Novel microwave oven capable of automatically powering off electronic transformer

Abstract

The utility model relates to a novel microwave oven capable of automatically powering off an electronic transformer. The electronic transformer is electrically connected with the power supply module; the magnetron is electrically connected with the electronic transformer; the first temperature sensor is located on the magnetron and electrically connected with the electronic transformer; the power-off switch module is electrically connected with the electronic transformer and the magnetron respectively, and when the first temperature sensor detects that the temperature of any power device of the electronic transformer and the magnetron exceeds a threshold value, the power-off switch module disconnects circuits of the electronic transformer and the magnetron in sequence; the second temperature sensor is arranged in the cooking cavity; the timer is electrically connected with the second temperature sensor; the control module is electrically connected with the electronic transformer, the second temperature sensor and the timer, and when the second temperature sensor exceeds a threshold value or the duration of a certain temperature section recorded by the timer exceeds a preset value, the control module controls the electronic transformer to stop working.

Description

Technical Field

[0001] This utility model relates to the technical field of microwave oven circuit safety, specifically to a novel microwave oven that can automatically disconnect power to the electronic transformer. Background Technology

[0002] A microwave oven is a modern cooking tool that uses microwave energy to heat food. Power devices such as the electronic transformer and magnetron are crucial components in existing microwave ovens. Since the power of a microwave oven is around 1200W, the electronic transformer can boost the magnetron's operating voltage to 2000V or even 4000V. Therefore, the operating temperature of these two main components needs to be monitored and limited. If the cooling fan or other circuitry malfunctions, the magnetron will heat up rapidly. To prevent overheating and damage to internal components, thus avoiding safety risks, the power must be disconnected immediately. Furthermore, current microwave ovens do not monitor the temperature inside the cooking cavity; they generally only control the internal temperature by controlling the operating power of the electronic transformer. However, improper use of the microwave oven, such as constantly changing the temperature, heating for excessively long periods, or starting heating when the oven is empty, can cause the temperature to rise and affect other circuit components. Prolonged heating of food, in particular, can cause overboiling and even produce carcinogens, thus affecting health. Therefore, at higher heating temperatures, if the control circuit fails to disconnect the electronic transformer and other components within the set time, other detection methods are needed to ensure the safe use of the microwave oven. Utility Model Content

[0003] To address the problems existing in the prior art, the present invention aims to provide a novel microwave oven capable of automatically cutting off power to the electronic transformer. This invention provides power-off protection for the electronic transformer, preventing it from being used in unreasonable working environments or for extended periods due to high temperatures or improper use, thereby reducing damage to the electronic transformer and extending its service life.

[0004] The present invention relates to a novel microwave oven capable of automatically cutting off power to an electronic transformer, comprising:

[0005] The power module is used to provide power;

[0006] An electronic transformer is electrically connected to the power module and is used for voltage transformation.

[0007] A magnetron, electrically connected to the electronic transformer, is used to generate microwave energy within the cooking cavity of the microwave oven.

[0008] A first temperature sensor is located on the magnetron and electrically connected to the electronic transformer. The first temperature sensor is used to detect the temperature of the electronic transformer and the magnetron.

[0009] The power-off switch module is electrically connected to the electronic transformer and the magnetron respectively. When the first temperature sensor detects that the temperature of the electronic transformer or the magnetron exceeds the threshold, the power-off switch module disconnects the circuit of the magnetron and the electronic transformer in sequence.

[0010] A second temperature sensor is disposed inside the cooking cavity, and the second temperature sensor is used to detect the temperature inside the cooking cavity;

[0011] A timer, electrically connected to the second temperature sensor, is used to record the duration of different temperature ranges reached in the cooking cavity.

[0012] The control module is electrically connected to the electronic transformer, the second temperature sensor, and the timer, respectively. The control module is used to control the output power of the electronic transformer according to a preset mode. When the second temperature sensor exceeds a threshold or the duration of a certain temperature segment recorded by the timer exceeds a preset value, the control module controls the electronic transformer to stop working.

[0013] In one embodiment, a discharge circuit is connected in parallel to the magnetron. The discharge circuit is used to release excess charge after the magnetron stops working, and an indicator light is electrically connected to the discharge circuit.

[0014] In one embodiment, the microwave oven is further provided with a turntable motor, and a Hall sensor is provided on the turntable of the turntable motor. The Hall sensor is used to detect whether the turntable on the turntable motor is rotating. The Hall sensor is electrically connected to the control module. When the turntable on the turntable motor does not rotate for a preset period of time, the control module controls the electronic transformer to stop working.

[0015] In one embodiment, the power-off switch module includes a relay and a pulse delay circuit. The relay is linked to the first temperature sensor via a first transistor and is located between the electronic transformer and the magnetron. The pulse delay circuit is linked to the first temperature sensor and the first transistor via a second transistor and is located between the power supply module and the electronic transformer.

[0016] In one embodiment, the power module includes a first rectifier and filter circuit for converting the input AC voltage into a DC voltage and electrically connecting it to the electronic transformer.

[0017] In one embodiment, the control module is electrically connected to the electronic transformer via a power conversion module, and the power conversion module is also electrically connected to the first rectifier filter circuit. The power conversion module is used to convert the DC voltage into an AC pulse voltage.

[0018] In one embodiment, a second rectifier and filter circuit is electrically connected to the electronic transformer. The second rectifier and filter circuit is electrically connected to the magnetron. The second rectifier and filter circuit is used to rectify and filter the voltage transformed by the electronic transformer and output DC high voltage to the magnetron.

[0019] Compared with the prior art, the beneficial effects of this utility model's technical solution are:

[0020] This invention provides power-off protection for the electronic transformer. A first temperature sensor prevents high temperatures from affecting the electronic transformer and magnetron, ensuring their operating temperatures do not exceed preset thresholds. The second temperature sensor, working in conjunction with a timer, ensures the cooking cavity temperature remains within the preset range, preventing damage to microwave oven components or food containers. The timer sets a heating time for each mode and continuously accumulates this time. Improper use, such as heating food for too long without exceeding the cooking cavity temperature, could lead to overheating and safety risks. Therefore, the control module promptly stops the electronic transformer from operating, preventing use in unsuitable environments or for extended periods, thus reducing damage from prolonged power supply and extending its lifespan. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the module connection of a novel microwave oven that can automatically disconnect power to the electronic transformer according to this utility model;

[0022] Figure 2 This is a circuit connection diagram of a novel microwave oven that can automatically disconnect power to the electronic transformer according to this utility model.

[0023] Explanation of reference numerals in the attached diagram: 1-Power supply module, 2-Electronic transformer, 3-Magnetron, 4-First temperature sensor, 5-Power-off switch module, 51-Relay, 52-Pulse delay circuit, 53-First transistor, 54-Second transistor, 6-Second temperature sensor, 7-Timer, 8-Control module, 9-Discharge circuit, 10-Hall sensor, 11-Power conversion module. Detailed Implementation

[0024] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can be described as the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 and Figure 2 As shown, this utility model discloses a novel microwave oven capable of automatically cutting off power to the electronic transformer, comprising:

[0027] Power module 1 is used to provide power;

[0028] Electronic transformer 2 is electrically connected to power module 1 and is used for voltage transformation.

[0029] Magnetron 3 is electrically connected to electronic transformer 2. Magnetron 3 is used to generate microwave energy in the cooking cavity of microwave oven.

[0030] The first temperature sensor 4 is located on the magnetron 3 and is electrically connected to the electronic transformer 2. The first temperature sensor 4 is used to detect the temperature of the electronic transformer 2 and the magnetron 3.

[0031] The power-off switch module 5 is electrically connected to the electronic transformer 2 and the magnetron 3 respectively. When the first temperature sensor 4 detects that the temperature of the electronic transformer 2 or the magnetron 3 exceeds the threshold, the power-off switch module 5 disconnects the circuit of the magnetron 3 and the electronic transformer 2 in sequence.

[0032] The second temperature sensor 6 is located inside the cooking cavity and is used to detect the temperature inside the cooking cavity.

[0033] Timer 7 is electrically connected to the second temperature sensor 6. Timer 7 is used to record the duration of different temperature ranges reached in the cooking cavity.

[0034] The control module 8 is electrically connected to the electronic transformer 2, the second temperature sensor 6, and the timer 7 respectively. The control module 8 is used to control the output power of the electronic transformer 2 according to a preset mode. When the second temperature sensor 6 exceeds the threshold or the duration of a certain temperature range recorded by the timer 7 exceeds the preset value, the control module 8 controls the electronic transformer 2 to stop working.

[0035] This invention provides automatic power-off protection for the electronic transformer 2. A first temperature sensor 4 prevents high temperatures from affecting the electronic transformer 2 and the magnetron 3. The first temperature sensor 4 is electrically connected to both the electronic transformer 2 and the magnetron 3 via a power-off switch module 5. When the temperature gradually rises above a certain value, such as 180°C, it may indicate excessive power or a heat dissipation failure, causing the high-voltage coil of the electronic transformer 2 to generate heat or the magnetron 3 to operate at an abnormal temperature. Therefore, the first temperature sensor 4, through the circuit connection of the power-off switch module 5, promptly disconnects the magnetron 3 and the electronic transformer 2 sequentially, ensuring that the operating temperatures of both the electronic transformer 2 and the magnetron 3 do not exceed preset thresholds. Furthermore, it first stops the load side, then delays the power supply side, preventing back-charging of the high-voltage magnetron 3 and its impact on other equipment. The second temperature sensor 6 and the timer 7 work together to ensure that the temperature inside the cooking cavity does not exceed a preset temperature, such as 120°C, or, for microwave ovens with a grilling function, the highest temperature setting. The temperature threshold is 200℃ to prevent damage to microwave oven components or normal heat-resistant food containers inside the cooking cavity. Timer 7 sets a corresponding heating time for each mode and continuously accumulates the heating time. For example, in defrost mode, the temperature cannot exceed 60℃ and the duration cannot exceed 20 minutes. In medium or high power mode, the cavity temperature can reach 70℃ to 100℃. For every 200W increase in power, the time limit is shortened by 1 to 2 minutes. For example, in medium power mode, the temperature is 70℃ to 80℃, and timer 7 limits it to no more than 10 minutes. In high power mode, the temperature is 90℃ to 100℃, and timer 7 limits it to no more than 8 minutes. Timer 7 is an accumulated time. That is, even if the usage time is not exceeded in medium power mode, if the cooking time is switched to high power mode in the same cooking cycle, timer 7 will not reset the timer by 8 minutes, but will continue to accumulate to no more than the above 10 minutes to effectively prevent improper use of the microwave oven. These temperature and time limit settings can be adjusted appropriately according to the actual maximum power and capacity of the microwave oven. If the maximum temperature limit in the cooking cavity is not exceeded, improper use may cause food to be heated at a high temperature for too long, resulting in over-boiling and posing a safety risk. Therefore, the control module 8 can use the above-mentioned preset settings to control the electronic transformer 2 to stop working in a timely manner, avoiding its use in an unreasonable working environment or for an extended period of time, thereby reducing the damage to the electronic transformer 2 caused by long-term energization and extending its service life.

[0036] In one embodiment, a discharge circuit 9 is connected in parallel to the magnetron 3. The discharge circuit 9 is used to release excess charge after the magnetron 3 stops working, and an indicator light is electrically connected to the discharge circuit 9. Since the magnetron 3 is a high-voltage power device, after prolonged operation and power failure due to its connection with the electronic transformer 2, excess charge may remain in its capacitors and other components. The connection of the discharge circuit 9 and the indicator light can remind the user that there is still voltage inside the microwave oven, avoiding direct disassembly and repair that could cause leakage or radiation.

[0037] To ensure even heating of food within the cooking cavity, most microwave ovens include a turntable motor. This invention adds a Hall sensor 10 to the turntable of the turntable motor. The Hall sensor 10 detects whether the turntable is rotating. The Hall sensor 10 is electrically connected to the control module 8. When the turntable does not rotate for a preset period, the control module 8 stops the electronic transformer 2. Turntable motor malfunctions, and after prolonged use, the turntable and rolling belt within the cooking cavity may melt, or food residue may obstruct the turntable's movement, potentially causing it to stop rotating. This results in uneven heating of the food and even overheating. Therefore, by using the Hall sensor 10 to detect the turntable's displacement, when the turntable stops rotating, the electronic transformer 2 will stop operating for a certain period to avoid safety risks, thus improving the safety of this microwave oven.

[0038] In one embodiment, the power-off switch module 5 includes a relay 51 and a pulse delay circuit 52. The relay 51 is linked to the first temperature sensor 4 via a first transistor 53 and is located between the electronic transformer 2 and the magnetron 3. The pulse delay circuit 52 is linked to the first temperature sensor 4 and the first transistor 53 via a second transistor 54 and is located between the power supply module 8 and the electronic transformer 2. When the first temperature sensor 4 detects an abnormal temperature of the electronic transformer 2 or the magnetron 3, it indicates that the circuit or component is overloaded or even at risk of burning out, requiring immediate power disconnection. To protect the electronic transformer 2 and the magnetron 3, the load side must be disconnected first, followed by a delayed power disconnection to prevent reverse charging. Therefore, when the first temperature sensor 4 heats up and its resistance increases, the base voltage of the first transistor 53 decreases, and the relay 51 directly disconnects the connection between the electronic transformer 2 and the magnetron 3, thereby stopping the magnetron 3 from working. Meanwhile, due to the disconnection of the emitter of the first transistor 53, the base of the second transistor 54 also becomes a low-voltage point, triggering the pulse delay circuit 52 to disconnect the power supply of the electronic transformer 2. The pulse delay circuit has already charged the capacitor C when it is powered on. When the second transistor 54 is disconnected, the capacitor C will discharge to keep the internal third transistor conducting. The relay is still engaged. After a period of discharge, when the voltage between the two terminals of the capacitor drops to a certain value, it is not enough to keep the third transistor conducting, and the relay is released. This internal connection can adopt most of the existing pulse delay circuit connection methods. The delay time of the capacitor C allows the discharge circuit 9 to release excess charge after the magnetron 3 is powered off, and then disconnect the circuit connection of the electronic transformer 2, which can protect other components from the impact of load charge.

[0039] In addition, the power supply module 8 includes a first rectifier and filter circuit, which converts the input AC voltage into DC voltage and is electrically connected to the electronic transformer 2 to provide a stable voltage to the electronic transformer 2 for operation through rectification and filtering. The control module 8 is electrically connected to the electronic transformer 2 via a power conversion module 11, which is also electrically connected to the first rectifier and filter circuit. The power conversion module 11 converts the DC voltage into AC pulse voltage. The operating power of the electronic transformer 2 depends on the mode selected by the control module 8. The power conversion module 11 facilitates the control module 8 in controlling the electronic transformer 2 and stopping its operation under the aforementioned safety conditions. Furthermore, a second rectifier and filter circuit is electrically connected to the electronic transformer 2 and is electrically connected to the magnetron 3. The second rectifier and filter circuit rectifies and filters the voltage converted by the electronic transformer 2 and outputs a high-voltage DC voltage to the magnetron 3. Similarly, the second rectifier and filter circuit provides a stable voltage to the magnetron 3 through rectification and filtering, thereby assisting the magnetron 3 in stable normal operation.

[0040] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application.

[0041] The positional relationships described in the figures are for illustrative purposes only and should not be construed as limiting this patent. Clearly, the above embodiments of this utility model are merely examples to clearly illustrate the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A novel microwave oven capable of automatically cutting off power to the electronic transformer, characterized in that, include: The power module is used to provide power; An electronic transformer is electrically connected to the power module and is used for voltage transformation. A magnetron, electrically connected to the electronic transformer, is used to generate microwave energy within the cooking cavity of the microwave oven. A first temperature sensor is located on the magnetron and electrically connected to the electronic transformer. The first temperature sensor is used to detect the temperature of the electronic transformer and the magnetron. The power-off switch module is electrically connected to the electronic transformer and the magnetron respectively. When the first temperature sensor detects that the temperature of the electronic transformer or the magnetron exceeds the threshold, the power-off switch module disconnects the circuit of the magnetron and the electronic transformer in sequence. A second temperature sensor is disposed inside the cooking cavity, and the second temperature sensor is used to detect the temperature inside the cooking cavity; A timer, electrically connected to the second temperature sensor, is used to record the duration of different temperature ranges reached in the cooking cavity. The control module is electrically connected to the electronic transformer, the second temperature sensor, and the timer, respectively. The control module is used to control the output power of the electronic transformer according to a preset mode. When the second temperature sensor exceeds a threshold or the duration of a certain temperature segment recorded by the timer exceeds a preset value, the control module controls the electronic transformer to stop working.

2. The novel microwave oven with automatic power-off capability for the electronic transformer according to claim 1, characterized in that, A discharge circuit is connected in parallel to the magnetron. The discharge circuit is used to release excess charge after the magnetron stops working, and an indicator light is electrically connected to the discharge circuit.

3. A novel microwave oven capable of automatically cutting off power to the electronic transformer according to claim 2, characterized in that, The microwave oven is also equipped with a turntable motor, and a Hall sensor is installed on the turntable of the turntable motor. The Hall sensor is used to detect whether the turntable on the turntable motor is rotating. The Hall sensor is electrically connected to the control module. When the turntable on the turntable motor does not rotate for a preset period of time, the control module controls the electronic transformer to stop working.

4. A novel microwave oven capable of automatically cutting off power to the electronic transformer according to claim 3, characterized in that, The power-off switch module includes a relay and a pulse delay circuit. The relay is linked to the first temperature sensor through a first transistor and is located between the electronic transformer and the magnetron. The pulse delay circuit is linked to the first temperature sensor and the first transistor through a second transistor and is located between the power supply module and the electronic transformer.

5. A novel microwave oven capable of automatically cutting off power to the electronic transformer according to any one of claims 1-4, characterized in that, The power module includes a first rectifier and filter circuit, which is used to convert the input AC voltage into DC voltage and is electrically connected to the electronic transformer.

6. A novel microwave oven capable of automatically cutting off power to the electronic transformer according to claim 5, characterized in that, The control module is electrically connected to the electronic transformer via a power conversion module, and the power conversion module is also electrically connected to the first rectifier and filter circuit. The power conversion module is used to convert the DC voltage into an AC pulse voltage.

7. A novel microwave oven capable of automatically cutting off power to the electronic transformer according to claim 6, characterized in that, The electronic transformer is electrically connected to a second rectifier and filter circuit, which is electrically connected to the magnetron. The second rectifier and filter circuit is used to rectify and filter the voltage after the electronic transformer is transformed and output DC high voltage to the magnetron.

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