CN219611343U - Microwave oven protection circuit and microwave oven - Google Patents
Microwave oven protection circuit and microwave oven Download PDFInfo
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- CN219611343U CN219611343U CN202320165905.9U CN202320165905U CN219611343U CN 219611343 U CN219611343 U CN 219611343U CN 202320165905 U CN202320165905 U CN 202320165905U CN 219611343 U CN219611343 U CN 219611343U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
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Abstract
The present disclosure relates to a microwave oven protection circuit and a microwave oven. The microwave oven protection circuit includes: one end of the voltage surge protection circuit is respectively connected with sampling points corresponding to the L line and the N line, and the other end of the voltage surge protection circuit is connected with the input end of the PWM signal output module; the output end of the PWM signal output module is connected with the first end of the DC-AC conversion circuit through a switching tube; the second end of the orthogonal conversion circuit is connected with the L line and the N line respectively; the third end of the DC-AC conversion circuit is connected with the magnetron. When the LN line has high-voltage surge signals, the surge detection voltage signals on the sampled L line and N line are raised, and when the voltage surge detection voltage signals are higher than the voltage surge protection threshold, the PWM signal output module can instantly close the output of the PWM signal output module to stop the work of the IGBT and prevent the IGBT from breakdown and short circuit caused by high-voltage surge.
Description
Technical Field
The disclosure relates to the technical field of household appliances, in particular to a microwave oven protection circuit and a microwave oven.
Background
In the existing frequency conversion microwave oven in the market, under the abnormal power grid surge condition, the frequency conversion microwave oven is easy to be impacted by high-voltage surges, and when the high-voltage surges are received, if the high-frequency switching tube IGBT in the frequency conversion microwave oven is not stopped in time, the frequency conversion microwave oven is easy to be broken down and short-circuited due to the high-voltage surges.
Therefore, how to protect the switching tube in the microwave oven from breakdown by the high voltage surge is a problem to be solved.
Disclosure of Invention
To overcome the problems in the related art, embodiments of the present disclosure provide a microwave oven protection circuit and a microwave oven. The technical scheme is as follows:
according to a first aspect of embodiments of the present disclosure, there is provided a microwave oven protection circuit, comprising:
the switching tube comprises a voltage surge protection circuit, an orthogonal conversion circuit, a switching tube and a PWM signal output module;
one end of the voltage surge protection circuit is connected with sampling points corresponding to the L line and the N line respectively, and the other end of the voltage surge protection circuit is connected with the input end of the PWM signal output module;
the output end of the PWM signal output module is connected with the first end of the DC-AC conversion circuit through the switching tube;
the second end of the orthogonal conversion circuit is respectively connected with the L line and the N line;
a third end of the DC-AC conversion circuit is connected with a magnetron;
the voltage surge protection circuit inputs the surge detection voltage signals in the L line and the N line to the PWM signal output module, the PWM signal output module detects whether the surge detection voltage signal is larger than a voltage surge protection threshold value, and if so, the output of the PWM signal to the switching tube is stopped to stop the work of the switching tube.
The technical scheme provided by the embodiment of the disclosure can comprise the following beneficial effects: the present disclosure provides a schematic diagram of a protection circuit of a microwave oven, comprising: the switching tube comprises a voltage surge protection circuit, an orthogonal conversion circuit, a switching tube and a PWM signal output module; one end of the voltage surge protection circuit is respectively connected with sampling points corresponding to the L line and the N line, and the other end of the voltage surge protection circuit is connected with the input end of the PWM signal output module; the output end of the PWM signal output module is connected with the first end of the DC-AC conversion circuit through a switching tube; the second end of the orthogonal conversion circuit is connected with the L line and the N line respectively; the third end of the DC-AC conversion circuit is connected with the magnetron. When LN line has high voltage surge signal (like thunderbolt, when high-power motor starts or other unusual conditions) to appear, the surge detection voltage signal on the L line of sampling and the N line is raised, when being higher than voltage surge protection threshold, PWM signal output module is when detecting that surge detection voltage signal is higher than voltage surge protection threshold, and PWM signal output module can close PWM signal output module's output in a few uS in the twinkling of an eye, stops IGBT's work, prevents that IGBT from receiving high voltage surge and breaking down the short circuit.
In one embodiment of the present utility model, in one embodiment,
further comprises: a first capacitor;
one end of the first capacitor is connected with the L line, and the other end of the first capacitor is connected with the N line;
the switch tube is an insulated gate bipolar transistor.
In one embodiment, the dc-to-ac conversion circuit includes:
the bridge stack, the second capacitor, the third capacitor, the step-up transformer and the rectifying module;
the first AC end of the bridge pile is connected with the L line, the second AC end of the bridge pile is connected with the N line, the first DC end of the bridge pile is respectively connected with one end of the third capacitor and one end of the primary of the step-up transformer, and the second DC end of the bridge pile is connected with the emitter of the switching tube;
one end of the second capacitor is connected with the first DC end of the bridge stack, and the other end of the second capacitor is respectively connected with the second DC end of the bridge stack and the ground;
the other end of the third capacitor is respectively connected with the other end of the primary of the step-up transformer and the collector of the switching tube;
the secondary of the step-up transformer is connected with the input end of the rectifying module, and the output end of the rectifying module is connected with the magnetron.
In one embodiment of the present utility model, in one embodiment,
the voltage surge protection circuit includes: the sampling module, the fourth capacitor, the fifth capacitor, the first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor;
one end of the sampling module is connected with sampling points corresponding to the L line and the N line respectively;
the other end of the sampling module is connected with one end of the fourth capacitor and one end of the first resistor;
the other end of the first resistor is connected with one end of the second resistor;
the other end of the fourth capacitor is connected with the other end of the second resistor and is also connected with one end of the third resistor;
the other end of the third resistor is connected with one end of the fourth resistor, and the other end of the fourth resistor is respectively connected with one end of the fifth capacitor, one end of the fifth resistor and the input end of the PWM signal output module;
the other end of the fifth capacitor and the other end of the fifth resistor are grounded.
In one embodiment of the present utility model, in one embodiment,
sampling points corresponding to the L line and the N line are positioned in the L line and the N line;
the sampling module comprises: a first diode and a second diode;
the positive electrode of the first diode is connected with the N line;
the positive pole of second diode is connected L line, the negative pole of second diode with the negative pole of first diode is connected, and still with the one end of fourth electric capacity and one end of first resistance.
In one embodiment of the present utility model, in one embodiment,
sampling points corresponding to the L line and the N line are positioned at a first DC end of the bridge stack;
the sampling module comprises: a third diode;
the anode of the third diode is connected with the first DC end of the bridge stack;
and the cathode of the third diode is connected with one end of the fourth capacitor and one end of the first resistor.
In one embodiment, the PWM signal output module includes:
the first MCU and the first driving amplifying module are connected in series;
the other end of the voltage surge protection circuit is connected with the input end of the first MCU;
the output end of the first driving amplification module is connected with the first end of the direct-alternating current conversion circuit through the gate electrode of the insulated gate bipolar transistor;
the other end of the fourth resistor is connected with the input end of the first MCU.
In one embodiment, the PWM signal output module includes:
the comparator, the second MCU and the second driving amplifying module are connected in series;
the other end of the voltage surge protection circuit is connected with the input end of the comparator;
and the output end of the second driving amplification module is connected with the first end of the direct-alternating current conversion circuit through the gate electrode of the insulated gate bipolar transistor.
In one embodiment, further comprising: a protective tube;
the protective tube is connected with the L line in series.
According to a second aspect of embodiments of the present disclosure, there is provided a microwave oven including a microwave oven protection circuit according to any one of the embodiments described above.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.
Fig. 1 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment.
Fig. 2 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment.
Fig. 3 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment.
Fig. 4 is a schematic diagram of a voltage surge protection circuit shown according to an example embodiment.
Fig. 5 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment.
Fig. 6 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment.
Detailed Description
Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.
Fig. 1 is a schematic diagram of a microwave oven protection circuit according to an exemplary embodiment, as shown in fig. 1, including:
the voltage surge protection circuit 11, the direct-alternating current conversion circuit 12, the switching tube 13 and the PWM signal output module 14;
one end of the voltage surge protection circuit 11 is respectively connected with sampling points corresponding to the L line and the N line, and the other end of the voltage surge protection circuit 11 is connected with the input end of the PWM signal output module 14;
the output end of the PWM signal output module 14 is connected with the first end of the DC-AC conversion circuit 12 through a switching tube 13;
the second end of the orthogonal transformation circuit 12 is respectively connected with an L line and an N line;
a third end of the DC-AC conversion circuit 12 is connected with a magnetron 15;
the voltage surge protection circuit 11 inputs the surge detection voltage signals in the L line and the N line to the PWM signal output module 14, and the PWM signal output module 14 detects whether the surge detection voltage signal is greater than a voltage surge protection threshold, and if so, stops outputting the PWM signal to the switching tube 13 to stop the operation of the switching tube 13.
The voltage surge protection circuit 11 may sample the voltage signals on the L line and the N line, and send the sampled surge detection voltage signals on the L line and the N line to the PWM signal output module 14, where the surge detection voltage signals are lower than a voltage surge protection threshold set in the PWM signal output module 14 under normal conditions, and the PWM signal output module 14 may normally output the PWM signal.
When the LN line has a high-voltage surge signal (like lightning stroke, when a high-power motor is started or other abnormal conditions occur), the surge detection voltage signals on the sampled L line and N line are raised, when the voltage surge protection threshold is higher, the PWM signal output module 14 can instantly close the output of the PWM signal output module 14 within a few uS when the surge detection voltage signal is detected to be higher than the voltage surge protection threshold, the work of the IGBT is stopped, and the IGBT is prevented from being broken down and short-circuited by the high-voltage surge.
In one implementation, as shown in fig. 2 and 3, further comprising: a first capacitor C1;
one end of the first capacitor C1 is connected with an L line, and the other end of the first capacitor C1 is connected with an N line; the first capacitor C1 is used for LN line filtering.
The switching transistor 13 is an insulated gate bipolar transistor (IGBT for short).
In one implementation, as shown in fig. 2 and 3, the dc-to-ac conversion circuit 12 includes:
bridge stack 121, second capacitor C2, third capacitor C3, step-up transformer 122, and rectifying module 123;
the first AC end a of the bridge stack 121 is connected to the L line, the second AC end b of the bridge stack 121 is connected to the N line, the first DC end e of the bridge stack 121 is connected to one end of the third capacitor C3 and one end of the primary of the step-up transformer 122, respectively, and the second DC end d of the bridge stack 121 is connected to the emitter of the switching tube 13;
one end of the second capacitor C2 is connected with the first DC end e of the bridge stack 121, and the other end of the second capacitor C2 is respectively connected with the second DC end d of the bridge stack 121 and the ground;
the other end of the third capacitor C3 is connected with the other end of the primary of the step-up transformer 122 and the collector of the switching tube 13 respectively;
the secondary of the step-up transformer 122 is connected to the input of a rectifying module 123, and the output of the rectifying module 123 is connected to the magnetron 15.
The bridge stack 121 may convert 220V ac to a pulsating dc signal, the C2 capacitor filters the pulsating dc signal output from the bridge stack 121 to a smoother dc signal, the primary components of the C3 and the step-up transformer 122 vibrate LC to convert the dc signal output from the C2 into a high-frequency ac signal, the secondary output of the step-up transformer 122 is boosted to obtain a high-frequency ac signal, and the rectification module 123 converts the ac signal into dc to supply power to the magnetron 15 to output microwaves.
In one implementation, as shown in fig. 4, the voltage surge protection circuit 11 includes: the sampling module 111, the fourth capacitor C4, the fifth capacitor C5, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5;
one end of the sampling module 111 is connected with sampling points corresponding to the L line and the N line respectively;
the other end of the sampling module 111 is connected with one end of a fourth capacitor C4 and one end of a first resistor R1;
the other end of the first resistor R1 is connected with one end of the second resistor R2;
the other end of the fourth capacitor C4 is connected with the other end of the second resistor R2 and also connected with one end of the third resistor R3;
the other end of the third resistor R3 is connected with one end of a fourth resistor R4, and the other end of the fourth resistor R4 is respectively connected with one end of a fifth capacitor C5, one end of the fifth resistor R5 and the input end of the PWM signal output module 14;
the other end of the fifth capacitor C5 and the other end of the fifth resistor R5 are grounded.
The voltage signal on the LN line is sampled through the sampling point, and a basic surge detection voltage signal is obtained through series voltage division of resistors R1, R2, R3, R4 and R5, the surge detection voltage signal is input to the PWM signal output module 14 through filtering of C5, the surge detection voltage signal is lower than a voltage surge protection threshold under normal conditions, and the PWM signal output module 14 can normally output PWM signals.
When the LN line has a high-voltage surge signal (similar to lightning stroke, when a high-power motor is started or other abnormal conditions are caused), the instantaneous high-voltage surge signal passes through the sampling module 111, and is directly connected to R3 through the high-voltage capacitor C4, which is equivalent to approximate short circuit of R1 and R2, at the moment, the surge detection voltage signal on C5 is instantaneously raised, when the surge detection voltage signal is higher than a voltage surge protection threshold value, the PWM signal output module 14 can instantaneously close the output of the PWM signal output module 14 within a few uS, the work of the IGBT is stopped, and the IGBT is prevented from being broken down and short-circuited due to high-voltage surge.
In one implementation, as shown in figure 2,
sampling points corresponding to the L line and the N line are positioned in the L line and the N line;
the sampling module 111 includes: a first diode D1 and a second diode D2;
the anode of the first diode D1 is connected with an N line;
the positive electrode of the second diode D2 is connected to the L line, the negative electrode of the second diode D2 is connected to the negative electrode of the first diode D1, and one end of the fourth capacitor C4 is also connected to one end of the first resistor R1.
In one implementation, as shown in figure 3,
the sampling points corresponding to the L line and the N line are positioned at a first DC end e of the bridge stack 121;
the sampling module 111 includes: a third diode D3;
the anode of the third diode is connected to the first DC terminal e of the bridge stack 121;
the negative electrode of the third diode is connected with one end of the fourth capacitor C4 and one end of the first resistor R1.
In one implementation, as shown in fig. 5 and 6, the PWM signal output module 14 includes:
a first MCU141 and a first driving amplification module 142 connected in series;
the other end of the voltage surge protection circuit 11 is connected with the input end of the first MCU 141;
the output end of the first driving amplification module 142 is connected with the first end of the direct-alternating conversion circuit 12 through the gate electrode of the insulated gate bipolar transistor;
the other end of the fourth resistor R4 is connected to the input terminal of the first MCU 141.
The first MCU141 outputs PWM, and outputs PWM driving through the first driving amplification module 142 to drive the switching of the IGBT.
Specifically, the voltage signal on the LN line is sampled by the sampling point, and a basic surge detection voltage signal is obtained by the series voltage division of the resistors R1, R2, R3, R4, and R5, and the surge detection voltage signal is input to the first MCU141 through the filtering of C5, and the surge detection voltage signal is lower than the voltage surge protection threshold under the normal condition, and the first MCU141 can normally output the PWM signal.
When the LN line has a high-voltage surge signal (similar to lightning stroke, when a high-power motor is started or other abnormal conditions are caused), the instantaneous high-voltage surge signal passes through D1 or D2 and directly reaches R3 through a high-voltage capacitor C4, which is equivalent to approximate short circuit of R1 and R2, at the moment, the surge detection voltage signal on C5 is instantaneously raised, when the voltage surge protection threshold value is higher than the voltage surge protection threshold value, the first MCU141 can instantaneously close the output of the first MCU141 in a few uS when the surge detection voltage signal is detected to be higher than the voltage surge protection threshold value, the work of the IGBT is stopped, and the IGBT is prevented from being broken down and short-circuited by the high-voltage surge.
In one implementation, the PWM signal output module 14 includes:
the comparator, the second MCU and the second driving amplifying module are connected in series;
the other end of the voltage surge protection circuit 11 is connected with the input end of the comparator;
the output terminal of the second driving amplification module is connected to the first terminal of the dc-ac conversion circuit 12 through the gate of the insulated gate bipolar transistor.
If the MCU has no function of a comparator, the circuit can be additionally provided with the comparator, the reference voltage of the comparator is a voltage surge protection threshold, when the surge detection voltage signal input by the input end of the comparator is higher than the voltage surge protection threshold, the comparator outputs a high level to the second MCU, the second MCU can turn off the output of the second MCU within a few uS instantly after receiving the high level, the work of the IGBT is stopped, and the IGBT is prevented from being broken down and short-circuited due to high voltage surge.
Specifically, the voltage signal on the LN line is sampled through the sampling point, a basic surge detection voltage signal is obtained through series voltage division of resistors R1, R2, R3, R4 and R5, the surge detection voltage signal is input to the comparator through filtering of C5, the surge detection voltage signal is lower than a voltage surge protection threshold under normal conditions, the comparator outputs a low level to the second MCU, and the second MCU can normally output a PWM signal.
When the LN line has high-voltage surge signals (similar to lightning stroke, when a high-power motor is started or other abnormal conditions are caused), the instantaneous high-voltage surge signals pass through D1 or D2 and pass through a high-voltage capacitor C4 to directly reach R3, which is equivalent to approximate short circuit of R1 and R2, at the moment, the surge detection voltage signals on C5 are instantaneously raised, when the voltage surge protection threshold value is higher than the voltage surge protection threshold value, the comparator outputs high level to the second MCU when the surge detection voltage signals are detected to be higher than the voltage surge protection threshold value, the second MCU can instantaneously close the output of the second MCU within a few uS after receiving the high level, the work of the IGBT is stopped, and the IGBT is prevented from being broken down and short-circuited by the high-voltage surge.
In one embodiment, referring to fig. 2, 3, 5 and 6, further comprising: a protective tube 16;
the protective tube 16 is connected in series with the L line for abnormal short circuit or large current protection at the later stage.
It is noted that the parameters of the resistor and the capacitor in the present disclosure can be actually adjusted to the sensitivity of the protection according to different products and power grid conditions. For example: the resistance values of R1, R2, R3, R4 and R5 can be determined according to the voltage of the mains supply and the input voltage required by the MCU or the comparator, and only the voltage of the mains supply is required to be reduced to the input voltage required by the MCU or the comparator.
For example, R1, R2, R3 and R4 may have a resistance of 120K, R5 may have a resistance of 4.3K, C4 may have a capacitance of 1000pF, a breakdown voltage of 500V, C5 may have a capacitance of 1000pF, and a breakdown voltage of 30V.
The present disclosure also provides a microwave oven including a microwave oven protection circuit as in any one of the above embodiments.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims (10)
1. A microwave oven protection circuit, comprising:
the switching tube comprises a voltage surge protection circuit, an orthogonal conversion circuit, a switching tube and a PWM signal output module;
one end of the voltage surge protection circuit is connected with sampling points corresponding to the L line and the N line respectively, and the other end of the voltage surge protection circuit is connected with the input end of the PWM signal output module;
the output end of the PWM signal output module is connected with the first end of the DC-AC conversion circuit through the switching tube;
the second end of the orthogonal conversion circuit is respectively connected with the L line and the N line;
a third end of the DC-AC conversion circuit is connected with a magnetron;
the voltage surge protection circuit inputs the surge detection voltage signals in the L line and the N line to the PWM signal output module, the PWM signal output module detects whether the surge detection voltage signal is larger than a voltage surge protection threshold value, and if so, the output of the PWM signal to the switching tube is stopped to stop the work of the switching tube.
2. The microwave oven protection circuit according to claim 1, wherein,
further comprises: a first capacitor;
one end of the first capacitor is connected with the L line, and the other end of the first capacitor is connected with the N line;
the switch tube is an insulated gate bipolar transistor.
3. The microwave oven protection circuit according to claim 2, wherein the dc-to-ac conversion circuit comprises:
the bridge stack, the second capacitor, the third capacitor, the step-up transformer and the rectifying module;
the first AC end of the bridge pile is connected with the L line, the second AC end of the bridge pile is connected with the N line, the first DC end of the bridge pile is respectively connected with one end of the third capacitor and one end of the primary of the step-up transformer, and the second DC end of the bridge pile is connected with the emitter of the switching tube;
one end of the second capacitor is connected with the first DC end of the bridge stack, and the other end of the second capacitor is respectively connected with the second DC end of the bridge stack and the ground;
the other end of the third capacitor is respectively connected with the other end of the primary of the step-up transformer and the collector of the switching tube;
the secondary of the step-up transformer is connected with the input end of the rectifying module, and the output end of the rectifying module is connected with the magnetron.
4. A microwave oven protection circuit according to claim 3, wherein,
the voltage surge protection circuit includes: the sampling module, the fourth capacitor, the fifth capacitor, the first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor;
one end of the sampling module is connected with sampling points corresponding to the L line and the N line respectively;
the other end of the sampling module is connected with one end of the fourth capacitor and one end of the first resistor;
the other end of the first resistor is connected with one end of the second resistor;
the other end of the fourth capacitor is connected with the other end of the second resistor and is also connected with one end of the third resistor;
the other end of the third resistor is connected with one end of the fourth resistor, and the other end of the fourth resistor is respectively connected with one end of the fifth capacitor, one end of the fifth resistor and the input end of the PWM signal output module;
the other end of the fifth capacitor and the other end of the fifth resistor are grounded.
5. The microwave oven protection circuit according to claim 4, wherein,
sampling points corresponding to the L line and the N line are positioned in the L line and the N line;
the sampling module comprises: a first diode and a second diode;
the positive electrode of the first diode is connected with the N line;
the positive pole of second diode is connected L line, the negative pole of second diode with the negative pole of first diode is connected, and still with the one end of fourth electric capacity and one end of first resistance.
6. The microwave oven protection circuit according to claim 4, wherein,
sampling points corresponding to the L line and the N line are positioned at a first DC end of the bridge stack;
the sampling module comprises: a third diode;
the anode of the third diode is connected with the first DC end of the bridge stack;
and the cathode of the third diode is connected with one end of the fourth capacitor and one end of the first resistor.
7. The microwave oven protection circuit according to any one of claims 4 to 6, wherein the PWM signal output module includes:
the first MCU and the first driving amplifying module are connected in series;
the other end of the voltage surge protection circuit is connected with the input end of the first MCU;
the output end of the first driving amplification module is connected with the first end of the direct-alternating current conversion circuit through the gate electrode of the insulated gate bipolar transistor;
the other end of the fourth resistor is connected with the input end of the first MCU.
8. The microwave oven protection circuit according to any one of claims 4 to 6, wherein the PWM signal output module includes:
the comparator, the second MCU and the second driving amplifying module are connected in series;
the other end of the voltage surge protection circuit is connected with the input end of the comparator;
and the output end of the second driving amplification module is connected with the first end of the direct-alternating current conversion circuit through the gate electrode of the insulated gate bipolar transistor.
9. The microwave oven protection circuit according to any one of claims 4 to 6, further comprising: a protective tube;
the protective tube is connected with the L line in series.
10. A microwave oven comprising a microwave oven protection circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320165905.9U CN219611343U (en) | 2023-02-02 | 2023-02-02 | Microwave oven protection circuit and microwave oven |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320165905.9U CN219611343U (en) | 2023-02-02 | 2023-02-02 | Microwave oven protection circuit and microwave oven |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219611343U true CN219611343U (en) | 2023-08-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320165905.9U Active CN219611343U (en) | 2023-02-02 | 2023-02-02 | Microwave oven protection circuit and microwave oven |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219611343U (en) |
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2023
- 2023-02-02 CN CN202320165905.9U patent/CN219611343U/en active Active
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