A strong current detection circuit, a door switch and a power-off memory multiplexing detection method

Abstract

The application relates to a strong current detection circuit, belonging to the technical field of dishwashers. The application comprises a door switch, a conduction and cutoff module, an optical coupling detection module, an upper pull circuit module and a detection port. The optical coupling detection module is electrically connected with the conduction and cutoff module and the upper pull circuit module, and is electrically connected with the door switch through the conduction and cutoff module. The detection port is electrically connected with the upper pull circuit module. The door switch is electrically connected with commercial power, and is used for controlling the connection and disconnection of the commercial power. The optical coupling detection module makes the output end thereof connected and disconnected according to the conduction and cutoff of the conduction and cutoff module. The detection port obtains a pulse level according to the connection and disconnection of the optical coupling detection module and the upper pull of the upper pull circuit module, so as to realize the detection of the door switch and power-off memory multiplexing. The detection port is used for the detection of the door switch and power-off memory, the use amount of chip ports is saved, the program overhead of chip operation is reduced, the stability of the dishwasher operation is improved, and the dishwasher is prevented from being stuck and the keys from being out of order in long-term use.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dishwashers, and particularly relates to a strong current detection circuit, a door switch and a power-off memory multiplexing detection method. BACKGROUND

[0002] Most dishwashers on the market are provided with power-off memory and door switch detection functions.

[0003] Power-off memory function: when power-off occurs during the washing process, the current running parameters can be recorded in the memory chip, and when the dishwasher is powered on again, the recorded parameters before power-off can be read to restore the running parameters before power-off, so that the dishwasher can continue to run; the running parameters involved include washing remaining time, washing steps, washing stages and the like.

[0004] Door switch detection: during the washing process, if the user opens the door of the dishwasher, the washing is paused, and the washing can be continued after the door of the dishwasher is closed.

[0005] The power-off memory and door switch detection functions of the dishwasher on the market are independent of each other and have independent circuits. The power-off memory uses the voltage comparator port of the chip, and the door switch detection uses the door switch detection port (i.e. a general I / O port). When used, the following problems exist:

[0006] (1) The voltage comparator port and the door switch detection port of the chip need to be used at the same time, and the I / O port of the chip is large in overhead;

[0007] (2) The interrupt response of the voltage comparator must be opened to reduce the resource overhead of the chip;

[0008] (3) The voltage comparator is used to respond to power-off, and the sensitivity is limited to several voltage values set in the chip.

[0009] Therefore, a new scheme needs to be proposed to solve the above problems. SUMMARY

[0010] The application mainly solves the technical problems of the prior art, and provides a strong current detection circuit and a door switch and power-off memory multiplexing detection method.

[0011] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: a high-voltage detection circuit, including a door switch, a conduction-to-cutoff module, an optocoupler detection module, a pull-up circuit module, and a detection port. The optocoupler detection module is electrically connected to the conduction-to-cutoff module and the pull-up circuit module, and is electrically connected to the door switch through the conduction-to-cutoff module. The detection port is electrically connected to the pull-up circuit module. The door switch is electrically connected to the mains power supply and is used to control the connection and disconnection of the mains power supply. The optocoupler detection module connects and disconnects its output terminal according to the conduction and cutoff of the conduction-to-cutoff module. The detection port obtains pulse levels according to the connection and disconnection of the optocoupler detection module and the pull-up restraint of the pull-up circuit module for door switch and power-off memory multiplexing detection.

[0012] Preferably, the conduction-off module includes resistors R23, R26, R29 and diode D1. Resistors R23, R26 and R29 are connected in series. One end of resistor R23 is connected to the door switch, one end of resistor R29 is connected to the positive terminal of diode D1, and the negative terminal of diode D1 is connected to port A of optocoupler IC3 in the optocoupler detection module.

[0013] Preferably, the pull-up circuit module includes resistors R24, R25, R27, R32, and transistor Q1. One end of resistor R24 ​​is connected to one end of resistor R25, and their common connection terminal is connected to a 5V voltage. The other end of resistor R24 ​​is connected to port C of optocoupler IC3 in the optocoupler detection module. The other end of resistor R25 is connected to one end of resistor R27 and the collector of transistor Q1. The other end of resistor R27 is connected to the detection port. The base of transistor Q1 is connected to one end of resistor R32. The other end of resistor R32 is connected to port E of optocoupler IC3 in the optocoupler detection module. The emitter of transistor Q1 is grounded.

[0014] The present invention also provides a door switch and power-down memory reuse detection method for a high-voltage detection circuit, including an interrupt detection method and a main loop detection method;

[0015] The interruption detection method includes the following steps:

[0016] A 1-millisecond reference timer detects the level of the detection port. If the level of the detection port is low (0), the variable A is decremented; if the level of the detection port is high (1), the variable A remains unchanged and is not decremented. Variable A is the count value of the door switch.

[0017] The main loop detection method includes the following steps:

[0018] Step 1: Every second, scan whether variable A is less than 10, and every 100 milliseconds, reload variable A with a value of 100.

[0019] Step 2: Check again whether variable A is less than 10. If variable A is less than 10, it can be identified that there is mains power and the door switch is closed. If variable A is greater than or equal to 10, it can be identified that there is no mains power or the door switch is open. In this state, the current washing state is saved. When there is mains power and the door switch is closed, the washing will continue to work in the current state.

[0020] The beneficial effects of this invention are as follows: This invention utilizes a detection port for door opening / closing and power-off memory detection, which saves on the number of chip ports used, reduces the program overhead of chip operation, improves the stability of dishwasher operation, and prevents the dishwasher from freezing or malfunctioning buttons during long-term use. Attached Figure Description

[0021] Figure 1 This is a circuit structure block diagram of the high-voltage detection circuit of the present invention;

[0022] Figure 2 This is a circuit diagram of the high-voltage detection circuit of the present invention;

[0023] Figure 3 This is a flowchart illustrating a door switch and power-off memory reuse detection method for a high-voltage detection circuit according to the present invention.

[0024] In the diagram: 1. Door switch; 2. On / off module; 3. Optocoupler detection module; 4. Pull-up circuit module; 5. Detection port. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0026] Example: A high-voltage detection circuit, such as Figure 1 , Figure 2 As shown, the device includes a door switch 1, a conduction-to-cutoff module 2, an optocoupler detection module 3, a pull-up circuit module 4, and a detection port 5. The optocoupler detection module 3 is electrically connected to the conduction-to-cutoff module 2 and the pull-up circuit module 4, and is also electrically connected to the door switch 1 through the conduction-to-cutoff module 2. The detection port 5 is electrically connected to the pull-up circuit module 4. The door switch 1 is electrically connected to the mains power supply and is used to control the connection and disconnection of the mains power. The optocoupler detection module 3 connects and disconnects its output terminal according to the conduction and cutoff of the conduction-to-cutoff module 2. The detection port 5 obtains pulse levels based on the connection and disconnection of the optocoupler detection module 3 and the pull-up restraint of the pull-up circuit module 4 for the detection of the door switch 1 and the power-off memory multiplexing.

[0027] The conduction / cutoff module 2 includes resistors R23, R26, and R29, and diode D1. Resistors R23, R26, and R29 are connected in series. One end of resistor R23 is connected to one end of door switch 1, and the other end of door switch 1 is connected to the live power wire. One end of resistor R29 is connected to the anode of diode D1, and the cathode of diode D1 is connected to port A of optocoupler IC3 in optocoupler detection module 3. Resistors R23, R26, and R29 work together to divide the voltage. Preferably, the resistance values ​​of resistors R23, R26, and R29 are all 510K ohms.

[0028] The pull-up circuit module 4 includes resistors R24, R25, R27, R32, and transistor Q1. One end of resistor R24 ​​is connected to one end of resistor R25, and their common connection terminal is connected to a 5V voltage. The other end of resistor R24 ​​is connected to port C of the optocoupler IC3 in the optocoupler detection module 3. The other end of resistor R25 is connected to one end of resistor R27 and the collector of transistor Q1. The other end of resistor R27 is connected to detection port 5, which serves as both a gate detection port and a power-down detection port. The base of transistor Q1 is connected to one end of resistor R32, and the other end of resistor R32 is connected to port E of the optocoupler IC3 in the optocoupler detection module 3. The emitter of transistor Q1 is grounded.

[0029] The optocoupler detection module 3 includes an optocoupler IC3, a resistor R31, and a diode D7. The optocoupler IC3 is a PC817. Ports A and K are located on the light-emitting side of the optocoupler IC3, and ports C and E are located on the sensing side of the optocoupler IC3. Diode D7 and resistor R31 are connected in parallel to ports A and K of the optocoupler IC3. Port K of the optocoupler IC3 is connected to the power supply neutral wire.

[0030] In use, connect to 220V AC power via the live wire and neutral wire. Since AC power is 50Hz, the voltage waveform includes a positive half-cycle and a negative half-cycle. During the positive half-cycle, the voltage enters the optocoupler IC3 through diode D1, exciting the light-emitting side of the optocoupler IC3, thereby triggering the optocoupler IC3 to conduct on its sensing side, i.e., connecting ports C and E, turning on transistor Q1, thus pulling down the detection port 5, which is pulled up to 5V, to 0V. During the negative half-cycle, since diode D1 is cut off, optocoupler IC3 cannot be excited, and ports C and E of optocoupler IC3 are disconnected, causing transistor Q1 to disconnect, thus pulling up the detection port 5, which is pulled up to 5V, to 5V.

[0031] When the aforementioned high-voltage detection circuit is connected to mains power, detection port 5 displays a square wave waveform, which is a 50Hz pulse level with varying high and low frequencies. When the mains power is off, detection port 5 remains at a constant 5V high level. Utilizing this characteristic, the number of pulses can be detected through detection port 5 (the chip's I / O port) to identify the presence or absence of mains power. If a power outage occurs, no pulse count can be detected, indicating a power failure. Simultaneously, by connecting door switch 1 in series, the open / closed state of door switch 1 can be detected. If door switch 1 is closed, mains power can enter optocoupler IC3, activating it; if door switch 1 is open, mains power cannot enter optocoupler IC3, preventing activation and thus the generation of a 50Hz pulse. By identifying the presence or absence of pulses, the open / closed state of door switch 1 can be determined.

[0032] Meanwhile, since the 5V voltage will remain stable after the mains power is connected, when the power suddenly fails, the detection port 5 will still be at a high level because there is still residual current in the front end of the circuit. Although there is no AC power at this time, the detection port 5 will be pulled low. After the power in the circuit is consumed, the power failure memory can be executed to save the parameters of the dishwasher's current operation, such as the remaining washing time, washing steps, and washing stages. After the mains power is restored and the dishwasher is powered on again, the saved operating parameters can be called to allow the dishwasher to continue washing in the state before the power failure.

[0033] like Figure 3 As shown, the present invention also provides a door switch 1 for a high-voltage detection circuit and a power-down memory reuse detection method, including an interrupt detection method and a main loop detection method;

[0034] The interruption detection method includes the following steps:

[0035] A 1-millisecond reference timer detects the level of detection port 5. If the level of detection port 5 is low (0), the variable A is decremented; if the level of detection port 5 is high (1), the variable A remains unchanged and is not decremented. Variable A is the count value of door switch 1.

[0036] The main loop detection method includes the following steps:

[0037] Step 1: Every second, scan whether variable A is less than 10, and every 100 milliseconds, reload variable A with a value of 100.

[0038] From the 50Hz pulse level mentioned above, we can derive a characteristic: every 10 milliseconds, there will be a negative half-cycle of low level. Within these 10 milliseconds, variable A can be decremented 10 times. Therefore, within 1 second, there are a total of 500ms of low level, so variable A will definitely decrement and will be <10.

[0039] Step 2: Determine again whether variable A is <10. If variable A is <10, it can be identified that there is mains power and door switch 1 is closed. If variable A is ≥10, it means that there is no negative half cycle of mains power within 1 second, which means that there is no mains power or door switch 1 is open. It can be identified that the mains power is off and door switch 1 is open.

[0040] The interrupt detection method is used to determine if a low level occurs at detection port 5. If so, the variable A is decremented. The main loop detection method is used to assign a value to variable A at intervals, and the state of door switch 1 is determined by judging the value of variable A. When door switch 1 is detected as open, it means that door switch 1 is open, and the dishwasher pauses washing. When a power failure or door switch 1 is detected, since there is still residual current in the front end of the circuit, power failure memory can be executed during this period to save the parameters of the dishwasher's current operation.

[0041] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. A door switch and power-off memory reuse detection method for a high-voltage detection circuit, wherein the high-voltage detection circuit includes a door switch (1), a conduction-to-cutoff module (2), an optocoupler detection module (3), a pull-up circuit module (4), and a detection port (5), wherein the optocoupler detection module (3) is electrically connected to the conduction-to-cutoff module (2) and the pull-up circuit module (4), and is electrically connected to the door switch (1) through the conduction-to-cutoff module (2); the detection port (5) is electrically connected to the pull-up circuit module (4); the door switch (1) is electrically connected to the mains power supply and is used to control the connection and disconnection of the mains power supply; the optocoupler detection module (3) connects and disconnects its output terminal according to the conduction and cutoff of the conduction-to-cutoff module (2); the detection port (5) obtains pulse levels according to the connection and disconnection of the optocoupler detection module (3) and the pull-up restraint of the pull-up circuit module (4) for the detection of the door switch (1) and power-off memory reuse, characterized in that, The method includes an interruption detection method and a main loop detection method; The interruption detection method includes the following steps: A 1-millisecond reference timer detects the level of the detection port (5). If the level of the detection port (5) is low (0), the variable A is decremented. If the level of the detection port (5) is high (1), the variable A remains unchanged and is not decremented. The variable A is the count value of the door switch (1). The main loop detection method includes the following steps: Step 1: Every second, scan whether variable A is less than 10, and every 100 milliseconds, reload variable A with a value of 100. Based on a 50Hz mains power supply, a negative half-cycle of low level will appear every 10 milliseconds. Within these 10 milliseconds, variable A is decremented 10 times. Therefore, there are a total of 500ms of low level in 1 second, so variable A will definitely decrement and will be less than 10. Step 2, check again whether variable A is <10. If variable A is <10, it is identified that there is mains power and the door switch (1) is closed. If variable A≥10, it indicates that there is no negative half cycle of mains power within 1 second, and it is identified as no mains power or door switch (1) is open. In this state, the current washing state is saved. When there is mains power and door switch (1) is closed, the current washing state is continued to work. The interrupt detection method is used to determine whether there is a low level at the detection port (5). If there is, the variable A is decremented. The main loop detection method is used to assign a value to the variable A at intervals and to determine the state of the door switch (1) by judging the value of the variable A.

2. The door switch and power-off memory reuse detection method for a high-voltage detection circuit according to claim 1, characterized in that, The conduction and cutoff module (2) includes resistors R23, R26, R29 and diode D1. Resistors R23, R26 and R29 are connected in series. One end of resistor R23 is connected to the door switch (1), one end of resistor R29 is connected to the positive terminal of diode D1, and the negative terminal of diode D1 is connected to port A of optocoupler IC3 in optocoupler detection module (3).

3. The door switch and power-off memory reuse detection method for a high-voltage detection circuit according to claim 1, characterized in that, The pull-up circuit module (4) includes resistors R24, R25, R27, R32 and transistor Q1. One end of resistor R24 ​​is connected to one end of resistor R25, and its common connection terminal is connected to a 5V voltage. The other end of resistor R24 ​​is connected to port C of optocoupler IC3 in optocoupler detection module (3). The other end of resistor R25 is connected to one end of resistor R27 and the collector of transistor Q1. The other end of resistor R27 is connected to detection port (5). The base of transistor Q1 is connected to one end of resistor R32. The other end of resistor R32 is connected to port E of optocoupler IC3 in optocoupler detection module (3). The emitter of transistor Q1 is grounded.

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