KR19980019384U - Non-rated breaker of microwave oven - Google Patents

Abstract

The present invention relates to a non-rated cut-off device of the microwave oven, and more particularly to a non-rated cut-off device of the microwave oven which stops the operation of the microwave by generating a warning sound when ± 10% or more of the rated voltage during the microwave operation. It is about.

Therefore, the structure of the present invention is a voltage sensing unit for comparing the voltage input and the voltage output at the secondary side of the low voltage transformer (LVT) for reducing the applied voltage, the voltage input voltage applied to the commercial power source and the voltage reduction The microcomputer includes a microcomputer for determining a signal applied by the voltage sensing unit, a power cutoff unit for cutting off the applied voltage as an output signal of the microcomputer, and a buzzer that emits an alarm sound simultaneously with the operation of the power cutoff unit.

The microwave non-rated cut-off device configured as described above can obtain stable microwaves in the magnetron by controlling excessive non-rated voltage applied to the microwave. In addition, as a result of this, by cutting off the power applied to the microwave oven at excessive non-rated voltage, it prevents food from burning or undercooking during cooking, thereby providing cooking reliability and preventing the microwave power device from being destroyed. And, when the microwave stops operating, it has a function to alert the user, thereby increasing the reliability of the microwave.

Description

Non-rated breaker of microwave oven.

The present invention relates to a non-rated cut-off device of the microwave oven, and more particularly to a non-rated cut-off device of the microwave oven which stops the operation of the microwave by generating a warning sound when ± 10% or more of the rated voltage during the microwave operation. It is about.

The microwave oven applies high voltage electricity to the ultra-high frequency oscillator tube called magnetron to generate 2,450M㎐ of ultra-high frequency, changing the direction of the electric field 2.45 billion times a second, causing the molecules of food to rotate and causing a lot of frictional heat. To cook food.

The blocking device for the applied power of the microwave oven is an overcurrent breaker, which is a fuse, and when a current of a predetermined current or more flows, it is melted to control the overcurrent applied to the microwave oven. However, the present invention relates to a blocking device for controlling a voltage having a close relationship with cooking.

1 is a circuit diagram illustrating a general microwave oven, and includes a noise filter 10, a low voltage transformer 20, a motor driving unit 30, and a high voltage transformer HVT HIGH VOLTAGE TRANSFORMER (FIG. 40), the magnetron (MAGETRON) 50 and the like.

The noise filter 10 is positioned immediately after the commercial power of the input and is intended to minimize noise generated inside the microwave from leaking to the distribution line and affecting other devices. The plurality of capacitors C and the resistor 11 And a choke coil (CHOKE COIL) 12.

The low voltage transformer 20 is provided at the rear end of the noise filter 10, and supplies power to the power element by applying power to the primary side and outputting the power reduced by a few volts from the secondary side. The lamp 21 for showing the inside of the stove is connected.

The motor driving unit 30 is provided at the rear end of the low pressure transformer 20 and for driving the motor 31 and the raising and lowering of the turntable to drive the turntable to rotate the position of the food so as to cook food evenly when cooking. The motor 32 and the fan motor 33 for forcibly sucking the outside air to cool the magnetron 50 and blow it into the microwave cooking chamber to discharge the smell of the cooking chamber out.

The high voltage transformer 40 is provided immediately after the motor driving part 30 and the high voltage diode 41 is connected to the secondary side to supply the DC power required for the magnetron 50 operation.

The magnetron 50 is connected to the secondary side of the high voltage transformer 40, and is a kind of electron tube that receives DC from the high voltage transformer 40 to oscillate microwave at 2,450 MHz to cook food.

In the microwave oven configured as described above, the high voltage transformer supplies power to the magnetron by boosting the voltage applied to the primary side on the secondary side. In the high voltage transformer, if the voltage supplied to the primary coil is e1, the number of turns n1, and the voltage to supply to the secondary coil is e2 and the number of turns is n2, the following equation is established between them.

e1 / e2 = n1 / n2

Therefore, since the turn ratio of n1 and n2 is constant, when the voltage applied to the primary side of the transistor fluctuates, the voltage generated by boosting on the secondary side of the transistor fluctuates. That is, the magnitude of the voltage applied to the magnetron is changed, which affects the oscillation of microwaves in the magnetron. The microwave oven operates at voltages other than the rated voltage. For example, if the voltage applied to the primary side of the high-voltage transformer is higher than the rated voltage, the microwave oven generates excessive microwaves at the secondary side due to excessive boosting. In addition, when the voltage applied to the primary side is lower than the rated voltage, by the above formula, the insufficient voltage at the secondary side causes excessive microwaves in the magnetron, which causes food to become less cooked when cooked. In addition, when developing a general microwave oven, it is developed based on ± 10% of the rated voltage (220V, 60Hz in Korea). When the voltage exceeds + 10%, there is a problem that a considerable crowd occurs in the power device.

The technical problem of the present invention is characterized in that when the voltage applied to the microwave is higher or lower than the rated voltage negatively affects the results of cooking, it automatically detects work to emit an alarm sound and cut off the applied power.

1 is a circuit diagram of a microwave oven showing a general internal connection,

Figure 2 is a control block diagram of the microwave non-rated blocking device according to the present invention.

Explanation of Signs of Major Parts of Drawings *

10: Noise filter 20: Low voltage transformer (L.V.T.)

30: motor drive part 40: high voltage transformer (H.V.T.)

50: magnetron

The structure of the present invention is a voltage sensing unit comparing the rated voltage and the applied voltage, an alarm that emits an alarm when the comparison value of the voltage sensing unit is higher or lower than the approved voltage, the power cut off at the same time as the operation of the alarm It is made of wealth.

The present invention will be described in detail with reference to the accompanying drawings as follows.

2 is a block diagram showing the configuration of a non-rated blocking device according to the present invention. The power input unit 100 to which commercial power is applied, the voltage sensing unit 200 for comparing the voltage output at the secondary voltage of the low voltage transformer LVT for reducing the applied voltage and the low voltage transformer with the value at the rated voltage decompression, Simultaneously with the operation of the microcomputer 300 to determine the signal applied from the voltage sensing unit 200, the power cut-off unit 400 and the power cut-off unit 400 to block the applied voltage by the output signal of the microcomputer 300. It consists of a buzzer 500 to emit.

In Korea, the power input value is a voltage supplied from an electric service provider. In general, 220V and 60Hz are standard voltages, and voltages to be maintained within 12V and 0.2Hz up and down. However, there is a case where the power input value exceeds ± 10% of the rated voltage due to the external voltage drop.

Therefore, when such an excessive non-rated voltage is applied to the microwave oven, the low voltage transformer 20 reduces the voltage applied to the primary side from the secondary side to several volts and applies it to the voltage sensing unit 200.

The voltage sensing unit 200 receives the voltage reduced in the low voltage transformer 20 and outputs an abnormal signal to the microcomputer 300 when the rated voltage is ± 10% or more higher than the voltage at the reduced pressure.

The microcomputer 300 receives the abnormal signal from the voltage sensing unit 200 and controls the power cutoff unit 400.

The power cut-off unit 400 receives the output signal of the microcomputer, switches the switch to cut off the power applied to the microwave oven, and closes the switching contact to the buzzer 500.

In this way, by controlling the excessive specific voltage applied to the microwave oven, it is possible to obtain a stable microwave in the magnetron. In addition, as a result of this, by cutting off the power applied to the microwave oven at excessive non-rated voltage, it prevents food from burning or undercooking during cooking, thereby providing cooking reliability and preventing the microwave power device from being destroyed. And when the microwave stops operating, it has a function to alert the user to increase the reliability of the microwave.

The present invention relates to a non-rated cut-off device of the microwave oven, by controlling the excessive non-rated voltage applied to the microwave can obtain a stable microwave in the magnetron. In addition, as a result of this, by cutting off the power applied to the microwave oven at excessive non-rated voltage, it prevents food from burning or undercooking during cooking, thereby providing cooking reliability and preventing the microwave power device from being destroyed. And, when the microwave stops operating, it has a function to alert the user, thereby increasing the reliability of the microwave.

Claims (3)

In a microwave oven equipped with a transformer and a magnetron for generating microwaves in response to a boosted power supply of the transformer, a pressure reducer for reducing the applied voltage when the applied voltage is excessively rated voltage so as to affect cooking. And a voltage detecting unit for receiving an output and comparing the voltage with a predetermined voltage value, and a power cut-off unit for switching the excessive non-rated voltage applied as a result of the voltage detecting unit. 2. The microwave non-rated breaker according to claim 1, wherein the excessive rated voltage is ± 10% or more of the rated voltage. The microwave non-rated cut-off device according to claim 1, further comprising an alarm means for switching off the power cut-off part.