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

Abstract

The utility model relates to the technical field of driving circuits, and discloses a constant-voltage alternating-current signal source generating circuit and combustion equipment, and the circuit comprises a voltage conversion module, a filtering module, a rectification module, a voltage stabilization module and a feedback module. Therefore, the constant-voltage alternating-current signal source generating circuit is provided with the voltage stabilizing module, the first alternating-current voltage signal output by the voltage conversion module charges the charging capacitor of the voltage stabilizing module after being rectified by the rectifying module, and voltage division is realized through the first resistor and the second resistor of the voltage stabilizing module; and voltage feedback of the voltage conversion module is realized through a voltage stabilizing tube of the voltage stabilizing module and the feedback module. Specifically, in the charging process of the charging capacitor by the power supply conversion module, when the charging voltage of the charging capacitor reaches a set voltage value, the voltage-regulator tube is subjected to avalanche breakdown and is fed back to the voltage conversion module through the feedback module, the peak value of a first alternating current signal output by the voltage conversion module is limited, and stable constant-voltage alternating current signal output is realized.

Description

Technical Field

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

[0002] Gas water heaters are widely used, and both the ignition circuit and the flame ionization signal sensing circuit in these heaters involve AC signal sources. However, the AC signal sources used in these technologies employ open circuit structures, resulting in unstable peak voltages. This significantly impacts the accuracy and sensitivity of signal detection during the use of gas water heaters, even affecting safety. For example, in flame ionization signal detection, due to performance variations in the components used in the AC signal source and the open circuit structure, different AC signal sources produce significantly different peak voltage values, leading to voltage fluctuations. This prevents the flame ionization signal sensing circuit from performing precise detection, affecting the sensitivity of flame ionization signal detection and potentially causing safety issues due to delayed detection. Therefore, improving the stability of AC signal sources is a pressing technical problem that needs to be solved. Utility Model Content

[0003] In view of this, the present invention provides a constant voltage AC signal source generating circuit and combustion device to solve the technical problem of how to improve the stability of AC signal source.

[0004] In a first aspect, this utility model provides a constant voltage AC signal source generating circuit, the circuit comprising:

[0005] The voltage conversion module has a first output terminal, a ground terminal and a feedback terminal, wherein the first output terminal outputs a first AC voltage signal;

[0006] The filtering module has one end connected to the first output terminal and the other end serving as the second output terminal, outputting a stable AC voltage signal obtained by processing the first AC voltage signal.

[0007] A rectifier module, one end of which is connected to the first output terminal, and the other end of which is connected to the first terminal of the charging capacitor of the voltage regulator module;

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

[0009] Feedback module;

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

[0011] The second terminal of the charging capacitor, the second terminal of the second resistor, and the second terminal of the protection capacitor are all grounded.

[0012] The first terminal of the feedback module is connected to the second terminal of the Zener diode, the second terminal of the feedback module is connected to the feedback terminal of the voltage conversion module, and the third terminal of the feedback module is grounded.

[0013] The constant voltage AC signal generator circuit provided by this utility model includes a voltage regulator module. The first AC voltage signal output by the voltage conversion module is rectified by the rectifier module and then charges the charging capacitor of the voltage regulator module. Voltage division is achieved through the first and second resistors of the voltage regulator module, and voltage feedback to the voltage conversion module is achieved through the Zener diode of the voltage regulator module and the feedback module. Specifically, during the charging process of the charging capacitor by the power conversion module, when the charging voltage of the capacitor reaches the set voltage value, the Zener diode undergoes avalanche breakdown, and the breakdown is fed back to the voltage conversion module through the feedback module, limiting the peak value of the first AC signal output by the voltage conversion module. This stabilizes the peak voltage of the output signal of the constant voltage AC signal generator circuit.

[0014] In some alternative implementations, the voltage conversion module includes: a pulse signal unit, a transformer unit, and a switching unit;

[0015] The first terminal of the switching unit is connected to the output terminal of the pulse signal unit, the second terminal is connected to the input terminal of the transformer unit, and the third terminal is grounded.

[0016] In some alternative implementations, the transformer unit includes:

[0017] The primary winding has a first primary end connected to the power supply end and a second primary end connected to the second end of the switching unit.

[0018] The secondary winding has a primary winding terminal that serves as the first output terminal. The primary winding terminal is connected to both the filter module and the rectifier module, while the secondary winding terminal is grounded.

[0019] In some alternative implementations, the pulse signal unit includes a feedback winding;

[0020] 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.

[0021] The constant voltage AC signal generator circuit provided by this utility model includes a pulse signal unit comprising a feedback winding, one end of which is connected to the power supply terminal and the other end is connected to the first terminal of the switch unit. The pulse signal is generated by the change in voltage difference between the two ends of the feedback winding and the action of the switch unit.

[0022] In some alternative implementations, the pulse signal unit includes a pulse signal generator;

[0023] The first signal terminal of the pulse signal generator is connected to the first terminal of the switching unit;

[0024] The second signal terminal of the pulse signal generator is connected to the second terminal of the feedback module.

[0025] In some alternative implementations, the switching unit includes an oscillating switch, a third resistor, and a compensation capacitor;

[0026] The first terminal of the oscillation switch is connected to one end of the first resistor and one end of the compensation capacitor, respectively. The second terminal of the oscillation switch is connected to the input terminal of the transformer unit. The third terminal of the oscillation switch is grounded. The oscillation switch is a current-type device.

[0027] The other end of the first resistor is connected to the pulse signal unit;

[0028] The other end of the compensation capacitor is grounded.

[0029] The constant voltage AC signal generator circuit provided by this utility model includes an oscillating switch, a third resistor, and a compensation capacitor in its switching unit. The oscillating switch is a current-type device. Therefore, a relatively simple switching unit can be formed using a current-type device, a third resistor, and a compensation capacitor, resulting in a simple connection structure.

[0030] In some alternative implementations, the switching unit includes an oscillating switch, a third resistor, and a fourth resistor;

[0031] The first terminal of the oscillation switch is connected to one end of the third resistor and one end of the fourth resistor respectively. The second terminal of the oscillation switch is connected to the input terminal of the transformer unit. The third terminal of the oscillation switch is grounded. The oscillation switch is a voltage-type device.

[0032] The other end of the third resistor is connected to the pulse signal unit;

[0033] The other end of the fourth resistor is grounded.

[0034] The constant voltage AC signal generator circuit provided by this utility model includes an oscillating switch, a third resistor, and a fourth resistor in the switching unit. The oscillating switch is a voltage-type device. Therefore, a switching unit can also be formed by combining a voltage-type device with two resistors. The device selection is flexible and the connection structure is simple.

[0035] In some alternative implementations, the feedback module includes a feedback switch, and the switching device types of the feedback switch and the oscillation switch are the same.

[0036] The constant voltage AC signal generator circuit provided by this utility model uses a switching device of the same type as the oscillation switch as a feedback switch to realize the function of the feedback module. The device selection is flexible and the circuit connection is simple.

[0037] In some alternative implementations, the filtering module includes a filtering capacitor, one end of which is connected to the first output terminal and the other end of which serves as the second output terminal.

[0038] Secondly, this utility model also provides a combustion device, including a flame signal sensing circuit or an ignition circuit;

[0039] The flame signal sensing circuit includes the constant voltage AC signal source generating circuit of the first aspect above or any corresponding embodiment thereof;

[0040] The ignition circuit includes the constant voltage AC signal source generating circuit of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0041] 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.

[0042] Figure 1 A schematic diagram of the circuit principle of an AC signal source module for a combustion device provided by related technologies is shown;

[0043] Figure 2 A schematic diagram of the circuit principle of the flame sensing signal processing module of the combustion device provided by the related technology is shown;

[0044] Figure 3 This is a schematic diagram of the constant voltage AC signal source generating circuit according to the first embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the constant voltage AC signal source generating circuit according to the second embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the constant voltage AC signal source generating circuit according to the third embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the constant voltage AC signal source generating circuit according to the fourth embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the constant voltage AC signal source generating circuit according to the fourth embodiment of the present invention;

[0049] Figure 8This is a schematic diagram of the composition structure of the combustion device provided according to an embodiment of the present utility model;

[0050] Figure 9 This is a schematic diagram of the circuit principle of applying the constant voltage AC signal source generating circuit of this utility model embodiment to the flame sensing circuit;

[0051] Figure 10 This is a schematic diagram of the circuit principle of the flame signal sensing circuit provided in this embodiment of the utility model.

[0052] Explanation of reference numerals in the attached figures

[0053] 11 Voltage conversion module; S1 First output terminal; GND Ground terminal; F1 Feedback terminal;

[0054] 12 Filtering module; 13 Rectifier module; 14 Voltage regulator module; 15 Feedback module;

[0055] S2 Second Output Terminal; E11 Primary Winding; E12 Secondary Winding; E2 Feedback Winding;

[0056] M1 pulse signal generator; VCC power supply terminal;

[0057] C1 is the charging capacitor; C2 is the protection capacitor; R1 is the first resistor; R2 is the second resistor; Z1 is the Zener diode;

[0058] 111 Pulse signal unit; 112 Transformer unit; 113 Switching unit; C3 Filter capacitor;

[0059] Q1 is the first transistor; Q2 is the second transistor;

[0060] T1 is the first MOSFET; T2 is the second MOSFET;

[0061] R3 is the third resistor; R4 is the fourth resistor; C4 is the compensation capacitor; D1 is the rectifier diode;

[0062] J1 flame detection electrode; Q0 transistor;

[0063] R01 is the first voltage divider resistor; R02 is the second voltage divider resistor; R03 is the third voltage divider resistor;

[0064] R04 is the fourth voltage divider resistor; R05 is the fifth voltage divider resistor; R06 is the sixth voltage divider resistor;

[0065] R07 is the seventh voltage divider resistor; C01 is the first capacitor; C02 is the second capacitor;

[0066] D01 is the first diode; D02 is the second diode. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0068] To better illustrate the constant voltage AC signal source generating circuit of this utility model embodiment, the application scenario of the constant voltage AC signal source generating circuit is first briefly described here. Specifically, in the use of combustion equipment such as gas water heaters and gas stoves, a flame signal sensing circuit including an AC signal source and an ignition circuit are required. The stability of the AC signal source has a significant impact on the accuracy and precision of the flame signal sensing.

[0069] Figure 1 This diagram illustrates the circuit principle of an AC signal source module for a combustion device provided by related technologies, such as... Figure 1 As shown, the AC signal source module used by the combustion equipment is implemented by the boost unit E0. The boost unit E0 includes a feedback winding E2 and a primary winding E11 and a secondary winding E12 of the boost transformer. In some optional embodiments, the primary winding is also referred to as the boost transformer main winding, and the secondary winding is referred to as the transformer secondary coil.

[0070] Furthermore, the first end of the feedback winding is connected to the power supply terminal VCC, and the other end is connected to the base of transistor Q0 through a series resistor R1. Therefore, when the base of transistor Q0 receives a high-level signal, the collector-emitter junction (CE junction) of transistor Q0 saturates and conducts, energizing the primary winding E11. A voltage difference is generated across the primary winding E11, and through magnetic field induction, the secondary winding E12 of the boost unit E0 forms a boost voltage through coil coupling, thereby generating an electrical signal. Further, a voltage difference is generated across the feedback winding E2. When a voltage difference forms across the feedback winding E2, the current received at the base of transistor Q0 decreases, causing the collector and emitter of transistor Q0 to cut off. This disconnects the primary winding E11 from the ground terminal GND, eliminating the voltage difference across the feedback winding E2, causing transistor Q0 to saturate and conduct again. This process repeats, generating an oscillation signal.

[0071] Therefore, when the AC signal source module 100 receives the DC voltage signal, it generates an AC voltage signal S0 under the combined action of the first voltage divider resistor R01, the first capacitor C01, and the transistor Q0 in the boost unit E0, and outputs the AC voltage signal S0 through the secondary winding E12 of the boost unit E0. Here, the AC voltage signal S0 can be connected to the flame detection electrode J1 of the flame signal sensing circuit. Furthermore, to avoid problems such as short circuits, a second voltage divider resistor R02 is provided between the AC voltage signal S0 and the flame detection electrode J1 of the flame signal sensing circuit.

[0072] Furthermore, an AC voltage signal can be output to the flame sensing signal processing module of the combustion device through the coupling effect of the second capacitor C02. For details, please refer to [reference needed]. Figure 2 Other embodiments of this application involving flame signal sensing circuits and ignition circuits will not be described in detail here.

[0073] It should be noted that, Figure 1 The transistor Q0 in the circuit can also be replaced by a voltage-mode MOSFET. When using a MOSFET, the first capacitor C01 needs to be replaced with a resistor. Furthermore, if a current-mode transistor is used, an NPN or PNP type transistor can be selected according to actual needs. If a voltage-mode MOSFET is used, a P-channel or N-channel MOSFET can be selected according to actual needs. The specific circuit connections are adjusted according to the specific type of transistor or MOSFET. The specific device parameters can also be selected and configured according to actual needs.

[0074] Figure 2 A schematic diagram of the circuit principle of the flame sensing signal processing module of a combustion device provided by related technology is shown. The above... Figure 1 The AC voltage signal S0 output by the AC signal source module 100 shown can be applied to Figure 2 The flame sensing signal processing module of a combustion device is shown.

[0075] like Figure 2 As shown, the AC signal source is represented by a sine wave pattern. When the flame burner 20 has no flame, no flame ionization signal is generated. At this time, the AC signal source does not form a loop after passing through the second capacitor C02 and the second voltage divider resistor R02, and the current in the branch formed by the AC signal source, the second capacitor C02, and the second voltage divider resistor R02 is zero. Therefore, when the flame burner 20 has no flame, the voltage value collected by the microprocessor 30 is the voltage value of the power supply terminal VCC.

[0076] When the flame burner 20 generates a flame ionization signal, this signal can be used as a signal generated by a unidirectional diode effect. Specifically, the flame ionization signal is connected to the third voltage divider resistor R03 and the power supply terminal VCC signal is connected to the fourth voltage divider resistor R04 to form a flame ionization signal determination circuit. This circuit is clamped by the first diode D01 and the second diode D02. Further, a voltage signal is input to the microprocessor 30 via the fifth voltage divider resistor R05. The microprocessor 30 can set a preset voltage range for determining whether the flame burner 20 generates a flame ionization signal, according to actual needs. When the voltage value of the voltage signal received by the microprocessor 30 meets the preset voltage range, it is determined that the flame burner 20 has generated a flame ionization signal. This enables the determination of whether the flame burner is in a combustion state with a flame.

[0077] However, due to Figure 1 In the illustrated embodiment, the magnitude of the AC signal voltage is affected by multiple factors, including the resistance deviation of the first voltage divider resistor R01, the amplification factor of transistor Q0, and the manufacturing process deviation of the boost unit E0. Therefore, Figure 1 In the illustrated embodiment, the voltage value of the AC voltage signal S0 output by the AC signal source module 100 fluctuates within a certain range. Therefore, the AC signal source module 100 provided in this embodiment will significantly affect the detection sensitivity of the flame sensing signal processing module using this module. Similarly, if this AC signal source module is applied to the ignition circuit of a combustion device, it will also have a significant adverse impact on the stability of the ignition circuit of the combustion device.

[0078] Based on this, the present invention provides a constant voltage AC signal source generating circuit to generate a stable AC voltage signal.

[0079] This utility model provides a constant voltage AC signal source generating circuit embodiment. It should be noted that the connection relationship shown in the accompanying drawings is only an illustrative example. However, in some cases, different connection relationships or specific devices may be used than those shown or described herein.

[0080] The constant voltage AC signal source generating circuit provided in this embodiment can be used in the flame signal sensing circuit and ignition circuit of combustion equipment, etc. Figure 3 The circuit principle diagram of the constant voltage AC signal source generating circuit according to the first embodiment of this utility model is as follows: Figure 3 As shown, the constant voltage AC signal source generation circuit includes a voltage conversion module 11, a filtering module 12, a rectifier module 13, a voltage regulator module 14, and a feedback module 15.

[0081] The voltage conversion module 11 has a first output terminal S1, a ground terminal GND, and a feedback terminal F1. The first output terminal S1 outputs a first AC voltage signal. One end of the filter module 12 is connected to the first output terminal S1, and the other end serves as the second output terminal S2. The filter module 12 outputs a stable AC voltage signal obtained by processing the first AC voltage signal. One end of the rectifier module 13 is connected to the first output terminal S1, and the other end is connected to the first terminal of the charging capacitor C1 of the voltage regulator module 14.

[0082] The voltage regulator module 14 includes a charging capacitor C1, a first resistor R1, a second resistor R2, a protection capacitor C2, and a Zener diode Z1. The first resistor R1 is connected to the first terminal of the charging capacitor C1, and its other terminal is connected to the first terminals of the second resistor R2, the first terminals of the protection capacitor C2, and the first terminal of the Zener diode Z1, respectively. The second terminals of the charging capacitor C1, the second resistor R2, and the protection capacitor C2 are all grounded. The first terminal of the feedback module 15 is connected to the second terminal of the Zener diode Z1, and the second terminal of the feedback module 15 is connected to the feedback terminal F1 of the voltage conversion module 11. The third terminal of the feedback module 15 is grounded.

[0083] The constant voltage AC signal generator circuit provided by this utility model includes a voltage regulator module. The first AC voltage signal output by the voltage conversion module is rectified by the rectifier module and then charges the charging capacitor of the voltage regulator module. Voltage division is achieved through the first and second resistors of the voltage regulator module, and voltage feedback to the voltage conversion module is achieved through the Zener diode of the voltage regulator module and the feedback module. Specifically, during the charging process of the charging capacitor by the power conversion module, when the charging voltage of the capacitor reaches the set voltage value, the Zener diode undergoes avalanche breakdown, and the breakdown is fed back to the voltage conversion module through the feedback module, limiting the peak value of the first AC signal output by the voltage conversion module. This stabilizes the peak voltage of the output signal of the constant voltage AC signal generator circuit.

[0084] The constant voltage AC signal source generating circuit provided in this embodiment can be used in the flame signal sensing circuit and ignition circuit of combustion equipment, etc. Figure 4 A schematic diagram of the constant voltage AC signal source generating circuit according to the second embodiment of this utility model.

[0085] like Figure 4 As shown, the constant voltage AC signal source generation circuit includes a voltage conversion module 11, a filtering module 12, a rectification module 13, a voltage regulation module 14, and a feedback module 15. The voltage conversion module 11 includes a pulse signal unit 111, a transformer unit 112, and a switching unit 113. The first terminal of the switching unit 113 is connected to the output terminal of the pulse signal unit 111, the second terminal is connected to the input terminal of the transformer unit 112, and the third terminal is grounded. Figure 4The medium voltage conversion module 11 is directly shown as a pulse signal unit 111, a transformer unit 112, and a switching unit 113.

[0086] In some alternative implementations, the filtering module 12 includes a filtering capacitor C3, one end of which is connected to the first output terminal S1, and the other end serves as the second output terminal S2.

[0087] In some optional implementations, the pulse signal unit 111 can be implemented in various ways. For example, a pulse generator can be used to directly generate a pulse voltage signal. Alternatively, a feedback winding can be used, which works in conjunction with other devices to generate a pulse voltage signal. Similarly, the transformer unit, switching unit, and feedback module can also have various implementations, and different implementations of multiple modules or units can be combined and varied according to actual needs. Some of these implementations are selected for illustrative purposes in this application.

[0088] In some optional embodiments, the transformer unit 112 includes a primary winding E11 and a secondary winding E12. The first primary terminal of the primary winding E11 is connected to the power supply terminal VCC, and the second primary terminal is connected to the second terminal of the switching unit 113. The first primary terminal of the secondary winding E12 serves as the first output terminal S1, and is connected to both the filter module 12 and the rectifier module 13; the second primary terminal is grounded.

[0089] In some alternative embodiments, the pulse signal unit 111 includes a feedback winding E2. One end of the feedback winding E2 is connected to the power supply terminal VCC, and the other end is connected to the first terminal of the switching unit 113.

[0090] In some optional embodiments, the switching unit 113 includes an oscillating switch, a third resistor R3, and a compensation capacitor C4. The first terminal of the oscillating switch is connected to one end of the first resistor R1 and one end of the compensation capacitor C4, respectively. The second terminal of the oscillating switch is connected to the input terminal of the transformer unit 112, and the third terminal of the oscillating switch is grounded. The other end of the first resistor R1 is connected to the pulse signal unit 111. The other end of the compensation capacitor C4 is grounded. Here, the oscillating switch is a current-type device.

[0091] Figure 4The following example illustrates the scheme using an NPN-type transistor Q1 as an example of an oscillation switch. Here, the feedback module 15 includes a feedback switch, which uses a second transistor Q2 of the same type as the oscillation switch. The base of the first transistor Q1 is connected to one end of the first resistor R1 and one end of the compensation capacitor C4, respectively. The collector of the first transistor Q1 is connected to one end of the primary winding E11 of the transformer unit 112, and the emitter of the first transistor Q1 is grounded. The other end of the first resistor R1 is connected to the feedback winding E2 of the pulse signal unit 111. The other end of the compensation capacitor C4 is grounded.

[0092] Therefore, the base of the first transistor Q1 is connected to the power supply terminal VCC through the first resistor R1 and the feedback winding E2. When the base of the first transistor Q1 receives a high-level signal, the CE junction of the first transistor Q1 saturates and conducts, energizing the primary winding E11 of the transformer unit 112. A voltage difference is generated across the primary winding E11. Under the influence of the magnetic field, the secondary winding E12 of the transformer unit 112 forms a boost voltage through coil coupling, thereby generating an electrical signal. A voltage difference is generated across the feedback winding E2. When a voltage difference is formed across the feedback winding E2, the current received at the base of the first transistor Q1 decreases, causing the collector and emitter of the second transistor Q2 to be cut off. The primary winding E11 of the transformer unit 112 is disconnected from the ground terminal GND, and there is no voltage difference across the feedback winding E2, causing the first transistor Q1 to saturate and conduct again. This process repeats, and the first output terminal S1 outputs the first AC voltage signal.

[0093] Furthermore, the first AC voltage signal output from the first output terminal S1 is rectified by the rectifier diode D2, and then used to charge the charging capacitor C1. The voltage is then divided by the first resistor R1 and the second resistor R2.

[0094] When the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1, the Zener diode Z1 undergoes avalanche breakdown. As a result, the CE junction of the second transistor Q2 is turned on, causing the first transistor Q1 to be in the cutoff state.

[0095] When the voltage division value of the first resistor R1 and the second resistor R2 does not meet the breakdown voltage of the Zener diode Z1, the first transistor Q1 switches and oscillates normally, and the transformer unit 112 boosts the voltage normally. When the condition that "the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1" is met again, the Zener diode Z1 undergoes avalanche breakdown, the CE junction of the second transistor Q2 conducts, and the first transistor Q1 is in the off state. This process repeats, and after being filtered by the filter capacitor C3 of the filter module 12, a stable AC voltage signal with a constant peak voltage is output through the second output terminal S2. Here, the waveform of the AC voltage signal is a sine wave.

[0096] Figure 4 For further detailed implementation information of the illustrated embodiments, please refer to [link / reference]. Figure 3 The embodiments shown are not described in detail here.

[0097] The constant voltage AC signal source generating circuit provided in this embodiment can be used in the flame signal sensing circuit and ignition circuit of combustion equipment, etc. Figure 5 A schematic diagram of the constant voltage AC signal source generating circuit according to the third embodiment of this utility model.

[0098] like Figure 5 As shown, the constant voltage AC signal source generation circuit also includes a voltage conversion module 11, a filter module 12, a rectifier module 13, a voltage regulator module 14, and a feedback module 15. The voltage conversion module 11 is shown as a pulse signal unit 111, a transformer unit 112, and a switching unit 113.

[0099] Figure 5 The constant voltage AC signal generator circuit shown is Figure 4 The embodiment shown differs in that the switching unit 113 includes an oscillating switch, a third resistor R3 and a fourth resistor R4, and the oscillating switch is a voltage-type device.

[0100] Figure 5 Taking the first MOSFET T1, which uses a P-channel type for the oscillation switch, as an example, the scheme will be further explained. Here, the feedback module 15 includes a feedback switch, which uses a second MOSFET T2 of the same type as the oscillation switch. The gate of the first MOSFET T1 is connected to one end of the third resistor R3 and one end of the fourth resistor R4, respectively. The source of the first MOSFET T1 is connected to the input terminal of the transformer unit 112, and the drain of the first MOSFET T1 is grounded. The other end of the third resistor R3 is connected to the pulse signal unit 111, and the other end of the fourth resistor R4 is grounded.

[0101] Therefore, the base of the first MOSFET T1 is connected to the power supply terminal VCC through the first resistor R1 and the feedback winding E2. When the base of the first MOSFET T1 receives a high-level signal, the source and drain of the first MOSFET T1 conduct, and the primary winding E11 of the transformer unit 112 is energized. A voltage difference is generated across the primary winding E11. Under the action of magnetic field induction, the secondary winding E12 of the transformer unit 112 forms a boost voltage through coil coupling, thereby generating an electrical signal. A voltage difference is generated across the feedback winding E2. When a voltage difference is formed across the feedback winding E2, the current received at the base of the first MOSFET T1 decreases, causing the source and drain of the second MOSFET T2 to be cut off. The primary winding E11 of the transformer unit 112 is disconnected from the ground terminal GND, and there is no voltage difference across the feedback winding E2, causing the first MOSFET T1 to saturate and conduct again. This process repeats, and the first output terminal S1 outputs the first AC voltage signal.

[0102] Furthermore, the first AC voltage signal output from the first output terminal S1 is rectified by the rectifier diode D2, and then used to charge the charging capacitor C1. The voltage is then divided by the first resistor R1 and the second resistor R2.

[0103] When the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1, the Zener diode Z1 undergoes avalanche breakdown. As a result, the source and drain of the second MOSFET T2 are connected, causing the first MOSFET T1 to be in the cutoff state.

[0104] When the voltage division value of the first resistor R1 and the second resistor R2 does not meet the breakdown voltage of the Zener diode Z1, the first MOSFET T1 switches and oscillates normally, and the transformer unit 112 boosts the voltage normally. When the condition that "the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1" is met again, the Zener diode Z1 undergoes avalanche breakdown, and the source and drain of the second MOSFET T2 conduct, causing the first MOSFET T1 to be in the off state. This process repeats, and after filtering by the filter capacitor C3 of the filter module 12, a stable AC voltage signal is output through the second output terminal S2. The peak value of the stable AC voltage signal is constant. Furthermore, the waveform of the AC voltage signal output by the second output terminal S2 is similar to... Figure 4 The waveform of the AC voltage signal output from the second output terminal S2 in the illustrated embodiment is the same, which is also a sine wave.

[0105] Figure 5 For further detailed implementation information of the illustrated embodiments, please refer to [link / reference]. Figure 3 and Figure 4 The embodiments shown are not described in detail here.

[0106] It should be noted that, regarding the above Figure 4 and Figure 5In the illustrated embodiment, the feedback winding E2, primary winding E11, and secondary winding E12 are typically integrated into a step-up transformer in actual engineering applications. This embodiment is only provided as an example to illustrate the circuit principle and does not limit actual engineering applications.

[0107] The constant voltage AC signal source generating circuit provided in this embodiment can be used in the flame signal sensing circuit and ignition circuit of combustion equipment, etc. Figure 6 A schematic diagram of the constant voltage AC signal source generating circuit according to the fourth embodiment of this utility model.

[0108] like Figure 6 As shown, the constant voltage AC signal source generation circuit includes a voltage conversion module 11, a filter module 12, a rectifier module 13, a voltage regulator module 14, and a feedback module 15. The voltage conversion module 11 is shown as a pulse signal unit 111, a transformer unit 112, and a switching unit 113.

[0109] Figure 6 The constant voltage AC signal generator circuit shown is Figure 4 The embodiment shown differs in that the pulse signal unit 111 includes a pulse signal generator M1. The first signal terminal of the pulse signal generator M1 is connected to the first terminal of the switching unit 113, and the second signal terminal of the pulse signal generator M1 is connected to the second terminal of the feedback module 15.

[0110] The pulse signal of the pulse signal generator M1 can be generated by a circuit consisting of a microcontroller, a 555 timer chip, an inverter, or an amplifier.

[0111] Compared to Figure 4 and Figure 5 In the embodiment shown, this invention does not require a feedback winding; therefore, a transformer with three windings is not needed. The transformer unit 112 can be a transformer with only two windings, a primary winding and a secondary winding, resulting in a simple structure and effectively reducing transformer costs.

[0112] Compared to Figure 4 In the embodiment shown, the driving signal for the first transistor Q1 is changed from a self-excited signal to a signal generated by a pulse signal generator M1, where the waveform generated by the pulse signal generator M1 is a square wave.

[0113] When the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1, the Zener diode Z1 undergoes avalanche breakdown, the CE junction of the second transistor Q2 is turned on, and the second transistor Q2 sends an enable signal to the pulse signal generator M1 through the second signal terminal, turning off the oscillation signal of the pulse signal generator, thereby causing the first transistor Q1 to be in the cut-off state.

[0114] When the voltage division value of the first resistor R1 and the second resistor R2 does not meet the breakdown voltage of the Zener diode Z1, the first transistor Q1 switches and oscillates normally, and the transformer unit 112 boosts the voltage normally.

[0115] When the condition that "the voltage division value of the first resistor R1 and the second resistor R2 meets the breakdown voltage of the Zener diode Z1" is met again, the Zener diode Z1 undergoes avalanche breakdown, and the CE junction of the second transistor Q2 conducts. The second transistor Q2 sends an enable signal to the pulse signal generator M1 through its second signal terminal, turning off the oscillation signal of the pulse signal generator, thus putting the first transistor Q1 in the off state. This process repeats, and after being filtered by the filter capacitor C3 of the filter module 12, a stable AC voltage signal with a constant peak voltage is output through the second output terminal S2. Here, the waveform of the AC voltage signal is a sine wave.

[0116] Figure 6 For further detailed implementation information of the illustrated embodiments, please refer to [link / reference]. Figures 3-5 The embodiments shown are not described in detail here.

[0117] The constant voltage AC signal source generating circuit provided in this embodiment can be used in the flame signal sensing circuit and ignition circuit of combustion equipment, etc. Figure 7 A schematic diagram of the constant voltage AC signal source generating circuit according to the fifth embodiment of this utility model. Figure 7 As shown, the constant voltage AC signal generator circuit includes:

[0118] like Figure 7 As shown, the constant voltage AC signal source generation circuit also includes a voltage conversion module 11, a filter module 12, a rectifier module 13, a voltage regulator module 14, and a feedback module 15. The voltage conversion module 11 is shown as a pulse signal unit 111, a transformer unit 112, and a switching unit 113.

[0119] Figure 7 The constant voltage AC signal generator circuit shown is Figure 6 The embodiment shown differs in that the switching unit 113 includes an oscillating switch, a third resistor R3 and a fourth resistor R4, and the oscillating switch is a voltage-type device.

[0120] Figure 7Taking the first MOSFET T1, which uses a P-channel type for the oscillation switch, as an example, the scheme will be further explained. Here, the feedback module 15 includes a feedback switch, which uses a second MOSFET T2 of the same type as the oscillation switch. The gate of the first MOSFET T1 is connected to one end of the third resistor R3 and one end of the fourth resistor R4, respectively. The source of the first MOSFET T1 is connected to the primary winding E11 of the transformer unit 112, and the drain of the first MOSFET T1 is grounded. The other end of the third resistor R3 is connected to the first signal terminal of the pulse signal generator M1, and the other end of the fourth resistor R4 is grounded.

[0121] Figure 7 For further detailed implementation information of the illustrated embodiments, please refer to [link / reference]. Figures 3-6 The embodiments shown are not described in detail here.

[0122] Based on the constant voltage AC signal source generating circuit provided in the above embodiments, this utility model also provides a combustion device, such as... Figure 8 As shown, the combustion device includes a flame signal sensing circuit 801 or an ignition circuit 802. The flame signal sensing circuit 801 includes a constant voltage AC signal source generating circuit 803 of the first aspect described above or any corresponding embodiment thereof. The ignition circuit 802 includes a constant voltage AC signal source generating circuit 803 of the first aspect described above or any corresponding embodiment thereof.

[0123] It should be noted that in the same combustion device, the flame signal sensing circuit 801 and the ignition circuit 802 can share a constant voltage AC signal source generating circuit 803. A schematic diagram of their connection can be found here. Figure 8 In some alternative implementations, a constant voltage AC signal source generating circuit 803 may also be configured for both the flame signal sensing circuit 801 and the ignition circuit 802.

[0124] Figure 9 Provided the above Figure 4 The illustrated embodiment provides a schematic diagram of the constant voltage AC signal generator circuit applied to a flame sensing circuit. Figure 9 As shown, the flame detection electrode J1 of the flame burner 20 is connected to the second output terminal S2 of the constant voltage AC signal source generating circuit via the fifth resistor R5, and the other end of the flame burner 20 is grounded. It should be noted that in the descriptions related to the circuit connections of the flame burner 20 in this application, the flame burner 20 is equipped with a dedicated flame signal sensing circuit, which can be configured with the flame detection electrode J1. In practical applications, the flame signal sensing circuit can adopt... Figure 2 The flame signal sensing circuit provided in the middle.

[0125] but, Figure 2The flame signal sensing circuit provided in the previous method only has two detection results: flame or no flame. This method can only detect the presence or absence of a flame and cannot perform detailed analysis and fine differentiation of flames under various conditions. Based on this, this embodiment of the present invention also provides a flame signal sensing circuit.

[0126] Figure 10 This is a schematic diagram of the circuit principle of the flame signal sensing circuit provided in this embodiment of the utility model, as shown below. Figure 10 As shown, the flame burner 20 is connected to the ground wire and the flame detection terminal ( Figure 10 (As shown in the image, flame detection electrode J1) forms a combustion circuit. Figure 3-7 The constant voltage AC voltage signal generating circuit provided in any embodiment receives a stable AC signal, and the peak voltage of the stable AC voltage signal is constant.

[0127] Therefore, when a flame is generated, the flame ionization signal generated by the flame burner 20 can be used as a signal generated by the unidirectional diode effect. The flame sensing detection end can detect a stable flame signal. After the flame signal is processed by the R03 front end, it becomes a signal that can be recognized by the amplifier. It is clamped by the first diode D01 and the second diode D02, and the signal amplification circuit is formed by the sixth voltage divider resistor R06 and the seventh voltage divider resistor R07.

[0128] When there is no flame signal, the main MCU (Microcontroller Unit) 40 of the combustion device receives a low-level ion current signal from the flame detection terminal. As the ion current signal detected by the flame detection terminal increases, the level detected by the main MCU 40 through the flame detection terminal increases proportionally with the amplification circuit formed by the sixth voltage divider resistor R06 and the seventh voltage divider resistor R07, thus achieving the purpose of following the change in the size of the flame ion current. A voltage value representing the flame size is generated through proportional amplification. The range of the voltage value representing the flame size detected by the flame detection terminal can be set according to the A / D value of the main MCU 40. The precision of flame detection by the flame signal sensing circuit depends on the range of the A / D value of the main MCU 40.

[0129] Therefore, the flame signal circuit provided in this embodiment of the present invention can achieve detailed flame detection and effectively detect changes in equipment operating conditions.

[0130] The constant voltage AC signal source generating circuit provided in this embodiment of the invention, after rectifying the first AC voltage signal output from the first output terminal S1 of the voltage conversion module, uses a resistor voltage divider to generate a trigger voltage to increase feedback, thereby achieving a constant peak value of the sinusoidal voltage of the AC source. Furthermore, a charging capacitor is coupled between the flame detection terminal (shown as flame detection electrode J1 in the figure) and the stable AC voltage signal output from the second output terminal S2, isolating the AC component at the flame detection terminal and making the flame signal easily detectable. Moreover, the oscillation switch of the constant voltage AC signal source generating circuit can be either a transistor or a MOSFET, using similar devices to achieve the same effect, offering flexibility in device selection.

[0131] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A constant voltage AC signal generator circuit, characterized in that, The circuit includes: The voltage conversion module (11) has a first output terminal (S1), a ground terminal (GND) and a feedback terminal (F1), wherein the first output terminal (S1) outputs a first AC voltage signal; The filtering module (12) has one end connected to the first output terminal (S1) and the other end as the second output terminal (S2), which outputs a stable AC voltage signal obtained by processing the first AC voltage signal. A rectifier module (13), one end of which is connected to the first output terminal (S1), and the other end of which is connected to the first end of the charging capacitor (C1) of the voltage regulator module (14); The voltage regulator module (14) includes: a charging capacitor (C1), a first resistor (R1), a second resistor (R2), a protection capacitor (C2), and a Zener diode (Z1); Feedback module (15); Wherein, the first resistor (R1) is connected to the first end of the charging capacitor (C1), and the other end is connected to the first end of the second resistor (R2), the first end of the protection capacitor (C2), and the first end of the Zener diode (Z1), respectively; The second terminal of the charging capacitor (C1), the second terminal of the second resistor (R2), and the second terminal of the protection capacitor (C2) are all grounded; The first end of the feedback module (15) is connected to the second end of the Zener diode (Z1), the second end of the feedback module (15) is connected to the feedback terminal (F1) of the voltage conversion module (11), and the third end of the feedback module (15) is grounded.

2. The circuit according to claim 1, characterized in that, The voltage conversion module (11) includes: a pulse signal unit (111), a transformer unit (112), and a switching unit (113); The first end of the switching unit (113) is connected to the output end of the pulse signal unit (111), the second end is connected to the input end of the transformer unit (112), and the third end is grounded.

3. The circuit according to claim 2, characterized in that, The transformer unit (112) includes: The primary winding (E11) has a first primary terminal connected to the power supply terminal (VCC) and a second primary terminal connected to the second terminal of the switching unit (113). The secondary winding (E12) has a primary winding terminal as the first output terminal (S1), which is connected to both the filter module (12) and the rectifier module (13), and the secondary winding terminal is grounded.

4. The circuit according to claim 2, characterized in that, The pulse signal unit (111) includes a feedback winding (E2); One end of the feedback winding (E2) is connected to the power supply terminal (VCC), and the other end is connected to the first end of the switching unit (113).

5. The circuit according to claim 2, characterized in that, The pulse signal unit (111) includes a pulse signal generator (M1); The first signal terminal of the pulse signal generator (M1) is connected to the first terminal of the switching unit (113); The second signal terminal of the pulse signal generator (M1) is connected to the second terminal of the feedback module (15).

6. The circuit according to claim 2, characterized in that, The switching unit (113) includes an oscillating switch, a third resistor (R3), and a compensation capacitor (C4); The first terminal of the oscillation switch is connected to one end of the first resistor (R1) and one end of the compensation capacitor (C4) respectively; the second terminal of the oscillation switch is connected to the input terminal of the transformer unit (112); the third terminal of the oscillation switch is grounded; and the oscillation switch is a current-type device. The other end of the first resistor (R1) is connected to the pulse signal unit (111); The other end of the compensation capacitor (C4) is grounded.

7. The circuit according to claim 2, characterized in that, The switching unit (113) includes an oscillating switch, a third resistor (R3), and a fourth resistor (R4); The first terminal of the oscillation switch is connected to one end of the third resistor (R3) and one end of the fourth resistor (R4) respectively, the second terminal of the oscillation switch is connected to the input terminal of the transformer unit (112), and the third terminal of the oscillation switch is grounded. The oscillation switch is a voltage-type device. The other end of the third resistor (R3) is connected to the pulse signal unit (111); The other end of the fourth resistor (R4) is grounded.

8. The circuit according to claim 6 or 7, characterized in that, The feedback module (15) includes a feedback switch, and the feedback switch and the oscillation switch are of the same type of switching device.

9. The circuit according to claim 1, characterized in that, The filtering module (12) includes a filtering capacitor (C3), one end of which is connected to the first output terminal (S1), and the other end serves as the second output terminal (S2).

10. A combustion device, characterized in that, This includes flame signal sensing circuits or ignition circuits; The flame signal sensing circuit includes the constant voltage AC signal source generating circuit as described in any one of claims 1-9; The ignition circuit includes the constant voltage AC signal source generating circuit according to any one of claims 1-9.

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