Residual voltage control method and circuit and household appliance using same

文档序号:1640752 发布日期:2019-12-20 浏览:14次 中文

阅读说明:本技术 残余电压的控制方法、电路及使用该方法的家用电器 (Residual voltage control method and circuit and household appliance using same ) 是由 曾彬 刘礼发 李桂荣 于 2018-06-12 设计创作,主要内容包括:本申请提供一种残余电压的控制方法,将跨接在火线或零线与地线之间的Y电容与一电子开关串联,该电子开关设置为处于导通状态;当系统掉电后,令该电子开关断开,切断连接该Y电容的火线或零线对地的回路。本申请还提供相应的残余电压的控制电路及使用该方法的家用电器。本申请通过增设一电子开关,能够在系统掉电后,断开回路,使连接该Y电容的火线或零线与地线之间的残余电压满足国标GB4706.1的要求。(The application provides a residual voltage control method, a Y capacitor bridged between a live wire or a zero line and a ground wire is connected in series with an electronic switch, and the electronic switch is set to be in a conducting state; when the system is powered down, the electronic switch is turned off to cut off the loop of the live wire or the zero wire of the Y capacitor to the ground. The application also provides a corresponding residual voltage control circuit and a household appliance using the method. This application can be after the system falls the electricity, the disconnection return circuit through addding an electronic switch, makes the residual voltage between live wire or the zero line of connecting this Y electric capacity and the ground wire satisfy national standard GB 4706.1's requirement.)

1. A method for controlling residual voltage, comprising: connecting a Y capacitor bridged between a live wire or a zero line and a ground wire in series with an electronic switch, wherein the electronic switch is set to be in a conducting state; when the system is powered down, the electronic switch is turned off to cut off the loop of the live wire or the zero wire of the Y capacitor to the ground.

2. A method of controlling a residual voltage according to claim 1, characterized by: the electronic switch is connected between the Y capacitor and the ground wire in series, and when the system is powered off, the electronic switch cuts off the connection between the Y capacitor and the ground wire.

3. A method of controlling a residual voltage according to claim 1, characterized by: the electronic switch is connected between the Y capacitor and the live wire or the zero line in series, and when the system is powered off, the electronic switch cuts off the connection between the Y capacitor and the live wire or the zero line.

4. A method of controlling a residual voltage according to claim 1, characterized by: when the system is powered off, the power failure detection module detects the power failure and sends a power failure signal to the control chip, and the control chip controls the electronic switch to be switched off.

5. A method of controlling a residual voltage according to claim 1, characterized by: the electronic switch is a photoelectric coupler, a relay or silicon-controlled switch.

6. A residual voltage control circuit comprises a Y capacitor and a control chip, wherein the Y capacitor and the control chip are bridged between a live wire or a zero wire and a ground wire, and the residual voltage control circuit is characterized in that: and an electronic switch connected with the Y capacitor in series is also arranged, is set to be in a conducting state and is controlled by the control chip to be disconnected when the system is powered down.

7. A control circuit for a residual voltage according to claim 6, characterized in that: one end of the electronic switch is connected with the Y capacitor, and the other end is grounded.

8. A control circuit for a residual voltage according to claim 6, characterized in that: the circuit is provided with two Y capacitors which are respectively bridged between a live wire and a ground wire and between a zero line and the ground wire.

9. A control circuit for a residual voltage according to claim 8, characterized in that: one end of the electronic switch is simultaneously connected with the two Y capacitors, and the other end of the electronic switch is grounded.

10. A control circuit for a residual voltage of claim 8, wherein: the electronic switch comprises two electronic switches, wherein one electronic switch is connected between a Y capacitor connected with a live wire and the live wire in series, and the other electronic switch is connected between the Y capacitor connected with a zero wire and the zero wire in series.

11. A household appliance, characterized by: the household appliance uses the control method of the residual voltage according to any one of claims 1 to 5.

Technical Field

The application relates to a control method and a control circuit of residual voltage of a household appliance and the household appliance using the control method.

Background

The current national standard requires the residual voltage of household appliances as follows: the power supply is powered by a rated voltage, the power supply is disconnected at the peak of the voltage, and the voltage between the pins of the plug is measured at 1S after disconnection, wherein the voltage should not exceed 34V. The existing household electrical appliance generally starts to discharge automatically by a bleeder resistor at the moment of power failure of the product; or the power failure detection module detects that the plug is unplugged, the load loop is immediately connected to discharge the residual voltage of the capacitor, and therefore the purpose of reducing the voltage between the pins is achieved. The method accelerates current consumption by conducting the bleeder circuit, and can quickly reduce the residual voltage between the L pin (live wire pin) and the N pin (zero wire pin) to be below a safety value.

But the method has no obvious improvement effect on L feet to the ground and N feet to the ground. After analysis and verification, the reason causing the residual voltage of the L pin to the ground and the N pin to the ground to be higher is Y capacitance. In household electrical appliances, the EMC filter is generally connected to Y capacitors, usually 2, with one pin connected to L line (live line) or N line (neutral line) and one pin connected to ground line. After power failure, the Y capacitor still discharges to the L line or the N line and the ground line loop continuously, and due to the particularity and safety of the loop, a discharge resistor cannot be added between the phase line and the ground, and the discharge loop has no obvious effect on the circuit by conducting the load.

In view of the above problems, it is desirable to provide a new method for controlling the residual voltage.

Disclosure of Invention

The application provides a control method for residual voltage caused by a Y capacitor and a household appliance using the same.

Specifically, the method is realized through the following technical scheme: a control method of residual voltage, connect the Y capacitor bridging between live wire or zero line and earth wire in series with an electronic switch, the electronic switch sets up to be in the conducting state; when the system is powered down, the electronic switch is turned off to cut off the loop of the live wire or the zero wire of the Y capacitor to the ground. According to the control method, the electronic switch is additionally arranged, a loop of the live wire or the zero wire connected with the Y capacitor to the ground can be cut off after power failure, and the residual voltage between the live wire or the zero wire connected with the Y capacitor and the ground is measured to be lower than 10V and far lower than 34V at the moment because the loop is cut off, so that the requirement of national standard GB4706.1 is met.

According to one embodiment of the present application, the electronic switch is connected in series between the Y capacitor and ground, and the electronic switch disconnects the Y capacitor from ground when the system is powered down.

According to one embodiment of the application, the electronic switch is connected in series between the Y capacitor and the live or neutral wire, and the electronic switch disconnects the Y capacitor from the live or neutral wire when the system is powered down.

According to one embodiment of the application, after the system is powered off, the power failure is detected through the power failure detection module, a power failure signal is sent to the control chip, and the control chip controls the electronic switch to be switched off. This application detects the power failure through power failure detection module to and this electronic switch of disconnection in time.

According to one embodiment of the present application, the electronic switch is a photo coupler, a relay, or thyristor. The electronic switch can select various existing types of electronic switches.

The application also provides the following technical scheme: a residual voltage control circuit comprises a Y capacitor and a control chip, wherein the Y capacitor and the control chip are bridged between a live wire or a zero wire and a ground wire, an electronic switch is connected with the Y capacitor in series, the electronic switch is set to be in a conducting state, and the electronic switch is controlled by the control chip and is disconnected when a system is powered off. This application control circuit can be after falling the power supply, the return circuit of live wire or zero line to ground of cutting off connection this Y electric capacity through addding an electronic switch, because the return circuit has been broken off, goes to measure the residual voltage between live wire or zero line and the ground wire of connecting this Y electric capacity this moment and is less than 10V, is far less than 34V, satisfies national standard GB 4706.1's requirement.

According to one embodiment of the present application, the electronic switch is connected to the Y capacitor at one end and to ground at the other end. The electronic switch is arranged between the Y capacitor and the ground wire, and the circuit design is simpler.

According to one embodiment of the application, the circuit is provided with two Y capacitors respectively connected between the live wire and the ground wire and between the zero wire and the ground wire in a cross mode.

According to one embodiment of the application, one end of the electronic switch is connected to the two Y capacitors at the same time, and the other end is grounded. The arrangement mode can only arrange one electronic switch aiming at a plurality of Y capacitors, and can reduce the circuit cost.

According to an embodiment of the application, the electronic switch comprises two electronic switches, wherein one electronic switch is connected between the Y capacitor of the live wire and the live wire in series, and the other electronic switch is connected between the Y capacitor of the zero wire and the zero wire in series. The electronic switch is arranged between the Y capacitor and the live wire or the zero wire.

The application also provides the following technical scheme: a household appliance uses the aforementioned residual voltage control method. After the household appliance is powered off, the residual voltage between the live wire or the zero wire connected with the Y capacitor and the ground wire is far less than 34V, and the requirement of national standard GB4706.1 is met.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

Fig. 1 shows a schematic diagram of the residual voltage control method of the present application.

Fig. 2 shows another schematic diagram of the residual voltage control method of the present application.

Fig. 3 shows a first embodiment of the residual voltage control circuit of the present application.

Fig. 4 shows a second embodiment of the residual voltage control circuit of the present application.

Fig. 5 shows a third embodiment of the residual voltage control circuit of the present application.

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 devices, systems, apparatuses, and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

Referring to fig. 1, an EMC filter in a household appliance is generally connected with a Y capacitor, one pin of the Y capacitor is connected across a live line (hereinafter referred to as an L line) or a zero line (hereinafter referred to as an N line), and one pin of the Y capacitor is connected across a ground line. In the prior art, when the household appliance is powered off, the Y capacitor continuously discharges to the L line or the N line and the ground wire, so that the residual voltage between the L line or the N line and the ground wire is higher, and particularly when the capacitance value of the Y capacitor is larger, the voltage at the position can be as high as more than 100, and the requirement of national safety regulations is not met. The electronic switch is added in the loop of the Y capacitor, and after the household appliance is powered off, the electronic switch is cut off, so that the loop of a live wire or a zero wire connected with the Y capacitor to the ground is cut off, and the aim of meeting the safety regulation detection requirement can be fulfilled.

As shown in fig. 1, the present application has an electronic switching element connected in series between the Y capacitor and ground. When the household appliance is powered on, the system defaults to enable the switch element to be in a conducting state and a closed state, at the moment, one pin of the Y capacitor is normally connected with the L line or the N line, the other pin of the Y capacitor is normally connected with the ground, the common mode rejection effect is achieved, and normal EMC filtering work is conducted. When the system is powered off, a power failure detection module detects the power failure and sends an electric signal to the control chip, the control chip controls the electronic switch element to be disconnected after receiving the power failure signal, so that the connection between the Y capacitor and the ground wire is disconnected, and the residual voltage between the L line or the N line connected with the Y capacitor and the ground wire is measured to be lower than 10V and far lower than 34V because the L line or the N line connected with the Y capacitor is disconnected with the ground wire, so that the requirement of national standard GB4706.1 can be met.

Fig. 2 shows another mode of the above control method, and in the foregoing fig. 1, the electronic switching element is disposed between the Y capacitor and the ground line, and in the present embodiment, the electronic switching element is disposed between the Y capacitor and the L line or the N line. Similarly, the system defaults to make the switch element be on and off, when the system is powered off, the power failure detection module detects the power failure, the control chip receives a power failure signal and then makes the electronic switch element be off, so that the connection between the Y capacitor and the L line or the N line is disconnected, and the residual voltage between the L line or the N line connected with the Y capacitor and the ground line is measured to be far less than 34V at the moment because the loop is disconnected.

Fig. 3 to 5 are control circuits of the residual voltage, wherein fig. 3 to 4 correspond to the control method shown in fig. 1, and fig. 5 corresponds to the control method shown in fig. 2. In fig. 3, a capacitor C1 is connected across between the L line and the N line for filtering out series mode interference, and R51, R52, and R53 are connected in series and then connected in parallel with C1 to serve as a discharge resistor, which can release current after power failure and reduce the residual voltage of the L line and the N line. Variable resistor VR1 is also used in parallel with C1. In this embodiment, a PC817 photocoupler is used as an electronic switch, and an inductor L2, an inductor L1, a capacitor CY2, and a photocoupler are connected in series in this order in the L line and ground line circuit. And the N line and the ground line loop are sequentially connected in series with another inductor L2, a capacitor CY1 and the photoelectric coupler. The capacitors CY1 and CY2 are Y capacitors and are used for filtering common-mode interference together with the inductor L2, so that the common-mode rejection effect is achieved, and EMC filtering work is performed. One end of the photoelectric coupler is connected with the ground wire, and the other end of the photoelectric coupler is connected with the capacitors CY1 and CY 2.

After the household appliance is powered on, the optocoupler switch is in a conducting state, namely voltage is supplied by the VP to enable the diode to emit light, then the triode receives a light signal and converts the light signal into an electric signal, and a loop from the L line and the N line to the ground line is conducted, so that the Y capacitors CY1 and CY2 work normally. And when the system is powered off, the power failure detection module detects the power failure and sends a power failure signal to the control chip, and the control chip controls the photoelectric coupler to be disconnected after receiving the power failure signal, so that a loop from the N line connected with the Y capacitor CY1 to the ground line and a loop from the L line connected with the Y capacitor CY2 to the ground line are cut off. At this time, the residual voltage between the L line and the ground line and the residual voltage between the N line and the ground line are both measured to be lower than 10V and far lower than 34V, which accords with the relevant regulations of the national standard.

The circuit connection of the second embodiment in fig. 4 is substantially the same as that of the first embodiment in fig. 3 described above, except that a relay, one end of which is connected to the ground and the other end of which is connected to the capacitors CY1 and CY2, is used as an electronic switch instead of the PC817 photocoupler, and the on/off of the switch is controlled by the change in magnetic force caused by electric power. Similarly, after power-on, the relay is in a conducting state, and a loop from the L line and the N line to the ground line is conducted, so that the Y capacitors CY1 and CY2 work normally; and when the system is powered off, the relay is controlled to be disconnected, and the N line-to-ground circuit connected with the Y capacitor CY1 and the L line-to-ground circuit connected with the Y capacitor CY2 are both disconnected. At this time, the residual voltage between the L line and the ground line and the residual voltage between the N line and the ground line are both measured to be lower than 10V and far lower than 34V, which accords with the relevant regulations of the national standard. In other embodiments, a thyristor may be used in place of the relay.

The third embodiment of fig. 5 provides another circuit connection, in which the electronic switch is exemplified by a photocoupler. In the previous 2 embodiments, the electronic switch is connected between the Y capacitor and the ground, but in this embodiment, 2 photo-couplers are used, which are respectively connected between the CY2 capacitor and the L line and between the CY1 capacitor and the N line, that is, between the Y capacitor and the L line or the N line. The working principle is the same, after the power is on, the two photoelectric couplers are in a conducting state, and the loops from the L line and the N line to the ground line are respectively conducted, so that the Y capacitors CY1 and CY2 work normally; and when the system is powered off, the two photoelectric couplers are in an off state, and the loop connecting the N line of the Y capacitor CY1 to the ground wire and the loop connecting the L line of the Y capacitor CY2 to the ground wire are respectively disconnected.

According to the control method and the control circuit of the residual voltage, the electronic switch is disconnected after the system is powered off through the arrangement of the electronic switch, and a loop connecting the L line or the N line of the Y capacitor to the ground wire is cut off, so that the measured voltage between the L line or the N line of the Y capacitor and the ground wire is far less than 34V, and the relevant national standard is completely met.

The present application also provides a home appliance using the aforementioned residual voltage control method. After the household appliance is powered off, the residual voltage between the live wire or the zero wire connected with the Y capacitor and the ground wire is lower than 10V and far smaller than 34V, and the requirement of national standard GB4706.1 is met.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

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