Control circuit of oven door and drawer and microwave oven

Abstract

The utility model provides an oven door and drawer control circuit and a microwave oven. The circuit comprises a controller, a motor detection control module, a key, a relay drive control module and a protection circuit, the controller is connected with the motor detection control module, the key, the relay driving control module and the protection circuit. The end, away from the controller, of the relay driving control module is connected with the protection circuit and the microwave relay. The motor detection control module comprises a surge suppression circuit and a push rod motor, one end of the surge suppression circuit and one end of the push rod motor are connected with the controller, and the other end of the surge suppression circuit is connected with the other end of the push rod motor; according to the control circuit of the oven door and the drawer and the microwave oven, the structure of the control circuit of the oven door and the drawer of the drawer type microwave oven can be simplified, and the oven door and the drawer can be automatically opened and closed, so that the use convenience and the experience satisfaction degree of consumers are improved; standby power consumption can be reduced; and surge current can be suppressed.

Description

Technical Field

[0001] This utility model relates to the field of microwave ovens, and more specifically, to a control circuit for the oven door and drawer, and a microwave oven. Background Technology

[0002] Traditional drawer-type microwave ovens typically require manual pulling to open, which is inconvenient due to the drawer's length and difficulty in doing so, resulting in a poor user experience. Other designs utilize push-rod motors, which lack surge current suppression, leading to low reliability. Still others suffer from high standby power consumption, failing to meet current standards. Therefore, researching ways to improve the reliability of automatic door and drawer opening and closing mechanisms in drawer-type microwave ovens and reduce standby power consumption is of significant importance.

[0003] Patent CN104456646B discloses a drawer-type microwave oven and its door opening and closing control method. The microwave oven includes a push rod, a control panel for receiving trigger commands from the user, a cavity and a drawer, a detection module for detecting the drawer's state, a motor for driving the drawer's movement, a current detection module connected to the motor, and a control module. The control module is connected to the control panel, the detection module, the motor, and the current detection module respectively. After receiving a user command, the control module controls the motor according to the drawer's state, thereby causing the motor to drive the drawer to move via the push rod. When the motor's operating current is greater than or equal to a preset current, the control module controls the motor to stop working. It can realize automatic and manual switching of door opening and closing. However, since the control method of this microwave oven does not suppress surge current, the reliability of the motor-controlled push rod is easily reduced. Utility Model Content

[0004] In view of this, the present invention aims to propose a control circuit for the oven door and drawer and a microwave oven to solve the problems of poor reliability of automatic opening and closing of the oven door and drawer in traditional drawer-type microwave ovens and high standby power consumption in the prior art; thereby simplifying the structure of the control circuit for the oven door and drawer of the drawer-type microwave oven, realizing automatic opening and closing of the oven door and drawer, thereby improving the convenience and satisfaction of consumers, and also reducing standby power consumption and suppressing surge current.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] This utility model relates to a control circuit for an oven door and drawer, and a microwave oven. The control circuit for the oven door and drawer includes a controller, a motor detection and control module, buttons, a relay drive module, and a protection circuit. The controller is connected to the motor detection and control module, buttons, relay drive module, and protection circuit. The end of the relay drive module furthest from the controller is connected to the protection circuit and a microwave relay. The motor detection and control module includes a surge suppression circuit and a push rod motor. One end of the surge suppression circuit and one end of the push rod motor are both connected to the controller, and the other end of the surge suppression circuit is connected to the other end of the push rod motor.

[0007] Furthermore, the motor detection and control module also includes a motor limit switch, which is connected to the controller.

[0008] Furthermore, the relay drive and control module includes a relay protection module and a relay control module. Both the relay protection module and the relay control module are connected to the controller. The relay protection module is connected to the protection circuit and the relay control module, respectively.

[0009] Furthermore, the control circuit also includes a fifth capacitor C5, one end of which is connected to pin 7 of the push rod motor, and the other end of which is grounded.

[0010] Furthermore, the controller is connected to the motor limit switch via port SW, to the surge suppression circuit via port Power, and to pins 4, 5, 6, and 7 of the push rod motor via ports PWM1, BRAKE, CW / CCW, and FG, respectively. The controller is connected to the button via port S1, to the protection circuit via port DOOR, to the relay protection module via port PWM2, and to the relay control module via port VPC.

[0011] Furthermore, the motor limit switch includes a first resistor R1, a second resistor R2, a first capacitor C1, and a limit switch CN1; one end of the first resistor R1 is connected to the power supply VCC, and the other end of the first resistor R1 is connected to the second resistor R2, one end of the first capacitor C1, and pin 1 of the limit switch CN1 respectively; the other end of the second resistor R2 is connected to the controller 1; and the other end of the first capacitor C1 is connected to ground in parallel with pin 3 of the limit switch CN1.

[0012] Furthermore, the surge suppression circuit includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first resistor R11, a second capacitor C2, a MOSFET Q3, and a fifth transistor Q5.

[0013] Furthermore, one end of the first resistor R11 is connected to the controller, and the other end of the first resistor R11 is connected to the base of the fifth transistor Q5. The emitter of the fifth transistor Q5 is connected to ground in parallel with pin 2 of the push rod motor. The collector of the fifth transistor Q5 is connected to one end of the second capacitor C2, the seventh resistor R7, and the eighth resistor R8 through the sixth resistor R6. The other end of the eighth resistor R8 is connected to the gate of the MOSFET Q3. The other end of the second capacitor C2, the seventh resistor R7, and the source of the MOSFET Q3 are connected in parallel and then connected to the power supply VDD2. The drain of the MOSFET Q3 is connected to pin 1 of the push rod motor.

[0014] Furthermore, the protection circuit includes a door switch CN3, a third diode D3, a first six-resistor R16, a first seven-resistor R17, and a sixth capacitor C6; pin 3 of the door switch CN3 is grounded, pin 1 of the door switch CN3 is connected to the relay protection module and the negative terminal of the third diode D3, the positive terminal of the third diode D3 is connected to one end of the first six-resistor R16 and the first seven-resistor R17, the other end of the first six-resistor R16 is connected to the switching power supply, the other end of the first seven-resistor R17 is connected to one end of the sixth capacitor C6 and the controller, and the other end of the sixth capacitor C6 is grounded.

[0015] A microwave oven includes a control circuit for a door and drawer, the control circuit being disposed inside the microwave oven.

[0016] Compared with the prior art, the control circuit for the oven door and drawer and the microwave oven described in this utility model have the following advantages:

[0017] By implementing the aforementioned circuit, the structure of the control circuit for the oven door and drawer of a drawer-type microwave oven can be effectively simplified, enabling automatic opening and closing of the door and drawer. This improves user convenience and experience, reduces standby power consumption, and suppresses inrush current. It also enhances the circuit's anti-interference capability and extends the motor's lifespan. Furthermore, incorporating this control circuit within the microwave oven improves the safety and convenience of opening and closing the door and drawer, reduces energy consumption during the opening and closing process, and contributes to energy conservation. Attached Figure Description

[0018] The accompanying drawings, which constitute a part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments and descriptions of the utility model are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0019] Figure 1 This is a schematic diagram of the control circuit.

[0020] Explanation of reference numerals in the attached diagram: 1. Controller; 2. Motor limit switch; 3. Surge suppression circuit; 4. Push rod motor; 5. Button; 6. Relay protection module; 7. Relay control module; 8. Protection circuit; 9. Microwave relay; 10. Motor detection and control module; 11. Relay drive and control module. Detailed Implementation

[0021] The inventive concepts of this disclosure will be described below using terminology commonly used by those skilled in the art to convey the essence of their work to others skilled in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] This embodiment is for a microwave oven. Similar to a conventional microwave oven, the overall structure consists of a door, a drawer, and a motor.

[0025] To address the issues of poor reliability and high standby power consumption in the automatic opening and closing of traditional drawer-type microwave ovens, this embodiment proposes a control circuit for the oven door and drawer, and a microwave oven in general. The control circuit includes a controller 1, a motor detection and control module 10, a button 5, a relay drive module 11, and a protection circuit 8. The controller 1 is connected to the motor detection and control module 10, the button 5, the relay drive module 11, and the protection circuit 8. The end of the relay drive module 11 furthest from the controller 1 is connected to the protection circuit 8 and a microwave relay 9. The motor detection and control module 10 includes a surge suppression circuit 3 and a push rod motor 4. One end of both the surge suppression circuit 3 and the push rod motor 4 is connected to the controller 1, and the other end of the surge suppression circuit 3 is connected to the other end of the push rod motor 4. Furthermore, the motor detection and control module 10 also includes a motor limit switch 2, which is connected to the controller 1 and used to detect the travel distance of the push rod motor 4.

[0026] By setting up the circuit, this application uses a push rod motor 4, a motor limit switch 2, a push rod motor 4 power control circuit, and a surge suppression circuit 3 in combination. This can effectively simplify the structure of the control circuit for the oven door and drawer of a drawer-type microwave oven, realize the automatic opening and closing of the oven door and drawer, thereby improving the convenience and satisfaction of consumers, and also reducing standby power consumption and suppressing surge current.

[0027] The relay drive and control module 11 includes a relay protection module 6 and a relay control module 7. Both the relay protection module 6 and the relay control module 7 are connected to the controller 1. The relay protection module 6 is connected to both the protection circuit 8 and the relay control module 7. The relay protection module 6 serves as a pre-stage control module for the relay, used to improve the circuit's anti-interference capability. The relay control module 7 is used to drive the relay.

[0028] By incorporating relay protection module 6, not only is the circuit's anti-interference capability improved, but it also prevents accidental microwave activation. Furthermore, the relay requires a specific square wave to activate, enhancing safety.

[0029] Controller 1 includes ports SW, Power, PWM1, PWM2, BRAKE, CW / CCW, FG, S1, DOOR, and VPC. Controller 1 is connected to the motor limit switch 2 via port SW, and to the surge suppression circuit 3 via port Power. Controller 1 is connected to pins 4, 5, 6, and 7 of the push rod motor 4 via ports PWM1, BRAKE, CW / CCW, and FG, respectively. Controller 1 is connected to button 5 via port S1, to protection circuit 8 via port DOOR, to relay protection module 6 via port PWM2, and to relay control module 7 via port VPC. Additionally, the control circuit includes a fifth capacitor C5, one end of which is connected to pin 7 of the push rod motor 4, and the other end is grounded. The push rod motor 4 is used to push open or pull back the furnace door and drawer. Button 5 is used for opening and closing the drawer and furnace door.

[0030] The controller 1 can be configured to monitor the status of relevant components in the microwave oven in real time and perform corresponding operations based on the status. By installing a fifth capacitor C5 between the push rod motor 4 and the controller 1, electromagnetic interference or noise interference generated during the operation of the push rod motor 4 can be effectively suppressed, thereby improving the accuracy of the control circuit in controlling the opening and closing of the oven door and drawer.

[0031] The motor limit switch 2 includes a first resistor R1, a second resistor R2, a first capacitor C1, and a limit switch CN1. One end of the first resistor R1 is connected to the power supply +VCC. The other end of the first resistor R1 is connected to the second resistor R2, one end of the first capacitor C1, and pin 1 of the limit switch CN1. The other end of the second resistor R2 is connected to port SW of the controller 1. The other end of the first capacitor C1 is connected to ground in parallel with pin 3 of the limit switch CN1.

[0032] By coordinating the components in the motor limit switch 2, it can function as a travel detection switch for the push rod motor 4, used to detect the travel distance of the push rod motor 4. This lays the foundation for the controller 1 to accurately issue control commands to the push rod motor 4, thereby improving the safety and accuracy of the control circuit operation.

[0033] The surge suppression circuit 3 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first resistor R11, a second capacitor C2, a MOSFET Q3, and a fifth transistor Q5. One end of the first resistor R11 is connected to the Power port of the controller 1, and the other end of the first resistor R11 is connected to the base of the fifth transistor Q5. The emitter of the fifth transistor Q5 is connected to ground in parallel with pin 2 of the push rod motor 4. The collector of the fifth transistor Q5 is connected to one end of the second capacitor C2, the seventh resistor R7, and the eighth resistor R8 through the sixth resistor R6. The other end of the eighth resistor R8 is connected to the gate G of the MOSFET Q3. The other end of the second capacitor C2, the seventh resistor R7, and the source S of the MOSFET Q3 are connected in parallel and then connected to the power supply +VDD2. The drain D of the MOSFET Q3 is connected to pin 1 of the push rod motor 4. In this embodiment, the surge suppression circuit 3 serves as the power control module for the push rod motor 4, used to control the power on and off of the push rod motor 4.

[0034] The surge suppression circuit 3 is used to control the power supply of the push rod motor 4. Through the MOSFET Q3, it can suppress the starting surge current of the push rod motor and turn off the power supply of the push rod motor 4 in standby and microwave operation, which can improve the service life of the push rod motor 4. In addition, it can also indirectly reduce the standby power consumption of the whole system.

[0035] The relay protection module 6 includes a fourth transistor Q4, a sixth transistor Q6, a third capacitor C3, a fourth capacitor C4, a ninth resistor R9, a tenth resistor R10, a first second resistor R12, a first third resistor R13, a first fourth resistor R14, and a first fifth resistor R15. One end of the first third resistor R13 is connected to the power supply +VCC, the emitter of the sixth transistor Q6, and one end of the first second resistor R12. The other end of the first third resistor R13 is connected to one end of the fourth capacitor C4 and the PWM2 port of the controller 1. The other end of the fourth capacitor C4 is connected to the other end of the first second resistor R12 and the base of the sixth transistor Q6 via the first fifth resistor R15. The collector of the sixth transistor Q6 is connected to one end of the third capacitor C3, the ninth resistor R9, the first fourth resistor R14, and the relay control module 7 via the tenth resistor R10. The third capacitor C3 and the other end of the first fourth resistor R14 are connected in parallel and grounded. The other end of the ninth resistor R9 is connected to the base of the fourth transistor Q4. The collector of the fourth transistor Q4 is connected to the relay control module 7. The emitter of the fourth transistor Q4 is connected to the protection circuit 8.

[0036] By configuring the components within the relay protection module 6, the protection of the relay control module 7 can be effectively improved. It can also enhance the circuit's anti-interference capability, improve circuit safety, and reduce losses during the circuit's control of the furnace door and drawer opening and closing process.

[0037] The relay control module 7 includes a first transistor Q1, a second transistor Q2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first diode D1, and a second diode D2. The microwave relay 9 includes a relay VPC and a relay Main. One end of the relay VPC and relay Main, along with the negative terminals of the first diode D1 and the second diode D2, are connected in parallel and then connected to the power supply VDD. The other end of the relay VPC is connected in parallel with the positive terminal of the first diode D1, and then connected to the collector of the fourth transistor Q4 in the relay protection module 6 through the first transistor Q1. The base of the first transistor Q1 is connected to the port VPC of the controller 1 through the fourth resistor R4. The other end of the relay Main is connected in parallel with the positive terminal of the second diode D2, and then sequentially connected to the end of the tenth resistor R10 in the relay protection module 6 furthest from the sixth transistor Q6 through the third resistor R3, the second transistor Q2, and the fifth resistor R5. The emitter of the second transistor Q2 is grounded.

[0038] By configuring the relay control module 7, precise control of different relays can be effectively achieved, improving the safety and stability of the driving relays.

[0039] The protection circuit 8 includes a door switch CN3, a third diode D3, a first six-resistor R16, a first seven-resistor R17, and a sixth capacitor C6. Pin 3 of the door switch CN3 is grounded. Pin 1 of the door switch CN3 is connected to the emitter of the fourth transistor Q4 in the relay protection module 6 and the cathode of the third diode D3. The anode of the third diode D3 is connected to one end of the first six-resistor R16 and the first seven-resistor R17. The other end of the first six-resistor R16 is connected to the switching power supply. The other end of the first seven-resistor R17 is connected to one end of the sixth capacitor C6 and the DOOR port of the controller 1. The other end of the sixth capacitor C6 is grounded. In this embodiment, the protection circuit 8 is a door detection switch circuit used to identify the door status. In this embodiment, the switching power supply is +5V, but the specific value can be set according to requirements and is not limited to this.

[0040] By setting the door switch CN3 in the protection circuit 8, the door status can be identified, and the microwave relay 9 can be disconnected in hardware when the door is open, so that the microwave operation stops when the door is open, thereby making it safer for users. At the same time, it can also be used as the start judgment condition for the operation of the push rod motor 4.

[0041] A microwave oven includes a control circuit for a door and drawer, the control circuit being disposed inside the microwave oven.

[0042] Working principle of the control circuit:

[0043] When the machine is powered on and the door is closed, by pressing and holding button 5, controller 1 recognizes that button 5 has been pressed and outputs a high Power signal. This slowly turns on the power supply +VDD2 of surge suppression circuit 3 through the DS pole of MOSFET Q3 to the power supply terminal of push rod motor 4. The output time of power supply +VDD2 can be adjusted through the second capacitor C2, the sixth resistor R6, and the seventh resistor R7, which can effectively suppress surge current. At this time, controller 1 transmits the forward and reverse rotation signal CW / CCW and the motor speed control signal PWM1 to push rod motor 4 in sequence. Then push rod motor 4 starts to run, opening the furnace door and drawer together. When push rod motor 4 runs to a certain position, motor limit switch 2 outputs a low-level signal SW. After controller 1 recognizes this, it sends a stop signal BRAKE to push rod motor 4 to stop push rod motor 4, and the door opening is completed. At this time, by pressing and holding button 5, controller 1 transmits forward / reverse signals CW / CCW and motor speed control signal PWM1 to push rod motor 4 in sequence. Push rod motor 4 starts to run in reverse, and the drawer and oven door begin to retract. At this time, when door switch CN3 is activated, the door switch CN3 signal DOOR changes from high to low, that is, the door is closed. At this time, controller 1 sends a stop signal BRAKE to push rod motor 4, causing push rod motor 4 to stop running, and the door closing is completed.

[0044] Alternatively, the oven door and drawer can be opened and closed without using button 5. When the door is closed after power-on, a light pull on the door causes controller 1 to detect the door signal change from low to high. Controller 1 then outputs a high Power signal, turning on the power supply +VDD2 of surge suppression circuit 3 to the push rod motor 4. Since the push rod motor 4 was pulled, its speed feedback signal FG changes. Controller 1 immediately transmits signals PWM1 and CW / CCW to push rod motor 4, causing it to start operating and push out the drawer and oven door. Subsequent processes are the same as button-controlled operation. Similarly, after the drawer and oven door are opened, a light push inwards causes another change in the speed feedback signal FG of push rod motor 4. Controller 1 immediately transmits signals PWM1 and CW / CCW to push rod motor 4, causing it to pull the drawer and oven door back. Subsequent processes are the same as button-controlled operation.

[0045] When the microwave operation is detected, controller 1 outputs a low POWER signal to turn off the push rod motor 4. Then, controller 1 outputs a square wave signal via PWM2 to the relay protection module 6. The relay protection module 6 shapes the square wave signal into a more stable DC signal and then sends it to the relay control module 7. At this time, the relay MAIN will turn on first. Then, controller 1 outputs a high VPC signal to turn on the relay VPC, which powers on the magnetron module of the microwave oven.

[0046] In this utility model, any microwave oven may include the control circuit and microwave oven structure of the oven door and drawer described in this embodiment. In addition to the relevant structure and assembly relationship of the door switch CN3 and surge suppression circuit 3 provided in this embodiment, the microwave oven also includes conventional components such as oven door, drawer, and motor. Since these are all prior art, they will not be described in detail here.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A control circuit for an oven door and drawer, characterized in that, The system includes a controller (1), a motor detection and control module (10), a button (5), a relay drive module (11), and a protection circuit (8). The controller (1) is connected to the motor detection and control module (10), the button (5), the relay drive module (11), and the protection circuit (8) respectively. The end of the relay drive module (11) away from the controller (1) is connected to the protection circuit (8) and the microwave relay (9) respectively. The motor detection and control module (10) includes a surge suppression circuit (3) and a push rod motor (4). One end of the surge suppression circuit (3) and the push rod motor (4) are both connected to the controller (1), and the other end of the surge suppression circuit (3) is connected to the other end of the push rod motor (4).

2. The control circuit for the oven door and drawer according to claim 1, characterized in that, The motor detection and control module (10) also includes a motor limit switch (2), which is connected to the controller (1).

3. The control circuit for the oven door and drawer according to claim 1, characterized in that, The relay drive module (11) includes a relay protection module (6) and a relay control module (7). Both the relay protection module (6) and the relay control module (7) are connected to the controller (1). The relay protection module (6) is connected to the protection circuit (8) and the relay control module (7) respectively.

4. The control circuit for the oven door and drawer according to claim 1, characterized in that, The control circuit also includes a fifth capacitor C5, one end of which is connected to pin 7 of the push rod motor (4), and the other end of which is grounded.

5. The control circuit for the oven door and drawer according to claim 3, characterized in that, The controller (1) is connected to the motor limit switch (2) via port SW, the controller (1) is connected to the surge suppression circuit (3) via port Power, and the controller (1) is connected to pins 4, 5, 6, and 7 of the push rod motor (4) via ports PWM1, BRAKE, CW / CCW, and FG respectively; the controller (1) is connected to the button (5) via port S1, the controller (1) is connected to the protection circuit (8) via port DOOR, the controller (1) is connected to the relay protection module (6) via port PWM2, and the controller (1) is connected to the relay control module (7) via port VPC.

6. The control circuit for the oven door and drawer according to claim 2, characterized in that, The motor limit switch (2) includes a first resistor R1, a second resistor R2, a first capacitor C1, and a limit switch CN1; one end of the first resistor R1 is connected to the power supply VCC, and the other end of the first resistor R1 is connected to the second resistor R2, one end of the first capacitor C1, and pin 1 of the limit switch CN1 respectively; the other end of the second resistor R2 is connected to the controller 1; the other end of the first capacitor C1 is connected to ground in parallel with pin 3 of the limit switch CN1.

7. The control circuit for the oven door and drawer according to claim 5, characterized in that, The surge suppression circuit (3) includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first resistor R11, a second capacitor C2, a MOSFET Q3, and a fifth transistor Q5.

8. The control circuit for the oven door and drawer according to claim 7, characterized in that, One end of the first resistor R11 is connected to the controller (1), and the other end of the first resistor R11 is connected to the base of the fifth transistor Q5. The emitter of the fifth transistor Q5 is connected to ground in parallel with pin 2 of the push rod motor (4). The collector of the fifth transistor Q5 is connected to one end of the second capacitor C2, the seventh resistor R7, and the eighth resistor R8 through the sixth resistor R6. The other end of the eighth resistor R8 is connected to the gate of the MOS transistor Q3. The other end of the second capacitor C2, the seventh resistor R7, and the source of the MOS transistor Q3 are connected in parallel and then connected to the power supply VDD2. The drain of the MOS transistor Q3 is connected to pin 1 of the push rod motor (4).

9. The control circuit for the oven door and drawer according to claim 1, characterized in that, The protection circuit (8) includes a door switch CN3, a third diode D3, a first six resistor R16, a first seven resistor R17, and a sixth capacitor C6; pin 3 of the door switch CN3 is grounded, pin 1 of the door switch CN3 is connected to the relay protection module (6) and the negative terminal of the third diode D3 respectively, the positive terminal of the third diode D3 is connected to one end of the first six resistor R16 and the first seven resistor R17 respectively, the other end of the first six resistor R16 is connected to the switching power supply, the other end of the first seven resistor R17 is connected to one end of the sixth capacitor C6 and the controller (1) respectively, and the other end of the sixth capacitor C6 is grounded.

10. A microwave oven, characterized in that, The microwave oven includes a control circuit for the oven door and drawer as described in any one of claims 1-9, the control circuit being disposed inside the microwave oven.

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