CN114481551A

CN114481551A - Washing machine door detection circuit and washing machine

Info

Publication number: CN114481551A
Application number: CN202111633833.8A
Authority: CN
Inventors: 刘伟; 吕杨; 高秋英
Original assignee: Qingdao Haier Washing Electric Appliance Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Washing Electric Appliance Co Ltd; Haier Smart Home Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-05-13

Abstract

The application provides a washing machine door detection circuitry and washing machine, the circuit includes: the door control system comprises a door switch module, a control module and a detection module; the door switch module is connected with the first power supply and the control module and used for outputting a signal of the first power supply to the control module when the door switch module is closed; the control module comprises a plurality of control branches connected in parallel, each control branch comprises a first control switch, the first end of each first control switch is connected with the second power supply, the first control switches of adjacent control branches are connected end to end, the second end of each first control switch in the last control branch is connected with the detection module, and each first control branch is used for responding to a signal of the corresponding first power supply and controlling the corresponding first control switch to be switched on; the detection module is used for responding to the signal of the second power supply and outputting a first signal, and the first signal is used for indicating that the door of the washing machine is closed. Through the design of a plurality of parallel control branches, the single-point failure problem of the circuit can be effectively prevented.

Description

Washing machine door detection circuit and washing machine

Technical Field

The application belongs to the technical field of electronics, especially relates to a washing machine door detection circuitry and washing machine.

Background

The strong electric door lock or door switch of the washing machine is an important part related to the use safety of the washing machine, and the strong electric door lock or door switch is manually or automatically conducted when the door of the washing machine is closed. The washing machine door state detection is a key step for ensuring the safety of the washing machine, and when the washing machine door is detected to be safely closed, namely the strong electric door lock or the door switch is switched on, the washing machine motor can normally work.

However, in the existing washing machine door state detection scheme, if some parts in the circuit are in failure and short circuit is caused, the problem of false detection is caused, namely, the washing machine door which is not closed is identified as normally closed, so that the problem of false operation of the washing machine is caused, and potential safety hazard is formed.

Therefore, there is a need for a door status detection circuit for a washing machine that prevents a single point failure of the circuit.

Disclosure of Invention

The application provides a washing machine door detection circuit and a washing machine, which are used for solving the problem of circuit single-point failure in the washing machine door state detection process.

In a first aspect, the present application provides a washing machine door detection circuit, comprising: the door control system comprises a door switch module, a control module and a detection module; wherein,

the door switch module is connected with a first power supply and the control module and is used for outputting a signal of the first power supply to the control module when the door switch module is closed;

the control module comprises a plurality of control branches connected in parallel, wherein each control branch comprises a first control switch, a first end of each first control switch is connected with a second power supply, a second end of each first control switch in each control branch is connected with a first end of each first control switch in an adjacent control branch, a second end of each first control switch in a tail control branch is connected with the detection module, and each first control branch is used for responding to a signal of the first power supply and controlling the first control switch to be conducted;

the detection module is used for responding to the signal of the second power supply and outputting a first signal, and the first signal indicates that the door of the washing machine is closed.

Optionally, the door switch module includes: a first door switch module, the first door switch module comprising: a door switch, a first impedance and a second impedance;

the first end of the door switch is connected with a third power supply, and the second end of the door switch is connected with the first end of the first impedance and the first end of the second impedance; the second end of the first impedance is connected with the control module and the ground, and the second end of the second impedance is grounded.

Optionally, the door switch module includes: the second door switch module comprises a door lock switch, a first optical coupling module and a second optical coupling module;

the positive electrode of the transmitting end of the first optical coupling module is connected with an alternating current commercial power live wire, the negative electrode of the transmitting end of the first optical coupling module is connected with the positive electrode of the transmitting end of the second optical coupling module, the negative electrode of the transmitting end of the second optical coupling module is connected with the first end of the door lock switch, and the second end of the door lock switch is connected with an alternating current commercial power ground wire;

the positive electrode of the receiving end of the first optical coupling module is connected with a fourth power supply, the negative electrode of the receiving end of the first optical coupling module is connected with the positive electrode of the receiving end of the second optical coupling module, and the negative electrode of the receiving end of the second optical coupling module is connected with the control module.

Optionally, the second door switch module further includes: a third impedance, a first diode, a fourth impedance and a second diode;

the anode of the first diode is connected with the alternating current commercial power live wire, and the cathode of the first diode is connected with the first end of the third impedance; the second end of the third impedance is connected with the positive electrode of the transmitting end of the first optical coupling module;

a first end of the fourth impedance is connected with a negative electrode of a receiving end of the second optocoupler module, and a second end of the fourth impedance is connected with an anode of the second diode; and the cathode of the second diode is connected with the control module.

Optionally, the control branch further includes: a second control switch, a third diode, a fifth impedance and a sixth impedance;

the anode of the third diode is connected with the gate switch module, and the cathode of the third diode is connected with the first end of the fifth impedance; the second end of the fifth impedance is connected with the first end of the sixth impedance and the control end of the second control switch, and the second end of the sixth impedance is grounded;

and the first end of the second control switch is connected with the control end of the first control switch and the second power supply, and the second end of the second control switch is grounded.

Optionally, the control branch further includes: a seventh impedance and an eighth impedance;

a first end of the seventh impedance is connected with a first end of the second control switch, and a second end of the seventh impedance is connected with a control end of the first control switch and a first end of the eighth impedance; the second end of the eighth impedance is connected to the first end of the first control switch.

Optionally, the control branch further includes: a ninth impedance, a tenth impedance, and an eleventh impedance;

a first end of the ninth impedance is connected with a first end of the second control switch and a second end of the tenth impedance, and a first end of the tenth impedance is connected with the second power supply;

the second end of the ninth impedance is connected with the control end of the first control switch and the first end of the eleventh impedance, and the second end of the eleventh impedance is connected with the first end of the first control switch.

Optionally, the control module further includes: a first capacitor;

the first end of the first capacitor is connected with the anode of the third diode in each control branch, and the second end of the first capacitor is grounded.

Optionally, the detection module includes: a plurality of detection branches, the detection branches including detection switches; the control ends of the detection switches in the adjacent detection branches are connected with each other and are connected to the relay power supply;

the control end of the detection switch in the detection branch is connected with the control module, the first end of the detection switch is connected with the corresponding detection signal and the fourth power supply, and the second end of the detection switch is grounded.

Optionally, the detection branch further includes: the voltage reduction resistor, the first shunt resistor and the second shunt resistor;

the first end of the voltage reduction resistor is connected with the control module, and the second end of the voltage reduction resistor is connected with the first end of the first shunt resistor and the first end of the second shunt resistor; the second end of the first shunt resistor is connected with the control end of the detection switch; and the second end of the second shunt resistor is connected with the second end of the detection switch.

Optionally, the detection branch further includes: the second pull-up resistor, the fourth current-limiting resistor and the second capacitor;

the first end of the second pull-up resistor is connected with the fourth power supply, and the second end of the second pull-up resistor is connected with the first end of the detection switch; the first end of the fourth current limiting resistor is connected with the second end of the second pull-up resistor, the second end of the fourth current limiting resistor is connected with the first end of the second capacitor and a detection signal corresponding to the detection switch, and the second end of the second capacitor is grounded.

In a second aspect, the present application provides a washing machine comprising: a washing machine door detection circuit, a microprocessor and an overload protection module as described in the first aspect; the overload protection module comprises a protection switch and a system main relay;

the microprocessor is connected with the washing machine door detection circuit; the control end of the system main relay is connected with the first end of the protection switch, and the second end of the protection switch is grounded; and the control end of the protection switch is connected with the microprocessor.

Optionally, the overload protection module further includes a twelfth impedance and a thirteenth impedance;

the first end of the twelfth impedance is connected with the microprocessor, the second end of the twelfth impedance is connected with the control end of the protection switch and the first end of the thirteenth impedance, and the second end of the thirteenth impedance is grounded.

The application provides a washing machine door detection circuitry and washing machine, the circuit includes: the door control system comprises a door switch module, a control module and a detection module; the door switch module is connected with a first power supply and the control module and used for outputting a signal of the first power supply to the control module when the door switch module is closed; the control module comprises a plurality of control branches connected in parallel, wherein each control branch comprises a first control switch, a first end of each first control switch is connected with a second power supply, a second end of each first control switch in each control branch is connected with a first end of each first control switch in an adjacent control branch, a second end of each first control switch in a tail control branch is connected with the detection module, and each first control branch is used for responding to a signal of the first power supply and controlling the first control switch to be conducted; the detection module is used for responding to the signal of the second power supply and outputting a first signal, and the first signal indicates that the door of the washing machine is closed. The switching signals are converted and responded through the control module, the switching signals are transmitted through the detection module, the microprocessor can identify and detect the switching signals, and meanwhile, single-point failure of the circuit can be effectively prevented due to the design of a plurality of parallel control branches.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application. Embodiments of the present application are described below with reference to the accompanying drawings in conjunction with circuit structures.

FIG. 1 is a schematic diagram of an application scenario for detecting the door status of a washing machine;

fig. 2 is a schematic structural diagram of a washing machine door detection circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a washing machine door detection circuit according to a second embodiment of the present application;

fig. 4 is a schematic structural diagram of a washing machine door detection circuit according to a third embodiment of the present application;

fig. 5 is a schematic structural diagram of a door detection circuit of another washing machine according to a third embodiment of the present application;

fig. 6 is a schematic structural diagram of a washing machine door detection circuit according to a fourth embodiment of the present application;

FIG. 7 is a schematic diagram of a door detection circuit of a washing machine according to a fourth embodiment of the present application;

fig. 8 is a schematic structural diagram of a door detection circuit of another washing machine according to a fourth embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a door detection circuit of a washing machine according to a fourth embodiment of the present application;

fig. 10 is a schematic structural diagram of a washing machine door detection circuit according to a fifth embodiment of the present application;

fig. 11 is a schematic structural diagram of a door detection circuit of another washing machine according to a fifth embodiment of the present application;

fig. 12 is a schematic structural diagram of a door detection circuit of another washing machine according to a fifth embodiment of the present application;

fig. 13 is a schematic structural view of a washing machine according to a sixth embodiment of the present application;

fig. 14 is a schematic structural view of another washing machine according to a sixth embodiment of the present application;

fig. 15 is a schematic structural view of another washing machine according to a sixth embodiment of the present application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

Fig. 1 is a schematic diagram of an application scenario of detecting a door state of a washing machine, which is used to illustrate a phenomenon of detecting a door state of a washing machine by mistake due to a single point failure of a circuit.

As shown in fig. 1, 1000 is a washing machine with a door state detection function, 101 is a door cover of the washing machine, and the door cover is in an open state at the time, and theoretically, a load part such as a motor of the washing machine should not be powered at the time. 102 is a door lock or a door switch of the washing machine, 103 is a motor of the washing machine, 104 is a microprocessor of the washing machine, 105 is a state display screen of the washing machine, and the door lock or the door switch 102, the motor 103 and the state display screen 105 are all connected to the microprocessor 104. When the door cover 101 is opened, the door lock or the door switch 102 is not conducted at this time, but a short circuit phenomenon occurs due to a fault of a certain component in the processing circuit, so that the microprocessor 104 receives an erroneous 102 closing signal, sends a signal to enable the control circuit to power on the motor 103, and the state display screen 105 displays that the washing machine is in a state that the door lock is conducted and the motor is ready. At this time, due to the occurrence of a single point failure condition in the circuit, the microprocessor 104 is subjected to false detection, the loads such as the motor 103 and the like are powered on by mistake, and if the start switch is touched by mistake to cause false start, great potential safety hazard is brought. Meanwhile, 102 can be a strong current door lock or a weak current door switch, and when 102 adopts different devices, the corresponding detection circuit structures have larger differences and cannot be compatible. Therefore, it is required to design a door detection circuit of a washing machine, which is compatible with various door cover switches and can prevent the single-point failure phenomenon.

The technical means of the present application and the technical means of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. In the description of the present application, unless otherwise explicitly specified and defined, each term should be understood broadly in the art. Embodiments of the present application will be described below with reference to the accompanying drawings.

Example one

Fig. 2 is a schematic structural diagram of a washing machine door detection circuit according to an embodiment of the present invention, and as shown in fig. 2, the circuit includes: a door switch module 11, a control module 12 and a detection module 13; wherein,

the door switch module 11 is connected with the first power supply and control module 12, and is used for outputting a signal of the first power supply to the control module 12 when the door switch module 11 is closed;

the control module 12 includes a plurality of control branches connected in parallel, where the control branches include a first control switch 101, a first end of the first control switch is connected to the second power supply, a second end of the first control switch in the control branch is connected to a first end of the first control switch in an adjacent control branch, a second end of the first control switch in the last control branch is connected to the detection module, and the first control branch is configured to control the first control switch to be turned on in response to a signal of the first power supply;

and a detection module 13 for outputting a first signal in response to the signal of the second power supply, the first signal indicating that the door of the washing machine is closed.

The present embodiment is described in detail with reference to specific application scenarios: the door switch module 11 is connected to a first power supply, which may be an ac mains supply or a dc power supply for driving the door switch, so that the present application is applicable to a strong current door lock and a weak current switch. The door switch module 11 is configured to output a signal of the first power source to the control module 12 when the door switch module 11 is closed, that is, the control module 12 can receive the information that the door switch is closed.

As shown, the control module 12 comprises a plurality of parallel control branches, wherein the control branches comprise a first control switch 101. It should be noted that, in the figure, only the first control switch 101, which is a key component of the control branch, should be used together with a series of other components in practical application, otherwise the first control switch 101 may not be able to operate normally under some conditions. The first control switch 101 is typically a transistor, and a PNP transistor is illustrated as an example. The first end of the first control switch 101 is connected with the second power supply, the second end is connected with the first end of the first control switch 101 in the adjacent control branch, the first control switches 101 corresponding to the multiple parallel control branches are connected end to end according to the rule, the second end of the first control switch 101 in the tail control branch is connected with the detection module, the first control branch is used for responding to the signal of the first power supply and controlling the conduction of the first control switch 101, at the moment, the detection module 13 can respond to the signal of the second power supply and output a first signal representing the closing of the washing machine door, and the detection of the door opening and closing state is completed.

The embodiment provides a washing machine door detection circuit, including: the door control system comprises a door switch module, a control module and a detection module; the door switch module is connected with a first power supply and the control module and used for outputting a signal of the first power supply to the control module when the door switch module is closed; the control module comprises a plurality of control branches connected in parallel, wherein each control branch comprises a first control switch, a first end of each first control switch is connected with a second power supply, a second end of each first control switch in each control branch is connected with a first end of each first control switch in an adjacent control branch, a second end of each first control switch in a tail control branch is connected with the detection module, and each first control branch is used for responding to a signal of the first power supply and controlling the first control switch to be conducted; the detection module is used for responding to the signal of the second power supply and outputting a first signal, and the first signal indicates that the door of the washing machine is closed. The switching signals are converted and responded through the control module, the switching signals are transmitted through the detection module, the microprocessor can identify and detect the switching signals, and meanwhile, single-point failure of the circuit can be effectively prevented due to the design of a plurality of parallel control branches.

Example two

Fig. 3 is a schematic structural diagram of a washing machine door detection circuit according to a second embodiment of the present application, and on the basis of any other embodiment, as shown in fig. 3, a door switch module 11 specifically includes:

a first door switch module 21, the first door switch module 21 including: door switch 201, first impedance 202 and second impedance 203;

the first end of door switch 201 is connected with a third power supply, and the second end of door switch 201 is connected with the first end of first impedance 202 and the first end of second impedance 203; the second terminal of the first impedance 202 is connected to the control module 12 and ground, and the second terminal of the second impedance 203 is grounded.

The present embodiment is described in detail with reference to specific application scenarios: the first door switch module 21 is a weak current switch and the third power supply is a dc power supply, i.e. normally VCC. The third power supply may also be identical to the second power supply, but fig. 3 only shows a case where the third power supply and the second power supply are designed separately. First door switch module 21 further includes first impedance 202 and second impedance 203, the first terminal of door switch 201 is connected to the third power source, and the second terminal of door switch 201 is connected to the first terminal of first impedance 202 and the first terminal of second impedance 203; the second terminal of the first impedance 202 is connected to the control module 12 and ground, and the second terminal of the second impedance 203 is grounded. The first impedance 202 is a current limiting resistor to limit the current flowing into the control module and prevent damage to the components in the control module, and the second impedance 203 is a pull-down resistor to clamp the potential of the first end of the second impedance at a low potential when the circuit is not connected to an external power source.

The present embodiment provides a washing machine door sensing circuit, the door opening and closing module including: a first door switch module, the first door switch module comprising: a door switch, a first impedance and a second impedance; the first end of the door switch is connected with a third power supply, and the second end of the door switch is connected with the first end of the first impedance and the first end of the second impedance; the second end of the first impedance is connected with the control module and the ground, and the second end of the second impedance is grounded. Through the design of the weak current door switch module matching circuit, the control module can receive the conduction information of the door switch and the detection module can make corresponding response.

EXAMPLE III

Fig. 4 is a schematic structural diagram of a washing machine door detection circuit according to a third embodiment of the present application, and on the basis of any other embodiment, as shown in fig. 4, a door switch module 11 specifically includes:

the second door switch module 31, the second door switch module 31 includes a door lock switch 301, a first optical coupler module 302 and a second optical coupler module 303;

the anode of the transmitting end of the first optical coupling module 302 is connected with an alternating current commercial power live wire, the cathode of the transmitting end of the first optical coupling module 302 is connected with the anode of the transmitting end of the second optical coupling module 303, the cathode of the transmitting end of the second optical coupling module 303 is connected with the first end of the door lock switch 301, and the second end of the door lock switch 301 is connected with an alternating current commercial power ground wire;

the positive electrode of the receiving end of the first optical coupling module 302 is connected with a fourth power supply, the negative electrode of the receiving end of the first optical coupling module 302 is connected with the positive electrode of the receiving end of the second optical coupling module 303, and the negative electrode of the receiving end of the second optical coupling module 303 is connected with the control module.

The present embodiment is described in detail with reference to specific application scenarios: the second door switch module 31 is a switch module applied to a strong current door lock, and includes a door lock switch 301, a first optical coupler module 302 and a second optical coupler module 303, where the optical coupler module may be used for signal transmission and isolation between strong and weak current loops.

the positive electrode of the receiving end of the first optocoupler module 302 is connected with a fourth power supply, and the fourth power supply is a direct current power supply and is used for driving a phototriode to work. The negative electrode of the receiving end of the first optical coupling module 302 is connected with the positive electrode of the receiving end of the second optical coupling module 303, and the negative electrode of the receiving end of the second optical coupling module 303 is connected with the control module. It should be noted that, if only one optical coupling module is provided, a corresponding function can also be completed, and this embodiment provides an example in which two optical coupling modules are connected in series for preventing a single point of optical coupling from failing. In practical application, the number of the optocoupler modules connected in series can be selected according to requirements of parameters such as power consumption and the like.

An example, fig. 5 is a schematic structural diagram of a door detection circuit of a washing machine according to a third embodiment of the present application, and as shown in fig. 5, the second door switch module 31 further includes: a third impedance 304, a first diode 305, a fourth impedance 306, and a second diode 307;

the anode of the first diode 305 is connected to the ac power line, and the cathode is connected to the first end of the third impedance 304; a second end of the third impedance 304 is connected with the positive electrode of the transmitting end of the first optical coupler module 302;

a first end of the fourth impedance 306 is connected to a negative electrode of a receiving end of the second optical coupler module 303, and a second end of the fourth impedance 306 is connected to an anode of the second diode 307; the cathode of the second diode 307 is connected to the control module 12.

The diode is used to limit the current flowing in the loop, and the third impedance 304 and the fourth impedance 306 are current limiting resistors, which prevent the elements behind the current limiting resistors from being damaged, specifically, the third impedance 304 is used to limit the current in the strong current side loop, and the fourth impedance 306 prevents the current flowing in the control module 12 from being too large. The front and rear positions of the third impedance 304 and the first diode 305 can be exchanged and the series relation is kept; the fourth impedance 306 is the same as the second diode 307.

Example four

Fig. 6 is a schematic structural diagram of a washing machine door detection circuit according to a fourth embodiment of the present application, and on the basis of any other embodiment, as shown in fig. 6, the control branch further includes:

a second control switch 401, a third diode 402, a fifth impedance 403, and a sixth impedance 404;

the anode of the third diode 402 is connected to the gate switch module 11, and the cathode of the third diode 402 is connected to the first end of the fifth impedance 403; a second end of the fifth impedance 403 is connected to a first end of the sixth impedance 404 and a control end of the second control switch 401, and a second end of the sixth impedance 404 is grounded;

a first terminal of the second control switch 401 is connected to the control terminal of the first control switch 101 and the second power supply, and a second terminal of the second control switch 401 is grounded.

The present embodiment is described in detail with reference to specific application scenarios: fig. 6 shows the structure of only one of the control branches to illustrate the operation principle thereof, and in practical applications, each control branch may be configured to have a similar structure to prevent a single point failure phenomenon. The third diode 402 is used to limit the current from conducting in one direction, the fifth impedance 403 is used to limit the current, and the sixth impedance 404 is a pull-down resistor at the control terminal of the second control switch 401 in the control branch. The second control switch 401 may be an N-enhancement fet as shown, and the type of the second control switch is selected according to the situation in practical application.

Fig. 7 is a schematic structural diagram of a door detection circuit of a washing machine according to another embodiment of the present invention, and as shown in fig. 7, the control module 12 further includes: a first capacitor 405;

a first terminal of the first capacitor 405 is connected to the anode of the third diode 402 in each control branch, and a second terminal of the first capacitor 405 is connected to ground. The first capacitor 405 is used for delaying the turn-off of the second control switch 401, and preventing the damage of the control branch components caused by the sudden change of voltage.

An example, fig. 8 is a schematic structural diagram of a door detection circuit of a washing machine according to a fourth embodiment of the present application, and as shown in fig. 8, the control branch further includes:

a seventh impedance 406 and an eighth impedance 407;

a first end of the seventh impedance 406 is connected to a first end of the second control switch 401, and a second end of the seventh impedance 406 is connected to a control end of the first control switch 101 and a first end of the eighth impedance 407; a second terminal of the eighth impedance 407 is connected to a first terminal of the first control switch 101. The seventh impedance 406 is a bias resistor for providing a bias current for the first control switch to normally operate, and the eighth impedance 407 is a load resistor for implementing a voltage amplification function. The embodiment is used for the first control branch in the parallel control branches, that is, the first end of the first control switch corresponding to the branch is directly connected with the power supply, rather than the second ends of other first control switches.

An example, fig. 9 is a schematic structural diagram of a door detection circuit of a washing machine according to a fourth embodiment of the present application, and as shown in fig. 9, the control branch further includes:

a ninth impedance 408, a tenth impedance 409, and an eleventh impedance 410;

a first end of the ninth impedance 408 is connected to a first end of the second control switch 401 and a second end of the tenth impedance 409, and a first end of the tenth impedance 409 is connected to the second power supply;

a second terminal of the ninth impedance 408 is connected to the control terminal of the first control switch 101 and a first terminal of the eleventh impedance 410, and a second terminal of the eleventh impedance 410 is connected to the first terminal of the first control switch 101.

Accordingly, the ninth impedance 408 functions similarly to the seventh impedance 406 in the previous embodiment, the eleventh impedance 410 functions similarly to the eighth impedance 407 in the previous embodiment, and the tenth impedance 409 serves as a pull-up resistor at the first end of the second control switch 401. This embodiment shows a possible scheme except for the first control branch among a plurality of parallel control branches, and the structure of the last control branch is shown in the figure, and in fact, if there are more than two parallel control branches, the structure may be applied to other control branches except for the uppermost control branch as described in the above embodiment.

The present embodiment provides a washing machine door detection circuit, wherein the control branch further comprises: a second control switch, a third diode, a fifth impedance and a sixth impedance; the anode of the third diode is connected with the gate switch module, and the cathode of the third diode is connected with the first end of the fifth impedance; the second end of the fifth impedance is connected with the first end of the sixth impedance and the control end of the second control switch, and the second end of the sixth impedance is grounded; and the first end of the second control switch is connected with the control end of the first control switch and the second power supply, and the second end of the second control switch is grounded. The single-point failure prevention function of the washing machine door detection circuit can be realized through the design of a plurality of parallel control branches with two control switches.

EXAMPLE five

Fig. 10 is a schematic structural diagram of a washing machine door detection circuit according to a fifth embodiment of the present application, and based on any other embodiment, as shown in fig. 10, the detection module 13 includes: a plurality of detection branches, including detection switch 501; control ends of the detection switches 501 in the adjacent detection branches are connected with each other and connected to the relay power supply;

the control end of the detection switch 501 in the detection branch is connected with the control module 12, the first end of the detection switch 501 is connected with the corresponding detection signal and the fourth power supply, and the second end of the detection switch 501 is grounded.

The present embodiment is described in detail with reference to specific application scenarios: the detection module 13 includes a plurality of detection branches, the detection branches include detection switches 501, an embodiment of a dual detection branch is shown in the figure, two detection switches are respectively connected to two paths of detection signals, which are actually different pins of the microprocessor, and the fourth power supply supplies power to the microprocessor at the same time. The relay power source is a network symbol for indicating the information output by the control module. The detection switch 501 is an NPN-type transistor in this embodiment, and the type selection should be performed according to specific situations in actual application.

Fig. 11 is a schematic structural diagram of a door detection circuit of a washing machine according to a fifth embodiment of the present invention, and as shown in fig. 11, the detection branch further includes: a voltage-reducing resistor 502, a first shunt resistor 503, and a second shunt resistor 504;

a first end of the voltage-reducing resistor 502 is connected with the control module 12, and a second end of the voltage-reducing resistor 502 is connected with a first end of the first shunt resistor 503 and a first end of the second shunt resistor 504; a second end of the first shunt resistor 503 is connected to a control end of the detection switch 501; a second terminal of second shunt resistor 504 is connected to a second terminal of detection switch 501. The voltage reduction resistor 502, the first shunt resistor 503 and the second shunt resistor 504 have the function of ensuring that the signals output by the control module do not damage the components in the detection module, and the detection switch 501 can work normally. The figure shows the structure of only one detection branch, which can be used for all detection branches in the application.

Fig. 12 is a schematic structural diagram of a door detection circuit of a washing machine according to a fifth embodiment of the present invention, and as shown in fig. 12, the detection branch further includes: a second pull-up resistor 505, a fourth current-limiting resistor 506, and a second capacitor 507;

a first end of the second pull-up resistor 505 is connected to the fourth power supply, and a second end of the second pull-up resistor 505 is connected to a first end of the detection switch 501, and is used for limiting a high potential of the first end of the detection switch 501; a first end of the fourth current limiting resistor 506 is connected to a second end of the second pull-up resistor 505, a second end of the fourth current limiting resistor 506 is connected to a first end of the second capacitor 507 and a detection signal corresponding to the detection switch 501, a second end of the second capacitor 507 is grounded, and the fourth current limiting resistor 506 is used for limiting an electrical signal input to the microprocessor and forms a filter circuit with the second capacitor 507. The figure shows the structure of only one detection branch, which can be used for all detection branches in the application.

The embodiment provides a washing machine door detection circuit, the detection module comprises: a plurality of detection branches, the detection branches including detection switches; control ends of the detection switches in the adjacent detection branches are connected with each other and connected to the relay power supply; the control end of the detection switch in the detection branch is connected with the control module, the first end of the detection switch is connected with the corresponding detection signal and the fourth power supply, and the second end of the detection switch is grounded. Through the design of a plurality of detection branches, the single-point failure prevention function on the detection branch is realized.

EXAMPLE six

Fig. 13 is a schematic structural diagram of a washing machine according to a sixth embodiment of the present application, and based on any other embodiment, as shown in fig. 13, the washing machine includes a washing machine door detection circuit, a microprocessor 61, and an overload protection module 62 as described above; the overload protection module comprises a protection switch 601 and a system main relay 602;

the microprocessor 61 is connected with the washing machine door detection circuit; the control end of the system main relay 602 is connected with the first end of the protection switch 601, and the second end of the protection switch 601 is grounded; the control terminal of the protection switch 601 is connected to the microprocessor 61. The protective switch can be a triode, the system main relay is used for executing actions and controlling loads such as a motor and the like in the washing machine, and the microprocessor can control the main relay to act after receiving a switch normal closing signal transmitted by the detection module.

Fig. 14 is a schematic structural diagram of another washing machine according to a sixth embodiment of the present invention, and as shown in fig. 14, the overload protection module 62 further includes a twelfth impedance 603 and a thirteenth impedance 604;

a first terminal of the twelfth impedance 603 is connected to the microprocessor 61, a second terminal of the twelfth impedance 603 is connected to the control terminal of the protection switch 601 and a first terminal of the thirteenth impedance 604, and a second terminal of the thirteenth impedance 604 is connected to ground. Similar to the previous embodiment, the twelfth impedance 603 is used for current limiting and the thirteenth impedance 604 is used for pull down.

Fig. 15 is a schematic structural diagram of another washing machine according to a sixth embodiment of the present disclosure, and as shown in fig. 15, the washing machine is an example combining various embodiments.

(1) When the system is connected with the electric door lock

SW2 is the internal switch of strong electric door lock, after the door lock is closed, SW2 is closed. And the live wire L returns to the neutral wire N through a diode D2, a resistor R11, an optical coupler O1, O2 and SW 2. After the optical coupler is conducted, VCC charges a capacitor C3 through the optical coupler, a resistor R17 and a diode D3. At this time, MOS1 and MOS2 are turned on, and Q2 and Q3 are turned on. At this time, VCC _ relay is powered, and provides power for the system main relay, and makes Q1 and Q4 conduct, and the main chip detects the door lock signal, carries out corresponding action.

When the door lock is opened, SW2 is opened, MOS1 and MOS2 are cut off after the C3 capacitor is discharged, and Q2 and Q3 are cut off. VCC _ relay is powered off, a system main relay is powered off, all loads are cut off, and the purpose of opening and closing the loads by the door is achieved.

(2) When the system is connected with the weak current switch

SW1 is a door switch, and SW1 is closed when the door switch is closed. VCC passes through resistors R8, D1 and D4 via SW1, at which time MOS1 and MOS2 are turned on and Q2 and Q3 are turned on. At this time, VCC _ relay is powered, and provides power for the system main relay, and makes Q1 and Q4 conduct, and the main chip detects the door lock signal, carries out corresponding action.

When gate switch SW1 is turned off, MOS1 and MOS2 are turned off, and Q2 and Q3 are turned off after C3 capacitor finishes discharging. VCC _ relay is powered off, a system main relay is powered off, all loads are cut off, and the purpose of opening and closing the loads by the door is achieved.

In the embodiment, the MOS tube and the triode are designed in a double-path mode so as to prevent a single-point failure fault when the door lock or the door switch is disconnected. For example, point H and point I are shown shorted, and although VCC reaches point I, the door lock is open and Q3 cannot conduct, thereby avoiding the potential false detection problem of the circuit when Q2 fails.

The embodiment provides a washing machine including: the washing machine door detection circuit, the microprocessor and the overload protection module according to any embodiment; the overload protection module comprises a protection switch and a system main relay; the microprocessor is connected with the washing machine door detection circuit; the control end of the system main relay is connected with the first end of the protection switch, and the second end of the protection switch is grounded; and the control end of the protection switch is connected with the microprocessor. The system main relay is connected with the load, and the on-off of the system main relay is controlled by the protection switch, so that the single-point failure prevention function of the washing machine door detection circuit can be realized in an actual application scene.

So far, the technical solutions of the present application have been described with reference to the embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present application is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the present application, and the technical scheme after the changes or substitutions will fall into the protection scope of the present application.

Claims

1. A washing machine door detection circuit, comprising: the door control system comprises a door switch module, a control module and a detection module; wherein,

2. The circuit of claim 1, wherein the door switch module comprises: a first door switch module, the first door switch module comprising: a door switch, a first impedance and a second impedance;

3. The circuit of claim 1, wherein the door switch module comprises: the second door switch module comprises a door lock switch, a first optical coupling module and a second optical coupling module;

4. The circuit of claim 3, wherein the second door switch module further comprises: a third impedance, a first diode, a fourth impedance and a second diode;

5. The circuit of claim 1, wherein the control branch further comprises: a second control switch, a third diode, a fifth impedance and a sixth impedance;

6. The circuit of claim 5, wherein the control branch further comprises: a seventh impedance and an eighth impedance;

7. The circuit of claim 5, wherein the control branch further comprises: a ninth impedance, a tenth impedance, and an eleventh impedance;

8. The circuit of claim 5, wherein the control module further comprises: a first capacitor;

9. The circuit of any one of claims 1-8, wherein the detection module comprises: a plurality of detection branches, the detection branches including detection switches; the control ends of the detection switches in the adjacent detection branches are connected with each other and are connected to the relay power supply;

10. The circuit of claim 9, wherein the detection branch further comprises: the voltage reduction resistor, the first shunt resistor and the second shunt resistor;

11. The circuit of claim 9, wherein the detection branch further comprises: the second pull-up resistor, the fourth current-limiting resistor and the second capacitor;

12. A washing machine, characterized by comprising: the washing machine door detection circuit, microprocessor and overload protection module of claims 1-10; the overload protection module comprises a protection switch and a system main relay;

13. The circuit of claim 12, wherein the overload protection module further comprises a twelfth impedance and a thirteenth impedance;