Power-off protection circuit, method and device for electrical equipment

Abstract

The invention provides a power-off protection circuit of electrical equipment. The power-off protection circuit comprises a live wire, a zero wire, a power switch, a power failure detection module, a first voltage detection module and a processor module, a first voltage detection module is additionally arranged at the front end of a power switch, after a power failure detection module detects a power failure signal, a first voltage signal in a live wire is detected through the first voltage detection module, whether the power switch is in an abnormal power-off state or not is judged according to the first voltage signal, and if the power switch is in the abnormal power-off state, a protection mechanism is started. According to the invention, the electrical equipment can be prevented from being directly started to cause harm when the electrical equipment is powered on again after accidental power failure, so that the personal and property safety of a user is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment control, and in particular to a power-off protection circuit, method and device for electrical equipment. Background Art

[0002] There are electrical appliances on the market that use a toggle switch to turn on and off the power, such as high-speed hair dryers, electric irons, electric ovens, electric heating guns, electric blankets, etc. After a sudden power outage, the user is very likely to forget to turn the toggle switch to the "OFF (shutdown)" position, resulting in the appliance being powered on directly after the power is restored because the toggle switch is in the "ON (power on)" position. If the user does not find or handle it in time, if the appliance is placed or close to flammable items or close to human skin, it will cause high temperature to damage the items or burn the human body, or even cause a fire. Therefore, there are safety issues when the existing electrical equipment is powered on again after an unexpected power outage. Summary of the invention

[0003] The embodiment of the present invention provides a power-off protection method for electrical equipment, aiming to solve the safety problem existing in the prior electrical equipment when it is powered on again after an accidental power-off. By adding a first voltage detection module at the front end of the power switch, after the power-off detection module detects a power-off signal, the first voltage detection module detects a first voltage signal in the live wire, and determines whether it is an abnormal shutdown state according to the first voltage signal. If it is an abnormal shutdown state, the protection mechanism is activated, which can prevent the electrical equipment from being directly turned on when the power is on again after an accidental power-off, thereby protecting the personal and property safety of the user.

[0004] In a first aspect, an embodiment of the present invention provides a power-off protection circuit for an electrical device, the power-off protection circuit comprising: a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module, and a processor module;

[0005] One end of the live wire is used to be electrically connected to the mains power supply, and the other end of the live wire is electrically connected to the front end of the power switch and the input end of the first voltage detection module respectively;

[0006] The rear end of the power switch is electrically connected to the first input end of the power failure detection module, the output end of the power failure detection module is electrically connected to the first input end of the processor module, and the power failure detection module is used to detect a power failure signal;

[0007] The output end of the first voltage detection module is electrically connected to the second input end of the processor module, and the first voltage detection module is used to detect a first voltage signal of the live wire;

[0008] One end of the neutral line is used to be electrically connected to the mains power supply, and the other end of the neutral line is electrically connected to the third input terminal of the processor module;

[0009] The processor module is used to determine whether the electrical device is in an abnormal shutdown state based on the first voltage signal when detecting that the electrical device is powered off, and if it is in an abnormal shutdown state, start a preset protection mechanism.

[0010] Optionally, the first voltage detection module includes a step-down unit and an isolation unit, the input end of the step-down unit is electrically connected to the other end of the live wire, the first output end of the step-down unit is grounded, the second output end of the step-down unit is electrically connected to the input end of the isolation unit, and the output end of the isolation unit is electrically connected to the second input end of the processor module.

[0011] Optionally, the step-down unit includes a rectifier circuit and a first step-down circuit, the input end of the rectifier circuit is electrically connected to the other end of the live wire, the output end of the rectifier circuit is connected to the input end of the first step-down circuit, the first output end of the first step-down circuit is grounded, and the second output end of the first step-down circuit is electrically connected to the input end of the isolation unit.

[0012] Optionally, the isolation unit includes a first filtering circuit and a first isolation circuit, the first filtering circuit is electrically connected to the first output end of the step-down unit and the second output end of the step-down unit, respectively, the input end of the first isolation circuit is electrically connected to the second output end of the step-down unit, and the output end of the first isolation circuit is electrically connected to the second input end of the processor module.

[0013] Optionally, the power-off protection circuit also includes a second voltage detection module, an input end of the second voltage detection module is electrically connected to the neutral line, an output end of the second voltage detection module is electrically connected to a fourth input end of the processor module, and the second voltage detection module is used to detect a second voltage signal of the neutral line.

[0014] Optionally, the power-off detection module includes a second step-down circuit, a second filtering circuit and a second isolation circuit, the input end of the second step-down circuit is electrically connected to the rear end of the power switch, the first output end of the second step-down circuit is grounded, the second output end of the second step-down circuit is electrically connected to the input end of the second isolation circuit, and the second filtering circuit is electrically connected to the first output end of the second step-down circuit and the second output end of the second step-down circuit, respectively.

[0015] Optionally, the power-off protection circuit also includes a power-off battery life module, the output end of the power-off battery life module is electrically connected to the second input end of the power-off detection module and the fifth input end of the processor module, respectively, and the power-off battery life module is used to provide working power to the power-off detection module and the processor module when the electrical device loses power.

[0016] In a second aspect, an embodiment of the present invention provides a power-off protection method for an electrical device, wherein the electrical device has multiple working gears, and the electrical device includes a power-off protection circuit for the electrical device as described in any one of the embodiments of the present invention, and the method includes the following steps:

[0017] After detecting a power-off signal, acquiring a first voltage signal;

[0018] determining, according to the first voltage signal, whether the live wire is in a voltage maintaining state;

[0019] If the live wire is in the voltage maintenance state, determining that the electrical device is normally shut down, and saving the current gear information of the electrical device;

[0020] If the live wire is not in the voltage maintenance state, it is determined that the electrical device is abnormally shut down, the current gear information of the electrical device is saved, and a preset protection mechanism is started.

[0021] Optionally, after the power-off signal is detected and before the step of acquiring the first voltage signal, the method further includes:

[0022] After the electrical device is powered on, it detects whether the live wire and the neutral wire of the wall are connected in reverse;

[0023] In the case that the live wire and the neutral wire of the wall are not connected reversely, the step of acquiring the first voltage signal after detecting the power-off signal is performed.

[0024] In the third aspect, an embodiment of the present invention further provides a power-off protection device for electrical equipment, the power-off protection device for electrical equipment comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of a power-off protection method for electrical equipment as described in any one of the embodiments of the present invention.

[0025] In an embodiment of the present invention, a power-off protection circuit includes a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module and a processor module; by adding a first voltage detection module at the front end of the power switch, after the power-off detection module detects a power-off signal, the first voltage detection module detects a first voltage signal in the live wire, and determines whether it is an abnormal shutdown state according to the first voltage signal. If it is an abnormal shutdown state, the protection mechanism is activated, which can prevent the electrical equipment from being directly turned on when the power is restored again after an accidental power failure, thereby protecting the personal and property safety of the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of a power-off protection circuit of an electrical device provided by an embodiment of the present invention;

[0028] Figure 2 is a structural schematic diagram of a first voltage detection module provided by an embodiment of the present invention;

[0029] Figure 3 is a structural schematic diagram of another first voltage detection module provided by an embodiment of the present invention;

[0030] Figure 4 is a structural schematic diagram of another first voltage detection module provided by an embodiment of the present invention;

[0031] Figure 5 is a structural schematic diagram of another first voltage detection module provided by an embodiment of the present invention;

[0032] Figure 6 It is a structural schematic diagram of another power-off protection circuit of an electrical device provided by an embodiment of the present invention;

[0033] Figure 7 It is a schematic diagram of a voltage detection circuit of an isolation resistor version provided by an embodiment of the present invention;

[0034] Figure 8 It is a schematic diagram of a voltage detection circuit of an optical coupling component version provided by an embodiment of the present invention;

[0035] Fig. 9 is a circuit diagram of a power failure detection module provided by an embodiment of the present invention;

[0036] Fig.10 The present invention is a flowchart of a power-off protection method for electrical equipment provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, Figure 1 It is a structural diagram of a power-off protection circuit of an electrical device provided by an embodiment of the present invention, and the power-off protection circuit includes: a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module and a processor module; one end of the live wire is used to be electrically connected to the mains power supply, and the other end of the live wire is electrically connected to the front end of the power switch and the input end of the first voltage detection module respectively; the rear end of the power switch is electrically connected to the first input end of the power-off detection module, the output end of the power-off detection module is electrically connected to the first input end of the processor module, and the power-off detection module is used to detect a power-off signal; the output end of the first voltage detection module is electrically connected to the second input end of the processor module, and the first voltage detection module is used to detect a first voltage signal of the live wire; one end of the neutral wire is used to be electrically connected to the mains power supply, and the other end of the neutral wire is electrically connected to the third input end of the processor module; the processor module is used to determine whether the electrical device is in an abnormal shutdown state based on the first voltage signal when detecting that the electrical device is powered off, and if it is in an abnormal shutdown state, start a preset protection mechanism.

[0039] In an embodiment of the present invention, the electrical device may be provided with a plurality of gears, and different gears may correspond to different powers or modes.

[0040] The live wire and the neutral wire are used to connect to the mains power supply to provide power to the electrical equipment. The power switch is set on the live wire to turn on and off the user's electrical equipment. When the power switch is closed, the electrical equipment is powered on, and when the power switch is opened, the electrical equipment is powered off.

[0041] The power-off protection circuit of the electrical equipment may also include a power-off battery life module, which is used to provide working power to the power-off detection module and the processor module when the electrical equipment is powered off, so that the power-off detection module and the processor module can still work normally after the electrical equipment is powered off.

[0042] The power-off detection module is connected to the rear end of the power switch and is used to detect whether there is voltage on the power switch. Generally speaking, when the power-off detection module detects that there is voltage on the power switch, it means that the power switch is closed and the AC power supply is normal. When the power-off detection module detects that there is no voltage on the power switch, it means that the power switch is disconnected or the AC power supply is abnormal (such as power outage). The power-off signal is the signal generated when the power-off detection module detects that there is no voltage on the power switch.

[0043] The first voltage detection module is connected to the front end of the power switch and is used to detect whether the live wire has voltage. Generally speaking, when the mains power supply is normal, the live wire has voltage, and when the mains power supply is not, the live wire has no voltage.

[0044] By performing voltage detection on the front and back ends of the power switch through the power failure detection module and the first voltage detection module, it is possible to accurately determine whether the electrical device is in a normal shutdown state or an abnormal shutdown state. The normal shutdown state is a shutdown state caused by the user disconnecting the power switch. At this time, the power failure detection module detects that there is no voltage, and the first voltage detection module detects that there is voltage on the live wire. The abnormal shutdown state is a shutdown state caused by a non-user disconnecting the power switch. At this time, the power failure detection module detects that there is no voltage, and the first voltage detection module detects that there is no voltage on the live wire.

[0045] According to the above principle, it can be determined whether the electrical device is in an abnormal shutdown state when the electrical device loses power.

[0046] After receiving the power-off signal of the electrical detection module and the first voltage signal of the first voltage detection module, the processor module determines whether the electrical device is in an abnormal shutdown state according to the power-off signal and the first voltage signal. If the electrical device is determined to be in an abnormal shutdown state, a preset protection mechanism is activated. The protection mechanism can be used to prevent the electrical device from starting up in an abnormal shutdown state, thereby preventing the electrical device from directly starting up after an accidental power failure and when the power is on again, thereby protecting the personal and property safety of the user.

[0047] For example, when a user is using an electrical device, a power outage occurs suddenly. The power-off detection module monitors that the voltage of the power switch is 0, and transmits a power-off signal to the processor module. At this time, the power-off battery life module works to supply power to the power-off detection module and the processor module to maintain the operation of the power-off detection module and the processor module. The first voltage detection module transmits the first voltage signal on the live wire to the processor module, and the processor module determines whether it is an abnormal shutdown state according to the first voltage signal. Specifically, if the first voltage signal remains unchanged, it is judged to be a normal shutdown state, and if the first voltage signal is 0, it is judged to be an abnormal shutdown state. In the normal shutdown state, the processor module saves the current operation information, and when the electrical device is normally turned on next time, it is restored to the operation state before the normal shutdown through the saved operation information. In the abnormal shutdown state, the processor module saves the current operation information, and at the same time, the locked electrical device cannot be turned on normally, and a fault prompt is reported; when the user triggers the unlocking operation (such as long pressing a button on the electrical device, or shutting down normally once), the electrical device is unlocked and restored to normal use. The operation information can be saved by using a storage unit in the processor module or an external storage module.

[0048] It should be noted that the power-off battery life module in this embodiment is not necessary. When the power-off battery life module is not set, when the electrical device is shut down normally, the live wire detection circuit at the front end of the switch has voltage, and it is still connected to the processor module. Therefore, if the detection result is "the live wire at the front end of the voltage switch has voltage, and the circuit at the back end of the voltage switch has no voltage", it can be considered as a normal shutdown. At this time, based on the power supply between the front end of the switch and the processor module, the processor module can write the corresponding mark, such as mark 1; if the detection result is "there is no voltage at both the front and rear ends of the voltage switch", it can be considered as an "abnormal shutdown", and the processor module cannot write the mark because there is no connected circuit power supply, and the default mark is mark 0; in this way, the processor module can directly generate "normal shutdown mark 1" and "abnormal shutdown mark 0", and the overall circuit is simpler and the cost is lower.

[0049] Furthermore, the first voltage detection module includes a step-down unit and an isolation unit, the input end of the step-down unit is electrically connected to the other end of the live wire, the first output end of the step-down unit is grounded, the second output end of the step-down unit is electrically connected to the input end of the isolation unit, and the output end of the isolation unit is electrically connected to the second input end of the processor module.

[0050] The step-down unit is used to reduce the voltage on the live line to a safe range to prevent the processor module from being burned out by excessive voltage. The isolation unit is used to further protect the processor module. Through the step-down unit and the isolation unit, the processor module can receive a safe voltage signal.

[0051] Further, such as Figure 2 As shown, Figure 2 is a schematic diagram of the structure of a first voltage detection module provided by an embodiment of the present invention, Figure 2 In the embodiment, the step-down unit includes a rectifier circuit and a first step-down circuit, the input end of the rectifier circuit is electrically connected to the other end of the live wire, the output end of the rectifier circuit is connected to the input end of the first step-down circuit, the first output end of the first step-down circuit is grounded, the second output end of the first step-down circuit is electrically connected to the input end of the isolation unit, the rectifier circuit includes two rectifier diodes connected in series, and the first step-down circuit includes two step-down resistors connected in series.

[0052] The above rectifier circuit is used to convert the AC power on the live wire into DC power. The processor module needs to input DC power, so the AC power needs to be converted into DC power through the rectifier circuit. The first step-down circuit is used to reduce the higher DC power to safe DC power to avoid damage to the processor module.

[0053] The above-mentioned rectifier circuit includes a first rectifier diode D1 (model 1N4007W) and a second rectifier diode D2 (model 1N4007W). The above-mentioned first step-down circuit includes a first step-down resistor R1 (100k ohms) and a second step-down resistor R2 (5.6k ohms).

[0054] The first rectifier diode D1 and the second rectifier diode D2 are connected in series, the positive electrode of the first rectifier diode D1 is electrically connected to the live wire, the negative electrode of the first rectifier diode D1 is electrically connected to the positive electrode of the second rectifier diode D2, the negative electrode of the second rectifier diode D2 is electrically connected to one end of the first step-down resistor R1, the other end of the first step-down resistor R1 is electrically connected to one end of the second step-down resistor R2, and the other end of the second step-down resistor R2 is grounded as the first output end of the first step-down circuit. The common end of the second step-down resistor R2 and the first step-down resistor R1 serves as the second output end of the first step-down circuit.

[0055] Furthermore, the isolation unit includes a first filtering circuit and a first isolation circuit, the first filtering circuit is electrically connected to the first output end of the step-down unit and the second output end of the step-down unit, respectively, the input end of the first isolation circuit is electrically connected to the second output end of the step-down unit, the output end of the first isolation circuit is electrically connected to the second input end of the processor module, the first filtering circuit includes at least one filtering capacitor, and the first isolation circuit includes an isolation resistor or an optical coupling component.

[0056] The first filter circuit is used to filter out the noise in the rectified output voltage, so that the voltage signal input to the processor module is more stable. The first isolation circuit is used to isolate the processor module from the step-down unit, to prevent a large voltage from being directly input to the processor module, and to protect the processor module.

[0057] The first filter circuit includes a first filter capacitor C1 (0.1 microfarad). One end of the first filter capacitor C1 is electrically connected to the first output end of the step-down unit, and the other end is electrically connected to the second output end of the step-down unit. Specifically, one end of the first filter capacitor C1 is electrically connected to the ground end of the second step-down resistor R2 (the first output end of the first step-down circuit), and the other end is electrically connected to the common end of the second step-down resistor R2 and the first step-down resistor R1 (i.e., the second output end of the first step-down circuit).

[0058] In some possible embodiments, Figure 3 As shown, the above-mentioned first filtering circuit may also include a second filtering capacitor C2 (1 microfarad), the first filtering capacitor C1 is a high-frequency filtering capacitor, used to filter high-frequency noise, and the above-mentioned second filtering capacitor C2 is a low-frequency filtering capacitor, used to filter high-frequency noise. The first filtering capacitor C1 is connected in parallel with the second filtering capacitor C2. After the first filtering capacitor C1 is connected in parallel with the second filtering capacitor C2, one end is electrically connected to the first output end of the step-down unit, and the other end is electrically connected to the second output end of the step-down unit. Specifically, after the first filtering capacitor C1 is connected in parallel with the second filtering capacitor C2, one end of the parallel connection is electrically connected to the ground end of the second step-down resistor R2 (the first output end of the first step-down circuit), and the other end of the parallel connection is electrically connected to the common end of the second step-down resistor R2 and the first step-down resistor R1 (i.e., the second output end of the first step-down circuit).

[0059] The above-mentioned first isolation circuit is an isolation resistor R3 (1k ohm), one end of the isolation resistor R3 is electrically connected to the common end of the second step-down resistor R2 and the first step-down resistor R1 (that is, the second output end of the first step-down circuit), and the other end of the isolation resistor R3 is electrically connected to the second input end of the processor module.

[0060] In a possible embodiment, the first isolation circuit is an optical coupling component U1 (model TLP292 (BL-TPL.E)), such as Figure 4 As shown, the first input end of the optical coupling component U1 is electrically connected to the second output end of the first buck circuit, and the second input end of the optical coupling component U1 is electrically connected to the first output end of the first buck circuit (i.e., grounded). The third input end of the optical coupling component U1 is electrically connected to the power supply VCC, and the output end of the optical coupling component U1 is electrically connected to the second input end of the processor module.

[0061] The isolation resistor or optocoupler component can be determined based on cost, with the cost of the optocoupler component being higher than the isolation resistor.

[0062] In a possible embodiment, an optical coupling component U1 may be connected in series to the other end of the isolation resistor R3. Figure 5As shown, the other end of the isolation resistor R3 is electrically connected to the first input end of the optical coupling component U1, and the second input end of the optical coupling component U1 is electrically connected to the first output end of the first step-down circuit (i.e., grounded). The third input end of the optical coupling component U1 is electrically connected to the power supply VCC through the resistor R4 (1k ohm), and the output end of the optical coupling component U1 is electrically connected to the second input end of the processor module.

[0063] Further, such as Figure 6 As shown, Figure 6 is a schematic diagram of the structure of another power-off protection circuit of an electrical device provided by an embodiment of the present invention. Figure 6 In the embodiment, the power-off protection circuit also includes a second voltage detection module, an input end of the second voltage detection module is electrically connected to the neutral line, an output end of the second voltage detection module is electrically connected to the fourth input end of the processor module, and the second voltage detection module is used to detect a second voltage signal of the neutral line.

[0064] The second voltage detection module may have the same circuit structure as the first voltage detection module. The second voltage detection module is used to detect whether the live wire and the neutral wire of the mains power supply are connected reversely with the live wire and the neutral wire of the electrical device.

[0065] Adding a second voltage detection module can realize the judgment of the neutral and live wires, and prevent the wrong judgment caused by the opposite of the neutral and live wires of the mains power supply and the neutral and live wires of the electrical equipment. Specifically, a circuit similar to the "first voltage detection circuit" (i.e., the second voltage detection circuit) is superimposed on the neutral wire, connected to different MCU pins (the fourth input terminal of the processor module), and the voltage conditions of the neutral and live wires can be used to accurately judge whether the neutral and live wires of the power supply are opposite to the neutral and live wires of the electrical equipment. See Figure 6 , Figure 7 , Figure 8 ,in, Figure 7 1 is a schematic diagram of a voltage detection circuit of an isolation resistor version provided by an embodiment of the present invention. Figure 8 This is a schematic diagram of a voltage detection circuit of an optical coupling component version provided by an embodiment of the present invention. If the zero and live wires of the mains power supply are opposite to the zero and live wires of the electrical equipment, the electrical equipment can generally operate normally after being inserted, but because the first voltage detection circuit in the electrical equipment is actually connected to the neutral wire, the result of the "first voltage detection module" is 0 regardless of whether there is a power outage or not. Therefore, a zero and live wire judgment is required to confirm that the zero and live wires of the mains power supply correspond to the zero and live wires of the electrical equipment and are not reversed, so that the power-off protection method of the electrical equipment in the embodiment of the present invention can be used normally.

[0066] In a possible embodiment, only the voltage detection module (the first voltage detection module or the second voltage detection module) can be used to determine whether the neutral and live wires of the wall are connected reversely, without the need to connect the corresponding voltage detection modules to the corresponding neutral and live wires of the product. Figure 1 After the power switch is closed, if there is voltage at the back end of the power switch (or Figure 1 If the detection result of the power-off detection circuit in the power switch is that there is no power-off), but there is no voltage in the "first voltage detection circuit" at the front end of the power switch, it is considered that the zero and live wires of the AC power supply are opposite to the zero and live wires of the electrical equipment, and the scheme of "determining whether it is an abnormal shutdown state" in the embodiment of the present invention cannot be used as a reference; but if there is voltage in the "first voltage detection circuit" at the front end of the power switch, it is considered that the zero and live wires of the AC power supply are normally corresponding to the zero and live wires of the electrical equipment, and the scheme of "determining whether it is an abnormal shutdown state" in the embodiment of the present invention can be used as a reference.

[0067] Furthermore, the power-off detection module includes a second step-down circuit, a second filtering circuit and a second isolation circuit, the input end of the second step-down circuit is electrically connected to the rear end of the power switch, the first output end of the second step-down circuit is grounded, the second output end of the second step-down circuit is electrically connected to the input end of the second isolation circuit, and the second filtering circuit is electrically connected to the first output end of the second step-down circuit and the second output end of the second step-down circuit, respectively.

[0068] like Fig. 9 As shown, the second step-down circuit includes a step-down resistor R9 (100k ohm), a step-down resistor R12 (100k ohm), and a step-down resistor R11 (5.6k ohm). The second filter circuit includes a filter capacitor C5 (0.1 microfarad) and a filter capacitor C6 (4.7 microfarad). The second isolation circuit includes an isolation resistor R10 (1k ohm). One end of the step-down resistor R9 is electrically connected to the rear end of the power switch, the other end of the step-down resistor R9 is electrically connected to one end of the step-down resistor R12, the other end of the step-down resistor R12 is electrically connected to one end of the step-down resistor R11, and the other end of the step-down resistor R11 is grounded. The common end of the step-down resistor R12 and the step-down resistor R11 (the output end of the second step-down circuit) is electrically connected to one end of the isolation resistor R10, and the other end of the isolation resistor R10 is electrically connected to the first input end of the processor module. The filter capacitor C5 is connected in parallel with the filter capacitor C6. After the filter capacitor C5 and the filter capacitor C6 are connected in parallel, one end of the parallel connection is electrically connected to the other end of the voltage-dropping resistor R11 (ie, grounded), and the other end of the parallel connection is electrically connected to the common end of the voltage-dropping resistor R12 and the voltage-dropping resistor R11.

[0069] like Fig.10 As shown, Fig.10The present invention provides a flowchart of a power-off protection method for an electrical device, wherein the electrical device has multiple working gears, and the electrical device includes a power-off protection circuit for the electrical device according to any one of the embodiments of the present invention. The power-off protection method for the electrical device includes the following steps:

[0070] 101. After detecting a power-off signal, obtain a first voltage signal.

[0071] In an embodiment of the present invention, a power-off protection circuit includes: a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module and a processor module; one end of the live wire is used to be electrically connected to the AC power supply, and the other end of the live wire is electrically connected to the front end of the power switch and the input end of the first voltage detection module respectively; the rear end of the power switch is electrically connected to the first input end of the power-off detection module, the output end of the power-off detection module is electrically connected to the first input end of the processor module, and the power-off detection module is used to detect a power-off signal; the output end of the first voltage detection module is electrically connected to the second input end of the processor module, and the first voltage detection module is used to detect a first voltage signal of the live wire; one end of the neutral wire is used to be electrically connected to the AC power supply, and the other end of the neutral wire is electrically connected to the third input end of the processor module; the processor module is used to determine whether the electrical equipment is in an abnormal shutdown state based on the first voltage signal when a power failure of the electrical equipment is detected, and if it is in an abnormal shutdown state, a preset protection mechanism is activated.

[0072] The power-off detection module is connected to the rear end of the power switch, and detects whether the power switch has voltage through the power-off detection module. Generally speaking, when the power-off detection module detects that the power switch has voltage, it means that the power switch is closed and the AC power supply is normal. When the power-off detection module detects that the power switch has no voltage, it means that the power switch is disconnected, or the AC power supply is abnormal (such as power outage). The power-off signal is the signal generated when the power-off detection module detects that the power switch has no voltage.

[0073] The first voltage detection module is connected to the front end of the power switch, and detects whether there is voltage on the live wire through the first voltage detection module, thereby sending a corresponding first voltage signal to the processor module. Generally speaking, when the mains power supply is normal, the live wire has voltage, and when the mains power supply is not, the live wire has no voltage.

[0074] 102. Determine whether the live wire is in a voltage maintenance state according to the first voltage signal.

[0075] In the embodiment of the present invention, by performing voltage detection on the front and rear ends of the power switch through the power failure detection module and the first voltage detection module, it is possible to accurately determine whether the electrical device is in a normal shutdown state or an abnormal shutdown state. The normal shutdown state is a shutdown state caused by the user disconnecting the power switch. At this time, the power failure detection module detects that there is no voltage, and the first voltage detection module detects that there is voltage on the live wire. The abnormal shutdown state is a shutdown state caused by a non-user disconnecting the power switch. At this time, the power failure detection module detects that there is no voltage, and the first voltage detection module detects that there is no voltage on the live wire.

[0076] According to the above principle, it can be determined whether the electrical device is in an abnormal shutdown state when the electrical device loses power.

[0077] 103. If the live wire is in a voltage maintenance state, it is determined that the electrical device is shut down normally, and the current gear information of the electrical device is saved.

[0078] In the embodiment of the present invention, the live wire is in a voltage maintenance state, indicating that the AC power supply is normal and the power failure is caused by normal shutdown by the user. After the processor module receives the power failure signal of the power detection module and the first voltage signal of the first voltage detection module, it determines whether the electrical device is in an abnormal shutdown state according to the power failure signal and the first voltage signal.

[0079] The power-off protection circuit may further include a power-off battery life module, the output end of the power-off battery life module is electrically connected to the second input end of the power-off detection module and the fifth input end of the processor module respectively, and the power-off battery life module is used to provide working power to the power-off detection module and the processor module when the electrical device loses power;

[0080] For example, when a user is using an electrical device, a power outage occurs suddenly. The power-off detection module monitors that the voltage of the power switch is 0, and transmits a power-off signal to the processor module. At this time, the power-off endurance module works to supply power to the power-off detection module and the processor module to maintain the operation of the power-off detection module and the processor module. The first voltage detection module transmits the first voltage signal on the live wire to the processor module, and the processor module determines whether it is an abnormal shutdown state based on the first voltage signal. Specifically, if the first voltage signal remains unchanged, it is judged to be a normal shutdown state. If the first voltage signal is 0, it is judged to be an abnormal shutdown state.

[0081] It should be noted that the above-mentioned power-off battery life module is not necessary. When the power-off battery life module is not set, when the electrical equipment is shut down normally, the live wire detection circuit at the front end of the switch has voltage, and it is still connected to the processor module. Therefore, if the detection result is "the live wire at the front end of the voltage switch has voltage, and the circuit at the back end of the voltage switch has no voltage", it can be considered as a normal shutdown. At this time, based on the power supply between the front end of the switch and the processor module, the processor module can write the corresponding mark, such as mark 1; if the detection result is "there is no voltage at both the front and rear ends of the voltage switch", it can be considered as an "abnormal shutdown", and the processor module cannot write the mark because there is no connected circuit power supply, and the default mark is mark 0; in this way, the processor module can directly generate "normal shutdown mark 1" and "abnormal shutdown mark 0", and the overall circuit is simpler and the cost is lower.

[0082] In the normal shutdown state, the processor module saves the current operation information, and when the electrical device is normally powered on next time, the saved operation information is used to restore the operation state before the normal shutdown. The above operation information may be gear information.

[0083] 104. If the live wire is not in a voltage maintenance state, it is determined that the electrical device is abnormally shut down, the current gear information of the electrical device is saved, and the preset protection mechanism is activated.

[0084] In the embodiment of the present invention, if the live line is not in the voltage maintenance state, it means that the mains power supply is not supplying power, and the power failure is caused by power failure, which can be determined as abnormal shutdown. If the first voltage signal is 0, it is determined to be an abnormal shutdown state.

[0085] If it is determined that the electrical device is in an abnormal shutdown state, a preset protection mechanism is activated. The above protection mechanism is used to prevent the electrical device from starting up in the abnormal shutdown state, thereby preventing the electrical device from directly starting up when the power is restored after an accidental power outage, thereby protecting the personal and property safety of the user.

[0086] In the abnormal shutdown state, the processor module saves the current operation information and starts the protection mechanism at the same time, locking the electrical equipment from normal startup and reporting a fault prompt; the above protection mechanism is used to prevent the electrical equipment from starting up in the abnormal shutdown state, thereby preventing the electrical equipment from directly starting up when the power is restored after an accidental power failure, thereby protecting the personal and property safety of the user. After the protection mechanism is released, normal use is resumed.

[0087] In an embodiment of the present invention, a power-off protection circuit includes a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module, a processor module, and a power-off endurance module; by adding a first voltage detection module at the front end of the power switch, after the power-off detection module detects a power-off signal, the first voltage signal in the live wire is detected by the first voltage detection module, and whether it is an abnormal shutdown state is determined according to the first voltage signal. If it is an abnormal shutdown state, the protection mechanism is activated, which can prevent the electrical equipment from being directly turned on when the power is restored again after an accidental power failure, thereby protecting the personal and property safety of the user.

[0088] Optionally, in the step of starting a preset protection mechanism, the electrical device can be locked in a state where it cannot be turned on, and a fault prompt can be reported; after receiving an unlocking signal, the state where it cannot be turned on is changed to a normal state where it can be turned on.

[0089] In an embodiment of the present invention, when a user triggers an unlocking operation (such as long pressing a button on the electrical device, or shutting down the device normally once), the electrical device is unlocked and restored to normal use. The storage of the operating information may be implemented by a storage unit in the processor module or an external storage module. The operating information may be gear information.

[0090] Optionally, after detecting the power-off signal and before the step of obtaining the first voltage signal, after the electrical device is powered on, it is also possible to detect whether the wall live wire and the wall neutral wire are connected reversely; when the wall live wire and the wall neutral wire are not connected reversely, execute the step of obtaining the first voltage signal after detecting the power-off signal.

[0091] In an embodiment of the present invention, the power-off protection circuit further includes a second voltage detection module, which is used to detect a second voltage signal of the neutral line. The second voltage detection module has the same circuit structure as the first voltage detection module. The second voltage detection module is used to detect whether the live wire and the neutral wire (the live wire of the wall and the neutral wire of the wall) of the mains power supply are connected reversely with the live wire and the neutral wire of the electrical equipment.

[0092] If the neutral and live wires of the AC power supply are opposite to those of the electrical equipment, the electrical equipment can generally operate normally after being plugged in. However, because the first voltage detection circuit in the electrical equipment is actually connected to the neutral wire, the result of the "first voltage detection module" is 0 regardless of whether there is a power outage or not. Therefore, a neutral and live wire judgment is required to confirm that the neutral and live wires of the AC power supply correspond to the neutral and live wires of the electrical equipment and are not connected reversely. Only then can the power-off protection method for the electrical equipment in the embodiment of the present invention be used normally.

[0093] In a possible embodiment, only the voltage detection module (the first voltage detection module or the second voltage detection module) can be used to determine whether the neutral and live wires of the wall are connected reversely, without the need to connect the corresponding voltage detection modules to the corresponding neutral and live wires of the product. Figure 1 After the power switch is closed, if there is voltage at the back end of the power switch (or Figure 1 If the detection result of the power-off detection circuit in the power switch is that there is no power-off), but there is no voltage in the "first voltage detection circuit" at the front end of the power switch, it is considered that the zero and live wires of the AC power supply are opposite to the zero and live wires of the electrical equipment, and the scheme of "determining whether it is an abnormal shutdown state" in the embodiment of the present invention cannot be used as a reference; but if there is voltage in the "first voltage detection circuit" at the front end of the power switch, it is considered that the zero and live wires of the AC power supply are normally corresponding to the zero and live wires of the electrical equipment, and the scheme of "determining whether it is an abnormal shutdown state" in the embodiment of the present invention can be used as a reference.

[0094] It is understandable that in the specific implementation of this application, related data such as device data and voltage data are involved. When the embodiments in this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of relevant data need to comply with relevant laws, regulations and standards of relevant countries and regions.

[0095] An embodiment of the present invention provides a power-off protection device for an electrical device. The power-off protection device for an electrical device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, the steps of a power-off protection method for an electrical device as described in any one of the embodiments of the present invention are implemented.

[0096] The power-off protection device for electrical equipment provided in the embodiment of the present invention can implement each process implemented by the power-off protection method for electrical equipment in the above method embodiment, and can achieve the same beneficial effects. To avoid repetition, it will not be described here.

[0097] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The computer-readable storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM).

[0098] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A power-off protection circuit for electrical equipment, characterized in that: The power-off protection circuit includes: a live wire, a neutral wire, a power switch, a power-off detection module, a first voltage detection module and a processor module; One end of the live wire is used to be electrically connected to the mains power supply, and the other end of the live wire is electrically connected to the front end of the power switch and the input end of the first voltage detection module respectively; The rear end of the power switch is electrically connected to the first input end of the power failure detection module, the output end of the power failure detection module is electrically connected to the first input end of the processor module, and the power failure detection module is used to detect a power failure signal; The output end of the first voltage detection module is electrically connected to the second input end of the processor module, and the first voltage detection module is used to detect a first voltage signal of the live wire; One end of the neutral line is used to be electrically connected to the mains power supply, and the other end of the neutral line is electrically connected to the third input terminal of the processor module; The processor module is used to determine whether the electrical device is in an abnormal shutdown state based on the first voltage signal when detecting that the electrical device is powered off, and if it is in an abnormal shutdown state, start a preset protection mechanism.

2. The power-off protection circuit for electrical equipment according to claim 1, characterized in that: The first voltage detection module includes a step-down unit and an isolation unit, the input end of the step-down unit is electrically connected to the other end of the live wire, the first output end of the step-down unit is grounded, the second output end of the step-down unit is electrically connected to the input end of the isolation unit, and the output end of the isolation unit is electrically connected to the second input end of the processor module.

3. The power-off protection circuit for electrical equipment according to claim 2, characterized in that: The step-down unit includes a rectifier circuit and a first step-down circuit, the input end of the rectifier circuit is electrically connected to the other end of the live wire, the output end of the rectifier circuit is connected to the input end of the first step-down circuit, the first output end of the first step-down circuit is grounded, and the second output end of the first step-down circuit is electrically connected to the input end of the isolation unit.

4. The power-off protection circuit for electrical equipment according to claim 2, characterized in that: The isolation unit includes a first filtering circuit and a first isolation circuit, the first filtering circuit is electrically connected to the first output end of the step-down unit and the second output end of the step-down unit, respectively, the input end of the first isolation circuit is electrically connected to the second output end of the step-down unit, and the output end of the first isolation circuit is electrically connected to the second input end of the processor module.

5. The power-off protection circuit of an electrical device according to any one of claims 1 to 4, characterized in that: The power-off protection circuit also includes a second voltage detection module, an input end of the second voltage detection module is electrically connected to the neutral line, an output end of the second voltage detection module is electrically connected to the fourth input end of the processor module, and the second voltage detection module is used to detect a second voltage signal of the neutral line.

6. The power-off protection circuit of an electrical device according to any one of claims 1 to 4, characterized in that: The power-off detection module includes a second step-down circuit, a second filtering circuit and a second isolation circuit, wherein the input end of the second step-down circuit is electrically connected to the rear end of the power switch, the first output end of the second step-down circuit is grounded, the second output end of the second step-down circuit is electrically connected to the input end of the second isolation circuit, and the second filtering circuit is electrically connected to the first output end of the second step-down circuit and the second output end of the second step-down circuit, respectively.

7. The power-off protection circuit of an electrical device according to any one of claims 1 to 4, characterized in that: The power-off protection circuit also includes a power-off battery life module, the output end of the power-off battery life module is electrically connected to the second input end of the power-off detection module and the fifth input end of the processor module respectively, and the power-off battery life module is used to provide working power to the power-off detection module and the processor module when the electrical device loses power.

8. A power-off protection method for electrical equipment, characterized in that: The electrical device has a plurality of working gears, the electrical device comprises a power-off protection circuit of the electrical device according to any one of claims 1 to 7, and the method comprises the following steps: After detecting a power-off signal, acquiring a first voltage signal; determining, according to the first voltage signal, whether the live wire is in a voltage maintaining state; If the live wire is in the voltage maintenance state, determining that the electrical device is normally shut down, and saving the current gear information of the electrical device; If the live wire is not in the voltage maintenance state, it is determined that the electrical device is abnormally shut down, the current gear information of the electrical device is saved, and a preset protection mechanism is started.

9. The power-off protection method for electrical equipment according to claim 8, characterized in that: After the power-off signal is detected and before the step of acquiring the first voltage signal, the method further includes: After the electrical device is powered on, it detects whether the live wire and the neutral wire of the wall are connected in reverse; In the case that the live wire and the neutral wire of the wall are not connected reversely, the step of acquiring the first voltage signal after detecting the power-off signal is performed.

10. A power-off protection device for electrical equipment, characterized in that: The power-off protection device of an electrical device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, the steps of the power-off protection method of the electrical device as described in claim 8 or 9 are implemented.

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