 inside the cooking chamber 22 so that microwaves are evenly introduced into the food.

In addition, the high-voltage transformer (HVT) supplies a high voltage to the magnetron (MGT) through the secondary coil, the magnetron (MGT) generates a microwave to release the inside of the cooking chamber 22, the food is injected into the desired Heated / cooked to temperature.

However, in the conventional microwave oven, as described above, the lamp for illuminating the inside of the cooking chamber is normally turned on / off in accordance with the opening / closing of the door, and during driving, in conjunction with the fan motor and the driving motor. Since it is set to be always on, when the user opens the door to ventilate or clean the inside of the cooking chamber or when cooking is performed for a long time, there is a problem in that the lamp is always lit and unnecessary power is consumed.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above, and to automatically turn on or off the user of the lamp for illuminating the interior of the cooking chamber of the microwave oven automatically when a predetermined time elapses. It is to provide a power saving circuit of the microwave oven to prevent the unnecessary power consumption by turning off.

1 is an exploded perspective view showing main parts of a conventional microwave oven;

2 is a circuit diagram of FIG.

3 is a circuit diagram showing a preferred embodiment of a microwave power saving circuit according to the present invention.

Explanation of symbols on the main parts of the drawings

2: lamp 3: fan motor

4: driving motor 10: microcomputer

HVT: High voltage transformer L1, L2: Commercial exchange line

SW1: Door switch SW2: Monitor switch

RY1: main relay RY2: power relay

RY10: Lamp Relay

The characteristics of the power saving circuit of the microwave oven according to the present invention for achieving this purpose, one end is connected to the input side of the commercial AC power supply, the high voltage transformer is connected to the other end via the door switch, the monitor switch and the power relay A microwave oven comprising a pair of commercial AC lines and a main relay connected between the pair of commercial AC lines to turn on / off a lamp, a fan motor, and a driving motor, wherein the lamp is connected to the fan motor and the driving motor. And a lamp relay to independently turn on or off the light, and a microcomputer to control an on / off operation of the lamp relay.

In addition, the microcomputer counts the lighting time of the lamp, and preferably turns off the lamp when the lighting time of the lamp has elapsed over a predetermined reference time.

Therefore, the user can arbitrarily turn on / off a lamp illuminating the inside of the cooking chamber through a separate lamp relay, and also prevents unnecessary power consumption by automatically turning off the lamp when a predetermined time elapses under the control of the microcomputer.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the power saving circuit of the microwave oven according to the present invention, the same components as the conventional will be described by applying the same reference numerals.

3 is a circuit diagram showing a preferred embodiment of the microwave power saving circuit according to the present invention.

Accordingly, one end of the first and second commercial AC lines L1 and L2 is connected to the noise filter 1 on the input side to input a normal commercial AC power supply AC 110V or 220V, and the other end thereof. It is connected to both ends of the high voltage transformer (HVT) primary coil. In addition, a first and a second temperature switch (TCO1) (TCO2), a door switch (SW1) and a monitor switch (SW2) are connected in series to the first commercial AC line (L1), the second commercial AC line The power relay RY3 and the inrush relay RY2 are connected in parallel to L2.

In addition, a lamp 2, a fan motor 3, a driving motor 4, and a low voltage transformer LVT are connected between the first commercial AC line L1 and the second commercial AC line L2. In addition, a main relay RY1 for turning on / off the operation of the lamp 2, the fan motor 3, and the driving motor 4 is connected to one end thereof. The other end of the main relay RY1 is connected to the second commercial AC line L2 via an inrush relay RY2 and a power relay RY3, which is similar to the related art.

However, the main feature of the present invention, as shown in one end of the lamp (2) to independently turn on or off with respect to the fan motor 3 and the drive motor (4) The lamp relay RY10 is further provided.

In addition, a microcomputer 10 for controlling the on / off operation of the lamp relay RY10 is provided, and the microcomputer 10 counts the lighting time of the lamp 2 and the lighting time of the lamp 2. When more than this preset reference time has elapsed, the lamp 2 is turned off. The microcomputer 10 is driven by the power supplied from the low voltage transformer LVT, and the lamp relay RY10 and the main relay RY1, the inrush relay RY2, and the power relay RY3 are turned on / off. Control off operation.

In addition, a key input unit 5 for inputting a user's command to the microcomputer 10 and a display unit 6 for displaying various operating states of the microwave under the control of the microcomputer 10 are provided. 10), the key input unit 5 and the display unit 6 are preferably arranged in the operation panel 25 shown in FIG.

Referring to the operation of the preferred embodiment according to the present invention configured as described in more detail as follows.

First, the user can arbitrarily turn on or off the lamp 2 as needed through the key input unit 5 of the operation panel 25. Therefore, when the user opens the door 21 to ventilate or clean the inside of the cooking chamber 22, the lamp off command is issued through the key input unit 5 before opening the door 21 or while the door is opened. Input to the microcomputer 10. The microcomputer 10 turns off the lamp relay RY10 so that the lamp 2 is not turned on even when the door 21 is opened, thereby preventing unnecessary power consumption.

In more detail, in general, the microcomputer 10 normally operates by the voltage supplied through the low voltage transformer LVT, and as the door 21 is opened, the door switch SW1 and the monitor switch SW2 are operated. Determine the off state and turn on the main relay RY1. In addition, the microcomputer 10 turns off the lamp relay RY10 when the lamp is turned off. Therefore, the fan motor 3, the driving motor 4 and other circuits behind the door switch SW1 are cut off by the door switch SW1, and the lamp 2 is turned on by the lamp relay RY10. Is blocked.

On the other hand, if the user wants to illuminate the inside of the cooking chamber 22, the lamp input command to the microcomputer 10 through the key input unit 5 as described above. The microcomputer 10 turns on the lamp relay RY10 to turn on the lamp 2 regardless of the open or closed state of the door 21 to illuminate the inside of the cooking chamber 22. Such lighting or turning off of the lamp 2 has no effect on the operation of other loads, and is performed independently.

In addition, a normal operation process for cooking food put into a microwave oven, that is, the lamp 2 is turned on, the fan motor 3 and the driving motor 4 are operated, and commercial exchange in the high voltage transformer (HVT). The operation of the lamp 2 in the process of outputting the microwave from the magnetron MTG by applying the power AC is as follows.

While the microwave oven is operating as described above, the lamp 2 is turned on in a state in which a lamp extinguishing command is not normally input by the user. As described above, the microcomputer 10 counts the lighting time of the lamp 2 while the lamp 2 is turned on. In the microcomputer 10, a reference time at which the lamp 2 can be turned on is set in advance. Accordingly, when the lighting time of the lamp 2 exceeds the preset reference time, the lamp relay RY10 is turned off to turn off the lamp. By turning off (2), unnecessary power consumption when cooking is performed for a long time is prevented.

The present invention is not limited to the above-described specific preferred embodiment, and any person having ordinary skill in the art to which the present invention pertains may make various modifications without departing from the gist of the present invention claimed in the claims. Of course, such changes are intended to fall within the scope of the claims set forth.

As described above, according to the power saving circuit of the microwave oven according to the present invention, a user can arbitrarily turn on / off a lamp that illuminates the inside of the cooking chamber through a separate lamp relay, and a predetermined time has elapsed under the control of the microcomputer. When the lamp is automatically turned off, unnecessary power consumption is prevented when the user opens the door to ventilate or clean the inside of the cooking chamber or when cooking is performed for a long time.

Claims (2)

One end thereof is connected to an input side of a commercial AC power supply, and is connected between a pair of commercial AC lines having a high voltage transformer connected to the other end via a door switch, a monitor switch, and a power relay, and a pair of commercial AC lines. In a microwave oven having a main relay for turning on and off the fan motor and the drive motor, A lamp relay configured to independently turn on or turn off the lamp with respect to the fan motor and the driving motor; And a microcomputer controlling the on / off operation of the lamp relay. 2. The power saving circuit of a microwave oven according to claim 1, wherein the microcomputer counts the lighting time of the lamp and turns off the lamp when the lighting time of the lamp exceeds a preset reference time.