A safety socket, a safety circuit and a safety on-off method thereof
By introducing a closed-loop circuit detection-analysis-control system and mechanical structure into the socket, combined with the detection of the pendulum's swing to detect the plug insertion, the problems of wear on the safety door and inconvenience in plugging and unplugging in existing sockets are solved, thus achieving a safe and stable power supply function for the socket.
Patent Information
- Application Number
- CN202210728442.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-24
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2042-06-24
AI Technical Summary
The existing safety door slider and spring connection structure is prone to wear during use, which increases the risk of children accidentally getting electric shocks. At the same time, it is difficult for adults to plug and unplug the plug, making it inconvenient to operate.
A closed-loop detection-analysis-control system is constructed using a circuit structure. Combined with a mechanical structure, the system detects the insertion of a plug by detecting the swing of a pendulum. It utilizes induction and control circuits to achieve time-sharing power supply and uses triple-judgment constraints on the power-on and power-off times to ensure safety and stability.
It achieves sensitive sensing and convenient operation during plugging and unplugging, prevents children from accidentally touching the wires, extends the lifespan of the sockets, and ensures a safe and stable power supply.
Smart Images
Figure CN115101965B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of socket, in particular to a safe socket. BACKGROUND
[0002] For safety considerations, the socket provided in the prior art is often provided with a safety door, which blocks the socket jack with an actual mechanical structure to avoid electric shock accidents caused by children's accidental touch.
[0003] The socket safety door provided in the prior art is mostly formed by a sliding block and a spring to achieve a locking structure, when there is no plug inserted in the socket, the spring presses the sliding block to make it in a closed position, blocking the socket jack; when the user forces to squeeze the sliding block to insert the plug, the sliding block is pushed away, and the safety door is in an open position, after all the pins of the plug are inserted, the pins contact the conductive spring sheet in the socket to realize the electrical connection between the plug and the socket.
[0004] When the above-mentioned sliding block and spring locking structure is applied to the actual socket safety door, in order to play a safety protection role as much as possible, the sliding block is often made of insulating plastic material, and the skilled person often makes further improvements to the structure of the sliding block, thinking that increasing the sliding resistance of the sliding block can avoid children from inserting their fingers into the sliding block to cause electric shock. However, because of this, adults will always encounter great resistance during the process of inserting and pulling out the plug, the socket is strongly blocked, and it is difficult for adults to accurately, quickly and conveniently insert the plug at one time; moreover, for the socket itself, the form of increasing the sliding resistance of the sliding block to avoid children's accidental touch will also wear the sliding block itself during the process of inserting and pulling out the plug, and the sliding block will be severely worn after a long time of use, the safety door itself will be stuck, and it may even completely fail to play a safety protection role, and the socket cannot be used stably and safely for a long time. SUMMARY
[0005] To solve the above-mentioned problems, the purpose of the present application is to provide a safe circuit, which detects, analyzes and controls the on-off of the control closed loop by circuit structure, realizes the function of detecting insertion and controlling power supply, and manages the external socket power supply by a more simple circuit structure to avoid electric shock accidents caused by children's accidental touch.
[0006] Another purpose of the present application is to provide a safe socket, which is plugged into the original external socket to realize the effect of detecting insertion and time-sharing power supply by mechanical structure combined with circuit.
[0007] Still another purpose of the present application is to provide a safe on-off method, which determines the on-off time point by three times of judgment and constraints, and the on-off method is safe and stable, and when applied to a specific socket, it can provide a safe on-off function for a long time to avoid electric shock accidents caused by children's accidental touch.
[0008] To achieve the above object, the technical scheme of the present application is as follows:
[0009] A safety socket, comprising: a plug post for connecting and conducting an external power supply; a control board for controlling on-off according to a detection result of a detection pendulum; a conductive spring for opening connection and conducting electricity to an external plug; and a detection pendulum for sensing whether the external plug is inserted or not;
[0010] The plug post is arranged below the control board, with its upper end connected to and conducting the control board; the conductive spring is arranged above the control board, with its lower end connected to and conducting the control board; the detection pendulum is suspended above the conductive spring, and the detection pendulum reciprocates between its initial position and its final position, and when the external plug is inserted, the detection pendulum swings to its final position; when the external plug is not inserted, the detection pendulum swings to its initial position; wherein,
[0011] The plug post is provided with two poles corresponding to two poles of the external power supply; the conductive spring is provided with two pieces corresponding to the plug post; the detection pendulum is provided with two corresponding to the conductive spring; and,
[0012] Each detection pendulum comprises a shell and a pendulum, the shell is arranged on the control board and connected to the control board; and each shell covers the corresponding conductive spring, the shell has a plug-in passage for inserting or pulling out the external plug inside, and the pendulum is hinged to the shell.
[0013] Further, the shell comprises a shell body and a hinge rod; the hinge rod is arranged on the shell body and connected to the shell body; when the pendulum is connected to the shell, the pendulum is hung on the hinge rod.
[0014] Further, the pendulum comprises a hook part, a swing part and a hammer part; the swing part is arranged between the hook part and the hammer part, and the hook part, the swing part and the hammer part are integrally connected; the pendulum presents an "L" shape, and when the pendulum is connected to the hinge rod, the hook part hooks the hinge rod.
[0015] Further, the detection pendulum further comprises a reset spring, the reset spring is arranged between the shell body and the pendulum, one end of the reset spring abuts against the shell body, and the other end of the reset spring abuts against the hammer part.
[0016] The safety socket provided by the present application has the following beneficial effects:
[0017] Firstly, the safety socket provided by the application can be used as a safety relay station between the external power supply and the external plug. The socket can be directly plugged into the external power supply, and the plug post in the socket remains connected with the external power supply and is in conduction. Only when the external plug is properly inserted into the safety socket provided by the application, the power supply of the external power supply can be conducted to the external plug along the plug post-control board-conductive spring sheet. The safety socket provided by the application provides a safe and reliable power supply relay for the connection between the external plug and the external power supply, and can be always plugged into the external power supply as a "safety door" of the external power supply when there is no external plug connected, so as to avoid electric shock accidents caused by accidental touch of children.
[0018] Secondly, the pendulum is hung on the hinge rod and reciprocates around the hinge rod. The resistance of the pendulum during the reciprocation mainly comes from the return spring. By setting a reasonable spring coefficient of the return spring, a comfortable plugging and unplugging feeling can be obtained, and the user can use it more conveniently.
[0019] Furthermore, when there is no external plug inserted, the pendulum under the elastic force of the return spring presents an "L" shaped pendulum which is inclined and protrudes from the shell body and hangs on the conductive spring sheet, thereby blocking the plugging channel in the shell body. When the external plug is inserted, the external plug gradually pushes the pendulum which is inclined and protrudes from the shell body, and the external plug pushes away the pendulum, so that the pendulum swings around the hinge rod from the original starting position to the terminal position. During this process, the pendulum only receives the downward force of the external plug and the elastic force of the return spring, and receives little or no friction force from the surrounding other mechanical mechanisms, so that the pendulum is less worn. When the user presses the external plug to the bottom, the pendulum is completely pushed to the terminal position, at this time, the external plug is in complete contact with the conductive spring sheet, the conductive spring sheet tightly clamps the external plug, the control board conducts the plug post and the conductive spring sheet, and the external power supply and the external plug are conducted. Once the user pulls out the plug, the pendulum under the elastic force of the return spring automatically returns and is again inclined and protrudes from the shell body and hangs on the conductive spring sheet, the control board again Truncation , the plug post and the conductive spring sheet are disconnected again, and the conductive spring sheet returns to the original non-electric state, waiting for the next plugging. The above plugging and unplugging process is convenient to operate, and the user does not need to make more actions. A simple plugging or unplugging action can obtain a stable and safe power supply. On the other hand, during the process of plugging, holding and unplugging of the external plug, the return spring and the pendulum cooperate to automatically reset, and repeated use also does not require the user to manually reset, so that the operation is very convenient. On the other hand, with the insertion and removal of the external plug, the swing position of the pendulum will change in real time, which will also provide a sensing basis for the sensing circuit in the safety circuit provided by the application, so as to ensure that the sensing circuit senses in time and effectively.
[0020] The application also provides a safety circuit based on the above safety socket. The safety circuit comprises:
[0021] The induction circuit is correspondingly provided with two paths based on two detection pendulums, and is used for outputting a detection signal according to the swing position of the corresponding detection pendulum, outputting a positive signal when the corresponding detection pendulum swings to the terminal position, and outputting a negative signal when the corresponding detection pendulum swings to the initial position;
[0022] The control circuit is correspondingly provided with two paths based on the plug and the conductive spring, each path has on-off capability, and is used for interaction with the corresponding induction circuit, turns on when the corresponding induction circuit outputs the positive signal, and turns off when the corresponding induction circuit outputs the negative signal.
[0023] The control circuit is printed on the control board, the input end of each control circuit is connected to the corresponding pole of the external power supply through the corresponding plug, the output end of each control circuit is connected to the corresponding conductive spring, and each induction circuit interacts with the control circuit.
[0024] Further, the control circuit comprises:
[0025] a master control chip used for receiving the output signals of all induction circuits, performing operation and analysis on the output signals, and outputting corresponding control signals;
[0026] and a switch used for cutting off the on-off state according to the control signals output by the master control chip, the switch is correspondingly provided with two plugs and conductive springs.
[0027] The power input end of each switch is connected to the corresponding pole of the external power supply through the corresponding plug, the power output end of each switch is connected to the corresponding conductive spring, and the control ends of all switches are connected to the master control chip.
[0028] The safety circuit provided by the application is correspondingly provided with the safety socket, the safety circuit fully utilizes the mechanical structure and the activity principle of the safety socket, associates the induction circuit with the detection pendulum, detects the insertion and extraction of the external plug through the action of the detection pendulum, can track the insertion and extraction of the external plug in real time, feeds back to the control circuit in time, and provides the control circuit with timely and effective front-end detection basis. In the specific implementation, the induction circuit can apply a Hall sensor, an infrared sensor, a laser ranging sensor and the like, the selected sensor is arranged and applied according to the activity principle of the detection pendulum, the effect that the insertion and extraction of the external plug are obtained through the swing of the detection pendulum is realized, the specific principle of the induction circuit, the selection of the corresponding sensor, how to arrange the specific sensor after the specific sensor is applied to the safety socket to realize the insertion and extraction detection and the like are all the common knowledge of the person skilled in the art, the person skilled in the art can realize the corresponding implementation by referring to the technical materials of the existing sensor, the structure of the induction circuit and the working principle thereof are not within the protection scope required by the application.
[0029] Meanwhile, the main control chip and the switcher involved in the control circuit provided by the application, the circuit structure, the internal structure of the circuit, and the working principle of the circuit itself are not the core of the application, and are not within the protection scope of the application. The skilled in the art can select appropriate control chips and appropriate switchers to apply to the circuit according to the specific implementation scene requirements. Any technical solution based on the application of the safety circuit architecture of the safety socket described above and making adaptive adjustment to part of the devices should be included in the protection scope of the application.
[0030] The application further discloses a safety on-off method based on the safety circuit, and the method is characterized in that the method is:
[0031] S1: the main control chip receives the output signals of all the induction circuits. If both of the two induction circuits output positive signals, jump to S2; otherwise, jump to S4.
[0032] S2: the main control chip records the time when the two induction circuits output positive signals, compares the time difference of the positive signals output by the two induction circuits, and judges whether the current plug-in is legal. If yes, jump to S3; otherwise, jump to S4.
[0033] S3: the main control chip captures the latest voltage zero point of the external power supply, and sends two control signals at the time of the latest voltage zero point of the external power supply to control the corresponding switcher to be turned on.
[0034] S4: the main control chip controls all the corresponding switchers to be turned off.
[0035] Further, S2 is specifically: a time difference threshold is set in advance, the main control chip records the time when the two induction circuits output positive signals, compares the time difference of the positive signals output by the two induction circuits, and compares the time difference with the time difference threshold. If the time difference is less than the time difference threshold, it is determined that the current plug-in is legal, and jump to S3; otherwise, it is determined that the current plug-in is illegal, and jump to S4.
[0036] Obviously, when the above-mentioned safe power-on method is implemented, the safety circuit determines that the current insertion is legal only when the two power terminals of the external plug are inserted into the safety socket at the same time, and the switch is turned on only when the safety circuit determines that the current insertion is legal, the external power supply is connected to the external plug through the safety circuit and the safety socket, and the external plug can obtain electricity from the safety socket. In this way, if a user mistakenly inserts a single hard object into one of the sockets of the safety socket, the hard object pushes away one of the hammers under the socket, one of the induction circuits arranged at the hammer outputs a positive signal, the positive signal is fed back to the master control chip, and at this time, the other induction circuit does not output a positive signal. The master control chip calculates that the time difference between the positive signals of the two induction circuits is large, greater than the time difference threshold, and determines that the current insertion is illegal, the switch is not turned on, and the conductive spring piece is still not electrified. Therefore, the user will not be electrocuted due to the mistaken insertion of a hard object.
[0037] At the same time, only when the safety circuit determines that the current insertion is legal, it can start to track the voltage waveform change of the external power supply, capture the nearest voltage zero crossing point, and turn on the switch at the voltage zero crossing point, which can effectively avoid the generation of sparks due to the natural defects of the switch structure of the switch, further ensure the safety of the user during plugging and unplugging, protect the stability of the structure of the switch, and prolong the service life of the entire socket.
[0038] In summary, the safety on-off method provided in the application is constrained by three safety determinations, i.e., the presence or absence of the output signals of the two induction circuits, the time difference between the positive signals output by the two induction circuits, and the position of the voltage zero crossing point of the external power supply, which can effectively ensure the safety of the entire safety circuit, protect the safety of the user during plugging and unplugging, and avoid accidents such as electric shock caused by the mistaken touching or insertion of foreign objects by children.
[0039] The advantages of the application are that, compared with the prior art, the safety circuit structure provided in the application is simple, the safety socket provided in the application is easy to use, sensitive to induction, and has high automation and can work stably for a long time without wear and sparking; and the safety on-off method provided in the application has high safety, can be applied to actual sockets, and can achieve good use effect. BRIEF DESCRIPTION OF DRAWINGS
[0040] Figure 1 is the overall structure principle diagram of the safety socket provided in the specific embodiment.
[0041] Figure 2 is the partial structure explosion diagram of the safety socket provided in the specific embodiment.
[0042] Figure 3 is the internal structure schematic diagram of the safety socket when the external plug is inserted, wherein A is the external plug.
[0043] Figure 4 is the internal structure schematic diagram of the safety socket provided in the specific embodiment when there is no external plug inserted.
[0044] Figure 5 is the specific structure schematic diagram of the shell in the safety socket provided in the specific embodiment.
[0045] Figure 6 is the specific structure schematic diagram of the pendulum in the safety socket provided in the specific embodiment.
[0046] Figure 7 is the structure schematic diagram of the combination of the shell and the pendulum in the safety socket provided in the specific embodiment.
[0047] Figure 8 is the circuit principle diagram of the safety circuit provided in the specific embodiment. Specific Embodiment
[0048] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.
[0049] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:
[0050] Please refer to Figures 1-7 .
[0051] In the specific embodiment, a safety socket is provided, which comprises an upper shell B and a lower shell B` ; the upper shell B and the lower shell B` form an accommodation space by being enclosed;
[0052] The safety socket further comprises a plug column 1 for connecting and conducting an external power source; a control panel 2 for controlling the on-off according to the detection result of the detection pendulum; a conductive spring 3 for opening the connection and the electric conduction to the external plug; and a detection pendulum 4 for sensing whether the external plug A is inserted or not;
[0053] The control panel 2 is embedded on the lower shell B` ; the plug column 1 is arranged below the control panel 2, and the upper end thereof is connected with and conducts the control panel 2; the conductive spring 3 is arranged above the control panel 2, and the lower end thereof is connected with and conducts the control panel 2; the detection pendulum 4 is suspended above the conductive spring 3, and the detection pendulum 4 always reciprocates between its initial position and its terminal position, and when the external plug A is inserted, the detection pendulum 4 swings to its terminal position; when there is no external plug A inserted, the detection pendulum 4 swings to its initial position.
[0054] Further, in the specific embodiment, two poles of the external power supply correspond to two columns of the plug 1; two conductive springs 3 correspond to two columns of the plug 1; two detection pendulums 4 correspond to two conductive springs 3.
[0055] Further, in the specific embodiment, each detection pendulum 4 includes a shell 41 and a pendulum 42, the shell 41 is arranged on the control panel 2 and connected with the control panel 2; and each shell 41 covers the corresponding conductive spring 3, the shell 41 has a plug-in channel for the external plug A to be inserted or pulled out, and the pendulum 42 is hinged to the shell 21.
[0056] Further, in the specific embodiment, the shell 41 includes a shell body 411 and a hinge rod 412; the hinge rod 412 is arranged on the shell body 411 and connected with the shell body 411; when the pendulum 42 is connected with the shell 41, the pendulum 42 is hung on the hinge rod 412.
[0057] Further, in the specific embodiment, the pendulum 42 includes a hook part 421, a swing part 422 and a hammer part 423; the swing part 422 is arranged between the hook part 421 and the hammer part 423, and the hook part 421, the swing part 422 and the hammer part 423 are integrally connected; the pendulum 42 is in the shape of "L", and when the pendulum 42 is connected with the hinge rod 412, the hook part 421 hooks the hinge rod 412.
[0058] Further, in the specific embodiment, the detection pendulum 4 further includes a reset spring 43, which is arranged between the shell body 411 and the pendulum 42, one end of the reset spring 43 abuts against the shell body 411, and the other end abuts against the hammer part 423.
[0059] Please refer to Figure 8 .
[0060] In the specific embodiment, a safety circuit is provided, which includes:
[0061] The induction circuit includes two detection pendulums 4, which are used to output a detection signal according to the swing position of the corresponding detection pendulum 4, output a positive signal when the corresponding detection pendulum 4 swings to the terminal position, and output a negative signal when the corresponding detection pendulum 4 swings to the initial position;
[0062] The control circuit includes two columns of the plug 1 and two conductive springs 3, each of which has an on-off ability, is used to interact with the corresponding induction circuit, is turned on when the corresponding induction circuit outputs a positive signal, and is turned off when the corresponding induction circuit outputs a negative signal;
[0063] The control circuit is printed on the control board 2, the input end of each control circuit is connected to the corresponding pole of the external power supply through the corresponding plug post 1; the output end of each control circuit is connected to the corresponding conductive spring 3; and each sensing circuit interacts with the control circuit.
[0064] Further, the control circuit comprises:
[0065] a main control chip U5 for receiving the output signals of all sensing circuits, performing operation and analysis on the output signals, and outputting corresponding control signals;
[0066] and a switch device for cutting off the on-off state according to the control signals output by the main control chip U5; the switch device is correspondingly provided with two plug posts 1 and conductive springs 3;
[0067] The power input end of each switch device is connected to the corresponding pole of the external power supply through the corresponding plug post 1, and the power output end is connected to the corresponding conductive spring 3; and the control ends of all switch devices are connected to the main control chip U5.
[0068] Further, in the specific embodiment, the sensing circuit comprises two Hall sensors (U8 / U2), and the models of the two Hall sensors (U8 / U2) are both LN4913; the control circuit comprises a main control chip U5, and the specific model of the main control chip U5 is FT60123 A ; the control circuit further comprises a relay REL1 and a triode Q3, one of the static contacts 4 in the relay REL1 is connected to the live wire L1 of the external power supply through the plug post 1, the other static contact 3 in the relay REL1 is connected to the corresponding conductive spring 3, one end 1 of the armature coil in the relay REL1 is connected to the system power supply VCC, the other end 2 of the armature coil is connected to the collector of the triode Q3, the emitter of the triode Q3 is grounded, and the base thereof is connected to the main control chip U5. The signal output ends of the two Hall sensors (U8 / U2) are connected to the main control chip U5.
[0069] In the specific embodiment, a safe on-off method is also provided, which is based on the above-mentioned safety circuit, and the method comprises the following steps:
[0070] S1: the main control chip U5 receives the output signals of all sensing circuits, if the two sensing circuits output positive signals, the process jumps to S2; otherwise, the process jumps to S4;
[0071] S2: the main control chip U5 records the time when the two sensing circuits output positive signals, compares the time difference of the two sensing circuits, and determines whether the current plug-in is legal, if yes, the process jumps to S3; otherwise, the process jumps to S4;
[0072] S3: the master control chip U5 captures the recent voltage zero point of the external power supply, and sends out two control signals at the moment of the recent voltage zero point of the external power supply to control the corresponding switch to be turned on;
[0073] S4: the master control chip U5 controls all the corresponding switches to be turned off.
[0074] Further, S2 is specifically: a time difference threshold is set in advance, the master control chip records the time when the positive signals of the two induction circuits are received, the time difference of the positive signals of the two induction circuits is compared, and the time difference is compared with the time difference threshold. If the time difference is less than the time difference threshold, it is determined that this time of insertion is legal, and S3 is jumped. Otherwise, it is determined that this time of insertion is illegal, and S4 is jumped.
[0075] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A safety socket, characterized in that, This safety socket includes: A plug for connecting and conducting external power; A control board used to control the on / off state based on the detection results of the pendulum. A conductive spring for opening the connection to an external plug and enabling electrical conduction; And a detection pendulum for sensing whether an external plug is inserted; The insertion post is located below the control board, with its upper end connected and conductive to the control board; the conductive spring is located above the control board, with its lower end connected and conductive to the control board; the detection pendulum is suspended above the conductive spring, and the detection pendulum always swings back and forth between its starting position and its ending position. When an external plug is inserted, the detection pendulum swings to its ending position; when no external plug is inserted, the detection pendulum swings to its starting position; wherein, two insertion posts are provided corresponding to the two poles of the external power supply; two conductive springs are provided corresponding to the insertion posts; two detection pendulums are provided corresponding to the conductive springs; each detection pendulum includes a housing and a pendulum, the housing is located on the control board and connected to the control board; and each housing covers its corresponding conductive spring, the housing has an insertion / removal channel for accommodating the insertion or removal of an external plug, and the pendulum is hinged to the housing; and... The housing includes a housing body and a hinge rod; the hinge rod is mounted on the housing body and connected to the housing body; when the pendulum is connected to the housing, the pendulum hangs on the hinge rod; the pendulum includes a hook, a pendulum, and a hammer; the pendulum is disposed between the hook and the hammer, and the hook, the pendulum, and the hammer are integrally formed and connected; when the pendulum is connected to the hinge rod, the hook hooks the hinge rod; the detection pendulum also includes a return spring, which is disposed between the housing body and the pendulum, with one end of the return spring abutting against the housing body and the other end abutting against the hammer.
2. A safety circuit based on the safety socket as claimed in claim 1, characterized in that, This safety circuit includes: The sensing circuit is configured with two corresponding paths based on the two detection pendulums. It outputs a detection signal according to the swing position of the corresponding detection pendulum. When the corresponding detection pendulum swings to its end position, it outputs a positive signal, and when the corresponding detection pendulum swings to its start position, it outputs an inverse signal. Control circuit: Two paths are set according to the corresponding insertion post and the conductive spring, each path has the ability to switch on and off, and is used to interact with the corresponding sensing circuit. It is turned on when the corresponding sensing circuit outputs a positive signal and turned off when the corresponding sensing circuit outputs an inverse signal. The control circuit is printed on the control board. The input terminal of each control circuit is connected to the corresponding terminal of the external power supply through its corresponding pin. The output terminal of each control circuit is connected to its corresponding conductive spring. Each sensing circuit interacts with the control circuit.
3. The safety circuit as described in claim 2, characterized in that, The control circuit includes: The main control chip is used to receive the output signals of all the aforementioned sensing circuits, perform calculations and analyses on them, and then output corresponding control signals. And a switch for cutting off its on / off state according to the control signal output by the main control chip; two switches are provided based on the corresponding posts and conductive springs; Each of the switches has its power input terminal connected to the corresponding terminal of an external power source via its corresponding pin, and its power output terminal connected to its corresponding conductive spring. The control terminals of all the switches are connected to the main control chip.
4. A safe power-on / off method, the method being based on the safety circuit as described in claim 3, characterized in that, The method is as follows: S1: The main control chip receives the output signals of all the sensing circuits. If both sensing circuits output positive signals, then jump to S2; otherwise, jump to S4. S2: The main control chip records the time when it receives the positive signals output by the two sensing circuits, compares the time difference between the positive signals output by the two sensing circuits, and determines whether the current connection is valid. If valid, it jumps to S3; otherwise, it jumps to S4. S3: The main control chip captures the nearest voltage zero-crossing point of the external power supply and sends two control signals at the moment of the nearest voltage zero-crossing point of the external power supply to control the corresponding switch to turn on. S4: The main control chip controls all corresponding switches to turn off.
5. The safe power-on / off method as described in claim 4, characterized in that, Specifically, S2 involves: setting a time difference threshold in advance; the main control chip recording the time when it receives the positive signals output by the two sensing circuits; comparing the time difference between the two positive signals output by the sensing circuits; comparing the time difference with the time difference threshold; if the time difference is less than the time difference threshold, the insertion is determined to be valid and the process jumps to S3; otherwise, the insertion is determined to be invalid and the process jumps to S4.