Secondary door opening complementary control circuit and microwave oven

Abstract

The utility model provides a secondary door opening complementary control circuit and a microwave oven. The secondary door opening complementary control circuit comprises an electromagnet, a first driving circuit, a second driving circuit, a protection circuit and a single chip microcomputer. One ends of the driving circuit I, the driving circuit II and the protection circuit are respectively connected with the electromagnet, the other end of the protection circuit is respectively connected with the driving circuit I and the driving circuit II, and the other ends of the driving circuit I and the driving circuit II are connected with the singlechip; the single-chip microcomputer comprises a first port IO1 and a second port IO2. The first driving circuit is connected with the first port IO1 through a first resistor R1. According to the secondary door opening complementary control circuit and the microwave oven provided by the utility model, the arrangement of the circuit structure can be simplified, and the condition that the unlocking coil and the locking coil work at the same time cannot occur no matter what state the singlechip IO port of the driving coil is in; and therefore, the accuracy and safety of locking and unlocking functions realized by using the electromagnet during secondary door opening are improved, and the service life of the electromagnet is prolonged.

Description

Technical Field

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

[0002] Currently, existing electronic double-door microwave ovens widely use electromagnets to achieve locking and unlocking functions. A typical electromagnet consists of two coils; supplying power to each coil individually controls the movement of the electromagnet's strut, thus achieving locking and unlocking, or enabling the electromagnet to move and maintain its position. Traditional solutions require two I / O ports of a microcontroller to control the drive circuit, which in turn implements locking and unlocking. However, in traditional solutions, interference or software malfunctions can cause the microcontroller's I / O ports to drive the locking and unlocking coils simultaneously, potentially damaging the electromagnet coils. Therefore, researching how to ensure that the unlocking and locking coils do not operate simultaneously regardless of the microcontroller's I / O port status is of great significance, as it improves the accuracy and security of electromagnet-controlled locking and unlocking.

[0003] Patent CN220911504U mentions a door opening control circuit and a microwave oven, including: a locking drive circuit, including a locking end connected to the first end of a first electromagnetic coil; an unlocking drive circuit, including an unlocking end connected to the first end of a second electromagnetic coil; a power supply, having a power supply terminal connected to the second end of the first electromagnetic coil and the second electromagnetic coil; a power regulation circuit, including a capacitor and a first resistor, the first end of the capacitor connected to the power supply terminal, the second end of the capacitor grounded, one end of the first resistor connected to the first end of the capacitor, and the second end of the first resistor used to connect to a first power supply terminal; and input / output ports, respectively connected to the locking drive circuit and the unlocking drive circuit. The input / output ports are used to control the locking end to lock or the unlocking end to unlock according to the output control signal, so that the power supplied by the power supply terminal can drive the solenoid valve to work normally. However, since this circuit focuses on solving the influence of the power supply terminal's power on the normal operation of the solenoid valve, it is still a controller that controls locking and unlocking. In the event of interference in the controller or software abnormality, it is still easy to drive the locking and unlocking coils to work simultaneously, which can lead to damage to the electromagnetic coil. Utility Model Content

[0004] In view of this, the present invention aims to propose a complementary control circuit for secondary door opening and a microwave oven, to solve the problem in the prior art where the microcontroller I / O port is interfered with or the software is abnormal, which can easily drive the locking and unlocking coils to work simultaneously, leading to damage to the electromagnetic coil. This simplifies the circuit structure and ensures that the unlocking and locking coils will not work simultaneously regardless of the state of the microcontroller I / O port driving the coil. Furthermore, it improves the accuracy and security of using electromagnets to achieve locking and unlocking functions for secondary door opening, extends the lifespan of the electromagnets, and reduces circuit costs.

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

[0006] This utility model relates to a complementary control circuit for secondary door opening and a microwave oven. The complementary control circuit for secondary door opening includes an electromagnet, a first drive circuit, a second drive circuit, a protection circuit, and a microcontroller. One end of the first drive circuit, the second drive circuit, and the protection circuit are respectively connected to the electromagnet. The other end of the protection circuit is respectively connected to the first drive circuit and the second drive circuit. The other ends of the first drive circuit and the second drive circuit are connected to the microcontroller. The microcontroller includes a first port IO1 and a second port IO2. The first drive circuit is connected to the first port IO1 through a first resistor R1. The first drive circuit and the second drive circuit are respectively connected to the second port IO2 through a third resistor R3 and a fourth resistor R4.

[0007] Furthermore, the electromagnet includes a power terminal 1, a control terminal 2, and a ground terminal 3; the power terminal 1, control terminal 2, and ground terminal 3 are all connected to the protection circuit; the control terminal 2 is connected to the second port IO2 and the first drive circuit respectively through the second drive circuit; the ground terminal 3 is connected to the first port IO1 through the first drive circuit.

[0008] Furthermore, the protection circuit includes a power supply VDD, a first diode D1, and a second diode D2; the power supply VDD is connected to the negative terminals of the first diode D1 and the second diode D2, and to power supply terminal 1, respectively; the positive terminal of the first diode D1 is connected to control terminal 2 and the second drive circuit, respectively; and the positive terminal of the second diode D2 is connected to ground terminal 3 and the first drive circuit, respectively.

[0009] Furthermore, both the first diode D1 and the second diode D2 are freewheeling diodes.

[0010] Furthermore, the power supply VDD value ranges from 10V to 14V.

[0011] Furthermore, the driving circuit includes a first transistor Q1, a second transistor Q2, a first resistor R1, and a second resistor R2; the collector of the first transistor Q1 is connected to the driving circuit, the collector of the first transistor Q1 is connected to the ground terminal 3, the protection circuit, and the third resistor R3 through the second transistor Q2, the emitter of the first transistor Q1 is connected in parallel with one end of the second resistor R2 and then grounded, the base of the first transistor Q1 is connected to the other end of the second resistor R2 and one end of the first resistor R1, and the other end of the first resistor R1 is connected to the first port IO1.

[0012] Furthermore, the second driving circuit includes a third transistor Q3, a fourth transistor Q4, a fifth resistor R5, and a sixth resistor R6.

[0013] Furthermore, the collector of the third transistor Q3 is connected to the base of the fourth transistor Q4 through the sixth resistor R6, the emitter of the fourth transistor Q4 is connected to the collector of the first transistor Q1, and the collector of the fourth transistor Q4 is connected to the protection circuit and the control terminal 2 respectively; the emitter of the third transistor Q3 is connected to the drive power supply and one end of the fifth resistor R5 respectively; and the base of the third transistor Q3 is connected to the other end of the fifth resistor R5 and the fourth resistor R4 respectively.

[0014] Furthermore, the drive power supply is set to 5V or 3.3V.

[0015] A microwave oven includes a secondary door opening complementary control circuit, the control circuit being disposed inside the microwave oven.

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

[0017] By incorporating the control circuit within the microwave oven, the circuit structure can be simplified, ensuring that the microcontroller's I / O port for the drive coil will never operate simultaneously with the locking coil, regardless of its state. This improves the accuracy and security of using electromagnets for locking and unlocking during secondary door opening, extends the electromagnet's lifespan, and reduces the cost of the control circuit. 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 circuit principle of the complementary control circuit for secondary door opening. Detailed Implementation

[0020] 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.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] This embodiment addresses a secondary door opening control circuit for a microwave oven. Similar to conventional secondary door opening control circuits, the overall structure consists of a microcontroller and an electromagnet. To address the problem in existing technologies where interference with the microcontroller's I / O port or software malfunctions can easily cause simultaneous operation of the locking and unlocking coils, leading to damage to the electromagnet, this embodiment proposes a complementary secondary door opening control circuit and a microwave oven. This complementary secondary door opening control circuit includes an electromagnet, a first drive circuit, a second drive circuit, a protection circuit, and a microcontroller. One end of each of the first drive circuit, the second drive circuit, and the protection circuit is connected to the electromagnet. The other end of the protection circuit is connected to the first drive circuit and the second drive circuit, respectively. The other ends of the first drive circuit and the second drive circuit are connected to the microcontroller. The microcontroller includes a first port I / O1 and a second port I / O2. The first drive circuit is connected to the first port I / O1 via a first resistor R1. The first drive circuit and the second drive circuit are connected to the second port I / O2 via a third resistor R3 and a fourth resistor R4, respectively.

[0024] By incorporating the control circuit within the microwave oven, the drive circuit configuration can be optimized, ensuring that the microcontroller I / O port of the drive coil will never experience simultaneous operation of the unlocking and locking coils, regardless of its state. This improves the accuracy and security of using electromagnets for locking and unlocking during secondary door opening, extends the electromagnet's lifespan, and reduces the cost of the control circuit.

[0025] The electromagnet includes a power terminal 1, a control terminal 2, and a ground terminal 3. Power terminal 1, control terminal 2, and ground terminal 3 are all connected to a protection circuit; control terminal 2 is connected to the second port IO2 and the first drive circuit respectively via a second drive circuit; ground terminal 3 is connected to the first port IO1 via a first drive circuit.

[0026] By connecting each terminal of the electromagnet to the protection circuit, the first drive circuit, and the second drive circuit, the safety and stability of the complementary control between the first port IO1 and the second port IO2 of the microcontroller can be achieved under the action of the protection circuit.

[0027] The protection circuit includes a power supply VDD, a first diode D1, and a second diode D2. The power supply VDD is connected to the negative terminals of both diodes D1 and D2, and to power supply terminal 1. The positive terminal of diode D1 is connected to control terminal 2 and a second drive circuit, and the positive terminal of diode D2 is connected to ground terminal 3 and a first drive circuit. Both diodes D1 and D2 are freewheeling diodes. The power supply VDD ranges from 10V to 14V. Preferably, VDD is typically set to 12V, but the specific setting depends on the requirements.

[0028] By placing a first diode D1 and a second diode D2 at both ends of the solenoid valve coil, the solenoid valve coil can be protected, the safety of the control circuit can be improved, the drive circuit can be stably operated, and damage to the solenoid coil caused by abnormal interference can be avoided.

[0029] The driving circuit includes a first transistor Q1, a second transistor Q2, a first resistor R1, and a second resistor R2. The collector of the first transistor Q1 is connected to the driving circuit. The collector of the first transistor Q1 is connected to the ground terminal 3, the positive terminal of the second diode D2 in the protection circuit, and the third resistor R3 through the second transistor Q2. The emitter of the first transistor Q1 is connected to ground in parallel with one end of the second resistor R2. The base of the first transistor Q1 is connected to the other end of the second resistor R2 and one end of the first resistor R1. The other end of the first resistor R1 is connected to the first port IO1.

[0030] By coordinating the various transistors and resistors within the driver circuit, the control circuit can be simplified, its cost reduced, and it can be used in conjunction with the driver circuit to achieve precise control of the first port IO1.

[0031] The driving circuit includes a third transistor Q3, a fourth transistor Q4, a fifth resistor R5, and a sixth resistor R6. The collector of the third transistor Q3 is connected to the base of the fourth transistor Q4 through the sixth resistor R6. The emitter of the fourth transistor Q4 is connected to the collector of the first transistor Q1. The collector of the fourth transistor Q4 is connected to the anode of the first diode D1 in the protection circuit and the control terminal 2. The emitter of the third transistor Q3 is connected to the driving power supply and one end of the fifth resistor R5. The base of the third transistor Q3 is connected to the other end of the fifth resistor R5 and the fourth resistor R4. In this embodiment, the driving power supply is set to +5V or +3.3V.

[0032] By adjusting the settings of the third transistor Q3, the fourth transistor Q4, and the various resistors within the driving circuit, the control circuit can be simplified, circuit costs reduced, and precise control of the second port IO2 can be achieved. This avoids the impact of external interference or software malfunctions on the electromagnet's unlocking and locking actions, thus improving the protection of the electromagnet.

[0033] In this embodiment, transistors Q1, Q2, and Q4 are all NPN transistors, and transistor Q3 is a PNP transistor. In the first and second driver circuits, transistors Q1, Q2, Q3, and Q4 can be replaced with MOS transistors. Specifically, transistors Q1, Q2, and Q4 are NMOS transistors, and transistor Q3 is a PMOS transistor.

[0034] Using transistors or MOSFETs to construct the drive circuit improves the flexibility of the internal component settings of the control circuit and expands its applicability. It also paves the way for locking and unlocking the solenoid valve by setting the high and low levels of the microcontroller's I / O ports.

[0035] Work process:

[0036] After the circuit is powered on, the drive signal output by the control circuit has four states depending on the high and low levels of the signals input to the first port IO1 and the second port IO2. These four states are as follows:

[0037] In the first state, when the first port IO1 is set to high level and the second port IO2 is set to low level, the first transistor Q1, the third transistor Q3, and the fourth transistor Q4 are turned on, the second transistor Q2 is turned off, and the power supply VDD is connected to the electromagnet unlocking coil.

[0038] The second state is when the first port IO1 is set to high level and the second port IO2 is set to high level, the first transistor Q1 and the second transistor Q2 are turned on, the third transistor Q3 and the fourth transistor Q4 are turned off, and the power supply VDD is connected to the electromagnet locking coil.

[0039] In the third state, when both the first port IO1 and the second port IO2 are set to low level, the first transistor Q1 is cut off, and the electromagnet does not operate.

[0040] In the fourth state, when the first port IO1 is set to low and the second port IO2 is set to high, the first transistor Q1 is cut off, and the electromagnet does not operate. See Table 1 below for the truth table of the control circuit operation process.

[0041] The high-level time of the first port IO1 is >200ms. This is used to ensure effective driving of the solenoid valve.

[0042] Table 1

[0043]

[0044] The microcontroller's first port IO1 is controlled by the complementary output of the second port IO2. No matter what state the first port IO1 and the second port IO2 are set to, the unlocking coil and the locking coil will not work at the same time.

[0045] In this utility model, any microwave oven may include the secondary door opening complementary control circuit and microwave oven structure described in this embodiment. In addition to the diode and transistor related structures and assembly relationships provided in this embodiment, the microwave oven also includes conventional components such as a microcontroller and an electromagnet. Since these are all prior art, they will not be described in detail here.

[0046] 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 complementary control circuit for secondary door opening, characterized in that, It includes an electromagnet, a first drive circuit, a second drive circuit, a protection circuit, and a microcontroller. One end of the first drive circuit, the second drive circuit, and the protection circuit are respectively connected to the electromagnet. The other end of the protection circuit is respectively connected to the first drive circuit and the second drive circuit. The other ends of the first drive circuit and the second drive circuit are connected to the microcontroller. The microcontroller includes a first port IO1 and a second port IO2. The first drive circuit is connected to the first port IO1 through a first resistor R1. The first drive circuit and the second drive circuit are respectively connected to the second port IO2 through a third resistor R3 and a fourth resistor R4.

2. The complementary control circuit for secondary door opening according to claim 1, characterized in that, The electromagnet includes a power terminal 1, a control terminal 2, and a ground terminal 3; the power terminal 1, control terminal 2, and ground terminal 3 are all connected to the protection circuit; the control terminal 2 is connected to the second port IO2 and the first drive circuit respectively through the second drive circuit; the ground terminal 3 is connected to the first port IO1 through the first drive circuit.

3. The complementary control circuit for secondary door opening according to claim 2, characterized in that, The protection circuit includes a power supply VDD, a first diode D1, and a second diode D2. The power supply VDD is connected to the negative terminals of the first diode D1 and the second diode D2, and to power supply terminal 1, respectively. The positive terminal of the first diode D1 is connected to control terminal 2 and the second drive circuit, respectively. The positive terminal of the second diode D2 is connected to ground terminal 3 and the first drive circuit, respectively.

4. The complementary control circuit for secondary door opening according to claim 3, characterized in that, Both the first diode D1 and the second diode D2 are freewheeling diodes.

5. The complementary control circuit for secondary door opening according to claim 3, characterized in that, The power supply VDD has a value range of 10V-14V.

6. The complementary control circuit for secondary door opening according to claim 2, characterized in that, The driving circuit includes a first transistor Q1, a second transistor Q2, a first resistor R1, and a second resistor R2. The collector of the first transistor Q1 is connected to the driving circuit. The collector of the first transistor Q1 is connected to the ground terminal 3, the protection circuit, and the third resistor R3 through the second transistor Q2. The emitter of the first transistor Q1 is connected in parallel with one end of the second resistor R2 and then grounded. The base of the first transistor Q1 is connected to the other end of the second resistor R2 and one end of the first resistor R1. The other end of the first resistor R1 is connected to the first port IO1.

7. The complementary control circuit for secondary door opening according to claim 6, characterized in that, The driving circuit includes a third transistor Q3, a fourth transistor Q4, a fifth resistor R5, and a sixth resistor R6.

8. The complementary control circuit for secondary door opening according to claim 7, characterized in that, The collector of the third transistor Q3 is connected to the base of the fourth transistor Q4 through the sixth resistor R6. The emitter of the fourth transistor Q4 is connected to the collector of the first transistor Q1. The collector of the fourth transistor Q4 is connected to the protection circuit and the control terminal 2. The emitter of the third transistor Q3 is connected to the driving power supply and one end of the fifth resistor R5. The base of the third transistor Q3 is connected to the other end of the fifth resistor R5 and the fourth resistor R4.

9. A complementary control circuit for secondary door opening according to claim 8, characterized in that, The drive power supply is set to 5V or 3.3V.

10. A microwave oven, characterized in that, The microwave oven includes a secondary door opening complementary control circuit as described in any one of claims 1-9, wherein the control circuit is disposed inside the microwave oven.

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