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CN-224230083-U - No-load detection circuit and microwave oven

CN224230083UCN 224230083 UCN224230083 UCN 224230083UCN-224230083-U

Abstract

The utility model provides an idle detection circuit and a microwave oven, wherein the circuit comprises an MCU, a control module and an infrared pair tube module, the MCU is respectively connected with one end of the control module and one end of the infrared pair tube module, the other end of the infrared pair tube module is arranged on the inner side wall of the microwave oven, the MCU and the control module are both arranged on a circuit board in the microwave oven, the infrared pair tube module is provided with n groups, n is a positive integer, one ends of the n groups of infrared pair tube modules are respectively connected with pins corresponding to the MCU, and the other ends of the n groups of infrared pair tube modules are respectively arranged on the inner side wall of the corresponding side surface of the microwave oven.

Inventors

  • FENG XIYAO
  • HU YISHUANG

Assignees

  • 广东格兰仕集团有限公司
  • 广东格兰仕电器制造有限公司
  • 广东格兰仕微波炉电器制造有限公司

Dates

Publication Date
20260512
Application Date
20250527

Claims (10)

  1. 1. A no-load detection circuit is characterized by comprising an MCU (1), a control module (2) and an infrared pair tube module (3), wherein the MCU (1) is connected with one end of the control module (2) and one end of the infrared pair tube module (3) respectively, the other end of the infrared pair tube module (3) is arranged on the inner side wall of a microwave oven, the MCU (1) and the control module (2) are both arranged on a circuit board in the microwave oven, n groups of infrared pair tube modules (3) are arranged, n is a positive integer, one ends of the n groups of infrared pair tube modules (3) are connected with pins corresponding to the MCU (1) respectively, and the other ends of the n groups of infrared pair tube modules (3) are arranged on the inner side wall of the corresponding side face of the microwave oven respectively.
  2. 2. The no-load detection circuit according to claim 1, wherein the MCU (1) comprises m pins, m being a positive integer, m being equal to or greater than 2n+1.
  3. 3. An idle detection circuit according to claim 1, characterized in that the control module (2) is an infrared power control module.
  4. 4. The no-load detection circuit according to claim 1, wherein the control module (2) comprises a control module (21), a triode Q and a control module (22), one end of the control module (21) is connected with the MCU (1), the other end of the control module (21) is respectively connected with a base electrode and an emitter electrode of the triode Q and the first power supply VCC, and a collector electrode of the triode Q is grounded through the control module (22).
  5. 5. The no-load detection circuit according to claim 4, wherein the control module (21) comprises a first resistor R1 and a second resistor R2, one end of the first resistor R1 is electrically connected with the first power supply VCC and the emitter of the triode Q respectively, the other end of the first resistor R1 is electrically connected with one end of the second resistor R2 and the base of the triode Q respectively, and the other end of the second resistor R2 is electrically connected with the MCU (1).
  6. 6. The no-load detection circuit according to claim 4, wherein the control two module (22) comprises a third resistor R3 and a first capacitor C1, one end of the third resistor R3 is electrically connected with the collector of the triode Q, the second power supply VCC-OUT and one end of the first capacitor C1 respectively, and the other end of the third resistor R3 is grounded after being connected with the other end of the first capacitor C1 in parallel.
  7. 7. The no-load detection circuit according to claim 1, wherein the infrared pair tube module (3) comprises an infrared emitting tube LED and an infrared receiving tube PT, the infrared emitting tube LED and the infrared receiving tube PT are arranged on the inner side wall of any one of the top side, the rear side, the left side and the right side of the microwave oven side by side, and the infrared receiving tube PT is connected with the MCU (1).
  8. 8. The no-load detection circuit according to claim 7, wherein the three groups of infrared pair tube modules (3) are respectively marked as a pair tube first module (31), a pair tube second module (32) and a pair tube third module (33), and the pair tube first module (31), the pair tube second module (32) and the pair tube third module (33) are respectively arranged on inner side walls of different sides of the microwave oven.
  9. 9. The no-load detection circuit according to claim 8, wherein the pair of tube-to-tube module (31) comprises a fourth resistor R4, an emitting tube LED1, a receiving tube PT1, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a second capacitor C2, one end of the fourth resistor R4 is electrically connected to the second power source VCC-OUT, the other end of the fourth resistor R4 is grounded through the emitting tube LED1, one end of the receiving tube PT1 is electrically connected to one end of the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7, the other ends of the fifth resistor R5 and the sixth resistor R6 are electrically connected to the pin SW1 of the MCU (1) and the second power source VCC-OUT, respectively, the other ends of the seventh resistor R7 are connected to the pin FB1 of the MCU (1) and one end of the second capacitor C2, respectively, and the other ends of the receiving tube PT1 and the second capacitor C2 are connected to the ground.
  10. 10. A microwave oven, characterized in that the microwave oven comprises an idle detection circuit according to any one of claims 1-9, said circuit being arranged in the microwave oven.

Description

No-load detection circuit and microwave oven Technical Field The utility model relates to the technical field of microwave ovens, in particular to an idle load detection circuit and a microwave oven. Background With the rapid development of technology, the security problem of intelligent electrical appliances is a non-negligible existence as one of the important concerns of users. In the traditional microwave oven, whether food is placed in the cavity of the microwave oven is not detected, so that the microwave oven is easy to run in a no-load mode, the magnetron heats seriously, the service life of the magnetron is greatly shortened, and the quality of the microwave oven is affected. Especially for some commercial type microwave ovens, the power is high, the use frequency is high, the condition that microwaves are opened for idle work due to no food is easy to occur, and the influence on the service life of products is larger. Therefore, the method has important significance in researching how to optimize the arrangement of circuits in the microwave oven, improving the use safety of the microwave oven and prolonging the service life of the microwave oven. At present, the existing detection method for the no-load operation of the microwave oven comprises the step of judging whether the microwave oven is no-load or not through the incident power and the reflected power of a microwave source of the microwave oven, and the detailed description of the detection method is shown in a patent CN106322452B. The method comprises the steps of firstly driving a rotary table of the microwave oven to rotate for a first time through a motor rotary shaft of the microwave oven, stopping driving the rotary table after the first time, detecting a first number of turns of the motor rotary shaft of the microwave oven due to inertia rotation of the rotary table in the first inertia time, judging whether the microwave oven is empty or not according to the first number of turns and a first preset number of turns, and particularly see patent CN107327878B. However, both the method of detecting the incident power and the reflected power and the method of adopting the first turn of the turntable rotating in the inertia time need to increase standby power consumption, and both the two detection methods are complex, which easily makes the detection cost higher. In patent CN104362922B, a control device and a control method for a transformer in a microwave oven are disclosed, which comprise an oven door detection module for outputting an opening command when an oven door of the microwave oven is opened according to a command of a user, and a zero crossing detection module for detecting input mains supply to output a zero crossing signal, wherein the zero crossing detection module 2 comprises a photoelectric coupler 201 and a first resistor R1. The first input end of the photoelectric coupler 201 is connected with a live wire L of a mains supply, the second input end of the photoelectric coupler 201 is connected with a ZERO line N of the mains supply, the first output end of the photoelectric coupler 201 is grounded GND, one end of the first resistor R1 is connected with the second output end of the photoelectric coupler 201, the other end of the first resistor R1 is an output end ZERO and is connected with the control module 5 to output a ZERO-crossing signal to the control module 5, and the first resistor R1 is used for output current limiting. The photoelectric coupler 201 is arranged to isolate strong current from weak current, but detection of whether the microwave oven is empty or not is not realized. Disclosure of utility model In view of the above, the utility model aims to provide an idle load detection circuit and a microwave oven, which solve the problems that whether the service life of a magnetron of the microwave oven running in idle load is seriously shortened due to the fact that the traditional microwave oven is started and not detected, and the existing microwave oven judges whether the microwave oven is idle or not by detecting the incident power and the reflected power of microwaves, and the detection method is relatively complex and high in cost. In order to achieve the above purpose, the technical scheme of the utility model is realized as follows: The utility model relates to an empty-load detection circuit and a microwave oven, wherein the empty-load detection circuit comprises an MCU, a control module and an infrared pair tube module, the MCU is respectively connected with one end of the control module and one end of the infrared pair tube module, the other end of the infrared pair tube module is arranged on the inner side wall of the microwave oven, the MCU and the control module are both arranged on a circuit board in the microwave oven, n groups of infrared pair tube modules are arranged, n is a positive integer, one ends of the n groups of infrared pair tube modules are respectively connected with pins correspo