Parallel discharge circuit and electric flame

Abstract

The application discloses a parallel discharge circuit and an electric flame stove, comprising a transformer and at least two groups of discharge branches; the two groups of discharge branches comprise a first discharge branch and a second discharge branch. The application adopts a single transformer to replace a multi-transformer scheme, reduces the multiple conversion loss of "electric energy-magnetic energy-electric energy", reduces electromagnetic interference, and simultaneously, the stove body does not need to be arranged with a large number of transformers, the volume is more compact, and the parallel demand of the high-power electric flame stove hundred groups of discharge devices is adapted; the application realizes the continuous control of the multi-discharge branch asynchronous breakdown and independent charging and discharging, adapts to the discharge device breakdown threshold difference and the voltage multiplication capacitor charging speed deviation among the discharge branches, does not need additional voltage equalization control, ensures that all the discharge branches can stably complete the charging and discharging closed loop, and has no discharge failure and mutual interference; and the application is suitable for multiple voltage inputs and realizes wide voltage input.

Description

Technical Field

[0001] This invention specifically relates to an electric flame stove and its circuitry. Background Technology

[0002] Electric flame stoves employ multiple high-voltage discharge devices (connected in parallel with positive and negative electrodes in an air-tight discharge configuration). Each device generates an electric field by breaking down the gas flow under high voltage. The gas flow collides with electrons in the electric field, ionizing the gas molecules and exciting plasma. This plasma has a temperature of over 1000 degrees Celsius and is used to heat cookware. Currently, electric flame stoves on the market are also known as electric fire stoves, electric fire starter stoves, electric flame stoves, electric gas stoves, electric open flame stoves, plasma stoves, etc. All of these stoves utilize the working principle of high-voltage air breakdown to excite plasma for heating cookware.

[0003] The ideal breakdown voltage of the high-voltage discharge device in an electric flame stove is between 8,000 and 10,000 volts. Therefore, in order to provide a continuous and stable high voltage, a transformer is needed to step up the voltage and then rectify it through the high-voltage discharge branch to output tens of thousands of volts of DC power to the positive terminal of the high-voltage discharge device.

[0004] In this field, the impedance of the load in an electric flame stove changes at high frequency, frequently switching between "airflow (high resistance) - plasma (low resistance) - airflow (high resistance) - plasma (low resistance)," resulting in high-frequency fluctuations in current. Existing electric flame stove technologies typically employ multiple, even hundreds, high-voltage discharge devices, using multiple sets of input terminals connected in parallel to the same transformer secondary winding in a voltage multiplier rectifier branch. Each branch supplies high-voltage DC power to its corresponding high-voltage discharge device. However, this circuit exhibits a phenomenon where some voltage multiplier rectifier branches (high-voltage discharge devices) have high current while others have no current. This is due to the combined effects of the breakdown voltage difference of the discharge load, the voltage clamping / voltage drop effect of the parallel circuit structure, and is further amplified by differences in capacitor parameters and design flaws.

[0005] like Figure 1 As shown, taking two sets of voltage multiplier rectifier branches as an example, the breakdown voltage of the discharge device (plasma discharge head) is affected by factors such as gap distance, gas medium, and temperature. The two sets cannot be completely identical, and the breakdown discharge times of the two discharge devices cannot be the same. For example... Figure 1 As shown, for example, the load breakdown voltage of the upper discharge branch is lower, and it reaches the breakdown threshold first. It then conducts instantaneously to form a low-resistance arc path, and a large current flows through it. After conduction, this load will "clamp" the output voltage of the transformer secondary to its breakdown voltage value. However, the load of the lower discharge branch requires a higher breakdown voltage. At this time, the secondary voltage has been pulled down and cannot reach its breakdown threshold. It remains in an open circuit state and therefore has no current.

[0006] exist Figure 1In the circuit, the input terminals of the two voltage multiplier rectifier branches are directly connected in parallel to the secondary winding of the same transformer. They are powered by the same power source, resulting in an imbalance in current / voltage distribution. When one load discharges prematurely and generates a large current, the internal resistance and leakage inductance of the transformer secondary winding will cause a significant voltage drop, and the secondary output voltage will be greatly reduced. The input voltage of the other voltage multiplier module is insufficient and cannot be boosted to the target high voltage. Its load naturally cannot break down and there is no current.

[0007] exist Figure 1 In the circuit, even if the breakdown voltage of the two loads is the same, the difference in capacitor parameters of the two voltage doubler rectifier branches will lead to different output voltages, triggering "single-group discharge". The leakage resistance and capacitance of the series capacitors are inconsistent, resulting in different boost efficiency of the voltage doubler rectifier branches. One group outputs high voltage to reach the breakdown threshold, while the other group outputs low voltage. This causes the group with higher output voltage to trigger load discharge first, thereby clamping the voltage and causing the other group to have no current.

[0008] The aforementioned design flaws only allow some discharge devices to break down and discharge, while others fail to do so. Therefore, those skilled in the art have improved the circuitry of existing technologies. For example, patent number 2024207121082 discloses an electric flame stove that uses an independent transformer at the input end of each voltage multiplier branch. This avoids multiple voltage multiplier branches sharing the same secondary winding. While this solves the problem of existing technologies, for high-power electric flame stoves with hundreds of discharge devices operating, hundreds of corresponding small transformers or secondary windings are required. This not only increases costs and makes the stove bulky, but also results in significant energy loss due to the cumulative energy loss from hundreds of transformers simultaneously performing "electrical energy to magnetic energy and then back to electrical energy." Furthermore, severe electromagnetic interference between numerous transformers affects circuit stability.

[0009] Therefore, those skilled in the art have continued to improve upon this technology. For example, patent number 2025115774709 discloses a high-voltage circuit for an electric flame stove, in which a coupling capacitor is provided in each voltage multiplier branch. This coupling capacitor blocks the DC component, allowing only the AC component to power the voltage multiplier module. The DC clamping and voltage drop of one group's discharge will not affect the AC input of the other group, and both groups can obtain sufficient AC boost energy. This coupling capacitor isolates the DC output terminals of the two voltage multiplier modules from each other, preventing the large DC current of one group's discharge from directly entering the other group, thus avoiding the phenomenon of low-resistance loads absorbing all the current. Multiple groups can independently complete voltage boosting and discharging. Even if the capacitor and diode parameters of the two voltage multiplier modules deviate, the coupling capacitor can make their AC input more independent, preventing the voltage boosting capability of the other group from being directly dragged down by the parameter problem of one group, thus achieving stable discharge of multiple voltage multiplier branches. However, the patented technology still has problems. The breakdown voltage of each group of discharge devices still has significant differences. Although some discharge devices will not have a phenomenon of "no current" at all, there will still be a situation where one group breaks down and discharges first, and the other group discharges later. The problems of discharge synchronization and uneven current distribution still exist.

[0010] Furthermore, current electric flame cooktops on the market are only compatible with 220V-240V voltages. For the 110V AC mains power used in the United States and Japan, a separate circuit system needs to be developed. Using molds for two sets of electric flame cooktop circuits not only increases production and R&D costs but also complicates production management.

[0011] Therefore, this invention develops a wide circuit that can adapt to both 220V-240V high voltage and 110V low voltage in different countries, and can also accommodate hundreds of discharge devices in the electric flame stove to discharge and generate plasma simultaneously. Summary of the Invention

[0012] To overcome the shortcomings mentioned above, the present invention aims to provide a technical solution that can solve the above problems.

[0013] A parallel discharge circuit includes: a transformer and at least two sets of discharge branches; the two sets of discharge branches include a first discharge branch and a second discharge branch.

[0014] The first discharge branch consists of a normally closed relay K1, capacitors C1, C2, C5, C6, C7, and C8, diodes D1, D2, D3, and D4, and a first discharge device. One end of the secondary winding of the transformer is connected to one end of capacitors C1, C7, and C8; the other end of the secondary winding of the transformer is connected to one end of capacitors C2, C5, and C6; and the other end of capacitor C1 is connected to the cathode of diode D1. The cathode of diode D2 is connected to the anode of diode D1, the cathode of diode D2 is connected to the anode of diode D3, and the other end of capacitor C5 is connected to the cathode of diode D1. The connection point of the other end of capacitor C6, the cathode of diode D2, and the anode of diode D3 is connected to the moving contact of normally closed relay K1. The other end of capacitor C2 is connected to the cathode of diode D3 and the anode of diode D4. The cathode of diode D4 is connected to the other end of capacitor C8. The other end of capacitor C7 is connected to the stationary contact of normally closed relay K1.

[0015] Preferably, a voltage transformer TR1 is connected in parallel between the two input terminals of the first discharge branch. The two ends of the secondary winding of the voltage transformer TR1 are connected to the two input terminals of the rectifier D100. The negative output terminal of the rectifier D100 is grounded, and the positive output terminal of the rectifier D100 is connected to the gate of the switching transistor Q3. The source of the switching transistor Q3 is connected to a 12V power supply, and its drain is connected to one end of the coil of the normally closed relay K1. The other end of the coil of the normally closed relay K1 is grounded.

[0016] Preferably, both capacitor C1 and capacitor C7 are low capacitive reactance capacitors;

[0017] Preferably, the second discharge branch includes a normally closed relay K2, capacitors C3, C4, C9, C10, C11, C12, diodes D5, D6, D7, D8, and a second discharge device; one end of the secondary winding of the transformer is also connected to one end of capacitor C3, one end of capacitor C11, and one end of capacitor C12; the other end of the secondary winding of the transformer is also connected to one end of capacitor C4, one end of capacitor C9, and one end of capacitor C10; the other end of capacitor C3 is connected to the cathode of diode D5 and the anode of diode D6; the anode of diode D5 is connected to the negative terminal of the second discharge device and the other end of capacitor C9; the connection point of the cathode of diode D6, the other end of capacitor C10, and the anode of diode D7 is connected to the moving contact of the normally closed relay K2; the cathode of diode D7 is connected to the anode of diode D8 and the other end of capacitor C4; and the stationary contact of the normally closed relay K2 is connected to the other end of capacitor C11.

[0018] Preferably, a voltage transformer TR2 is also connected in parallel between the two input terminals of the second discharge branch;

[0019] Preferably, both capacitor C3 and capacitor C11 are low capacitive reactance capacitors;

[0020] The present invention also proposes an electric flame stove, wherein the electric flame stove includes the parallel discharge circuit described in any of the above claims.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] This invention uses a single transformer instead of a multi-transformer scheme to reduce the losses from multiple conversions of "electrical energy → magnetic energy → electrical energy", reduce electromagnetic interference, and at the same time, the stove body does not need to be equipped with a large number of transformers, making it more compact and suitable for the parallel connection requirements of hundreds of discharge devices in high-power electric flame stoves.

[0023] This invention enables continuous control of asynchronous breakdown and independent charging and discharging of multiple discharge branches, adapts to the differences in breakdown threshold of discharge devices and the deviation in charging speed of voltage doubler capacitors between discharge branches, eliminates the need for additional voltage equalization control, and ensures that all discharge branches can stably complete the charging and discharging closed loop without discharge failure or mutual interference.

[0024] This invention is applicable to a variety of voltage inputs, achieving a wide voltage input range.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a parallel discharge branch in existing technology.

[0028] Figure 2 This is a schematic diagram of the circuit structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the principle of the present invention adapting to input voltage.

[0030] Figure 4 This is a schematic diagram of the working principle of the present invention when the input is 110V.

[0031] Figure 5This is a schematic diagram of the working principle of the present invention when the input is 220V. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," etc., 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; they can refer to the internal connection of two components; they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Please see Figure 2 In this embodiment of the invention, a parallel discharge circuit includes: a transformer and at least two sets of discharge branches; the two sets of discharge branches include a first discharge branch and a second discharge branch.

[0037] like Figure 2 As shown, the first discharge branch consists of normally closed relay K1, capacitors C1, C2, C5, C6, C7, and C8, diodes D1, D2, D3, and D4, and a first discharge device. The second discharge branch includes normally closed relay K2, capacitors C3, C4, C9, C10, C11, and C12, diodes D5, D6, D7, and D8, and a second discharge device. Among these, capacitors C1, C7, C3, and C11 are all low-capacitive-resistance capacitors; therefore, the voltage drop across these four capacitors is approximately zero, and they do not perform any voltage division function.

[0038] The voltage output of transformer T1 under ideal conditions is U. When normally closed relay K1 is in the open circuit state, the first discharge branch is equivalent to a voltage doubler rectifier circuit, that is, the DC voltage output of the first discharge branch is 2U. When normally closed relay K1 is in the closed state, the first discharge branch is equivalent to a voltage quadrupler rectifier circuit, that is, the DC voltage output of the first discharge branch is 4U.

[0039] like Figure 3 As shown, a voltage transformer TR1 is connected in parallel between the two input terminals of the first discharge branch. The two ends of the secondary winding of the voltage transformer TR1 are connected to the two input terminals of the rectifier D100. The negative output terminal of the rectifier D100 is grounded, and the positive output terminal of the rectifier D100 is connected to the gate of the switching transistor Q3. The source of the switching transistor Q3 is connected to a 12V power supply, and its drain is connected to one end of the coil of the normally closed relay K1. The other end of the coil of the normally closed relay K1 is grounded.

[0040] First embodiment method:

[0041] When the input mains voltage is 110V, the secondary output AC peak value of transformer T1 is approximately 2500V. At this time, the voltage across the secondary winding of voltage transformer TR1 is rectified by rectifier D100 to output 6V. This voltage cannot drive the switching transistor Q3 to conduct. Therefore, there is no current in the coil of normally closed relay K1, and normally closed relay K1 is in the closed state. The DC voltage output of the first discharge branch is approximately 4U≈10000V, reaching the breakdown threshold.

[0042] When the input mains voltage is 220V, the secondary output AC peak value of transformer T1 is approximately 5000V. At this time, the voltage across the secondary winding of voltage transformer TR1 is rectified by rectifier D100 to output 12V. This voltage drives the switching transistor Q3 to conduct. Therefore, the coil of normally closed relay K1 generates current, and normally closed relay K1 is in an open circuit state. The DC voltage output of the first discharge branch is approximately 2U≈10000V, which is close to the breakdown threshold of the first discharge device and will not cause the voltage to be too high, thus affecting the stability of the circuit.

[0043] The voltage transformer TR2 is also connected in parallel between the two input terminals of the second discharge branch, and its control principle is the same as that of the first discharge branch in terms of technical scheme and working principle.

[0044] By automatically switching between "110V input / 4x voltage output and 220V input / 2x voltage output", the output high voltage is basically consistent, eliminating the need to develop two sets of circuit molds and significantly reducing the R&D, production, and management costs of electric flame stoves.

[0045] Second implementation method:

[0046] Take, for example, the breakdown threshold of the second discharge device being low or the capacitor in the first discharge branch charging slowly.

[0047] When the input mains voltage is 110V, the second discharge branch breaks down the gas first, followed by the first discharge branch. The control method of the parallel discharge circuit of this invention is as follows:

[0048] like Figure 4 As shown, the voltage U of capacitor C4 is superimposed on the voltage of transformer T1 to charge capacitor C12. At this time, capacitor C12 reaches twice the voltage 2U. The voltages of capacitors C9 and C10 are superimposed on twice the voltage of capacitor C12, which forms the threshold of the positive electrode of the second discharge device to break down the gas in advance. The breakdown gas ionizes to generate plasma, forming a low-resistance DC path. The large DC current is completely blocked by capacitors C3 and C11 and cannot flow into transformer T1. Transformer T1 always outputs normal AC. The charging process of the capacitor in the first branch is uninterrupted and there is no voltage drop.

[0049] The charging process of the first branch is not affected by the breakdown of the second branch first. The capacitor continues to charge. In the first cycle, the secondary winding of transformer T1 is positive at the top and negative at the bottom. Capacitors C2 and C6 are charged. In the second cycle, capacitor C5 is charged. The voltage of capacitor C2 is superimposed on the voltage of transformer T1 to charge capacitor C8. The voltage of capacitor C8 is 2U. Finally, the double voltage of capacitor C8 is superimposed on the voltage of capacitors C5 and C6, which quickly forms a high voltage that can break down the gas.

[0050] This invention solves the problems of DC clamping interference and current imbalance in multiple branches of a high-voltage discharge system in an electric flame stove.

[0051] The third implementation method:

[0052] like Figure 5 As shown, when 220V AC mains power is input, normally closed relays K1 and K2 are open circuits, and capacitors C3 and C11 can be ignored and do not participate in any charging circuit. Taking the example of a lower breakdown threshold of the second discharge device or slower charging of the capacitor in the first discharge branch, the control method of the parallel discharge circuit of this invention is as follows:

[0053] When the voltage across the second discharge device approaches 2U, the breakdown threshold of the second discharge device is reached first, triggering gas breakdown discharge and forming a low-resistance DC path inside the second discharge branch. At this time, the second branch is equivalent to a short circuit and forms a large DC current. Meanwhile, capacitor C3 completely blocks the voltage clamping / voltage drop interference of the DC discharge of the second branch on the secondary side of transformer T1. Transformer T1 always outputs pure high-voltage AC, and the charging process of the first branch is not subject to any control interference, continuing to realize the double voltage charging sequence.

[0054] When the capacitor in the first discharge branch is charged to 2U, the voltage of capacitor C8 or the superimposed voltage of capacitors C5 and C6 is triggered to cause gas breakdown discharge in the first discharge device, forming a low-resistance DC path inside the first discharge branch. Capacitor C1 performs DC high-resistance blocking control, blocking the DC current from flowing into the secondary of transformer T1, and limiting the large DC discharge current of the first branch to a closed loop inside the first discharge device → D1 → D2 → D3 → D4 → first discharge device branch.

[0055] This invention enables continuous control of asynchronous breakdown and independent charging and discharging of multiple discharge branches, adapts to the differences in breakdown thresholds of discharge devices and the deviation in charging speed of voltage multiplier capacitors between discharge branches, eliminates the need for additional voltage equalization control, and ensures that all discharge branches can stably complete the charging and discharging closed loop without discharge failure or mutual interference.

[0056] Fourth implementation method:

[0057] When the input is 220V AC mains power, the peak AC output of the transformer secondary is U≈5000V. Taking the first discharge branch as an example, in the first cycle, during the positive half-cycle of the transformer secondary, D1 and D4 are reverse cut off, and D2 and D3 are forward conduction, charging capacitors C2 and C6 to U. When D1 and D4 are forward conduction and D2 and D3 are reverse cut off, capacitor C5 is charged to U. Capacitor C2, superimposed with the voltage of transformer T1, charges capacitor C8, and capacitor C8 is charged to 2U. At this time, the superimposed voltage of capacitors C5 and C6 is 2U. The two sets of 2U voltage outputs are complementary, preventing voltage drop and stabilizing the voltage between the positive and negative terminals of the first discharge device at around 10000V.

[0058] The present invention also proposes an electric flame stove, including a parallel discharge circuit.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A parallel discharge circuit, characterized in that, include: A transformer and at least two sets of discharge branches; the two sets of discharge branches include a first discharge branch and a second discharge branch. The first discharge branch consists of a normally closed relay K1, capacitors C1, C2, C5, C6, C7, and C8, diodes D1, D2, D3, and D4, and a first discharge device. One end of the secondary winding of the transformer is connected to one end of capacitors C1, C7, and C8; the other end of the secondary winding of the transformer is connected to one end of capacitors C2, C5, and C6; and the other end of capacitor C1 is connected to the cathode of diode D1. The cathode of diode D2 is connected to the anode of diode D1, the cathode of diode D2 is connected to the anode of diode D3, and the other end of capacitor C5 is connected to the cathode of diode D1. The connection point of the other end of capacitor C6, the cathode of diode D2, and the anode of diode D3 is connected to the moving contact of normally closed relay K1. The other end of capacitor C2 is connected to the cathode of diode D3 and the anode of diode D4. The cathode of diode D4 is connected to the other end of capacitor C8. The other end of capacitor C7 is connected to the stationary contact of normally closed relay K1. The second discharge branch includes a normally closed relay K2, capacitors C3, C4, C9, C10, C11, C12, diodes D5, D6, D7, D8, and a second discharge device. One end of the secondary winding of the transformer is also connected to one end of capacitor C3, one end of capacitor C11, and one end of capacitor C12. The other end of the secondary winding of the transformer is also connected to one end of capacitor C4, one end of capacitor C9, and one end of capacitor C10. The other end of capacitor C3 is connected to the cathode of diode D5 and the anode of diode D6. The anode of diode D5 is connected to the negative terminal of the second discharge device and the other end of capacitor C9. The connection point of the cathode of diode D6, the other end of capacitor C10, and the anode of diode D7 is connected to the moving contact of normally closed relay K2. The cathode of diode D7 is connected to the anode of diode D8 and the other end of capacitor C4. The stationary contact of normally closed relay K2 is connected to the other end of capacitor C11.

2. The parallel discharge circuit according to claim 1, characterized in that, A voltage transformer TR1 is connected in parallel between the two input terminals of the first discharge branch. The two ends of the secondary winding of the voltage transformer TR1 are connected to the two input terminals of the rectifier D100. The negative output terminal of the rectifier D100 is grounded, and the positive output terminal of the rectifier D100 is connected to the gate of the switching transistor Q3. The source of the switching transistor Q3 is connected to a 12V power supply, and its drain is connected to one end of the coil of the normally closed relay K1. The other end of the coil of the normally closed relay K1 is grounded.

3. The parallel discharge circuit according to claim 1, characterized in that, Both capacitors C1 and C7 are low capacitive reactance capacitors.

4. The parallel discharge circuit according to claim 1, characterized in that, A voltage transformer TR2 is also connected in parallel between the two input terminals of the second discharge branch.

5. The parallel discharge circuit according to claim 1, characterized in that, Both capacitor C3 and capacitor C11 are low capacitive reactance capacitors.

6. An electric flame stove, characterized in that, The electric flame stove includes a parallel discharge circuit according to any one of claims 1 to 5.

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