Safety protection circuit of household appliance and household appliance

Abstract

The utility model relates to a safety protection circuit of a household appliance and the household appliance, and the safety protection circuit of the household appliance comprises a cover opening detection switch which is switched off when a cover body of the household appliance is opened and is switched on when the cover body of the household appliance is closed; the load power supply control circuit comprises an electric control switch and a first switching circuit; the electric control switch is connected in series in a power supply loop of a load; the switch path of the first switch circuit and the cover opening detection switch are connected in series in a power supply loop of the electric control switch; and the cover opening detection circuit is used for detecting the opening and closing state of the cover opening detection switch, and controlling the switch path of the first switch circuit to be disconnected when detecting that the cover opening detection switch is disconnected. According to the safety protection circuit provided by the utility model, when the switch path of the first switch circuit is disconnected or the cover opening detection switch is disconnected, the power supply loop of the electric control switch is disconnected, so that the power supply loop of the load is disconnected and the load is powered off, the safety of household appliances and users is ensured, and the technical problem of poor safety in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to circuit technical field, specifically, it is related to a kind of safety protection circuit of household appliance and household appliance. BACKGROUND

[0002] With the development of electronic technology and internet technology, the degree of intelligence of household appliances is higher and higher.The market share of food processors is increasing, and people are paying more and more attention to the safety of household appliances such as food processors.

[0003] Currently, most manufacturers ensure the safety of the machine through MCU program and sensor, but this method has a disadvantage, which is that when the MCU program is wrong, it cannot guarantee its safety.

[0004] For example, most manufacturers currently use MCU to detect the cover door switch signal of the food processor to determine whether to disconnect the load.However, when the MCU program is wrong, it cannot guarantee the disconnection of the load, resulting in poor safety of the food processor. SUMMARY

[0005] The utility model provides a kind of safety protection circuit of household appliance, solve the technical problem of poor safety in prior art.

[0006] To achieve the above technical purpose, the utility model adopts the following technical scheme:

[0007] The safety protection circuit of household appliance comprises:

[0008] The cover opening detection switch is opened when the cover of the household appliance is opened, and is closed when the cover of the household appliance is closed.

[0009] The load power supply control circuit comprises an electric control switch and a first switch circuit.The electric control switch is connected in series in the power supply circuit of the load, and the switch path of the first switch circuit and the cover opening detection switch are connected in series in the power supply circuit of the electric control switch.

[0010] The cover opening detection circuit is used to detect the opening and closing state of the cover opening detection switch, and when the cover opening detection switch is detected to be disconnected, the switch path of the first switch circuit is controlled to be disconnected.

[0011] In some embodiments of the present application, the electric control switch is a relay.

[0012] The normally open contact of the relay is connected in series in the power supply circuit of the load.

[0013] The switch path of the first switch circuit and the cover opening detection switch are connected in series in the power supply circuit of the coil of the relay.

[0014] In some embodiments of the present application, the control end of the first switch circuit is connected to the cover detection circuit.

[0015] One end of the switch path of the first switch circuit is grounded, and the other end of the switch path of the first switch circuit is connected to one end of the coil of the relay, and the other end of the coil is connected to the power supply through the cover detection switch.

[0016] In some embodiments of the present application, a first diode is connected in series between the cover detection switch and the coil.

[0017] In some embodiments of the present application, the other end of the coil is grounded through an electrolytic capacitor.

[0018] In some embodiments of the present application, a second diode is connected in parallel across the two ends of the coil.

[0019] In some embodiments of the present application, the normally open contact of the relay has two, one of which is connected in series in the power supply circuit between the live wire and the load, and the other is connected in series in the power supply circuit between the zero line and the load.

[0020] In some embodiments of the present application, the cover detection circuit includes a control unit and a second switch circuit.

[0021] One end of the cover detection switch is connected to the power supply, and the other end is connected to the control end of the second switch circuit.

[0022] One end of the switch path of the second switch circuit is grounded, the other end is connected to the DC power supply through a current limiting resistor, and the other end is connected to the detection end of the control unit.

[0023] The output end of the control unit is connected to the control end of the first switch circuit.

[0024] In some embodiments of the present application, the detection end of the control unit is grounded through a capacitor.

[0025] Based on the design of the above-mentioned safety protection circuit, the utility model provides a household equipment, including the safety protection circuit.

[0026] Compared with the prior art, the home appliance safety protection circuit and the home appliance have the advantages and positive effects that: the home appliance safety protection circuit and the home appliance are characterized by the cover opening detection switch which is opened when the cover of the home appliance is opened and closed when the cover of the home appliance is closed; the load power supply control circuit comprises an electric control switch and a first switch circuit; the electric control switch is connected in series in the load power supply circuit, and the switch path of the first switch circuit and the cover opening detection switch are connected in series in the power supply circuit of the electric control switch; the cover opening detection circuit controls the switch path of the first switch circuit to be opened when the cover opening detection switch is detected to be opened. Therefore, the home appliance safety protection circuit of the utility model will cause the power supply circuit of the electric control switch to be opened, the electric control switch to be opened, and the load power supply circuit to be opened, the load to be powered off, and the home appliance to be inoperable, thereby ensuring the safety of the home appliance and the user. Even if the cover opening detection circuit fails, the power supply circuit of the electric control switch will still be opened due to the opening of the cover opening detection switch, the load power supply circuit is ensured to be opened, the circuit safety is improved, and the technical problem of poor safety in the prior art is solved.

[0027] Other features and advantages of the present application will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0029] Figure 1 is a circuit structure schematic diagram of an embodiment of the home appliance safety protection circuit proposed by the present application;

[0030] Figure 2 is a circuit principle diagram of an embodiment of the home appliance safety protection circuit proposed by the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will combine the drawings and embodiments to make a further detailed description of the present application.

[0032] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] Example 1

[0035] The safety protection circuit for the home appliance in this embodiment includes a lid opening detection switch CN8, a load power supply control circuit, a lid opening detection circuit, etc., see [link / reference]. Figure 1 , Figure 2 As shown.

[0036] Household appliances consist of a main body and a cover. The main body has an opening, and the cover is used to either cover or expose the opening. When the cover is closed, it covers the opening; when the cover is open, it exposes the opening. The appliance can only function properly after the cover is closed.

[0037] The cover opening detection switch CN8 is open when the cover of the household appliance is opened and closed when the cover of the household appliance is closed. When the cover is open, the cover opening detection switch CN8 is open; when the cover is closed, the cover opening detection switch CN8 is closed.

[0038] The load power supply control circuit includes an electronically controlled switch K1 and a first switching circuit. The electronically controlled switch K1 is connected in series in the load's power supply circuit. The switching path of the first switching circuit and the cover-opening detection switch CN8 are connected in series in the power supply circuit of the electronically controlled switch K1. When the power supply circuit of the electronically controlled switch K1 is disconnected, the electronically controlled switch K1 is disconnected, thereby causing the load's power supply circuit to disconnect as well.

[0039] The cover opening detection circuit is used to detect the open / closed state of the cover opening detection switch CN8.

[0040] When the lid opening detection circuit detects that the lid opening detection switch CN8 is open, it controls the switching path of the first switch circuit to be disconnected.

[0041] The cover opening detection circuit controls the switch path of the first switch circuit to be closed when detecting that the cover opening detection switch CN8 is closed.

[0042] The cover opening detection switch CN8 is closed when the cover is closed. The cover opening detection circuit controls the switch path of the first switch circuit to be closed when detecting that the cover opening detection switch CN8 is closed.

[0043] The cover opening detection switch CN8 is opened when the cover is opened. The cover opening detection circuit controls the switch path of the first switch circuit to be opened when detecting that the cover opening detection switch CN8 is opened.

[0044] Since the switch path of the first switch circuit and the cover opening detection switch CN8 are connected in series in the power supply circuit of the electric control switch K1, when the switch path of the first switch circuit is opened or the cover opening detection switch CN8 is opened, the power supply circuit of the electric control switch K1 is opened, the electric control switch K1 is opened, and then the power supply circuit of the load is opened, the load is powered off, the household appliance is not operated, and the safety of the household appliance and the user is ensured.

[0045] Even if the cover opening detection circuit fails to control the first switch circuit to be opened, since the cover opening detection switch CN8 is opened, the power supply circuit of the electric control switch K1 is still opened, the load is powered off, and the safety of the circuit is improved.

[0046] The safety protection circuit of the household appliance of the embodiment is designed by using the cover opening detection switch CN8 which is opened when the cover of the household appliance is opened and closed when the cover of the household appliance is closed. The load power supply control circuit includes the electric control switch K1 and the first switch circuit. The electric control switch K1 is connected in series in the power supply circuit of the load, and the switch path of the first switch circuit and the cover opening detection switch CN8 are connected in series in the power supply circuit of the electric control switch K1. The cover opening detection circuit controls the switch path of the first switch circuit to be opened when detecting that the cover opening detection switch CN8 is opened. Therefore, the safety protection circuit of the household appliance of the embodiment causes the power supply circuit of the electric control switch K1 to be opened, the electric control switch K1 to be opened, and then the power supply circuit of the load to be opened, the load to be powered off, and the household appliance to be not operated when the switch path of the first switch circuit is opened or the cover opening detection switch CN8 is opened, thereby ensuring the safety of the household appliance and the user. Even if the cover opening detection circuit fails, since the cover opening detection switch CN8 is opened, the power supply circuit of the electric control switch K1 is still opened, the power supply circuit of the load is opened, and the safety of the circuit is improved, thereby solving the technical problem of poor safety in the prior art.

[0047] In some embodiments of the present application, the electrically controlled switch K1 is a relay; the normally open contact of the relay is connected in series in the power supply circuit of the load, and the switch path of the first switch circuit and the cover opening detection switch CN8 are connected in series in the power supply circuit of the coil of the relay.

[0048] When the switch path of the first switch circuit is disconnected or the cover opening detection switch CN8 is disconnected, the power supply circuit of the coil of the relay is disconnected, the normally open contact of the relay is disconnected, and then the power supply circuit of the load is disconnected, and the load is powered off.

[0049] By designing the electrically controlled switch K1 as a relay, it is convenient to control whether the relay is powered on or not, and whether the load is powered on or not. Moreover, the relay has stable performance, convenient control, and low cost.

[0050] In some embodiments of the present application, the control end of the first switch circuit is connected to the cover opening detection circuit; one end of the switch path of the first switch circuit is connected to the ground, and the other end of the switch path of the first switch circuit is connected to one end of the coil of the relay, and the other end of the coil is connected to the power supply (such as +12V power supply) through the cover opening detection switch CN8. The power supply is used to supply power to the coil of the relay.

[0051] When the cover is opened, the cover opening detection switch CN8 is disconnected, and the power supply circuit between the power supply and the coil of the relay is disconnected; moreover, after the cover opening detection circuit detects that the cover opening detection switch CN8 is disconnected, a turn-off signal is output to the control end of the first switch circuit, and the switch path of the first switch circuit is controlled to be turned off, further ensuring that the power supply circuit of the coil of the relay is disconnected.

[0052] When the cover is closed, the cover opening detection switch CN8 is closed, and after the cover opening detection circuit detects that the cover opening detection switch CN8 is closed, the switch path of the first switch circuit is controlled to be closed. The current provided by the power supply flows into the ground through the cover opening detection switch CN8, the coil of the relay, and the switch path of the first switch circuit, that is, the power supply circuit of the coil of the relay is turned on, the coil of the relay is powered on, and the normally open contact of the relay is closed.

[0053] By designing the connection mode of the above-mentioned first switch circuit and the coil of the relay, it is convenient to control whether the power supply circuit of the coil of the relay is turned on or not.

[0054] In some embodiments of the present application, a first diode D23 is connected in series between the cover opening detection switch CN8 and the coil of the relay.

[0055] The anode of the first diode D23 is connected to the cover opening detection switch CN8, and the cathode of the first diode D23 is connected to the coil of the relay.

[0056] When the cover detection switch CN8 is closed and the switch path of the first switch circuit is closed, the current provided by the power supply flows through the cover detection switch CN8, the first diode D23, the coil of the relay, the switch path of the first switch circuit, and then flows into the ground.

[0057] The first diode D23 is used to ensure the correct flow direction of the current, avoid backflow, and ensure the safety of the circuit.

[0058] In some embodiments of the present application, the other end of the coil of the relay is connected to the ground through the electrolytic capacitor E8 for filtering, so as to ensure that a stable voltage is provided for the coil.

[0059] In some embodiments of the present application, the second diode D5 is connected in parallel across the coil of the relay. When the coil of the relay is powered off, the second diode D5 is turned on to eliminate the reverse electromotive force generated by the coil.

[0060] In some embodiments of the present application, the normally open contact of the relay has two, one of which is connected in series in the power supply circuit between the live wire and the load, and the other is connected in series in the power supply circuit between the zero wire and the load.

[0061] When the power supply circuit of the coil is disconnected, the coil is powered off, and the two normally open contacts are disconnected, which not only disconnects the power supply circuit between the live wire and the load, but also disconnects the power supply circuit between the zero wire and the load, further ensuring the disconnection of the load power supply circuit and improving the safety.

[0062] In some embodiments of the present application, the first switch circuit includes a first switch tube N1. The first switch tube N1 is a high-conduction voltage drop switch tube. For example, the first switch tube N1 is an NPN triode.

[0063] The control end of the first switch tube N1 is connected to the cover detection circuit through the resistor R23, one end of the switch path of the first switch tube N1 is connected to the ground, the other end of the first switch tube N1 is connected to one end of the coil of the relay, the other end of the coil is connected to the cathode of the first diode D23, and the anode of the first diode D23 is connected to the power supply through the cover detection switch CN8.

[0064] By designing the first switch circuit as the first switch tube N1, the on-off control is simple, the performance is stable, and the cost is low.

[0065] In some embodiments of the present application, the cover detection circuit includes a control unit and a second switch circuit.

[0066] One end of the cover detection switch CN8 is connected to the power supply (such as a +12V power supply), and the other end of the cover detection switch CN8 is connected to the control end of the second switch circuit.

[0067] One end of the switch path of the second switch circuit is connected to ground, and the other end of the switch path of the second switch circuit is connected to a DC power supply (for example, a DC power supply of +5V) through a current-limiting resistor R87, and the other end of the switch path of the second switch circuit is connected to the detection end of the control unit.

[0068] The control unit controls the level of the output end according to the level of the detection end.

[0069] When the cover opening detection switch CN8 is closed, the current provided by the power supply is transmitted to the control end of the second switch circuit through the cover opening detection switch CN8, and the switch path of the second switch circuit is turned on; the current provided by the DC power supply flows into the ground through the current-limiting resistor R87 and the switch path of the second switch circuit, and the detection end of the control unit is pulled to a low level, and the output end of the control unit outputs a conduction signal (for example, a high level) to the control end of the first switch circuit, thereby controlling the switch path of the first switch circuit to be turned on.

[0070] When the cover opening detection switch CN8 is disconnected, the detection end of the control unit is pulled to a high level under the action of the DC power supply, and the output end of the control unit outputs an off signal (for example, a low level) to the control end of the first switch circuit, thereby controlling the switch path of the first switch circuit to be disconnected.

[0071] Therefore, the control unit can know the opening and closing state of the cover opening detection switch CN8 according to the level of the detection end, and output a conduction signal or an off signal to the first switch circuit to control the first switch circuit to be turned on or turned off.

[0072] By designing the cover opening detection circuit with the above structure, the opening and closing state of the cover opening detection switch CN8 can be detected conveniently, and the circuit structure is simple, the control is convenient, and the cost is low.

[0073] In some embodiments of the present application, the detection end of the control unit is connected to ground through a capacitor C55 to filter out noise and ensure the accuracy of detection.

[0074] In some embodiments of the present application, the second switch circuit includes a second switch tube N5. The second switch tube N5 is a high-conduction-voltage-drop switch tube. For example, the second switch tube N5 is an NPN triode.

[0075] The control end of the second switch tube N5 is connected to the other end of the cover opening detection switch CN8 through a resistor R32; one end of the switch path of the second switch tube N5 is connected to ground, and the other end of the switch path of the second switch tube N5 is connected to a DC power supply (for example, a DC power supply of +5V) through a current-limiting resistor R87, and the other end of the switch path of the second switch tube N5 is connected to the detection end of the control unit through a resistor R88.

[0076] The second switch circuit is designed as the second switch tube N5, so that the on-off control is simple, the performance is stable, and the cost is low.

[0077] The implementation principle of the safety protection circuit will be described below in combination with Figure 2

[0078] When the cover of the household appliance is opened, the cover opening detection switch CN8 is disconnected, that is, the +12V power supply is disconnected, and the +12V power supply cannot supply power to the coil of the relay. At this time, the coil of the relay is powered off, the normally open contact cannot be attracted, the power supply loop of the load is disconnected, and the load is powered off. At this time, even if the control unit controls the first switch tube N1 to be turned on, the coil of the relay is still powered off.

[0079] When the cover of the household appliance is opened, the cover opening detection switch CN8 is disconnected, and the second switch tube N5 is turned off. At this time, the control unit (MCU) detects that the sw signal is high, the MCU controls the POW_CTR to be low, and the first switch tube N1 is turned off. The coil of the relay is powered off.

[0080] When the cover of the household appliance is closed, the cover opening detection switch CN8 is closed, that is, the +12V power supply is turned on, and the second switch tube N5 is turned on. At this time, the control unit (MCU) detects that the sw signal is low, and the control unit (MCU) controls the POW_CTR to be high, so that the first switch tube N1 is turned on, the coil of the relay is powered on, the normally open contact of the relay is attracted, the power supply loop of the load is turned on, and the load is powered on.

[0081] Therefore, when the control unit (MCU) has an error, as long as the cover opening detection switch CN8 is disconnected, the load can also be guaranteed to be powered off, thereby ensuring the safety in use.

[0082] The prior art only realizes safety protection control through an MCU program. The present application proposes a new safety protection circuit, which can realize software and hardware monitoring. When the control unit (MCU) is abnormal, since the cover opening detection switch CN8 is disconnected, the load can also be guaranteed to be powered off, thereby realizing the safety protection effect. The safety protection circuit of the embodiment can reliably turn off the load when the cover is opened, thereby ensuring the safety in use of the household appliance.

[0083] Embodiment two,

[0084] Based on the safety protection circuit in embodiment one, the household appliance in embodiment two is proposed.

[0085] The household appliance in the embodiment realizes the safety protection circuit, so that the load supply is disconnected when the cover of the household appliance is opened, the safety of the household appliance is improved, and the technical problem of poor safety in the prior art is solved.​

[0086] The household device of the embodiment can be a food processor, a blender, a juicer, a dishwasher, a washing machine, etc.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features therein can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A safety protection circuit for household appliances, characterized in that: include: The cover detection switch is deactivated when the cover of the home appliance is opened and deactivated when the cover of the home appliance is closed. A load power supply control circuit includes an electronically controlled switch and a first switching circuit; the electronically controlled switch is connected in series in the power supply circuit of the load, and the switching path of the first switching circuit and the cover opening detection switch are connected in series in the power supply circuit of the electronically controlled switch. The cover opening detection circuit is used to detect the open / closed state of the cover opening detection switch. When the cover opening detection switch is detected to be open, it controls the switching path of the first switch circuit to be disconnected.

2. The safety protection circuit according to claim 1, characterized in that: The electronically controlled switch is a relay; The normally open contact of the relay is connected in series in the power supply circuit of the load; The switching path of the first switching circuit and the cover opening detection switch are connected in series in the power supply circuit of the relay coil.

3. The safety protection circuit according to claim 2, characterized in that: The control terminal of the first switching circuit is connected to the cover opening detection circuit; One end of the switching path of the first switching circuit is grounded, and the other end of the switching path of the first switching circuit is connected to one end of the coil of the relay. The other end of the coil is connected to the power supply through the cover opening detection switch.

4. The safety protection circuit according to claim 3, characterized in that: A first diode is connected in series between the cover opening detection switch and the coil.

5. The safety protection circuit according to claim 3, characterized in that: The other end of the coil is grounded through an electrolytic capacitor.

6. The safety protection circuit according to claim 2, characterized in that: A second diode is connected in parallel across the two ends of the coil.

7. The safety protection circuit according to claim 2, characterized in that: The relay has two normally open contacts, one of which is connected in series in the power supply line between the live wire and the load, and the other normally open contact is connected in series in the power supply line between the neutral wire and the load.

8. The safety protection circuit according to any one of claims 1 to 7, characterized in that: The cover opening detection circuit includes a control unit and a second switch circuit; One end of the cover opening detection switch is connected to the power supply, and the other end is connected to the control terminal of the second switch circuit; One end of the switching path of the second switching circuit is grounded, and the other end is connected to a DC power supply through a current-limiting resistor, and the other end is connected to the detection terminal of the control unit. The output terminal of the control unit is connected to the control terminal of the first switching circuit.

9. The safety protection circuit according to claim 8, characterized in that: The detection terminal of the control unit is grounded via a capacitor.

10. A household appliance, characterized in that: Includes the safety protection circuit as described in any one of claims 1 to 9.

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