KR19980022860A - Microwave Heater Safety Control Circuit - Google Patents

Abstract

The present invention relates to a microwave heater safety control circuit, and more particularly to a microwave safety control circuit for preventing the heater from malfunctioning when the door is opened.

The configuration of the present invention is a heater operation unit for performing a grill function, a noise filter (NOISE FILTER) for removing the harmonics of the power applied to the microwave oven, by applying power to the primary side to supply the power reduced by a few volts from the secondary side Low voltage transformer (LVT LOW VOLTAGE TRANSFORMER) that supplies power to the power devices, and outputs the lamp to show the inside of the microwave when cooking, and rotates the food position to cook food evenly during cooking. A motor for driving the turntable, a motor for driving the turntable, and a fan motor that functions to suck the outside air to cool the magnetron and blow it into the microwave cooking chamber to discharge the smell of the cooking chamber outside. HVT HIGH VOLTAGE TRANSFORMER AND HIGH VOLTAGE DIode It is composed of a power supply, a kind of electron tube is supplied with a direct current from the high-voltage transformer to generate a microwave of 2,450MHz microwave to cook the food (MAGETRON).

Therefore, according to the configuration of the present invention, even if the heater relay is not correctly turned off due to the malfunction of the microcomputer, the power applied to the heater in the main relay can be controlled secondarily, even if the heater is touched when the food is opened and taken out during the microwave operation. It is effective to prevent accidents caused by heaters.

Description

Microwave Heater Safety Control Circuit

The present invention relates to a microwave heater safety control circuit, and more particularly to a microwave safety control circuit for preventing the heater from malfunctioning when the door is opened.

In general, microwave ovens alternately generate high-frequency of 2,450MHz to rearrange the aligned food molecules, so that friction occurs between molecules in the rearrangement process, and heat is generated. In addition, an electric heater was installed inside the microwave to add a grill oven function.

Figure 1 shows a front view of a typical microwave oven, showing that the heater 1 is installed on the inner ceiling of the microwave oven.

FIG. 2 is a circuit diagram showing a connection of a conventional grill oven type microwave heater, and is roughly configured as follows.

Heater operation unit 10 to perform the grill function, noise filter (NOISE FILTER) 20 to remove the harmonics of the power applied to the microwave oven, the power supply to the primary side by applying a power source to the pressure reduced by a few volts Low voltage transformer (LVT LOW VOLTAGE TRANSFORMER) that outputs power to the power device, and lamp (2) to show the inside of the microwave when cooking by connecting to the secondary side of low voltage transformer, and to cook food evenly to cook. The motor 3 for driving the turntable to rotate the position, the motor 4 for driving the turntable, and the outside air by forcibly sucking the outside air to cool the magnetron 6 and blowing it into the microwave cooking chamber to smell the smell of the cooking chamber. HVT HIGH VOLTAGE TRANSFORMER and high voltage diodes to supply DC power required for fan motor (5), magnetron (6) operation The power supply unit 30 is composed of a magnetron (MAGETRON) (6) for cooking food by oscillating a microwave of 2,450MHz by receiving a direct current from a high-voltage transformer as a kind of electron tube.

In the microwave oven configured as described above, when the grill function is selected, the microcomputer energizes the heater 12 by applying power to the heater relay 11 to turn on the heater relay 11. Therefore, the heater 12 performs a function of rapidly baking food in direct heat. In addition, when the door of the microwave oven is opened, when cooking is completed, when the grill TCO (THERMAL CUT OUT) 13 is operated due to overheating of the grill heater, the heater 12 is cut off by applying power to the heater 12. ) Is stopped. However, in the above case, the power of the heater is not cut off due to the malfunction of the microcomputer. In particular, when such a phenomenon occurs when the oven door is opened and food is put out while the microwave oven is operating, the heater is not contacted without protective equipment. If you do, you may be burned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave heater safety control circuit, and a technical problem is to enable a microwave heater safety control circuit to dually control heater driving by controlling power applied to a heater in a main relay.

1 is a front view showing the inside of a typical microwave oven,

2 is a schematic circuit diagram of a conventional microwave oven,

3 is a schematic circuit diagram of a microwave oven according to the present invention;

Therefore, in order to complete the above technical task is configured as follows. The heater control unit to perform the grill function is connected in parallel to the power line, and the grill TCO (THERMAL CUT OUT), the heater, the heater relay, and the main relay are provided in series. A noise filter for removing harmonics of the power supply is connected, and the power supply through the noise filter is applied to the low voltage transformer, and outputs the reduced power on the secondary side, and supplies it to the power device. In addition, there is provided a motor for driving the turntable for rotating the position of the food to cook food evenly during cooking and a motor for gaining and driving the turntable. In addition, a fan motor that functions to forcibly suck the outside air to cool the magnetron and blow it into the microwave cooking chamber to discharge the smell of the cooking chamber out is also connected, and a high voltage transformer (HVT HIGH) that supplies DC power required for the magnetron operation is connected. Power part consisting of VOLTAGE TRANSFORMER and high voltage diode is provided at the back of fan motor power line. In addition, as a kind of electron tube, a magnetron (MAGETRON) for cooking food by oscillating a microwave of 2,450 MHz by receiving a direct current from a high voltage transformer is connected to the secondary side of the high voltage transformer.

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

Figure 3 shows a schematic circuit diagram of the microwave oven of the microwave oven according to the present invention, the heater operation unit (100g) for performing the grill function is connected in parallel to the power line, which is the grill TCO 13, the heater 12 The heater relay 11 and the main relay 7 are provided in series. That is, the power of the heater 12 is to be dually controlled through the heater relay 11 and the main relay 7. For example, when the door is opened by the user's request while the microwave oven is running, the heater relay 11 cuts off the power of the heater 12 by a signal applied from a microcomputer (not shown) to operate the heater 12. To stop At this time, when the heater relay 11 is turned on due to a malfunction of the microcomputer and the power of the heater 12 is not cut off, there is a risk of burns when the heater 12 is touched when the food is put in and taken out without protective equipment. . Therefore, when the microwave oven door is opened, even if the heater relay 11 is not operated correctly, the main relay 7 is provided with a configuration that can accurately cut off the power applied to the heater 12. The main relay 7 is operated only when cooking the microwave and is turned off in other situations. Therefore, when the door of the microwave oven is opened, the main relay 7 together with the heater relay 11 controls the voltage applied to the heater 12 in duplicate. A noise filter 20 for removing harmonics of power applied to the microwave oven is connected to the rear end of the heater manipulator 100h, which is a fuse 21, a high frequency transformer 22, and a plurality of capacitors 23. Is provided. And, the magnetron TCO and grill TCO for preventing the temperature rise of the microwave oven is connected to the power line to protect the microwave oven by opening the power line when the temperature rises. The power supply via the noise filter 20 is applied to the low voltage transformer L.V.T. That is, a low voltage transformer (LVT LOW VOLTAGE TRANSFORMER) for supplying power to the power device is provided by applying power to the primary side and receiving a reduced voltage from the secondary side to several volts, and the low voltage transformer (LVT) is connected to the secondary side. When cooking, the lamp 2 for showing the inside of the microwave oven is connected. In addition, there is provided a motor 3 for driving the turntable for rotating the position of the food for cooking food evenly during cooking and a motor 4 for driving the turntable. The fan motor 5, which functions to forcibly suck the outside air to cool the magnetron and blow it into the microwave cooking chamber to exhaust the smell of the cooking chamber, is also connected, and the high pressure supplying the DC power required to operate the magnetron 6 is performed. A power supply unit 30 composed of a transformer (HVT HIGH VOLTAGE TRANSFORMER) and a high voltage diode (HVD) is provided at the rear end of the fan motor 5 power supply line. In addition, a magnetron (MAGETRON) 6, which is supplied with a direct current from a high voltage transformer (H.V.T.) and oscillates a microwave of 2,450 MHz, is connected to the secondary side of the high voltage transformer (H.V.T.).

According to the heater safety control circuit of the microwave oven configured as described above, even when the heater relay is not correctly turned off due to a malfunction of the microcomputer, the power applied to the heater in the main relay can be controlled secondarily. Even if the heater is in contact, there is an effect to prevent the accident caused by the heater.

The present invention relates to a microwave heater safety control circuit. That is, the present invention relates to a microwave safety control circuit for preventing the heater from malfunctioning when the door is opened. According to the configuration of the present invention, even if the heater relay is not turned off correctly due to a malfunction of the microcomputer, the power applied to the heater in the main relay is secondary. It can be controlled to prevent accidents caused by the heater even when the heater is touched when opening and removing food and opening the door during the operation of the microwave.

Claims (1)

A heater for cooking with radiant heat, a relay for supplying power to the heater when the user selects the radiant heat cooking function, and shutting off the power applied to the heater when the door of the microwave oven is opened during the radiant heat cooking function, a serial connection with the relay The main relay is turned on when the start of cooking is ordered by the user, and is turned off when the door of the microwave oven is opened. The main relay is turned off when the main relay is turned on even when the relay is continuously turned on. Microwave heater safety control circuit, characterized in that to cut off.