A gas valve control circuit and a cooking appliance

Abstract

The present invention discloses a gas valve control circuit and a gas appliance. The gas valve control circuit includes: a power supply module provided with a voltage output terminal, and the voltage output terminal is grounded through a voltage-dividing resistor to the secondary coil of a dual-coil solenoid valve in sequence; a controller provided with a voltage detection terminal, and the voltage detection terminal is connected between the voltage-dividing resistor and the secondary coil. With such a setting, when the controller detects a high level, it indicates that the secondary coil of the dual-coil solenoid valve is damaged, and the controller cannot be directly grounded, but instead the voltage of the power supply module is detected. Therefore, the user can determine whether the secondary coil of the dual-coil solenoid valve is damaged through the high and low level signals detected by the controller. When the secondary coil of the dual-coil solenoid valve is damaged, the user can manually close the dual-coil solenoid valve, thereby avoiding the occurrence of a fire and ensuring the safety of the user during use.

Description

Technical Field

[0001] The present invention relates to the technical field of gas valves, and in particular to a gas valve control circuit and a cooking appliance. Background Art

[0002] Currently, the gas valves of cooktops usually adopt solenoid valves. The solenoid valves have an auxiliary ignition power supply. When the user presses the ignition switch, the auxiliary ignition power supply supplies power to the solenoid valve, causing the solenoid valve to attract an iron sheet, thereby conducting the gas path. When the thermocouple has a sufficient temperature difference, it generates a sufficient voltage to supply power to the solenoid valve, and then the auxiliary ignition power supply is turned off and no longer supplies power to the solenoid valve.

[0003] In some new cooktops with timing and dry-burning prevention functions, the gas valves usually adopt double-coil solenoid valves. The closing of the double-coil solenoid valve is achieved by applying a current in the secondary coil that is opposite to the direction of the holding current, and through the magnetic field, a reverse current is generated in the primary coil to cancel out the current generated by the thermocouple, causing the valve body to disengage, thereby realizing automatic valve closing.

[0004] For a double-coil solenoid valve, if the secondary coil of the double-coil solenoid valve is damaged during use and the user is unaware, once the timing time is up or the dry-burning prevention function is activated, due to the damage of the secondary coil, the valve body cannot be controlled to disengage in the primary coil, so automatic valve closing cannot be achieved.

[0005] Therefore, in the prior art, users cannot know whether the secondary coil of the solenoid valve is damaged, which may lead to the occurrence of a fire and seriously endanger the user's safety during use. Summary of the Invention

[0006] Therefore, the embodiments of the present invention aim to solve the problem in the prior art that users cannot know whether the secondary coil of the solenoid valve is damaged, and thus provide a new gas valve control circuit and a cooking appliance.

[0007] To achieve the above object, an embodiment of the present invention provides a gas valve control circuit, which includes:

[0008] A power supply module provided with a voltage output terminal, and the voltage output terminal is grounded through a voltage-dividing resistor to the secondary coil of the double-coil solenoid valve in sequence;

[0009] A controller provided with a voltage detection terminal, and the voltage detection terminal is connected between the voltage-dividing resistor and the secondary coil.

[0010] Optionally, the gas valve control circuit further includes:

[0011] A current-limiting resistor, one end of the current-limiting resistor is connected to the voltage detection terminal, and the other end of the current-limiting resistor is connected between the voltage-dividing resistor and the secondary coil.

[0012] Optionally, the gas valve control circuit further includes:

[0013] A current increasing module, wherein a switching circuit is arranged inside the current increasing module;

[0014] Under the action of the switching circuit, the current increasing module has a state of being connected in parallel with the voltage dividing resistor and a state of disconnecting from the access circuit; after the current increasing module is connected in parallel with the voltage dividing resistor, the current flowing through the secondary coil becomes larger, and the double-coil solenoid valve closes.

[0015] Optionally, the current increasing module includes:

[0016] A current increasing resistor, one end of the current increasing resistor is connected to the voltage output end through the switching circuit, and the other end of the current increasing resistor is connected between the voltage dividing resistor and the secondary coil; the resistance value of the current increasing resistor is much smaller than the resistance value of the voltage dividing resistor.

[0017] Optionally, the switching circuit is a switching tube, the control end of the switching tube is connected to the signal output end of the controller, the first end of the switching tube is connected to the power supply module, and the second end of the switching tube is connected to between the voltage dividing resistor and the secondary coil through the current increasing resistor.

[0018] Optionally, the current increasing module further includes:

[0019] An optocoupler, which is provided with a light emitter and a light receiver, one end of the light emitter is connected to the current increasing resistor, and the other end of the light emitter is connected to between the voltage dividing resistor and the secondary coil;

[0020] The first end of the light receiver is grounded, and the second end of the light receiver is connected to a high-level signal;

[0021] The feedback end of the controller is connected to the high-level signal.

[0022] Optionally, the current increasing module further includes:

[0023] A first resistor, one end of the first resistor is connected to the voltage output end, and the other end of the first resistor is grounded through the voltage dividing resistor and the secondary coil of the double-coil solenoid valve in sequence.

[0024] Optionally, the current increasing module further includes:

[0025] A first filtering module, which is connected in parallel with the circuit formed by the series connection of the voltage dividing resistor and the secondary coil.

[0026] Optionally, the current increasing module further includes:

[0027] A second filtering module, which is connected in parallel with the secondary coil.

[0028] An embodiment of the present invention provides a cooking appliance, which includes the gas valve control circuit described in any one of the above embodiments.

[0029] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0030] 1. An embodiment of the present invention provides a gas valve control circuit, which includes: a power supply module provided with a voltage output terminal, and the voltage output terminal is grounded through a voltage-dividing resistor to the secondary coil of a dual-coil solenoid valve in sequence; a controller provided with a voltage detection terminal, and the voltage detection terminal is connected between the voltage-dividing resistor and the secondary coil.

[0031] With such a setting, when the controller detects a low level, it indicates that the secondary coil of the solenoid valve is normally conducting, enabling the controller to be directly grounded; while when the controller detects a high level, it indicates that the secondary coil of the dual-coil solenoid valve has been damaged and the controller cannot be directly grounded, and instead the voltage of the power supply module is detected. Therefore, the user can determine whether the secondary coil of the dual-coil solenoid valve is damaged based on the high and low level signals detected by the controller. When the secondary coil of the dual-coil solenoid valve has been damaged, the user can close the dual-coil solenoid valve personally, thereby avoiding the occurrence of fire and ensuring the user's safety in use.

[0032] 2. When the controller detects a low level, it indicates that the secondary coil of the electro dual-coil solenoid valve is working normally. In an embodiment of the present invention, by setting a signal output terminal and a feedback terminal on the controller, when the cooking appliance reaches the timing time or the anti-dry-burning time, the controller directly controls the signal output terminal to output a control signal, causing the switching tube to close and the current-increasing module to be connected to the circuit, thereby increasing the current passing through the secondary coil of the dual-coil solenoid valve and enabling the solenoid valve to close normally, thus avoiding the occurrence of fire and ensuring the user's safety in use. Moreover, when the switching tube closes, the optocoupler will be turned on and the signal at the feedback terminal changes, and the controller can thereby notify the user whether the solenoid valve is closed according to the feedback given by the feedback terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0034] Figure 1 It is a structural diagram of the gas valve control circuit according to an embodiment of the present invention.

[0035] Reference Signs:

[0036] R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the current-increasing resistor; R6, the current-limiting resistor; R7, the voltage-dividing resistor; C1, the first filtering module; C2, the second filtering module; Q1, the switching transistor; U1, the optocoupler. Detailed implementation manners

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can also be the internal communication of two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] Currently, the gas valves of cookers usually adopt solenoid valves. The solenoid valves have an auxiliary ignition power supply. When the user presses the ignition switch, the auxiliary ignition power supply supplies power to the solenoid valve, causing the solenoid valve to attract the iron sheet and making the gas path conductive. When the thermocouple has a sufficient temperature difference, it generates a sufficient voltage to supply power to the solenoid valve, and then the auxiliary ignition power supply is turned off and no longer supplies power to the solenoid valve.

[0042] In some new cookers with timing and dry-burning prevention functions, a dual-coil solenoid valve is usually adopted for the gas valve. The closing of the dual-coil solenoid valve relies on adding a current in the secondary coil that is opposite to the holding current direction, and through the magnetic field, a reverse current is generated in the primary coil to cancel out the current generated by the thermocouple, causing the valve body to disengage, thereby achieving automatic valve closing.

[0043] For a dual-coil solenoid valve, if the secondary coil of the dual-coil solenoid valve is damaged during use and the user is unaware of it, once the timing time arrives or the dry-burning prevention function is activated, due to the damage of the secondary coil, the valve body cannot be controlled to disengage in the primary coil, so automatic valve closing cannot be achieved.

[0044] Therefore, in the prior art, the user cannot know whether the secondary coil of the solenoid valve is damaged, which may lead to the occurrence of a fire and seriously endanger the user's safety in use.

[0045] The embodiment of the present invention aims to solve the problem in the prior art that the user cannot know whether the secondary coil of the solenoid valve is damaged, and thus provides a new gas valve control circuit and a cooking appliance.

[0046] Embodiment 1

[0047] As Figure 1 shown, the embodiment of the present invention provides a gas valve control circuit, which includes a power supply module and a controller.

[0048] Specifically, in the embodiment of the present invention, the power supply module is provided with a voltage output terminal, and the voltage output terminal is grounded through a voltage-dividing resistor R7 to the secondary coil of the dual-coil solenoid valve in sequence. The controller is provided with a voltage detection terminal, and the voltage detection terminal is connected between the voltage-dividing resistor R7 and the secondary coil. As Figure 1 shown, the voltage detection terminal is the controller IO port 3.

[0049] During the actual working process, when the cooker is ignited by electric ignition and is in a normal working state, the voltage-dividing resistor R7 and the secondary coil generate voltage division, and the voltage divided by the secondary coil enters the voltage detection terminal. Since the secondary coil is grounded, the voltage detection terminal actually detects a low level. At this time, the controller can judge whether the solenoid valve is disconnected according to the voltage value divided by the secondary coil.

[0050] Assume that the solenoid valve is disconnected, that is to say, the secondary coil is damaged. Then the secondary coil is in an open state, there is no loop in the circuit, and the voltage-dividing resistor R7 does not divide voltage with the secondary coil. At this time, the voltage detected by the voltage detection terminal is actually the voltage of the power supply module, which is a relatively high level. In this way, it can be judged that the solenoid valve is disconnected, thus realizing the detection of the solenoid valve.

[0051] With such a setting, when the controller detects a low level, it indicates that the secondary coil of the solenoid valve is normally conducting, causing the controller to be directly grounded; while when the controller detects a high level, it means that the secondary coil of the double-coil solenoid valve is damaged, and the controller cannot be directly grounded, and instead the voltage of the power supply module is detected. Therefore, the user can determine whether the secondary coil of the double-coil solenoid valve is damaged based on the high and low level signals detected by the controller. When the secondary coil of the double-coil solenoid valve is damaged, the user can manually close the double-coil solenoid valve, thereby avoiding the occurrence of a fire and ensuring the user's safety in use.

[0052] Further, in an alternative embodiment of the present invention, the gas valve control circuit further includes a current-limiting resistor R6. One end of the current-limiting resistor R6 is connected to the voltage detection terminal, and the other end of the current-limiting resistor R6 is connected between the voltage-dividing resistor R7 and the secondary coil.

[0053] Further, in an alternative embodiment of the present invention, the gas valve control circuit further includes: a current-increasing module. A switching circuit is provided inside the current-increasing module; under the action of the switching circuit, the current-increasing module has a state of being connected in parallel with the voltage-dividing resistor R7 and a state of disconnecting from the access circuit; after the current-increasing module is connected in parallel with the voltage-dividing resistor R7, the current flowing through the secondary coil becomes larger, and the double-coil solenoid valve closes.

[0054] Specifically, the current-increasing module includes a current-increasing resistor R5. One end of the current-increasing resistor R5 is connected to the voltage output terminal through the switching circuit, and the other end of the current-increasing resistor R5 is connected between the voltage-dividing resistor R7 and the secondary coil. The resistance value of the current-increasing resistor R5 is much smaller than the resistance value of the voltage-dividing resistor R7.

[0055] Further, the switching circuit can be a switching transistor Q1. The control terminal of the switching transistor Q1 is connected to the signal output terminal of the controller through a second resistor R2. The first end of the switching transistor Q1 is connected to the power supply module. The second end of the switching transistor Q1 is connected to between the voltage-dividing resistor R7 and the secondary coil through the current-increasing resistor R5. A third resistor R3 is connected between the first end and the control terminal of the switching transistor Q1. As Figure 1 shown, the signal output terminal is the controller IO port 1. And the switching transistor Q1 can be a triode or a MOS transistor. Those skilled in the art can change it according to the actual situation as long as the same technical effect can be achieved.

[0056] When the controller detects a low level, it indicates that the secondary coil of the electro - double - coil solenoid valve is working properly. In the embodiment of the present invention, by setting a signal output terminal and a feedback terminal on the controller, when the cooking appliance reaches the timing time or the time for preventing dry - burning, the controller directly controls the signal output terminal to output a control signal, causing the switching transistor Q1 to close, enabling the current - increasing module to be connected to the circuit, thereby increasing the current passing through the secondary coil of the double - coil solenoid valve, causing the solenoid valve to close normally, thus avoiding the occurrence of a fire and ensuring the safety of users during use.

[0057] Further, in an optional embodiment of the present invention, the current - increasing module further includes an opto - coupler U1. The opto - coupler U1 is provided with a light emitter and a light receiver. One end of the light emitter is connected to the current - increasing resistor R5, and the other end of the light emitter is connected between the voltage - dividing resistor R7 and the secondary coil; the first end of the light receiver is grounded, and the second end of the light receiver is connected to a high - level signal; the feedback terminal of the controller is connected to the high - level signal through the fourth resistor R4. As Figure 1 shown, the feedback terminal is the IO port 2 of the controller.

[0058] When the controller detects a high level, it indicates that the secondary coil of the electro - double - coil solenoid valve is damaged, the opto - coupler U1 will not be turned on, and the signal received by the feedback terminal is a high level. When the controller detects a low level, it indicates that the secondary coil of the electro - double - coil solenoid valve is working properly. In the embodiment of the present invention, by setting a signal output terminal and a feedback terminal on the controller, when the cooking appliance reaches the timing time or the time for preventing dry - burning, the controller directly controls the signal output terminal to output a control signal, causing the switching transistor Q1 to close, enabling the current - increasing module to be connected to the circuit, thereby increasing the current passing through the secondary coil of the double - coil solenoid valve, causing the solenoid valve to close normally, thus avoiding the occurrence of a fire and ensuring the safety of users during use. And when the switching transistor Q1 closes, the opto - coupler U1 will be turned on, and the signal at the feedback terminal changes from a high level to a low level, enabling the controller to notify the user whether the solenoid valve is closed according to the feedback given by the feedback terminal.

[0059] Further, in an optional embodiment of the present invention, the current - increasing module further includes a first resistor R1, a first filtering module C1, and a second filtering module C2. One end of the first resistor R1 is connected to the voltage output terminal, and the other end of the first resistor R1 is grounded through the voltage - dividing resistor R7 and the secondary coil of the double - coil solenoid valve in sequence. The first filtering module C1 is connected in parallel with the circuit formed by the series connection of the voltage - dividing resistor R7 and the secondary coil. The second filtering module C2 is connected in parallel with the secondary coil.

[0060] Both the first filtering module C1 and the second filtering module C2 can be set as capacitors. When the second filtering module C2 is provided, the current-limiting resistor R6 is used to absorb the electrical energy of the capacitor in the second filtering module C2, prevent the discharge current of the capacitor from being too large, and avoid damaging the solenoid valve connected in parallel therewith.

[0061] When the first filtering module C1 and the first resistor R1 are set at the same time, the capacitor of the first filtering module C1 plays a role in preventing voltage mutation and absorbing the overvoltage in the spike state. The series-connected first resistor R1 plays a damping role, and the resistor consumes the energy of the overvoltage. Generally, they are used in combination to play a role in suppressing circuit oscillation. Of course, those skilled in the art can also not set the first filtering module C1 and the first resistor R1 at the same time according to the actual situation.

[0062] The embodiment of the present invention provides a gas appliance, and the gas appliance includes the gas valve control circuit described in any one of the above embodiments.

[0063] With such a setting, when the controller detects a low level, it indicates that the secondary coil of the solenoid valve is normally conducting, so that the controller is directly grounded; when the controller detects a high level, it indicates that the secondary coil of the double-coil solenoid valve has been damaged, and the controller cannot be directly grounded, and instead the voltage of the power supply module is detected. Therefore, the user can judge whether the secondary coil of the double-coil solenoid valve is damaged through the high and low level signals detected by the controller. When the secondary coil of the double-coil solenoid valve has been damaged, the user can close the double-coil solenoid valve in person, thereby avoiding the occurrence of a fire and ensuring the use safety of the user.

[0064] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For ordinary workers in the field, other different forms of changes or alterations can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or alterations derived therefrom are still within the protection scope of the present invention.

Claims

1. A gas valve control circuit, characterized in that, Comprising: A power supply module is provided with a voltage output terminal, and the voltage output terminal is grounded through a voltage-dividing resistor (R7) with the secondary coil of a double-coil solenoid valve in sequence; A controller is provided with a voltage detection terminal, and the voltage detection terminal is connected between the voltage-dividing resistor (R7) and the secondary coil; A current-increasing module, and a switching circuit is arranged inside the current-increasing module; Under the action of the switching circuit, the current-increasing module has a state of being in parallel with the voltage-dividing resistor (R7) and a state of disconnecting from the access circuit; after the current-increasing module is in parallel with the voltage-dividing resistor (R7), the current flowing through the secondary coil becomes larger and the double-coil solenoid valve closes; The current-increasing module includes: A current-increasing resistor (R5), one end of the current-increasing resistor (R5) is connected to the voltage output terminal through the switching circuit, and the other end of the current-increasing resistor (R5) is connected between the voltage-dividing resistor (R7) and the secondary coil; the resistance value of the current-increasing resistor (R5) is much smaller than the resistance value of the voltage-dividing resistor (R7); An optocoupler (U1) is provided with a light emitter and a light receiver, one end of the light emitter is connected to the current-increasing resistor (R5), and the other end of the light emitter is connected between the voltage-dividing resistor (R7) and the secondary coil; The first end of the light receiver is grounded, and the second end of the light receiver is connected to a high-level signal; The feedback terminal of the controller is connected to the high-level signal.

2. The gas valve control circuit according to claim 1, wherein Further comprising: A current-limiting resistor (R6), one end of the current-limiting resistor (R6) is connected to the voltage detection terminal, and the other end of the current-limiting resistor (R6) is connected between the voltage-dividing resistor (R7) and the secondary coil.

3. The gas valve control circuit according to claim 2, wherein, The switching circuit is a switching transistor (Q1), the control terminal of the switching transistor (Q1) is connected to the signal output terminal of the controller, the first end of the switching transistor (Q1) is connected to the power supply module, and the second end of the switching transistor (Q1) is connected to between the voltage-dividing resistor (R7) and the secondary coil through the current-increasing resistor (R5).

4. The gas valve control circuit according to any one of claims 1 to 3, characterized in that, Further comprising: A first resistor (R1), one end of the first resistor (R1) is connected to the voltage output terminal, and the other end of the first resistor (R1) is grounded through the voltage-dividing resistor (R7) with the secondary coil of the double-coil solenoid valve in sequence.

5. The gas valve control circuit according to any one of claims 1 to 3, characterized in that, Further comprising: A first filtering module (C1) is connected in parallel with the circuit after the voltage-dividing resistor (R7) and the secondary coil are connected in series.

6. The gas valve control circuit according to any one of claims 1 to 3, characterized in that, Further comprising: A second filtering module (C2) is connected in parallel with the secondary coil.

7. A cooking appliance, characterized in that, Comprising: The gas valve control circuit according to any one of claims 1 to 6.

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