Starting circuit of electromagnetic valve

Abstract

The utility model provides a starting circuit of an electromagnetic valve. The starting circuit comprises a preset detection module, a voltage boosting module and a voltage reducing module. One end of the preset detection module is connected with input voltage, and the control end of the preset detection module controls one of the boost module and the buck module to be output and connected to a power supply line of the electromagnetic valve. The preset detection module has a first control state and a second control state in sequential time in each period of controlling the electromagnetic valve, and in the first control state, the input voltage is input into the boosting module to be boosted and then output to the electromagnetic valve to be used for starting the electromagnetic valve; and the second control state is that after the first control state exceeds the preset duration, the input voltage is switched to be reduced by the voltage reduction module and then is output to the electromagnetic valve for keeping the state after the electromagnetic valve is started. Through the arrangement, the electromagnetic valve is simple in structure, the electromagnetic valve can be quickly started, temperature rise is effectively prevented by reducing the working voltage of the electromagnetic valve after the electromagnetic valve is started, and the service life of the electromagnetic valve is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic valve driving, in particular to a starting circuit of an electromagnetic valve. Background Art

[0002] In existing technology, some household appliances with liquid pipeline control often rely on solenoid valves to complete startup, maintenance, and disconnection. The solenoid valve startup process requires a large electromagnetic force. To ensure the electromagnetic force required during startup, there are two approaches to solenoid valve design. The first approach is to increase the number of windings. However, due to the limited internal space of the solenoid valve, this is limited. The other approach is to increase the starting current, but this method will cause the solenoid valve to heat up, shorten the life of the solenoid valve, and even risk burnout after long-term use.

[0003] After the solenoid valve is started, the solenoid valve in the household appliance usually operates with the power supply voltage as the operating voltage, which consumes a lot of energy and affects the service life of the solenoid valve. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings and deficiencies of the prior art and to provide a starting circuit for a solenoid valve.

[0005] The technical solution adopted by the utility model is as follows: comprising a preset detection module, a boost module and a buck module;

[0006] One end of the preset detection module is connected to the input voltage, and its control end controls the boost module and the buck module to select one output connected to the power supply line of the solenoid valve; the preset detection module has a first control state and a second control state in time sequence in each cycle of controlling the solenoid valve, wherein the first control state is to input the input voltage to the boost module for boosting and then output it to the solenoid valve for starting the solenoid valve; the second control state is that after the first control state exceeds the preset time length, the input voltage is switched to the buck module for bucking and then output to the solenoid valve for maintaining the state after the solenoid valve is started.

[0007] Through this setting, the inventor of the utility model discovered that the holding state of the solenoid valve after startup does not actually need to maintain the same electromagnetic force as at the moment of startup, and the holding state is the main working state of the solenoid valve during its operation. If the solenoid valve operates at a higher working voltage in the holding state, it will cause the solenoid valve to be in a high energy consumption state for a long time, affecting the service life of the solenoid valve.

[0008] Preferably, a rectifier module is further included, and the rectifier module is arranged between the input voltage and the preset detection module, and is used to rectify the input voltage.

[0009] Preferably, the boost ratio of the output to the input of the boost module is 1<a≤1.5.

[0010] Preferably, the voltage reduction ratio between the output and input of the voltage reduction module is 0.5<b≤1.

[0011] Preferably, the boost module includes an inductor L1, a capacitor C1, a first switch S1 and a transistor Q1, wherein the first switch S1, the inductor L1 and the capacitor C1 are connected in series in sequence, the transistor Q1 and the capacitor C1 are connected in parallel, one end of the first switch S1 is connected to the output end of the rectifier module, and one end of the capacitor C1 is grounded;

[0012] Both ends of capacitor C1 are connected to the power supply line of the solenoid valve.

[0013] Preferably, the boost module includes a diode D1, the anode of the diode D1 is connected to one end of the inductor L1, and the cathode of the diode D1 is connected to one end of the capacitor C1; the boost module includes a coil L2, and the coil L2 is connected in parallel with C1.

[0014] Preferably, the structure of the voltage-reducing module is a voltage-dividing circuit added to the voltage-reducing module, and the voltage-dividing circuit is used to reduce the output voltage across the capacitor C1.

[0015] Preferably, when the preset detection module is in the first control state, the preset detection module controls the first switch S1 to be closed, the second switch S2 to be opened, and the transistor Q1 to be closed first and then opened;

[0016] When the preset detection module is in the second control state, the preset detection module controls the first switch S1 to be opened, the second switch S2 to be closed, and the transistor Q1 to be disconnected.

[0017] The beneficial effects of the present invention are as follows: the present invention has a simple structure. First, the voltage is increased by the boost module so that the solenoid valve can quickly complete the opening action. At the same time, the preset detection module calculates the boost time. If the boost time exceeds the preset time, the preset detection module will switch the first control state in the boost state to the second control state in the step-down state for controlling the step-down module. The solenoid valve can still remain in the open state in the second control state. At the same time, due to the voltage drop, the power consumption of the solenoid valve is reduced, electric energy is saved, and the temperature rise is effectively reduced, thereby extending the service life of the solenoid valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0019] Figure 1 This is the circuit schematic diagram of the utility model;

[0020] In the figure, 1-input voltage, 2-rectifier module, 3-preset detection module, 4-boost module, 5-step-down module, 6-solenoid valve. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0022] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two non-identical entities or non-identical parameters with the same name. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. Subsequent embodiments will not explain this one by one.

[0023] The directional and positional terms used in this invention, such as "upper," "lower," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are used solely to refer to the directions or positions in the accompanying drawings. Therefore, the directional and positional terms used are intended to illustrate and facilitate understanding of this invention and are not intended to limit the scope of protection of this invention.

[0024] To solve the above problems, Figure 1 As shown, the embodiment of the present application provides a solenoid valve starting circuit, which includes a preset detection module 3, a boost module 4 and a buck module 5;

[0025] The preset detection module 3 includes:

[0026] A controller for timing the boost duration. When the solenoid valve is powered on, the controller starts timing the boost duration from zero and compares the boost duration with a preset duration.

[0027] The switch control module determines whether to switch the switch state according to the comparison result of the boosting time and the preset time. When the boosting time exceeds the preset time, the first control state in the boosting state is switched to the second control state in the step-down state of the step-down module 5.

[0028] It can be understood that the controller of this embodiment can use all chips that have the preset detection function, and the switch control module can use electronic components with switching functions. For example, the controller can use STM32F103, and the switch control module can use electronic components such as relays, transistors and diodes.

[0029] One end of the preset detection module 3 is connected to the input voltage 1, and the control end of the preset detection module 3 controls the boost module 4 and the buck module 5 respectively and selects one output to be connected to the power supply line of the solenoid valve 6; the preset detection module 3 has a first control state and a second control state in time sequence in each cycle of controlling the solenoid valve 6, wherein the first control state is to input the input voltage 1 into the boost module 4 for boosting and then output it to the solenoid valve 6 for starting the solenoid valve 6; the second control state is that after the first control state exceeds the preset time length, the input voltage 1 is switched to the buck module 5 for bucking and then output to the solenoid valve 6 for maintaining the state after the solenoid valve 6 is started.

[0030] It is understandable that since the interior of the solenoid valve 6 is usually composed of an energized coil, a static iron core, and a moving iron core, when a large current is passed through the energized coil, the static iron core and the moving iron core are attracted. After the static iron core and the moving iron core are attracted, only a small energized current is required to maintain the attracted state of the static iron core and the moving iron core, wherein when the static iron core and the moving iron core are in the initial state, the solenoid valve 6 is in a closed state; when the static iron core and the moving iron core are in the attracted state, the solenoid valve 6 is in an open state. A large starting voltage is applied to the solenoid valve 6 by the boost module 4, so that the solenoid valve 6 starts quickly. Since the static iron core and the moving iron core in the solenoid valve 6 are attracted, only a small energized voltage is required to satisfy the static iron core and the moving iron core attracted state. Therefore, when the solenoid valve 6 is started, the step-down module 5 reduces the working voltage of the solenoid valve 6, which is a relatively high starting voltage, to a holding voltage lower than the input voltage 1. Thereafter, the solenoid valve 6 operates at the holding voltage, achieving low-power operation of the solenoid valve 6.

[0031] When the starting voltage is used as the working voltage of the solenoid valve 6, the working time of the solenoid valve 6 is the boost time. The preset detection module 3 has a switch selection function and a detection function. By detecting the boost time and comparing the boost time with the preset time, if the boost time exceeds the preset time, the preset detection module 3 switches the first control state in the boost state to the second control state in the step-down state for controlling the step-down module 5; if the boost time does not exceed the preset time, the utility model is always in the first control state in the boost state.

[0032] The preset duration is a relatively reasonable value obtained through multiple tests. Ideally, the preset duration is equal to the time difference from the moment the solenoid valve 6 is started to the moment the electromagnet inside the solenoid valve 6 is attracted. In practice, in order to leave a certain amount of time for the device, the preset duration is slightly greater than the time difference.

[0033] Through the above settings, the solenoid valve 6 can be quickly started, and after the solenoid valve 6 is started, it can maintain its started state at a lower working voltage, with low power consumption, and effectively reduce temperature rise, thereby extending the service life of the solenoid valve 6.

[0034] The first control state is at 0-T a Time period, the second control state is in T a -T0 time period. After T0, the solenoid valve 6 is in a power-off state. If the solenoid valve 6 needs to be restarted, it needs to be powered on again.

[0035] The device further includes a rectifier module 2, which is disposed between the input voltage 1 and the preset detection module 3 and is used to rectify the input voltage 1. It is understood that rectifying the input voltage 1 can ensure that the input voltage 1 signal is stable, thereby ensuring that the subsequent solenoid valve 6 can operate normally.

[0036] The preset time length is related to the model of the inductor L1; it can be understood that the present application is connected to the power supply U0, after passing through the rectifier module 2, at this time the first switch S1 is turned on, the second switch S2 is turned off, when the transistor Q1 is turned on, the U0 voltage passes, at this time the inductor L1 is charged, when the inductor L1 current reaches a, generally a < 0.2A, the transistor Q1 is disconnected, at this time the voltage flowing through the coil L2 is equivalent to a * the resistance of the coil L2, recorded as aU0, at this time 1 < a ≤ 1.5, at the same time the capacitor C1 is charged after the transistor Q1 is disconnected, for example model 10 A 000uF capacitor can be fully charged in about 55ms with a current of 0.2A and a voltage of 220V. When the capacitor C1 is fully charged, the transistor Q1 is disconnected, the first switch S1 is disconnected, and the second switch S2 is opened. After the conduction, the voltage passes through the voltage divider resistor R1 and then passes through the coil L2. At this time, the actual voltage applied to the coil L2 is equivalent to bU0, which reduces the voltage applied to the coil L2, reduces the power consumption of the coil L2, and extends the working life of the coil L2. The role of the capacitor C1 is to ensure that the discharge is powered to the coil L2 at the moment of the switch switching. It can be seen that the preset duration of this application is related to the time when the inductor L1 current reaches a and the time when the capacitor C1 is fully charged.

[0037] The boost ratio of the output to the input of the boost module 4 is 1<a≤1.5. Specifically, it can be 1.2 or 1.3. It is understood that the value of the boost ratio can vary. The boost ratio is related to the duty cycle and is proportional to the duty cycle. In the present invention, the duty cycle of the boost module 4 is the transistor Q1 on time / transistor Q1 off time. When the transistor Q1 is on for a longer time, more energy is stored in the inductor L1. When the transistor Q1 is off, the inductor L1 and the input voltage 1 both charge the capacitor C1. As the output voltage across the capacitor C1 increases, the input voltage of the solenoid valve 6 increases, allowing the solenoid valve 6 to open quickly.

[0038] The step-down ratio between the output and input of the step-down module 5 is 0.5 < b ≤ 1. It is understood that the value of the step-down ratio is variable; when the values ​​of certain components within the step-down module 5 change, the step-down ratio changes accordingly. The present invention utilizes resistor R1 to divide the voltage across capacitor C1, thereby reducing the output voltage across capacitor C1. This reduces the input voltage of the solenoid valve 6, achieving low power consumption and effectively reducing temperature rise.

[0039] The boost module 4 includes an inductor L1, a capacitor C1, a first switch S1, and a transistor Q1. The inductor L1 and the first switch S1 are connected in series. One end of the first switch S1 is connected to the output end of the rectifier module 2. One end of the inductor L1 is connected to one end of the transistor Q1 and one end of the capacitor C1, respectively. The other ends of the transistor Q1 and the other ends of the capacitor C1 are both grounded. It can be understood that the voltage across the capacitor C1 is primarily controlled by the charge and discharge state transitions of the inductor L1.

[0040] The boost module 4 includes a diode D1, with its anode connected to the other end of the inductor L1 and its cathode connected to one end of the capacitor C1. Diode D1 ensures that current flows in only one direction, protecting other components in the circuit from damage and providing reverse voltage protection.

[0041] The boost module 4 includes a coil L2 , and the coil L2 is connected in parallel with C1 .

[0042] The step-down module 5 adds a resistor R1 and a second switch S2 to the boost module 4. The resistor R1 and the second switch S2 are connected in series, with the other end of the resistor R1 connected to one end of the capacitor C1. One end of the second switch S2 is connected to the output end of the rectifier module 2. Resistor R1 acts as a voltage divider to reduce the voltage across coil L2, thereby lowering the output voltage. This simplifies the circuit, reduces size, and reduces cost.

[0043] The rectifier module 2 utilizes a bridge full-wave rectifier circuit, which rectifies both the positive and negative half-cycles of the AC voltage to produce a more stable DC output. The input voltage, which passes through the bridge full-wave rectifier circuit, converts a sinusoidal wave with positive and negative polarity into a positive voltage signal. In this utility model, the input voltage refers to household power, as this utility model typically uses household electricity directly as the input voltage in actual use. The rectifier module 2 stabilizes the direction of the current flowing to coil L2 and ensures that the voltage across coil L2 remains unchanged. Simultaneously, it does not change the frequency of the current, and has no effect on the inductor L1, coil L2, and capacitor C1 in the circuit.

[0044] In the embodiment of the present invention, the starting circuit of the solenoid valve 6 starts and maintains the solenoid valve 6 by controlling the turning on and off of different switches. The specific working process is as follows:

[0045] (1) When the first switch S1 is closed, the second switch S2 is open, and the transistor Q1 is closed, the input voltage charges the inductor L1. At this time, the direction of the induced voltage across the inductor L1 is positive on the left and negative on the right.

[0046] (2) When the first switch S1 is closed, the second switch S2 is opened, and the transistor Q1 changes from the closed state to the open state, the current in the circuit changes from large to small. The induced current in the inductor L1 is consistent with the direction of the circuit current, flowing from left to right. Because the induced voltage and induced current of the inductor L1 are in opposite directions, the induced voltage direction at both ends of the inductor L1 is negative on the left and positive on the right. At this time, the inductor L1 and the input voltage 1 act as the circuit power supply to charge the capacitor C1 and the coil L2. At this time, the voltage across the coil L2 is the sum of the voltage of the inductor L1 and the external power supply 1. The voltage increases, and the output voltage is aUo.

[0047] (3) When the first switch S1 changes from a closed state to an open state, the second switch S2 changes from an open state to a closed state, and the transistor Q1 changes from a closed state to an open state, the resistor R1 is connected to the circuit. Since the direction of the current does not change, the voltage direction across the resistor R1 is negative on the left and positive on the right, which in turn causes the voltage across the coil L2 to decrease. The output voltage at this time is bUo.

[0048] The switch state of the above steps (1) and (2) changes to the first control state, and the switch state of the above step (3) changes to the second control state. The total time of steps (1) and (2) is the boost time. The ratio of step (1) to the boost time is the duty cycle, and the duty cycle is proportional to the boost ratio. After completing the above steps (1) to (2), the solenoid valve 6 can be quickly started. After the solenoid valve 6 is started, the preset detection module 3 detects the boost time and determines whether the boost time exceeds the preset time. If it exceeds the preset time, the first control state is switched to the second control state.

[0049] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A solenoid valve starting circuit, characterized in that: It includes a preset detection module, a boost module and a buck module; One end of the preset detection module is connected to the input voltage, and the control end of the preset detection module controls the boost module and the buck module respectively and selects one output to be connected to the power supply line of the solenoid valve; the preset detection module has a first control state and a second control state in a time sequence in each cycle of controlling the solenoid valve, wherein the first control state is to input the input voltage to the boost module for boosting and then output it to the solenoid valve for starting the solenoid valve; the second control state is that after the first control state runs for more than a preset time, the input voltage is switched to the buck module for bucking and then output to the solenoid valve for maintaining the state after the solenoid valve is started.

2. The solenoid valve starting circuit according to claim 1, characterized in that: It also includes a rectifier module, which is arranged between the input voltage and the preset detection module and is used to rectify the input voltage.

3. The solenoid valve starting circuit according to claim 1, characterized in that: The boost ratio of the output to the input of the boost module is 1<a≤1.

5.

4. The solenoid valve starting circuit according to claim 1, characterized in that: The voltage reduction ratio between the output and input of the voltage reduction module is 0.5<b≤1.

5. The solenoid valve starting circuit according to claim 2, characterized in that: The boost module includes an inductor L1, a capacitor C1, a first switch S1 and a transistor Q1. The first switch S1, the inductor L1 and the capacitor C1 are connected in series in sequence. The transistor Q1 and the capacitor C1 are connected in parallel. One end of the first switch S1 is connected to the output end of the rectifier module, and one end of the capacitor C1 is grounded. Both ends of capacitor C1 are connected to the power supply line of the solenoid valve.

6. The solenoid valve starting circuit according to claim 5, characterized in that: The boost module includes a diode D1 , the anode of the diode D1 is connected to one end of the inductor L1 , and the cathode of the diode D1 is connected to one end of the capacitor C1 ; the boost module includes a coil L2 , and the coil L2 is connected in parallel with C1 .

7. The solenoid valve starting circuit according to claim 5 or 6, characterized in that: The step-down module includes a voltage divider circuit added on the basis of the step-up module, and the voltage divider circuit is used to reduce the output voltage across the capacitor C1.

8. The solenoid valve starting circuit according to claim 1, characterized in that: When the preset detection module is in the first control state, the preset detection module controls the first switch S1 to be closed, the second switch S2 to be opened, and the transistor Q1 to be closed first and then opened; When the preset detection module is in the second control state, the preset detection module controls the first switch S1 to be opened, the second switch S2 to be closed, and the transistor Q1 to be disconnected.

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