Constant-voltage alternating-current signal generating circuit and combustion equipment

Abstract

The utility model relates to the technical field of voltage conversion, and discloses a constant-voltage AC signal generating circuit and combustion equipment, and the constant-voltage AC signal generating circuit comprises a voltage conversion module, a voltage stabilization module and a feedback module, the voltage stabilizing module comprises a charging capacitor, a first resistor, a second resistor and a voltage stabilizing tube; wherein one end of the charging capacitor is connected with the output end of the voltage conversion module and the first end of the first resistor, and the other end of the charging capacitor is connected with one end of the second resistor and grounded; the second end of the first resistor is respectively connected with the other end of the second resistor and one end of the voltage-regulator tube; the other end of the voltage stabilizing tube is connected with the first end of the feedback module; the second end of the feedback module is connected with the voltage feedback end of the voltage conversion module, and the third end is connected with the voltage conversion module and grounded; the first end of the first resistor serves as the output end of the voltage stabilizing module and is used for outputting an alternating-current voltage signal. Therefore, closed-loop control over the output alternating-current voltage signal is formed, and it is guaranteed that the alternating-current voltage signal is constant.

Description

Technical Field

[0001] This utility model relates to the field of voltage conversion technology, and in particular to a constant voltage AC signal generating circuit and a combustion device. Background Technology

[0002] Gas water heaters are widely used, and constant-voltage AC signals are involved in both the ignition circuit and flame ionization signal detection processes. However, in related technologies, constant-voltage AC signals typically employ open circuit structures, resulting in unstable peak voltages. This significantly impacts the accuracy and sensitivity of some signal detection during gas water heater operation, even affecting safety. For example, in flame ionization signal detection, due to performance variations in components and the open circuit structure, different AC signal sources output voltage values ​​that fluctuate within a certain range. This hinders precise detection of the flame ionization signal, affecting its sensitivity, and in severe cases, can lead to safety issues due to delayed detection. Therefore, improving the stability of AC signal sources is a pressing technical problem that needs to be addressed. Utility Model Content

[0003] The first technical problem solved by this invention is to provide a constant voltage AC signal generating circuit, which effectively solves the problem of poor stability of AC signal sources.

[0004] The second technical problem solved by this invention is to provide a combustion device that effectively solves the problem of poor stability of AC signal sources.

[0005] The first technical problem mentioned above is solved by the following technical solution:

[0006] A constant voltage AC signal generating circuit includes:

[0007] Voltage conversion module, voltage regulation module, and feedback module;

[0008] The voltage regulator module includes: a charging capacitor, a first resistor, a second resistor, and a Zener diode;

[0009] One end of the charging capacitor is connected to the output terminal of the voltage conversion module and the first end of the first resistor, respectively, and the other end is connected to one end of the second resistor and grounded.

[0010] The second end of the first resistor is connected to the other end of the second resistor and one end of the Zener diode, respectively.

[0011] The other end of the Zener diode is connected to the first end of the feedback module;

[0012] The second terminal of the feedback module is connected to the voltage feedback terminal of the voltage conversion module, and the third terminal is connected to the voltage conversion module and grounded;

[0013] The first end of the first resistor serves as the output terminal of the voltage regulator module, used to output AC voltage signals.

[0014] Compared with the prior art, the constant voltage AC signal generating circuit of this utility model has the following advantages: by setting a Zener diode in the voltage regulator module, and setting one end of the Zener diode to be connected to the second end of the first resistor and the other end of the second resistor respectively, and the other end to be connected to the first end of the feedback module, the Zener diode provides feedback on the output AC voltage signal; at the same time, the feedback module controls the operation of the voltage conversion module according to the feedback of the Zener diode, thereby forming a closed-loop control of the output AC voltage signal and ensuring that the AC voltage signal is constant.

[0015] In one embodiment, the voltage conversion module includes: a pulse unit, a transformer unit, a switching unit, and a rectification unit; the first terminal of the switching unit serves as the voltage feedback terminal of the voltage conversion module.

[0016] The output terminal of the pulse unit is connected to the first terminal of the switching unit and the second terminal of the feedback module, respectively.

[0017] The input terminal of the transformer unit is connected to the second terminal of the switching unit, and the output terminal of the transformer unit is connected to one end of the rectifier unit.

[0018] The other end of the rectifier unit is connected to one end of the charging capacitor and the first end of the first resistor, respectively.

[0019] The third terminal of the switching unit is connected to the third terminal of the feedback module and grounded.

[0020] In one embodiment, the transformer unit includes the primary winding and secondary winding of the transformer, and the pulse unit includes the feedback winding of the transformer.

[0021] One end of the feedback winding is connected to the power supply, and the other end is connected to the first end of the switching unit and the second end of the feedback module, respectively.

[0022] One end of the primary winding is connected to the power supply, and the other end is connected to the second end of the switching unit.

[0023] One end of the secondary winding is connected to one end of the rectifier unit, and the other end is grounded.

[0024] In one embodiment, the transformer unit includes a primary winding and a secondary winding of a transformer, and the pulse unit includes a pulse signal generator;

[0025] The first end of the pulse signal generator is connected to the second end of the feedback module, and the second end of the pulse signal generator is connected to the first end of the switching unit.

[0026] One end of the primary winding is connected to the power supply, and the other end is connected to the second end of the switching unit.

[0027] One end of the secondary winding is connected to one end of the rectifier unit, and the other end is grounded.

[0028] In one embodiment, the transformer unit includes an I-shaped inductor, and the pulse unit includes a pulse signal generator;

[0029] The first end of the pulse signal generator is connected to the second end of the feedback module, and the second end of the pulse signal generator is connected to the first end of the switching unit.

[0030] One end of the I-shaped inductor is connected to the power supply, and the other end is connected to the second terminal of the switching unit and one end of the rectifier unit, respectively.

[0031] In one embodiment, the voltage conversion module includes a voltage divider unit, a transformer unit, and a switching unit;

[0032] The transformer unit includes an I-shaped inductor, and the voltage divider unit includes a third resistor, a fourth resistor, a fifth resistor, and a second diode.

[0033] One end of the third resistor is connected to the power supply, and the other end is connected to the second end of the switching unit and one end of the fourth resistor, respectively.

[0034] The other end of the fourth resistor is connected to the second end of the feedback module, one end of the fifth resistor, and one end of the second diode, respectively.

[0035] The other end of the fifth resistor is connected to the first end of the switching unit;

[0036] The other end of the second diode is connected to ground.

[0037] One end of the I-shaped inductor is connected to the third terminal of the switching unit, and the other end is connected to one end of the charging capacitor and one end of the first resistor, respectively.

[0038] In one embodiment, the feedback module includes a first transistor, and the switching unit includes a second transistor, a sixth resistor, and a second capacitor;

[0039] Among them, the first transistor and the second transistor are current-type devices; the first terminal of the second transistor is connected to one end of the sixth resistor and one end of the second capacitor respectively, the second terminal is connected to the input terminal of the transformer unit, and the third terminal is connected to ground.

[0040] The other end of the sixth resistor is connected to the pulse unit;

[0041] The other end of the second capacitor is connected to ground.

[0042] In one embodiment, the feedback module includes a first transistor, and the switching unit includes a second transistor, a sixth resistor, and a seventh resistor;

[0043] Among them, the first transistor and the second transistor are voltage-type devices; the first terminal of the second transistor is connected to one end of the sixth resistor and one end of the seventh resistor respectively, the second terminal is connected to the input terminal of the transformer unit, and the third terminal is connected to ground.

[0044] The other end of the sixth resistor is connected to the pulse unit;

[0045] The other end of the seventh resistor is connected to ground.

[0046] In one embodiment, the circuit further includes:

[0047] The filtering module includes a filter capacitor, one end of which is connected to the first end of the first resistor, and the other end serves as the output terminal of the constant voltage AC signal generating circuit for outputting an AC voltage signal.

[0048] The second technical problem mentioned above is solved by the following technical solution:

[0049] A combustion device includes a constant voltage AC signal generating circuit as described in any of the above embodiments. Attached Figure Description

[0050] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of a constant voltage AC signal generating circuit according to an embodiment of the present invention;

[0052] Figure 2 This is a circuit diagram of a voltage regulator module in a constant voltage AC signal generating circuit according to an embodiment of the present invention;

[0053] Figure 3 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0054] Figure 4 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0055] Figure 5 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0056] Figure 6This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0057] Figure 7 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0058] Figure 8 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0059] Figure 9 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0060] Figure 10 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model;

[0061] Figure 11 This is a circuit diagram of a flame ion detection circuit according to an embodiment of the present invention.

[0062] Explanation of reference numerals in the attached figures:

[0063] 11. Voltage conversion module; 111. Pulse unit; 112. Transformer unit; 113. Switching unit; 114. Rectifier unit; 115. Voltage divider unit; 12. Voltage regulator module; 13. Feedback module. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0066] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0067] Gas water heaters are widely used, and constant-voltage AC signals are involved in both the ignition circuit and flame ionization signal detection processes. However, in related technologies, constant-voltage AC signals typically employ open circuit structures, resulting in unstable peak voltages. This significantly impacts the accuracy and sensitivity of some signal detection during gas water heater operation, potentially affecting safety. For example, in flame ionization signal detection, due to component performance variations and the open circuit structure, different AC signal sources output voltage values ​​that fluctuate within a certain range. This makes precise detection of the flame ionization signal impossible, affecting its sensitivity and, in severe cases, potentially leading to safety issues due to delayed detection.

[0068] To address the aforementioned problems, this invention provides a constant voltage AC signal generating circuit, comprising: a voltage regulator module, including: a charging capacitor, a first resistor, a second resistor, and a Zener diode; wherein, one end of the charging capacitor is connected to the output terminal of the voltage conversion module and the first end of the first resistor, and the other end is connected to one end of the second resistor and grounded; the second end of the first resistor is connected to the other end of the second resistor and one end of the Zener diode; the other end of the Zener diode is connected to the first end of a feedback module; the second end of the feedback module is connected to the voltage feedback terminal of the voltage conversion module, and the third end is connected to the voltage conversion module and grounded; the first end of the first resistor serves as the output terminal of the voltage regulator module, used to output an AC voltage signal. Thus, the Zener diode provides feedback on the output AC voltage signal, and the feedback module controls the operation of the voltage conversion module based on the feedback from the Zener diode, forming a closed-loop control of the output AC voltage signal, ensuring a constant AC voltage signal.

[0069] The following is combined Figures 1 to 11 The following describes embodiments of the present invention.

[0070] According to an embodiment of the present invention, a constant voltage AC signal generating circuit is provided. Figure 1 This is a schematic diagram of a constant voltage AC signal generating circuit according to an embodiment of the present invention, as shown below. Figure 1As shown, the constant voltage AC signal generating circuit includes: a voltage conversion module 11, a voltage regulator module 12, and a feedback module 13. The voltage conversion module 11 performs voltage conversion to generate an AC voltage; the voltage regulator module 12 regulates the AC voltage generated by the voltage conversion module 11 to output an AC voltage signal; the feedback module 13 is connected to both the voltage conversion module 11 and the voltage regulator module 12, and transmits feedback from the voltage regulator module 12 to the voltage conversion module 11, thereby forming a closed-loop control of the AC voltage signal and ensuring a constant AC voltage signal.

[0071] Specifically, Figure 2 This is a circuit diagram of a voltage regulator module in a constant voltage AC signal generating circuit according to an embodiment of this utility model, as shown below. Figure 2 As shown, the voltage regulator module 12 includes: a charging capacitor C1, a first resistor R1, a second resistor R2, and a Zener diode Z1.

[0072] In this circuit, one end of the charging capacitor C1 is connected to the output terminal of the voltage conversion module 11 and the first end of the first resistor R1, and the other end is connected to one end of the second resistor R2 and grounded. The second end of the first resistor R1 is connected to the other end of the second resistor R2 and one end of the Zener diode Z1. The first end of the first resistor R1 serves as the output terminal of the voltage regulator module 12, used to output an AC voltage signal. Thus, the first resistor R1 and the second resistor R2 are connected in series and in parallel with the charging capacitor C1. The voltage across the first resistor R1 and the second resistor R2 is the voltage generated by the charging capacitor C1 during charging. At the same time, the first resistor R1 and the second resistor R2 form a voltage divider circuit.

[0073] The Zener diode Z1 has one end connected to the first end of the feedback module 13; the second end of the feedback module 13 is connected to the voltage feedback terminal F1 of the voltage conversion module 11, and the third end is connected to the voltage conversion module 11 and grounded. Thus, one end of the Zener diode Z1 corresponds to its negative terminal and is connected between the first resistor R1 and the second resistor R2, while the other end of the Zener diode Z1 corresponds to its positive terminal and is connected to the feedback module 13, forming a closed-loop control of the output AC voltage signal. When the voltage division value of the first resistor R1 and the second resistor R2 does not trigger avalanche breakdown of the Zener diode Z1, no current signal is generated on the Zener diode Z1, and the feedback module 13 cannot receive a feedback signal. When the voltage division value of the first resistor R1 and the second resistor R2 triggers avalanche breakdown of the Zener diode Z1, a current signal is generated on the Zener diode Z1, the feedback module 13 receives the feedback signal, and the feedback module 13 controls the operation of the voltage conversion module 11 according to the feedback signal.

[0074] In one embodiment, the voltage conversion module 11 can be implemented based on boosting and inverting a low-voltage DC signal. Specifically, the voltage conversion module 11 includes: a pulse unit 111, a transformer unit 112, a switching unit 113, and a rectifier unit 114. The first terminal of the switching unit 113 serves as the voltage feedback terminal of the voltage conversion module 11 and is connected to the feedback module 13; the output terminal of the pulse unit 111 is connected to the first terminal of the switching unit 113 and the second terminal of the feedback module 13, respectively; the input terminal of the transformer unit 112 is connected to the second terminal of the switching unit 113, and the output terminal of the transformer unit 112 is connected to one end of the rectifier unit 114; the other end of the rectifier unit 114 is connected to one end of the charging capacitor C1 and the first end of the first resistor R1, respectively; the third terminal of the switching unit 113 is connected to the third terminal of the feedback module 13 and grounded. In the voltage conversion module 11, the pulse unit 111 is used to output pulse signals to the switching unit 113. At the same time, the feedback module 13 is also connected to the switching unit 113 and works with the pulse unit 111 to control the switching unit 113 to control whether the transformer unit 112 is working.

[0075] In one embodiment, the rectifier unit 114 can be a rectifier circuit of any structure, such as a full-bridge rectifier circuit, a half-bridge rectifier circuit, etc. In this embodiment, in order to simplify the circuit structure, the rectifier unit 114 adopts a rectifier diode D1. The positive terminal of the rectifier diode D1 is connected to the output terminal of the transformer unit 112, and the negative terminal is connected to one end of the charging capacitor C1 and the first end of the first resistor R1, respectively.

[0076] In one embodiment, Figure 3 and Figure 4 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model, as shown below. Figure 3 and Figure 4 As shown, the transformer unit 112 includes a primary winding and a secondary winding of the transformer, and the pulse unit 111 includes a feedback winding of the transformer. One end of the feedback winding is connected to a power source, and the other end is connected to the first terminal of the switching unit 113 and the second terminal of the feedback module 13, respectively. One end of the primary winding is connected to a power source, and the other end is connected to the second terminal of the switching unit 113. One end of the secondary winding is connected to one end of the rectifier unit 114, and the other end is grounded.

[0077] In this embodiment, the transformer unit 112 and the pulse unit 111 constitute a complete transformer. When the primary winding is connected to the power supply and energized, the secondary winding forms a boost voltage through coil coupling, thereby generating an AC signal. At this time, a voltage difference is generated across the feedback winding. When the voltage difference across the feedback winding reaches a certain value, the switch unit 113 is disconnected, thereby disconnecting the primary winding from ground and stopping the secondary winding from boosting voltage. At this time, there is no voltage difference across the feedback winding, and the switch unit 113 is reconnected, so that the primary winding is energized again and the secondary winding boosts voltage.

[0078] In one embodiment, such as Figure 3 and Figure 4 As shown, the feedback module 13 may include a first transistor Q1, and the switching unit 113 may include a second transistor Q2. When there is no voltage difference across the feedback winding, the second transistor Q2 is turned on, energizing the primary winding and boosting the secondary winding voltage. When the voltage difference across the feedback winding reaches a certain value, the second transistor Q2 is turned off, disconnecting the primary winding from ground and stopping the secondary winding voltage boosting. When the Zener diode Z1 is not broken down, the first transistor Q1 is turned off, and the second transistor Q2 operates normally. When the Zener diode Z1 breaks down, the first transistor Q1 is turned on, turning off the second transistor Q2.

[0079] In one embodiment, Figure 5 and Figure 6 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model, as shown below. Figure 5 and Figure 6 As shown, the transformer unit 112 includes a primary winding and a secondary winding of a transformer, and the pulse unit 111 includes a pulse signal generator. The first terminal of the pulse signal generator is connected to the second terminal of the feedback module 13, and the second terminal of the pulse signal generator is connected to the first terminal of the switching unit 113. One end of the primary winding is connected to a power supply, and the other end is connected to the second terminal of the switching unit 113. One end of the secondary winding is connected to one end of the rectifier unit 114, and the other end is grounded.

[0080] Compared to Figure 3 and Figure 4 In the embodiment shown, a pulse signal generator is used instead of the feedback winding of the transformer, thereby reducing the use of winding coils. At this time, the first end of the switching unit 113 is connected to the feedback module 13 through the pulse signal generator, and the feedback module 13 is used to control the operation of the pulse signal generator.

[0081] In one embodiment, such as Figure 5 and Figure 6As shown, the feedback module 13 may include a first transistor Q1, and the switching unit 113 may include a second transistor Q2. When the pulse signal generator outputs a high-level signal, the second transistor Q2 is turned on, energizing the primary winding and boosting the secondary winding; when the pulse signal generator outputs a low-level signal, the second transistor Q2 is turned off, disconnecting the primary winding from ground and stopping the secondary winding from boosting. When the Zener diode Z1 is not broken down, the first transistor Q1 is turned off, and the pulse signal generator and the second transistor Q2 operate normally; when the Zener diode Z1 breaks down, the first transistor Q1 is turned on, triggering the pulse signal generator to turn off, thus turning off the second transistor Q2.

[0082] In one embodiment, Figure 7 and Figure 8 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model, as shown below. Figure 7 and Figure 8 As shown, the transformer unit 112 includes an I-shaped inductor L1, and the pulse unit 111 includes a pulse signal generator. The first terminal of the pulse signal generator is connected to the second terminal of the feedback module 13, and the second terminal of the pulse signal generator is connected to the first terminal of the switching unit 113. One end of the I-shaped inductor L1 is connected to the power supply, and the other end is connected to the second terminal of the switching unit 113 and one terminal of the rectifier unit 114, respectively. Compared to... Figure 5 and Figure 6 In the embodiment shown, an I-shaped inductor L1 is used to replace the primary and secondary windings of the transformer, thereby further reducing the use of winding coils.

[0083] In one embodiment, such as Figure 7 and Figure 8 As shown, the feedback module 13 may include a first transistor Q1, and the switching unit 113 may include a second transistor Q2. When the pulse signal generator outputs a high-level signal, the second transistor Q2 is turned on, connecting the I-inductor L1 to ground, enabling normal voltage boosting; when the pulse signal generator outputs a low-level signal, the second transistor Q2 is turned off, disconnecting the I-inductor L1 from ground, stopping voltage boosting. When the Zener diode Z1 is not broken down, the first transistor Q1 is turned off, and the pulse signal generator and the second transistor Q2 operate normally; when the Zener diode Z1 breaks down, the first transistor Q1 is turned on, triggering the pulse signal generator to turn off, causing the second transistor Q2 to turn off.

[0084] In the above embodiments, the waveform generated by the pulse generator is a square wave waveform; at the same time, the pulse signal generator can also be replaced by any circuit structure that can generate pulse signals, such as a microcontroller, a 555 chip, an inverter, or an amplifier.

[0085] In one embodiment, the voltage conversion module 11 can be implemented based on the step-down and inversion of a low-voltage DC signal. Specifically, the voltage conversion module 11 includes: a voltage divider unit 115, a transformer unit 112, and a switching unit 113. Figure 9 and Figure 10 This is a circuit diagram of a specific embodiment of a constant voltage AC signal generating circuit according to this utility model, as shown below. Figure 9 and Figure 10 As shown, the transformer unit 112 includes an I-shaped inductor L1, and the voltage divider unit 115 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a second diode D2.

[0086] In this circuit, one end of the third resistor R3 is connected to a power source, which is a high-voltage direct current (VDC) power supply, and the other end is connected to the second terminal of the switching unit 113 and one end of the fourth resistor R4, respectively. The other end of the fourth resistor R4 is connected to the second terminal of the feedback module 13, one end of the fifth resistor R5, and one end of the second diode D2, respectively. The third resistor R3 serves as a current-limiting resistor and a load resistor for the VDC power supply when it is conducting. Furthermore, it forms a series voltage divider circuit with the fourth resistor R4 and the second diode D2.

[0087] The fifth resistor R5 is connected to the first terminal of the switching unit 113. R5 acts as a current-limiting resistor, protecting the switching unit 113. The voltage passing through the second diode D2 in the forward direction reaches the switching unit 113 via R5, thus turning on the switching unit 113. The other end of the second diode D2 is grounded. One end of the I-shaped inductor L1 is connected to the third terminal of the switching unit 113, and the other end is connected to one end of the charging capacitor C1 and one end of the first resistor R1, respectively.

[0088] In one embodiment, such as Figure 9 and Figure 10 As shown, the feedback module 13 may include a first transistor Q1, and the switching unit 113 may include a second transistor Q2. When the voltage reaches the second transistor Q2 through the fifth resistor R5, the second transistor Q2 is turned on, and the I-shaped inductor L1 is connected to the power supply, enabling normal voltage boosting. During the voltage boosting process of the I-shaped inductor L1, the voltage at the third terminal of the second transistor Q2 gradually increases. When the voltage at the third terminal of the second transistor Q2 is greater than the voltage at the first terminal, the second transistor Q2 is turned off, the I-shaped inductor L1 is disconnected from the power supply, and voltage boosting stops. When the Zener diode Z1 is not broken down, the first transistor Q1 is turned off, and the voltage divider unit 115 and the switching unit 113 operate normally. When the Zener diode Z1 breaks down, the first transistor Q1 is turned on. At this time, the voltage generated by the voltage divider of the third resistor R3 and the fourth resistor R4 passes through the first transistor Q1 to ground, instead of passing through the fifth resistor R5 to reach the second transistor Q2, and the second transistor Q2 is turned off.

[0089] In one embodiment, the types of the first transistor Q1 and the second transistor Q2 are not limited, as long as they are the same type of device. Specifically, the first terminal of the first transistor Q1 is the first terminal of the feedback module 13, the second terminal of the first transistor Q1 is the second terminal of the feedback module 13, and the third terminal of the first transistor Q1 is the second terminal of the feedback module 13; similarly, the first terminal of the second transistor Q2 is the first terminal of the switching unit 113, the second terminal of the second transistor Q2 is the second terminal of the switching unit 113, and the third terminal of the second transistor Q2 is the third terminal of the switching unit 113.

[0090] In one embodiment, such as Figure 3 , Figure 5 and Figure 7 As shown, to protect the second transistor Q2 in the switching unit 113, the switching unit 113, in addition to the second transistor Q2, also includes a sixth resistor R6 and a second capacitor C2. In this case, the first transistor Q1 and the second transistor Q2 are current-type devices. Specifically, the first terminal of the second transistor Q2 is connected to one end of the sixth resistor R6 and one end of the second capacitor C2, the second terminal is connected to the input terminal of the transformer unit 112, and the third terminal is grounded. The other end of the sixth resistor R6 is connected to the pulse unit 111; the other end of the second capacitor C2 is grounded.

[0091] In one embodiment, such as Figure 4 , Figure 6 and Figure 8 As shown, to protect the second transistor Q2 in the switching unit 113, the switching unit 113 also includes a sixth resistor R6 and a seventh resistor R7 in addition to the second transistor Q2. In this case, the first transistor Q1 and the second transistor Q2 are voltage-type devices. Specifically, the first terminal of the second transistor Q2 is connected to one end of the sixth resistor R6 and one end of the seventh resistor R7, the second terminal is connected to the input terminal of the transformer unit 112, and the third terminal is grounded; the other end of the sixth resistor R6 is connected to the pulse unit 111; and the other end of the seventh resistor R7 is grounded.

[0092] In one embodiment, the circuit further includes a filtering module. The filtering module includes a filtering capacitor C3, which filters the AC voltage signal output by the voltage regulator module 12. One end of the filtering capacitor C3 is connected to the first end of the first resistor R1, and the other end serves as the output terminal S2 of the constant voltage AC signal generator circuit, used to output the AC voltage signal.

[0093] In one embodiment, the voltage regulator module 12 further includes a bypass capacitor C4. One end of the bypass capacitor C4 is connected to one end of the second resistor R2, and the other end is connected to the other end of the second resistor R2. The bypass capacitor C4 is used to filter the voltage obtained by the voltage division of the first resistor R1 and the second resistor R2.

[0094] The constant voltage AC signal generating circuit provided by this utility model sets a Zener diode in the voltage regulator module, and sets one end of the Zener diode to the second end of the first resistor and the other end of the second resistor respectively, and the other end to the first end of the feedback module, so that the Zener diode can provide feedback on the output AC voltage signal; at the same time, the feedback module controls the operation of the voltage conversion module according to the feedback of the Zener diode, thereby forming a closed loop control of the output AC voltage signal to ensure that the AC voltage signal is constant.

[0095] According to an embodiment of the present invention, another aspect provides a combustion device, including a constant voltage AC signal generating circuit as described in any of the above embodiments. The constant voltage AC signal generating circuit can be used to provide a stable AC voltage signal to any circuit or structure in the combustion device that requires an AC voltage signal, such as an ignition circuit or a flame ionization detection circuit.

[0096] In one embodiment, the combustion device includes at least a constant voltage AC signal generating circuit as described in any of the above embodiments, and a flame ionization detection circuit; wherein the constant voltage AC signal generating circuit is used to provide a constant AC voltage signal to the flame ionization detection circuit, and the flame ionization detection circuit is used to detect the flame ionization signal to determine the combustion state of the flame in the combustion device.

[0097] In one embodiment, Figure 11 This is a circuit diagram of a flame ionization detection circuit according to an embodiment of the present invention, as shown below. Figure 11 As shown, the flame ion detection circuit includes: voltage divider resistor R8, front-end resistor R9, input resistor R10, feedback resistor R11, amplifier, and processor.

[0098] One end of the voltage divider resistor R8 is connected to the flame detection electrode S3, and the other end is connected to the constant voltage AC signal generating circuit and one end of the front-end resistor R9. The other end of the front-end resistor R9 is connected to one end of the input resistor R8. The voltage divider resistor R8 is used to protect the flame detection electrode S3 and prevent the voltage input to the constant voltage AC signal generating circuit from exceeding the voltage range that the flame detection electrode S3 can withstand.

[0099] The input resistor R10 is connected to the first terminal of the amplifier and one terminal of the feedback resistor R11, respectively. The other terminal of the feedback resistor R11 is connected to the third terminal of the amplifier. The second terminal of the amplifier is grounded, and the third terminal is connected to the processor. The first terminal of the amplifier corresponds to the negative input terminal, the second terminal corresponds to the positive input terminal, and the third terminal corresponds to the output terminal. This forms an inverting amplifier that amplifies the flame ion signal detected by the flame detection electrode S3, enabling the processor to perform refined detection of the flame ion signal.

[0100] In one embodiment, the flame signal sensing circuit further includes a first clamping diode D3 and a second clamping diode D4. One end of the first clamping diode D3 is connected to the power supply, and the other end is connected to the other end of the front-end resistor R9, one end of the input resistor R10, and one end of the second clamping diode D4, respectively. The other end of the second clamping diode D4 is connected to ground, thereby forming a clamp to ground and to VCC.

[0101] In one embodiment, the flame signal sensing circuit further includes a twelfth resistor R12 and a sixth capacitor C6. The twelfth resistor R12 and the sixth capacitor C6 constitute an RC filter circuit, used to filter the amplified flame ion signal to improve the accuracy of the amplified flame ion signal. One end of the twelfth resistor R12 is connected to the third terminal of the amplifier, and the other end is connected to the processor and one end of the sixth capacitor C6, respectively; the other end of the sixth capacitor C6 is grounded.

[0102] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0103] The specific embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A constant-voltage AC signal generating circuit characterized by comprising: The application relates to a voltage conversion module (11), a voltage stabilizing module (12) and a feedback module (13). The voltage stabilizing module (12) comprises a charging capacitor, a first resistor, a second resistor and a voltage stabilizing tube. One end of the charging capacitor is connected with an output end of the voltage conversion module (11) and a first end of the first resistor respectively, the other end is connected with one end of the second resistor and grounded. The second end of the first resistor is connected with the other end of the second resistor and one end of the voltage stabilizing tube respectively. The other end of the voltage stabilizing tube is connected with a first end of the feedback module (13). The second end of the feedback module (13) is connected with a voltage feedback end of the voltage conversion module (11), and the third end is connected with the voltage conversion module (11) and grounded. The first end of the first resistor is used as an output end (S1) of the voltage stabilizing module (12) and used for outputting an alternating voltage signal. The voltage conversion module (11) comprises a pulse unit (111), a voltage transformation unit (112), a switching unit (113) and a rectification unit (114), and a first end of the switching unit (113) is used as a voltage feedback end of the voltage conversion module (11).

2. The circuit of claim 1, wherein, The output end of the pulse unit (111) is connected with a first end of the switching unit (113) and a second end of the feedback module (13) respectively. The input end of the voltage transformation unit (112) is connected with a second end of the switching unit (113), and the output end of the voltage transformation unit (112) is connected with one end of the rectification unit (114). The other end of the rectification unit (114) is connected with one end of the charging capacitor and the first end of the first resistor respectively. The third end of the switching unit (113) is connected with the third end of the feedback module (13) and grounded. The voltage transformation unit (112) comprises a primary winding and a secondary winding of a transformer, and the pulse unit (111) comprises a feedback winding of the transformer.

3. The circuit of claim 2, wherein, One end of the feedback winding is connected with a power supply, and the other end is connected with a first end of the switching unit (113) and a second end of the feedback module (13) respectively. One end of the primary winding is connected with a power supply, and the other end is connected with a second end of the switching unit (113). One end of the secondary winding is connected with one end of the rectification unit (114), and the other end is grounded. The voltage transformation unit (112) comprises a primary winding and a secondary winding of a transformer, and the pulse unit (111) comprises a pulse signal generator.

4. The circuit of claim 2, wherein, One end of the pulse signal generator is connected with a second end of the feedback module (13), and the other end is connected with a first end of the switching unit (113). One end of the primary winding is connected with a power supply, and the other end is connected with a second end of the switching unit (113). One end of the secondary winding is connected with one end of the rectification unit (114), and the other end is grounded. The voltage transformation unit (112) comprises an I-shaped inductor, and the pulse unit (111) comprises a pulse signal generator.

5. The circuit of claim 2, wherein, ​ The first end of the pulse signal generator is connected to the second end of the feedback module (13), and the second end of the pulse signal generator is connected to the first end of the switch unit (113); One end of the I-shaped inductor is connected to a power supply, and the other end is connected to the second end of the switch unit (113) and one end of the rectifier unit (114), respectively.

6. The circuit of claim 1, wherein, The voltage conversion module (11) comprises a voltage division unit (115), a voltage transformation unit (112) and a switch unit (113); The voltage transformation unit (112) comprises an I-shaped inductor, and the voltage division unit (115) comprises a third resistor, a fourth resistor, a fifth resistor and a second diode; One end of the third resistor is connected to a power supply, and the other end is connected to the second end of the switch unit (113) and one end of the fourth resistor, respectively. The other end of the fourth resistor is connected to the second end of the feedback module (13), one end of the fifth resistor and one end of the second diode, respectively. The other end of the fifth resistor is connected to the first end of the switch unit (113); The other end of the second diode is grounded. One end of the I-shaped inductor is connected to the third end of the switch unit (113), and the other end is connected to one end of the charging capacitor and one end of the first resistor, respectively.

7. The circuit of any one of claims 2-5, wherein, The feedback module (13) comprises a first transistor, and the switch unit (113) comprises a second transistor, a sixth resistor and a second capacitor; Wherein, the first transistor and the second transistor are current type devices; the first end of the second transistor is connected to one end of the sixth resistor and one end of the second capacitor, respectively, the second end is connected to the input end of the voltage transformation unit (112), and the third end is grounded; The other end of the sixth resistor is connected to the pulse unit (111); The other end of the second capacitor is grounded.

8. The circuit of any one of claims 2-5, wherein, The feedback module (13) comprises a first transistor, and the switch unit (113) comprises a second transistor, a sixth resistor and a seventh resistor; Wherein, the first transistor and the second transistor are voltage type devices; the first end of the second transistor is connected to one end of the sixth resistor and one end of the seventh resistor, respectively, the second end is connected to the input end of the voltage transformation unit (112), and the third end is grounded; The other end of the sixth resistor is connected to the pulse unit (111); The other end of the seventh resistor is grounded.

9. The circuit of claim 1, wherein, The circuit further comprises: A filter module comprising a filter capacitor, one end of which is connected to the first end of the first resistor, and the other end serves as the output end (S2) of the constant-voltage alternating-current signal generation circuit, for outputting the alternating voltage signal.

10. A combustion apparatus characterized by comprising: The constant-voltage alternating-current signal generation circuit of any one of claims 1-9.

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