Control circuit and device for low-temperature microwave sterilization

Abstract

The utility model provides a kind of low-temperature microwave sterilization control circuit and device, it is related to the technical field of microwave sterilization, including power supply circuit, trigger circuit, control switch circuit, signal amplification circuit, signal indicating circuit and protection circuit;The output end of power supply circuit is connected respectively the input end of trigger circuit and the input end of control switch circuit, the output end of trigger circuit connects the input end of power supply circuit, the output end of control switch circuit connects the input end of signal amplification circuit, the output end of signal amplification circuit connects the input end of signal indicating circuit, the output end of signal indicating circuit connects the input end of protection circuit.The utility model can reduce equipment energy consumption, simplify operation, stable signal, realize heating uniform, real-time monitoring, high safety.

Description

Technical Field

[0001] This utility model relates to the technical field of microwave sterilization, and in particular to a control circuit and device for low-temperature microwave sterilization. Background Technology

[0002] Low-temperature microwave sterilization technology utilizes the thermal and non-thermal effects of microwaves to kill or inhibit the growth of microorganisms. The thermal effect involves the heating action of microwaves, which denatures the proteins of microorganisms, thereby achieving sterilization. The non-thermal effect involves the electromagnetic field of microwaves interfering with the function of the cell membrane and organelles of microorganisms, thus achieving sterilization. Low-temperature microwave sterilization technology has been widely used in the fresh food industry, such as the preservation of fresh meat, fresh-cut fruits and vegetables. This technology can extend the shelf life of food while maintaining its quality and nutritional value. In addition, low-temperature microwave sterilization equipment has the advantages of simple operation, energy saving and environmental protection, and small footprint, making it suitable for industrial applications.

[0003] Currently, low-temperature microwave sterilization equipment has significant technological advantages in the food processing field. The core component of this equipment is the control circuit. While existing control circuits can achieve sterilization, they suffer from the following drawbacks: First, the equipment consumes a lot of energy during operation, resulting in high operating costs and limiting its widespread application. Second, the equipment is complex to operate, requiring specialized technicians for operation and circuit maintenance, increasing the difficulty of application. Third, microwave signals are easily affected by environmental factors during transmission, leading to signal instability and interference, impacting reliability and sterilization effectiveness. Fourth, the control circuit is prone to uneven heating during microwave heating, resulting in incomplete sterilization or overheating in some areas, affecting food quality and safety. Fifth, the lack of real-time monitoring makes it difficult to assess sterilization effectiveness and ensure operational safety and reliability. Finally, microwave leakage may occur during operation, threatening operator safety, and the environmental impact requires further evaluation. Summary of the Invention

[0004] To address the problems of high energy consumption, complex operation, unstable signal, uneven heating, lack of real-time monitoring, and insufficient safety in the existing technology, this utility model proposes a control circuit and device for low-temperature microwave sterilization, which can reduce equipment energy consumption, simplify operation, stabilize the signal, achieve uniform heating, real-time monitoring, and high safety.

[0005] To achieve the above-mentioned technical effects, the technical solution of this utility model is as follows:

[0006] A control circuit for low-temperature microwave sterilization includes: a power supply circuit, a trigger circuit, a control switch circuit, a signal amplification circuit, a signal indication circuit, and a protection circuit;

[0007] The output terminal of the power supply circuit is connected to the input terminal of the trigger circuit and the input terminal of the control switch circuit, respectively. The output terminal of the trigger circuit is connected to the input terminal of the power supply circuit. The output terminal of the control switch circuit is connected to the input terminal of the signal amplification circuit. The output terminal of the signal amplification circuit is connected to the input terminal of the signal indication circuit. The output terminal of the signal indication circuit is connected to the input terminal of the protection circuit.

[0008] Preferably, it further includes: a magnetic control circuit, wherein the input terminal of the magnetic control circuit is connected to the output terminal of the trigger circuit, and the output terminal of the magnetic control circuit is connected to the input terminal of the power supply circuit.

[0009] Preferably, the magnetic control circuit includes a first magnetron CU1 and a second magnetron CU2 connected in parallel.

[0010] Preferably, the power supply circuit includes an AC power supply and a fuse FU, the output terminal of the AC power supply is connected to one end of the fuse FU, and the other end of the fuse FU triggers the input terminal of the circuit.

[0011] Preferably, the trigger circuit includes a first relay contact K1, a second relay contact K2, a first resistor R1, a first capacitor C1, a second capacitor C2, a thyristor SCR, a second resistor R2, a third resistor R3, and a transistor Q. The output terminal of the power supply circuit is connected to the first relay contact K1, the second relay contact K2, and the input terminal of the control switch circuit. The first relay contact K1 is connected to one end of the first resistor R1 and the first capacitor C1. The other end of the first resistor R1 and the first capacitor C1 is connected to the base of the transistor Q. The collector of the transistor Q is connected to one end of the second capacitor C2, one end of the second resistor R2, and the input terminal of the thyristor SCR. The other end of the second capacitor C2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the second resistor R2 and the output terminal of the thyristor SCR. The emitter of the transistor Q is connected to the input terminal of the power supply circuit.

[0012] Preferably, the control switch circuit includes a transformer T1, a control switch S, a rectifier bridge 4XIN4004, a third capacitor C3, a fourth capacitor C4, and a positive voltage linear regulator LDO. One end of the primary winding of the transformer T1 is connected to the output terminal of the power supply circuit, and the other end of the primary winding of the transformer T1 is connected to the input terminal of the power supply circuit. One end of the secondary winding of the transformer T1 is connected to one end of the control switch S, and the other end of the control switch S is connected to the first pin of the rectifier bridge 4XIN4004. The third pin of the rectifier bridge 4XIN4004 is connected to the other end of the secondary winding of the transformer T1. The third pin of the rectifier bridge 4XIN4004 is connected to one end of the third capacitor C3 and the first pin of the positive voltage linear regulator LDO. The second pin of the positive voltage linear regulator LDO is connected to one end of the fourth capacitor C4. The third pin of the positive voltage linear regulator LDO, the other end of the fourth capacitor C4, and the other end of the third capacitor C3 are all connected to the fourth pin of the rectifier bridge 4XIN4004.

[0013] The signal amplification circuit includes a fourth resistor R4, a first indicator LED1, a current diode D6, a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6, a normally open relay switch AN1, a sixth capacitor C6, a timer NE555, and a seventh capacitor C7. One end of the fourth resistor R4 is connected to one end of the fourth capacitor C4, the negative terminal of the current diode D6, one end of the fifth capacitor C5, one end of the fifth resistor R5, one end of the sixth resistor R6, and the fourth and eighth pins of the timer NE555. The other end of the fourth resistor R4 is connected to the positive terminal of the first indicator LED1, and the current diode D6... The positive terminal of the fifth capacitor C5, the other end of the fifth resistor R5, and the other end of the sixth resistor R6 are all connected to one end of the normally open relay switch AN1. The other end of the sixth resistor R6 is connected to one end of the normally open relay switch AN1, the seventh pin, the sixth pin, the second pin of the timer NE555, and one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the other end of the fourth capacitor C4, the negative terminal of the first indicator LED1, the other end of the normally open relay switch AN1, the first pin of the timer NE555, and one end of the seventh capacitor C7. The other end of the seventh capacitor C7 is connected to the fifth pin of the timer NE555.

[0014] Preferably, the signal indication circuit includes a second indicator LED2 and a seventh resistor R7. One end of the seventh resistor R7 is connected to the third pin of the timer NE555, the other end of the seventh resistor R7 is connected to the positive terminal of the second indicator LED2, and the negative terminal of the second indicator LED2 is connected to one end of the seventh capacitor C7.

[0015] Preferably, the protection circuit includes a reverse diode D11 and a relay K3. The positive terminal of the reverse diode D11 is connected to the negative terminal of the second indicator LED2 and one end of the relay K3, respectively. The other end of the relay K3 is connected to the negative terminal of the reverse diode D11 and the third pin of the timer NE555.

[0016] The present invention also proposes a low-temperature microwave sterilization device, including the control circuit for low-temperature microwave sterilization as described above.

[0017] Compared with the prior art, the beneficial effects of this utility model's technical solution are:

[0018] This invention proposes a control circuit for low-temperature microwave sterilization, comprising a power supply circuit, a trigger circuit, a control switch circuit, a signal amplification circuit, a signal indicator circuit, and a protection circuit. First, the power supply circuit efficiently converts the input electrical energy into alternating current, providing a stable operating voltage and reducing equipment energy consumption. Second, the trigger circuit receives the stable voltage output from the power supply circuit and generates a precise trigger signal. This trigger signal is fed back to the power supply circuit for closed-loop control and simultaneously triggers the microwave signal through the control switch circuit, ensuring the stability and accuracy of the microwave signal triggering. Then, the control switch circuit precisely controls the on / off sequence of the microwave generator based on the trigger signal, achieving automated control, reducing manual intervention, simplifying the operation process, and transmitting the control signal to the signal amplification circuit. Next, the signal amplification circuit amplifies the control signal and shapes its waveform, ensuring uniform distribution of microwave energy, avoiding localized overheating or incomplete sterilization, achieving uniform microwave distribution in food, and improving the sterilization effect. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of a control circuit for low-temperature microwave sterilization proposed in an embodiment of the present invention.

[0020] Figure 2 This is another structural block diagram of a control circuit for low-temperature microwave sterilization proposed in an embodiment of the present invention;

[0021] Figure 3 This diagram illustrates a control circuit for low-temperature microwave sterilization as described in an embodiment of this utility model.

[0022] 1. Power supply current; 2. Trigger circuit; 3. Control switch circuit; 4. Signal amplification circuit; 5. Signal indication circuit; 6. Protection circuit; 7. Magnetic control circuit. Detailed Implementation

[0023] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0024] It is understandable to those skilled in the art that some well-known details may be omitted from the accompanying drawings;

[0025] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0026] Example 1

[0027] like Figure 1 As shown, this embodiment proposes a control circuit for low-temperature microwave sterilization, including: a power supply circuit 1, a trigger circuit 2, a control switch circuit 3, a signal amplification circuit 4, a signal indication circuit 5, and a protection circuit 6.

[0028] The output terminal of the power supply circuit 1 is connected to the input terminal of the trigger circuit 2 and the input terminal of the control switch circuit 3, respectively. The output terminal of the trigger circuit 2 is connected to the input terminal of the power supply circuit 1. The output terminal of the control switch circuit 3 is connected to the input terminal of the signal amplification circuit 4. The output terminal of the signal amplification circuit 4 is connected to the input terminal of the signal indication circuit 5. The output terminal of the signal indication circuit 5 is connected to the input terminal of the protection circuit 6.

[0029] First, the power supply circuit 1 efficiently converts the input electrical energy into alternating current, providing a stable operating voltage for the circuit and reducing equipment energy consumption. Second, the trigger circuit 2 receives the stable voltage output from the power supply circuit 1 and generates a precise trigger signal. This trigger signal is fed back to the power supply circuit 1 to achieve closed-loop control, and also triggers the microwave signal through the control switch circuit 3, ensuring the stability and accuracy of the microwave signal triggering. Then, the control switch circuit 3 precisely controls the on / off sequence of the microwave generator according to the trigger signal, achieving automated control, reducing manual intervention, simplifying the operation process, and transmitting the control signal to the signal amplification circuit 4. Next, the signal amplification circuit 4 amplifies the power and shapes the waveform of the control signal to ensure uniform distribution of microwave energy, avoid local overheating or incomplete sterilization, achieve uniform microwave distribution in food, and improve the sterilization effect.

[0030] See Figure 2 and Figure 3 The control circuit further includes a magnetic control circuit 7. The input terminal of the magnetic control circuit 7 is connected to the output terminal of the trigger circuit 2, and the output terminal of the magnetic control circuit 7 is connected to the input terminal of the power supply circuit 1. The magnetic control circuit 7 includes a first magnetron CU1 and a second magnetron CU2 connected in parallel, with a model of 300W / 220V. The first magnetron CU1 and the second magnetron CU2 generate microwaves when the second relay contact K2 of the trigger circuit 2 is closed. However, if one of the first magnetron CU1 or the second magnetron CU2 is damaged, the other magnetron can still maintain 50% sterilization capability.

[0031] The power supply circuit 1 includes an AC power supply and a fuse FU. The output terminal of the AC power supply is connected to one end of the fuse FU, and the other end of the fuse FU triggers the input terminal of the circuit 2. The fuse FU is a low-impedance fuse with an overload current of 10A. The AC power supply input is 220V AC, which provides power to the entire circuit. The low-impedance fuse FU can not only reduce power line losses and improve the overall energy conversion efficiency, but also achieve millisecond-level fast circuit breaking to prevent equipment damage caused by short circuits or overloads.

[0032] The trigger circuit 2 includes a first relay contact K1, a second relay contact K2, a first resistor R1, a first capacitor C1, a second capacitor C2, a thyristor SCR, a second resistor R2, a third resistor R3, and a transistor Q. The output terminal of the power supply circuit 1 is connected to the first relay contact K1, the second relay contact K2, and the input terminal of the control switch circuit 3. The first relay contact K1 is connected to one end of the first resistor R1 and the first capacitor C1. The other end of the first resistor R1 and the first capacitor C1 is connected to the base of the transistor Q. The collector of the transistor Q is connected to one end of the second capacitor C2, one end of the second resistor R2, and the input terminal of the thyristor SCR. The other end of the second capacitor C2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the second resistor R2 and the output terminal of the thyristor SCR. The emitter of the transistor Q is connected to the input terminal of the power supply circuit 1. The first relay contact K1 and the second relay contact K2 are the two contacts of the relay, used to control the on and off of the circuit; the first resistor R1 is used to limit the current and protect the relay coil; the first capacitor C1 and the second capacitor C2 are used to smooth voltage fluctuations and protect the circuit from voltage spikes; the thyristor SCR controls the generation of microwaves under the action of the trigger circuit 2, and the second resistor R2 and the third resistor R3 are used to limit the current flowing through the thyristor SCR and protect the thyristor SCR.

[0033] Example 2

[0034] See Figure 3The control switch circuit 3 includes a transformer T1, a control switch S, a rectifier bridge 4XIN4004, a third capacitor C3, a fourth capacitor C4, and a positive voltage linear regulator LDO. One end of the primary winding of the transformer T1 is connected to the output terminal of the power supply circuit 1, and the other end of the primary winding of the transformer T1 is connected to the input terminal of the power supply circuit 1. One end of the secondary winding of the transformer T1 is connected to one end of the control switch S, and the other end of the control switch S is connected to the first pin of the rectifier bridge 4XIN4004. The third pin of the rectifier bridge 4XIN4004 is connected to the other end of the secondary winding of the transformer T1. The third pin of the rectifier bridge 4XIN4004 is connected to one end of the third capacitor C3 and the first pin of the positive voltage linear regulator LDO. The second pin of the positive voltage linear regulator LDO is connected to one end of the fourth capacitor C4. The third pin of the positive voltage linear regulator LDO, the other end of the fourth capacitor C4, and the other end of the third capacitor C3 are all connected to the fourth pin of the rectifier bridge 4XIN4004. Control switch S is used to start and stop the entire device; transformer T1 converts 220V AC to the required low-voltage AC; rectifier bridge 4XIN4004 is used to convert old AC to DC, working with positive voltage linear regulator LDO to ensure output stability; third capacitor C3 and fourth capacitor C4 are used for smoothing and filtering to smooth the DC voltage.

[0035] The signal amplification circuit 4 includes a fourth resistor R4, a first indicator LED1, a current diode D6, a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6, a normally open relay switch AN1, a sixth capacitor C6, a timer NE555, and a seventh capacitor C7. One end of the fourth resistor R4 is connected to one end of the fourth capacitor C4, the negative terminal of the current diode D6, one end of the fifth capacitor C5, one end of the fifth resistor R5, one end of the sixth resistor R6, and the fourth and eighth pins of the timer NE555. The other end of the fourth resistor R4 is connected to the positive terminal of the first indicator LED1, and the current diode D6... The positive terminal of the fifth capacitor C5, the other end of the fifth resistor R5, and the other end of the sixth resistor R6 are all connected to one end of the normally open relay switch AN1. The other end of the sixth resistor R6 is connected to one end of the normally open relay switch AN1, the seventh pin, the sixth pin, the second pin of the timer NE555, and one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the other end of the fourth capacitor C4, the negative terminal of the first indicator LED1, the other end of the normally open relay switch AN1, the first pin of the timer NE555, and one end of the seventh capacitor C7. The other end of the seventh capacitor C7 is connected to the fifth pin of the timer NE555.

[0036] The NE555 timer is used to generate pulse signals to control microwave generation; the current diode D6 is used for unidirectional conduction, that is, it allows current to flow from the anode to the cathode and prevents reverse current; the fifth resistor R5 and the fifth capacitor C5 are connected in parallel to match the impedance; the first indicator LED1 is used to show whether the signal amplifier circuit 4 is working properly; the fourth resistor R4 and the sixth resistor R6 are used to adjust the frequency and duty cycle of the pulse signal; the fifth capacitor C5 and the sixth capacitor C6, together with the resistors, adjust the time constant of the pulse signal; the seventh capacitor C7 is used to filter the current flowing into the fifth pin of the NE555 timer.

[0037] The signal indication circuit 5 includes a second indicator LED2 and a seventh resistor R7. One end of the seventh resistor R7 is connected to the third pin of the timer NE555, and the other end of the seventh resistor R7 is connected to the positive terminal of the second indicator LED2. The negative terminal of the second indicator LED2 is connected to one end of the seventh capacitor C7. The second indicator LED2 displays the operating status of the overall low-temperature microwave sterilization control circuit; the seventh resistor R7 is used to limit the current flowing through the second indicator LED2 to prevent the operating current of the second indicator LED2 from being too high.

[0038] The protection circuit 6 includes a reverse diode D11 and a relay K3. The positive terminal of the reverse diode D11 is connected to the negative terminal of the second indicator LED2 and one end of the relay K3. The other end of the relay K3 is connected to the negative terminal of the reverse diode D11 and the third pin of the timer NE555. The reverse diode D11 prevents reverse current flow, protecting the relay K3 and other circuit components from damage by reverse voltage. The relay K3 acts as a safety switch, cutting off the power supply when microwave leakage or other abnormal conditions are detected, ensuring the safety of the equipment and operators.

[0039] Example 3

[0040] This embodiment also proposes a low-temperature microwave sterilization device, including a control circuit for low-temperature microwave sterilization as described in the above embodiment, comprising: a power supply circuit 1, a trigger circuit 2, a control switch circuit 3, a signal amplification circuit 4, a signal indication circuit 5, and a protection circuit 6.

[0041] The output terminal of the power supply circuit 1 is connected to the input terminal of the trigger circuit 2 and the input terminal of the control switch circuit 3, respectively. The output terminal of the trigger circuit 2 is connected to the input terminal of the power supply circuit 1. The output terminal of the control switch circuit 3 is connected to the input terminal of the signal amplification circuit 4. The output terminal of the signal amplification circuit 4 is connected to the input terminal of the signal indication circuit 5. The output terminal of the signal indication circuit 5 is connected to the input terminal of the protection circuit 6.

[0042] First, the power supply circuit 1 efficiently converts the input electrical energy into alternating current, providing a stable operating voltage for the circuit and reducing equipment energy consumption. Second, the trigger circuit 2 receives the stable voltage output from the power supply circuit 1 and generates a precise trigger signal. This trigger signal is fed back to the power supply circuit 1 to achieve closed-loop control, and also triggers the microwave signal through the control switch circuit 3, ensuring the stability and accuracy of the microwave signal triggering. Then, the control switch circuit 3 precisely controls the on / off sequence of the microwave generator according to the trigger signal, achieving automated control, reducing manual intervention, simplifying the operation process, and transmitting the control signal to the signal amplification circuit 4. Next, the signal amplification circuit 4 amplifies the power and shapes the waveform of the control signal to ensure uniform distribution of microwave energy, avoid local overheating or incomplete sterilization, achieve uniform microwave distribution in food, and improve the sterilization effect.

[0043] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this 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 protection scope of the claims of this utility model.

Claims

1. A control circuit for low-temperature microwave sterilization, characterized in that, include: Power supply circuit (1), trigger circuit (2), control switch circuit (3), signal amplification circuit (4), signal indication circuit (5) and protection circuit (6); The output terminal of the power supply circuit (1) is connected to the input terminal of the trigger circuit (2) and the input terminal of the control switch circuit (3), respectively. The output terminal of the trigger circuit (2) is connected to the input terminal of the power supply circuit (1), the output terminal of the control switch circuit (3) is connected to the input terminal of the signal amplification circuit (4), the output terminal of the signal amplification circuit (4) is connected to the input terminal of the signal indicator circuit (5), and the output terminal of the signal indicator circuit (5) is connected to the input terminal of the protection circuit (6).

2. The control circuit for low-temperature microwave sterilization according to claim 1, characterized in that, Also includes: The magnetic control circuit (7) has its input terminal connected to the output terminal of the trigger circuit (2) and its output terminal connected to the input terminal of the power supply circuit (1).

3. The control circuit for low-temperature microwave sterilization according to claim 2, characterized in that, The magnetic control circuit (7) includes a first magnetron CU1 and a second magnetron CU2 connected in parallel.

4. The control circuit for low-temperature microwave sterilization according to claim 1, characterized in that, The power supply circuit (1) includes an AC power supply and a fuse FU. The output end of the AC power supply is connected to one end of the fuse FU, and the other end of the fuse FU triggers the input end of the circuit (2).

5. The control circuit for low-temperature microwave sterilization according to claim 1, characterized in that, The trigger circuit (2) includes a first relay contact K1, a second relay contact K2, a first resistor R1, a first capacitor C1, a second capacitor C2, a thyristor SCR, a second resistor R2, a third resistor R3, and a transistor Q. The output terminal of the power supply circuit (1) is connected to the first relay contact K1, the second relay contact K2, and the input terminal of the control switch circuit (3). The first relay contact K1 is connected to one end of the first resistor R1 and the first capacitor C1. The other end of the first resistor R1 and the first capacitor C1 is connected to the base of the transistor Q. The collector of the transistor Q is connected to one end of the second capacitor C2, one end of the second resistor R2, and the input terminal of the thyristor SCR. The other end of the second capacitor C2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the second resistor R2 and the output terminal of the thyristor SCR. The emitter of the transistor Q is connected to the input terminal of the power supply circuit (1).

6. The control circuit for low-temperature microwave sterilization according to claim 1, characterized in that, The control switch circuit (3) includes a transformer T1, a control switch S, a rectifier bridge 4XIN4004, a third capacitor C3, a fourth capacitor C4, and a positive voltage linear regulator LDO. One end of the primary winding of the transformer T1 is connected to the output terminal of the power supply circuit (1), and the other end of the primary winding of the transformer T1 is connected to the input terminal of the power supply circuit (1). One end of the secondary winding of the transformer T1 is connected to one end of the control switch S, and the other end of the control switch S is connected to the first pin of the rectifier bridge 4XIN4004. The third pin of the rectifier bridge 4XIN4004 is connected to the other end of the secondary winding of the transformer T1. The third pin of the rectifier bridge 4XIN4004 is connected to one end of the third capacitor C3 and the first pin of the positive voltage linear regulator LDO. The second pin of the positive voltage linear regulator LDO is connected to one end of the fourth capacitor C4. The third pin of the positive voltage linear regulator LDO, the other end of the fourth capacitor C4, and the other end of the third capacitor C3 are all connected to the fourth pin of the rectifier bridge 4XIN4004.

7. The control circuit for low-temperature microwave sterilization according to claim 6, characterized in that, The signal amplification circuit (4) includes a fourth resistor R4, a first indicator LED1, a current diode D6, a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6, a normally open relay switch AN1, a sixth capacitor C6, a timer NE555, and a seventh capacitor C7. One end of the fourth resistor R4 is connected to one end of the fourth capacitor C4, the negative terminal of the current diode D6, one end of the fifth capacitor C5, one end of the fifth resistor R5, one end of the sixth resistor R6, and the fourth and eighth pins of the timer NE555. The other end of the fourth resistor R4 is connected to the positive terminal of the first indicator LED1. The current diode D6... The positive terminal of capacitor 6, the other end of the fifth capacitor C5, and the other end of the fifth resistor R5 are all connected to one end of the normally open relay switch AN1. The other end of the sixth resistor R6 is connected to one end of the normally open relay switch AN1, the seventh pin, the sixth pin, the second pin of the timer NE555, and one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is connected to the other end of the fourth capacitor C4, the negative terminal of the first indicator LED1, the other end of the normally open relay switch AN1, the first pin of the timer NE555, and one end of the seventh capacitor C7. The other end of the seventh capacitor C7 is connected to the fifth pin of the timer NE555.

8. The control circuit for low-temperature microwave sterilization according to claim 7, characterized in that, The signal indication circuit (5) includes a second indicator LED2 and a seventh resistor R7. One end of the seventh resistor R7 is connected to the third pin of the timer NE555, and the other end of the seventh resistor R7 is connected to the positive terminal of the second indicator LED2. The negative terminal of the second indicator LED2 is connected to one end of the seventh capacitor C7.

9. The control circuit for low-temperature microwave sterilization according to claim 8, characterized in that, The protection circuit (6) includes a reverse diode D11 and a relay K3. The positive terminal of the reverse diode D11 is connected to the negative terminal of the second indicator LED2 and one end of the relay K3, respectively. The other end of the relay K3 is connected to the negative terminal of the reverse diode D11 and the third pin of the timer NE555.

10. A low-temperature microwave sterilization device, characterized in that, It includes the control circuit for low-temperature microwave sterilization as described in any one of claims 1-9.

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