KR20000027336A - Cooler for microwave oven - Google Patents

Abstract

PURPOSE: A cooler for a microwave oven is provided to increase the cooling efficiency by improving the ventilating power through a DC fan motor. CONSTITUTION: A cooler is performed by: reducing AC power by forming a tap to a primary coil(7a) of a HVT(high voltage transformer); converting the AC power into DC power through a bridge-type rectifier of a rectifier(120); and feeding the stable power to a fan motor(100). The fan motor is for DC power to increase the rotational frequency in proportion to the fed voltage. Therefore, the cooler increases the cooling efficiency by improving the ventilating power through the increased rotational frequency of the fan motor.

Description

Microwave Chiller

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling apparatus for a microwave oven, and more particularly, to a microwave cooling apparatus for cooling various components installed in an apparatus chamber of a microwave oven using a fan motor.

In general, a microwave oven is a device for heating / cooking food using microwaves, and a conventional high voltage transformer and a magnetron are provided. This high voltage transformer generates a predetermined high voltage to drive the magnetron, and the magnetron emits microwaves of a predetermined frequency (about 2450 MHz) in an enclosed space in which food is stored. The emitted microwave vibrates the water molecules contained in the food, and heats and cooks the food by generating molecular friction heat according to the vibration of the water molecules.

1 is a partially cutaway perspective view showing such a conventional microwave oven. According to this, the main body 20 of the microwave oven is divided into left and right spaces, and the cooking chamber 22 having an open front is provided at one side, and the lamp 2, the fan motor 3, the magnetron (MGT), and the high voltage transformer at the other side. An apparatus chamber 23 in which various components such as an HVT and a high pressure capacitor HVC are installed is provided. An operation panel 25 for operating a microwave oven and displaying the state thereof is coupled to the front of the apparatus room 23, and the top and side surfaces of the main body 20 are wrapped with a cover 29. The operation panel 25 is provided with a timer knob 26 and the output adjustment knob 27 to be operated by the user. In addition, a door 21 for opening and closing the front of the cooking chamber 22 is rotatably fixed to one side of the main body 20, and a rotating plate 24 is installed in the cooking chamber 22 to place food to be cooked. The rotary plate 24 is rotated by a drive motor (not shown) on the bottom of the main body 20 to increase cooking efficiency.

FIG. 2 is a detailed circuit diagram of FIG. 1, in which the first and second alternating lines L1 and L2 for inputting a normal AC power source (110V AC or 220V) are connected to the high voltage transformer HVT through the noise filter 1. ) Are connected to both ends of the primary coil 7a. The noise filter 1 is composed of a main fuse FUSE1, capacitors C1 to C3, a coil inductor L, a resistor R1, and the like, and the operation of the noise filter is the same as that of a conventional noise filter. The detailed description will be omitted. The magnetron temperature switch TCO1, the first door switch SW1 and the monitor switch SW4 are connected to the first alternating line L1, and the main body temperature switch TCO2 and the timer switch are connected to the second alternating line L2. SW3), second door switch SW2 and inrush switch 6b are connected. The magnetron temperature switch TCO1 and the main body temperature switch TCO2 block overheating generated in the magnetron MTG and the main body 20 of the microwave oven, respectively. The first and second door switches SW1 and SW2 and the monitor switch SW4 are turned on / off according to the opening / closing state of the door 21 to perform a safety function of the microwave oven. One side of the monitor switch SW4 is connected to the primary coil 7a of the high voltage transformer HVT, and the other side thereof is connected to the second door switch SW2 via the monitor fuse FUSE2. In addition, the inrush coil 6a is connected to the monitor switch SW4 in parallel to turn on / off the inrush switch 6b. The current limiting resistor R2 is connected in parallel to the inrush switch 6b. As the current limiting resistor R2, a normal cement resistor is used. The inrush switch 6b and the current limiting resistor R2 are operated by the inrush coil 6a when the initial power is turned on, and the inrush is caused by the high counter electromotive force generated in the primary coil 7a of the high voltage transformer HVT. Remove the current.

In addition, the cooking chamber lamp 2, the fan motor 3, the driving motor 4, and the timer 5 are connected between the first alternating line L1 and the second alternating line L2. The timer switch SW3 is turned on by the user's operation of the timer knob 26. The timer switch SW3 is turned on by the user of the cooking chamber lamp 2, the fan motor 3, the driving motor 4, the timer 5, and the high voltage transformer HVT. An AC power source AC is applied to the car coil 7a. The lamp 2 illuminates the inside of the cooking chamber 22, and the fan motor 3 blows wind to cool various components of the apparatus chamber 23. The drive motor 4 rotates the rotating plate shown in Fig. 1, and the timer 5 counts the set time to automatically turn off the timer switch SW3.

A high voltage transformer (HVT) is a device that receives AC power from one circuit and supplies power to another circuit by electromagnetic induction, and normally inputs a commercial AC voltage and boosts the voltage to a high voltage to output it. Therefore, the high voltage transformer HVT inputs a commercial AC voltage through the primary coil 7a and boosts it to a high voltage of about 2000V through the secondary coil 7b. In addition, a magnetron (MGT), a high pressure fuse (H.V.FUSE), a high pressure capacitor (HVC), and a high voltage diode (HVD) are connected to the secondary coil 7b of the high voltage transformer HVT. The high voltage diode HVD and the high voltage capacitor HVC double the high voltage to about 4000V and supply the same to the magnetron MGT. On the other hand, the magnetron (MGT) is preheated by the voltage supplied through the filament coil 8, and then driven by a voltage of about 4000V supplied from the high voltage diode (HVD) and the high voltage capacitor (HVC) to emit a predetermined microwave do. Therefore, the food is heated / cooked by the microwaves emitted from the magnetron (MGT). The high voltage fuse (H.V.FUSE) cuts off the overcurrent on the side of the high voltage transformer (HVT) secondary coil 7b.

However, such a conventional microwave oven uses a fan motor driven by an AC power supply of about 24V to cool components such as magnetron, high voltage transformer, and high voltage capacitor which generate a lot of heat. As used, it is impossible for this AC fan motor to exceed the maximum rotation speed of about 3000 rpm. Therefore, the cooling efficiency is lowered due to the limitation of the blowing force, and there is a problem in that manufacturing cost is increased by adding respective cooling functions to components such as magnetron and high voltage transformer.

Therefore, the present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to provide a cooling apparatus of a microwave oven by further increasing the cooling efficiency by increasing the blowing force by applying a fan motor for DC. have.

1 is a partially cutaway perspective view showing a conventional microwave oven,

2 is a detailed circuit diagram of FIG. 1;

3 is a detailed circuit diagram showing a cooling apparatus of a microwave oven according to the present invention.

Explanation of symbols on the main parts of the drawings

7a: high voltage transformer primary coil 100: fan motor

110: smoothing means 120: rectification means

HVT: High voltage transformer BD: Bridge rectifier circuit

D: Diode C: Capacitor

Features of the microwave oven cooling apparatus according to the present invention for achieving this object, the rectifying means for converting the AC power reduced in the primary coil of the high-voltage transformer into a DC power source, and the DC power converted by the rectifying means It includes a smoothing means for smoothing and a fan motor driven by a DC power smoothed by the smoothing means.

The rectifying means is preferably a bridge rectifying circuit composed of a plurality of diodes.

The smoothing means is composed of a diode connected in series to one end of the fan motor and a condenser connected in parallel to both ends of the fan motor.

Therefore, by applying a fan motor driven by a DC power source, the blowing force is increased to further increase the cooling efficiency, reducing the cooling function added to the components such as magnetron and high-voltage transformer can reduce the manufacturing cost.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the cooling apparatus of the microwave oven according to the present invention, the same components as in the prior art will be described by applying the same reference numerals.

3 is a detailed circuit diagram showing a cooling apparatus of a microwave oven according to the present invention. Here, the microwave oven of the present invention is a magnetron temperature switch TCO1, a first door switch SW1, a monitor switch SW4, a main body temperature switch TCO2, a timer switch SW3, a second door switch SW2, and An inrush switch 6b is provided, one side of the monitor switch SW4 is connected to the primary coil 7a of the high voltage transformer HVT, and the other side thereof is connected to the second door switch SW2 via the monitor fuse FUSE2. Is connected to. In addition, the cooking chamber lamp 2, the driving motor 4, and the timer 5 are connected between the first alternating line L1 and the second alternating line L2. The high voltage transformer HVT inputs a commercial AC voltage through the primary coil 7a, and boosts it to a high voltage of about 2000V through the secondary coil 7b. In addition, a magnetron (MGT), a high pressure fuse (H.V.FUSE), a high pressure capacitor (HVC), and a high voltage diode (HVD) are connected to the secondary coil 7b of the high voltage transformer HVT. The high voltage diode HVD and the high voltage capacitor HVC double the high voltage to about 4000V and supply the same to the magnetron MGT. On the other hand, the magnetron (MGT) is preheated by the voltage supplied through the filament coil 8, and then driven by a voltage of about 4000V supplied from the high voltage diode (HVD) and the high voltage capacitor (HVC) to emit a predetermined microwave do. Therefore, the food is heated / cooked by the microwaves emitted from the magnetron (MGT). The high voltage fuse (H.V.FUSE) cuts off the overcurrent on the side of the high voltage transformer (HVT) secondary coil 7b.

The configuration as described above is the same as the prior art, but the main feature of the present invention is to eliminate the AC motor fan motor 3 in the prior art and rectifying means 120, smoothing means 110 and fan motor 100 for DC power ). The rectifying means 120 converts the AC power reduced in the primary coil 7a of the high voltage transformer (HVT) into a DC power, and the smoothing means 110 smoothes the DC power converted by the rectifying means 120. The fan motor 100 is driven by a DC power smoothed by the smoothing means 110. Here, the rectifying means 120 is preferably a bridge rectifying circuit (BD) consisting of a plurality of diodes. The smoothing means 110 is composed of a diode (D10) connected in series to one end of the fan motor 100 and a capacitor (C10) connected in parallel to both ends of the fan motor (100).

Therefore, according to the cooling apparatus of the microwave oven according to the present invention, by forming a tab on the primary coil (7a) of the high-voltage transformer (HVT) to reduce the AC power source, this AC power source is bridge rectification of the rectifying means 120 It is converted into DC power while passing through the circuit BD. After the smoothing means 110 is smoothed with a stable power supply is supplied to the fan motor 100. The fan motor 100 is a fan motor for a direct current power source, and can increase the rotation speed in proportion to the applied voltage. Therefore, since the rotation speed of the fan motor 100 is increased according to the predetermined voltage value of the DC power supply, the blowing force is increased to further increase the cooling efficiency, and is added to components such as magnetron (MGT) and high voltage transformer (HVT). Reduced cooling function can reduce manufacturing cost.

As described above, according to the microwave cooling apparatus according to the present invention, by applying a fan motor driven by a DC power supply, the blowing force is increased to further increase the cooling efficiency, and added to parts such as magnetron and high voltage transformer. It is effective to reduce manufacturing cost by reducing cooling function.

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 are intended to fall within the scope of the claims set forth.

Claims (3)

Rectifying means for converting the AC power reduced in the primary coil of the high voltage transformer into DC power; Smoothing means for smoothing the DC power converted by the rectifying means; And And a fan motor driven by a direct current power source smoothed by the smoothing means. The method of claim 1, wherein the rectifying means Cooling apparatus for a microwave oven, characterized in that the bridge rectifier circuit composed of a plurality of diodes. The method of claim 1, wherein the smoothing means A diode connected in series to one end of the fan motor; And Cooling apparatus of the microwave oven, characterized in that consisting of a condenser connected in parallel to both ends of the fan motor.