CN211828642U

CN211828642U - Circuit structure for controlling relay current zero-crossing breaking

Info

Publication number: CN211828642U
Application number: CN202020781355.XU
Authority: CN
Inventors: 王楠
Original assignee: Taizhou Vocational and Technical College
Current assignee: Taizhou Shengyao Technology Co ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2020-10-30
Anticipated expiration: 2030-05-12

Abstract

The utility model provides a disconnected circuit structure of control relay current zero passage belongs to relay technical field. It has solved the prior art when damaging, needs the problem of whole change. The circuit structure for controlling the relay current zero-crossing breaking comprises a circuit board I and a circuit board II, wherein a relay is arranged on the circuit board I, a current zero-crossing breaking circuit is arranged on the circuit board II, two notches are formed in the same side edge of the circuit board I, a circuit board block is arranged between the two notches, a first conducting wire connected with a first relay switch contact pin is arranged on the circuit board block, the current zero-crossing breaking circuit comprises a current transformer which is sleeved on the circuit board block and used for detecting a current signal on the first conducting wire, a second conducting wire connected with a second relay switch contact pin is further arranged on the circuit board I, one side edge of the circuit board I provided with the notch is detachably connected with the circuit board II, and the circuit board I. The utility model discloses can be convenient for maintain.

Description

Circuit structure for controlling relay current zero-crossing breaking

Technical Field

The utility model belongs to the technical field of the relay, a disconnected circuit structure of control relay current zero passage is related to.

Background

The relay is widely applied to various electronic and electrical equipment, is used as a driving device for controlling large signals by small signals, and has the advantages of strong load carrying capacity, good electrical isolation, strong contact overload capacity and the like. However, the relay is a mechanical switch, has a certain mechanical life, the relay contact also has an electrical life, the loss of the contact is an accumulated process, the electric arc is a main reason for the loss of the contact, and the voltage and the current during the switching of the contact are main factors of the intensity of the electric arc, so that in an alternating current circuit, the zero-crossing moment of the voltage of the contact is closed or the zero-crossing moment of the current is disconnected, the intensity of the electric arc can be effectively reduced, the electric erosion of the contact is reduced, the contact life is prolonged, and meanwhile, the EMI problem of a circuit system can be reduced.

In the prior art, although there is disclosed an electromagnetic relay self-adjusting zero-crossing control circuit [ application No.: CN201220540508.7, including relay circuit, load circuit, sampling circuit, control chip circuit and drive circuit, the sampling circuit includes alternating current zero-crossing sampling circuit and relay disconnection detection circuit, the alternating current zero-crossing sampling circuit performs zero-crossing detection on the alternating current waveform output to the load circuit by the relay circuit, and the relay disconnection detection circuit detects when the contact of the electromagnetic relay is disconnected. The sampling circuit outputs the zero-crossing signal and the relay state signal to the control chip circuit, and the control chip circuit judges and processes the received signal and then adjusts and outputs the relay on-off signal to the driving circuit so as to control the on-off of the relay circuit. Although the circuit can reduce the electric arc intensity, reduce the electric erosion of the contact and prolong the service life of the contact, when the circuit is applied, the relay and the self-adjusting zero-crossing control circuit are installed on the same circuit board in the prior art, the design has the defects that the circuit board has large use area, and when the relay or the self-adjusting zero-crossing control circuit is damaged, the whole replacement is needed, and the cost is high; in addition, the relay originally applied to various electronic and electrical equipment cannot be directly replaced by the relay with the current zero-crossing breaking function, a circuit board needs to be redesigned, and the relay is inconvenient to use and high in cost.

Disclosure of Invention

The utility model aims at the above-mentioned problem that prior art exists, provide a control relay current zero passage divides disconnected circuit structure, the technical problem that this relay structure will solve is: how to facilitate maintenance.

The purpose of the utility model can be realized by the following technical proposal: a circuit structure for controlling current zero-crossing breaking of a relay comprises a circuit board I and a circuit board II, and is characterized in that the circuit board I is provided with the relay, the circuit board II is provided with a current zero-crossing breaking circuit used for being connected with a relay coil, the same side edge of the circuit board I is provided with two notches, a circuit board block is arranged between the two notches, a first conducting wire connected with a contact pin I of the relay switch is distributed on the circuit board block, a second conducting wire connected with the contact pin II of the relay switch is also distributed on the circuit board I, the current zero-crossing breaking circuit comprises a current transformer which is sleeved on the circuit board block and used for detecting a current signal on the first conducting wire, the circuit board II is provided with a first live wire interface L1 connected with the first conducting wire and a second live wire interface L2 connected with the second conducting wire, and one side edge of the circuit board I provided with the notches, the first circuit board and the second circuit board are perpendicular to each other.

The circuit structure for controlling the relay current zero-crossing breaking is characterized in that a relay and a current zero-crossing breaking circuit are respectively arranged on different circuit boards, the relay is arranged on a first circuit board, the current zero-crossing breaking circuit is arranged on a second circuit board, the first circuit board and the second circuit board are detachably connected, when a fault occurs, only the relay on the first circuit board needs to be replaced or maintained if the relay fails, and only the circuit on the second circuit board needs to be replaced or maintained if the current zero-crossing breaking circuit fails, so that the problem that one circuit needs to be integrally replaced when a problem occurs or another part is damaged during maintenance is avoided; in addition, the first circuit board and the second circuit board are arranged vertically, so that the volume of the relay structure is effectively reduced, and the space occupation in the horizontal direction can be effectively reduced; in addition, the current transformer is sleeved on the circuit board block between the gaps in a mode of forming the gaps on the first circuit board, signal connection on the two circuit boards is reliably established, the relay structure achieves the purpose of convenient maintenance, and meanwhile, the effectiveness and the reliability of the current zero-crossing breaking function can be guaranteed.

In the above circuit structure for controlling relay current zero-crossing breaking, the current zero-crossing breaking circuit includes an MCU, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a diode D1, a diode D2, a capacitor C1, a capacitor C2 and a switch tube Q1, one end of the resistor R1 is connected to the MCU, the other end of the resistor R1 is connected to the positive terminal of the diode D1, the negative terminal of the diode D1 is connected to one end of the resistor R2 and the positive terminal of the capacitor C1, the negative terminal of the capacitor C1 is grounded, the other end of the resistor R2 is connected to the MCU, the negative terminal of the diode D2 and the positive terminal of the capacitor C2, the positive terminal of the diode D2 and the negative terminal of the capacitor C2 are grounded, one end of the resistor R4 is connected to the MCU, the other end of the resistor R4 is grounded to the resistor R5, and the current transformer is connected to both ends of the resistor R5, the MCU is connected with the base electrode of the switch tube Q1 through a resistor R3, and a relay coil is connected between the collector electrode of the switch tube Q1 and the positive electrode of the capacitor C1. In the current zero-crossing breaking circuit, a resistor R2, a diode D2 and a capacitor C2 form a power supply circuit of an MCU, a resistor R3 and a switching tube Q1 are drive circuits of a relay, a resistor R1 is used for input command detection, a diode D1 and a capacitor C1 form an electric energy maintaining circuit, when a command of closing the relay is received and before a relay contact is released, power supply is continuously maintained for a period of time, and effective application of a current zero-crossing breaking function is guaranteed.

In the circuit structure for controlling the relay to perform current zero-crossing breaking, a first connecting wire connected with the positive end of the capacitor C1 and a second connecting wire connected with the collector electrode of the switching tube Q1 are arranged on the second circuit board, the first connecting wire and the second connecting wire respectively extend to the junction of the second circuit board and the first circuit board, a third conducting wire and a fourth conducting wire connected with coil pins of the relay are arranged on the first circuit board, and the third conducting wire and the fourth conducting wire respectively extend to the junction of the first circuit board and the second circuit board and are respectively butted with the first connecting wire and the second connecting wire. When the first circuit board and the second circuit board are installed, the first connecting wire and the third conducting wire are just butted, and the second connecting wire and the fourth conducting wire are just butted, so that the first connecting wire and the second connecting wire are more convenient to assemble and connect.

In the above circuit structure for controlling relay current zero-crossing breaking, the first conductive wire and the second conductive wire extend to a junction between the first circuit board and the second circuit board, the second circuit board is provided with a third connecting wire connected with the first live wire interface L1 and a fourth connecting wire connected with the second live wire interface L2, the third connecting wire extends to a junction between the second circuit board and the first circuit board and is in butt joint with the first conductive wire, and the fourth connecting wire extends to a junction between the second circuit board and the first circuit board and is in butt joint with the second conductive wire.

In the above circuit structure for controlling relay current zero-crossing breaking, a butt joint of the third conducting wire and the first connecting wire is connected in a welding manner, a butt joint of the fourth conducting wire and the second connecting wire is connected in a welding manner, a butt joint of the first conducting wire and the third connecting wire is connected in a welding manner, and a butt joint of the second conducting wire and the fourth connecting wire is connected in a welding manner.

In the above circuit structure for controlling the relay to perform zero-crossing current breaking, the second circuit board is further provided with a first conductive hole connected with the resistor R1 and the diode D1, and a second conductive hole connected with a ground wire. The first conductive hole and the second conductive hole can be used for establishing connection between the current zero-crossing breaking circuit and the original circuit relay coil through the first conductive hole and the second conductive hole, a control circuit of original electrical equipment does not need to be changed, application is more convenient, and meanwhile maintenance is facilitated when a fault occurs.

In the above circuit structure for controlling relay current zero-crossing breaking, the relay structure further includes an L-shaped mounting bracket, the mounting bracket includes a first fixing plate and a second fixing plate, two side edges of the first fixing plate are provided with a first clamping groove, the second circuit board is inserted into the first clamping groove, two side edges of the second fixing plate are provided with a second clamping groove, and the first circuit board is inserted into the second clamping groove. Due to the design of the flanging, the first circuit board and the second circuit board can be limited and fixed.

Compared with the prior art, the relay zero-crossing breaking circuit structure for controlling the relay current zero-crossing breaking is characterized in that the relay and the current zero-crossing breaking circuit are respectively installed on the two circuit boards and are installed in a mutually perpendicular mode, the size of the circuit boards is effectively reduced, the relay structure can be out of order, the first circuit board is only required to be replaced or the second circuit board is only required to be replaced, the whole structure is not required to be replaced, the convenience of later maintenance is improved, and meanwhile the use cost can also be reduced.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of the circuit wiring of the present invention.

Fig. 3 is a schematic structural diagram of the mounting rack of the present invention.

Fig. 4 is a schematic circuit diagram of the present invention.

FIG. 5 is a schematic diagram of the first circuit board of the present invention

In the figure, 1, a first circuit board; 11. a first conductive line; 12. a second conductive line; 13. conducting wire III; 14. conducting wire four; 15. a notch; 16. a circuit board block; 2. a second circuit board; 21. a first connecting line; 22. a second connecting line; 23. a third connecting line; 24. a fourth connecting line; 25. a first conductive hole; 26. a second conductive hole; 27. a third conductive hole; 3. a relay; 4. a current zero-crossing breaking circuit; 41. a current transformer; 5. a mounting frame; 51. a first fixing plate; 52. a second fixing plate; 53. a first clamping groove; 54. and a second clamping groove.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

The first embodiment is as follows:

as shown in fig. 1 and 5, the circuit structure for controlling the relay current zero-crossing breaking comprises a first circuit board 1 and a second circuit board 2, wherein a relay 3 is arranged on the first circuit board 1, a current zero-crossing breaking circuit 4 for connecting with a coil of the relay 3 is arranged on the second circuit board 2, the current zero-crossing breaking circuit 4 comprises a current transformer 41 for detecting a load current connected to an alternating current, two notches 15 are formed in the same side edge of the first circuit board 1, a circuit board block 16 is arranged between the two notches 15, a first conductive wire 11 connected with a switch contact pin I of the relay 3 is arranged on the circuit board block 16, the current transformer 41 is sleeved on the circuit board block 16 and used for detecting a current signal on the first conductive wire 11, the current transformer 41 is connected with the current zero-crossing breaking circuit 4 arranged on the second circuit board 2 through a conductive wire, a second conductive wire 12 connected with the switch contact pin II of, the second circuit board 2 is provided with a first live wire interface L1 connected with the first conducting wire 11 and a second live wire interface L2 connected with the second conducting wire 12, one side of the first circuit board 1 provided with the notch 15 is detachably connected with the second circuit board 2, and the first circuit board 1 is perpendicular to the second circuit board 2.

Preferably, as shown in fig. 2 and 4, the current zero-crossing breaking circuit 4 comprises an MCU, a resistor R1, a resistor R2, a resistor R3 and a resistor R4, the high-voltage switch comprises a resistor R5, a diode D1, a diode D2, a capacitor C1, a capacitor C2 and a switch tube Q1, wherein one end of the resistor R1 is connected with the MCU, the other end of the resistor R1 is connected with the positive electrode end of the diode D1, the negative electrode end of the diode D1 is respectively connected with one end of the resistor R2 and the positive electrode end of the capacitor C1, the negative electrode end of the capacitor C1 is grounded, the other end of the resistor R2 is respectively connected with the MCU, the negative electrode end of the diode D2 and the positive electrode end of the capacitor C2, the positive electrode end of the diode D2 and the negative electrode end of the capacitor C2 are connected with the ground after being connected, one end of the resistor R4 is connected with the MCU, the other end of the resistor R4 is connected with the resistor R5 and then grounded, a current transformer 41 is connected with two ends of the resistor R5 through a lead, the base of the MCU and the switch tube Q36. In the current zero-crossing breaking circuit 4, a resistor R2, a diode D2 and a capacitor C2 form a power supply circuit of the MCU, the resistor R3 and a switch tube Q1 are driving circuits of the relay 3, the resistor R1 is used for detecting input commands, the diode D1 and the capacitor C1 form an electric energy maintaining circuit, when a command of closing the relay 3 is received, but before a contact of the relay 3 is released, power supply is continuously maintained for a period of time, and effective application of a current zero-crossing breaking function is guaranteed. Preferably, the switching transistor Q1 is an NPN transistor, and the switching transistor Q1 may be a MOS transistor.

Preferably, the second circuit board 2 is provided with a first connecting line 21 connected with the positive terminal of the capacitor C1 and a second connecting line 22 connected with the collector of the switching tube Q1, the first connecting line 21 and the second connecting line 22 extend to the junction of the second circuit board 2 and the first circuit board 1 respectively, the first circuit board 1 is provided with a third conducting wire 13 and a fourth conducting wire 14 connected with the coil pin of the relay 3, and the third conducting wire 13 and the fourth conducting wire 14 extend to the junction of the first circuit board 1 and the second circuit board 2 respectively and are in butt joint with the first connecting line 21 and the second connecting line 22 respectively. When the circuit board I1 and the circuit board II 2 are installed, the connecting line I21 is just butted with the conducting wire III 13, and the connecting line II 22 is just butted with the conducting wire IV 14, so that the assembly and the connection of the connecting line I21 and the conducting wire IV are more convenient.

Preferably, the first conductive wire 11 and the second conductive wire 12 extend to a junction between the first circuit board 1 and the second circuit board 2, the second circuit board 2 is provided with a third connection line 23 connected to the first live wire interface L1 and a fourth connection line 24 connected to the second live wire interface L2, the third connection line 23 extends to a junction between the second circuit board 2 and the first circuit board 1 and is in butt joint with the first conductive wire 11, and the fourth connection line 24 extends to a junction between the second circuit board 2 and the first circuit board 1 and is in butt joint with the second conductive wire 12. The first conducting wire 11, the second conducting wire 12, the third conducting wire 13 and the conducting wire 14 on the first circuit board 1 extend towards the side edge with the notch and extend to the position of the junction of the second circuit board 2, and similarly, the first connecting wire 21, the second connecting wire 22, the third connecting wire 23 and the fourth connecting wire 24 on the second circuit board 2 extend to the position of the junction of the first circuit board 1, and the positions of the first connecting wire 21, the second connecting wire 12, the third connecting wire 13 and the fourth connecting wire 14 can be respectively and correspondingly connected with the first conducting wire 11, the second conducting wire 12, the third conducting.

Preferably, the butt joint of the conductive wire three 13 and the connecting wire one 21 is connected by welding, the butt joint of the conductive wire four 14 and the connecting wire two 22 is connected by welding, the butt joint of the conductive wire one 11 and the connecting wire three 23 is connected by welding, and the butt joint of the conductive wire two 12 and the connecting wire four 24 is connected by welding. As another connection method, the two may be connected by a wire in addition to the soldering connection.

The first conducting wire 11, the second conducting wire 12, the third conducting wire 13, the first connecting wire 14, the second connecting wire 22, the third connecting wire 23 and the fourth connecting wire 24 are made of metal materials and are directly embedded on the first circuit board and the second circuit board.

As another scheme, the first conductive line 11, the second conductive line 12, the third conductive line 13, the first conductive line 14, the first connecting line 21, the second connecting line 22, the third connecting line 23, and the fourth connecting line 24 may be conductive lines, for example, a collector terminal of the transistor Q1 is connected to an interface, an anode of the capacitor C2 is connected to an interface, the two interfaces are directly connected to coil pins of the relay 3 through conductive lines, and similarly, a switch contact of the relay 3 is directly connected to the first live wire interface L1 and the second live wire interface L2 through conductive lines.

Preferably, the second circuit board 2 is further provided with a first conductive hole 25 for connecting the resistor R1 and the diode D1, and a second conductive hole 26 for connecting the ground. The arrangement of the first conductive hole 25 and the second conductive hole 26 can enable the current zero-crossing breaking circuit 4 to be connected with the coil of the original circuit relay 3 through the first conductive hole 25 and the second conductive hole 26, the control circuit of original electrical equipment does not need to be changed, application is more convenient, and meanwhile maintenance is facilitated when a fault occurs.

Preferably, as shown in fig. 1 and 3, the relay structure further includes an L-shaped mounting bracket 5, where the mounting bracket 5 includes a first fixing plate 51 and a second fixing plate 52, two sides of the first fixing plate 51 have a first slot 53, the second circuit board 2 is inserted into the first slot 53, two sides of the second fixing plate 52 have a second slot 54, and the first circuit board 1 is inserted into the second slot 54. When the circuit board is installed, two side edges of the first circuit board 1 are inserted opposite to the second clamping groove 54, two side edges of the second circuit board 2 are inserted opposite to the first clamping groove 53, and the first circuit board 1 and the second circuit board 2 can be limited and fixed.

The working principle of the circuit structure for controlling the zero-crossing breaking of the relay current is as follows: when the relay is applied, a load and alternating current are connected through a second live wire interface L2 and a first live wire interface L1, when a relay 3 is switched off, the load is electrified to work, a current transformer 41 sleeved on a circuit board block 16 detects current on a conducting wire I11 and transmits the current to an MCU (microprogrammed control unit), the MCU acquires current data through a resistor R4 and a resistor R5 and is used for judging when an alternating current waveform output to the load crosses zero and when a switch of the relay 3 is switched off, the current zero-crossing on-off control of the MCU is the prior art, when the MCU receives a zero-crossing signal, firstly, an on-off signal of the relay 3 is output according to preset delay time and passes through the resistor R3 to a switch tube Q1, so that a coil of the relay 3 is powered off, after the coil of the relay 3 is powered off, the switch of the relay 3 is switched off, the switch is, continuously detecting the current on the first conducting wire through the current transformer 41, and judging and recording the off time of the relay switch; when the relay is electrified, the circuit outputs different delay time when the relay is released every time, so that the switch off time approaches to the minimum value, thereby playing the roles of reducing the electric arc intensity, reducing the electric erosion of the contact and prolonging the service life of the contact.

Preferably, as shown in fig. 2, the positions of the first conductive hole 25 and the second conductive hole 26 on the second circuit board 2 are used to correspond to the interface of the original circuit board for installing and connecting the relay coil, the positions of the first live wire interface L1 and the second live wire interface L2 on the second circuit board 2 are used to correspond to the interface of the original circuit board for installing and connecting the relay switch, and the second circuit board 2 is further provided with a third conductive hole 27 for corresponding to the interface of the original circuit board for installing and connecting the relay switch. The original circuit board is a circuit board of an original electric circuit, a relay on the original circuit board is directly connected in an alternating current circuit, a current zero-crossing breaking circuit 4 is not arranged, and the circuit structure for controlling the zero-crossing breaking of the relay current enables the first conductive hole 25, the second conductive hole 26, the first live wire interface L1 and the second live wire interface L2 to correspond to the pin positions of the relay on the original circuit board through the design of the first conductive hole 25, the second conductive hole 26, the first live wire interface L1 and the second live wire interface L2, so that the circuit structure for controlling the zero-crossing breaking of the relay current can directly replace the relay on the original circuit board, and the installation is more convenient.

Preferably, the interface at the position of the coil of the relay 3 arranged on the original circuit can be connected with the first conductive hole 25 and the second conductive hole 26 on the second circuit board through leads, so that the current zero-crossing breaking function of the relay 3 can be realized under the condition of not changing the original electric circuit, the service life of the circuit is prolonged, the maintenance is convenient, and the replacement of the whole circuit board is not needed when the circuit is damaged.

Example two:

the technical solution in this embodiment is substantially the same as that in the first embodiment, except that the first circuit board 1 and the second circuit board 2 are fixed by screws.

Example three:

the technical scheme in the embodiment is basically the same as that in the first embodiment, except that the sides of the first circuit board 1 and the second circuit board 2 which are connected with each other are respectively provided with a cross opening, the first circuit board 1 and the second circuit board 2 are connected in a clamping manner, and then the first circuit board 1 and the second circuit board 2 are welded and fixed after being clamped.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. A circuit structure for controlling relay current zero-crossing breaking comprises a first circuit board (1) and a second circuit board (2), and is characterized in that a relay (3) is arranged on the first circuit board (1), a current zero-crossing breaking circuit (4) used for being connected with a coil of the relay (3) is arranged on the second circuit board (2), two notches (15) are formed in the same side edge of the first circuit board (1), a circuit board block (16) is arranged between the two notches (15), a first conductive wire (11) connected with a switch contact pin of the relay (3) is arranged on the circuit board block (16), a second conductive wire (12) connected with the other switch contact pin of the relay (3) is arranged on the first circuit board (1), the current zero-crossing breaking circuit (4) comprises a current transformer (41) which is sleeved on the circuit board block (16) and used for detecting a current signal on the first conductive wire (11), be provided with the first live wire interface L1 of being connected with conducting wire (11) and the second live wire interface L2 of being connected with conducting wire two (12) on circuit board two (2), circuit board one (1) is equipped with one side of breach (15) and can dismantle with circuit board two (2) and be connected, circuit board one (1) and circuit board two (2) mutually perpendicular.

2. The circuit structure for controlling relay current zero-crossing breaking according to claim 1, wherein the current zero-crossing breaking circuit (4) comprises an MCU, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a diode D1, a diode D2, a capacitor C1, a capacitor C2 and a switch tube Q1, one end of the resistor R1 is connected with the MCU, the other end of the resistor R1 is connected with the positive terminal of the diode D1, the negative terminal of the diode D1 is respectively connected with one end of a resistor R2 and the positive terminal of a capacitor C1, the negative terminal of the capacitor C1 is grounded, the other end of the resistor R2 is respectively connected with the MCU, the negative terminal of the diode D2 and the positive terminal of a capacitor C2, the positive terminal of the diode D2 and the negative terminal of the capacitor C2 are connected with the ground, one end of the resistor R2 is connected with the MCU, the other end of the resistor R2 is connected with the ground, and the two ends of the current transformer (R3641) are connected with the current transformer, the base electrodes of the MCU and the switch tube Q1 are connected through a resistor R3, and a coil of a relay (3) is connected between the collector electrode of the switch tube Q1 and the positive electrode of the capacitor C1.

3. The circuit structure for controlling the zero-crossing breaking of the relay current according to claim 2, wherein a first connecting wire (21) connected with the positive terminal of the capacitor C1 and a second connecting wire (22) connected with the collector electrode of the switch tube Q1 are arranged on the second circuit board (2), the first connecting wire (21) and the second connecting wire (22) respectively extend to the junction of the second circuit board (2) and the first circuit board (1), a third conducting wire (13) and a fourth conducting wire (14) connected with the coil pin of the relay (3) are arranged on the first circuit board (1), and the third conducting wire (13) and the fourth conducting wire (14) respectively extend to the junction of the first circuit board (1) and the second circuit board (2) and are respectively butted with the first connecting wire (21) and the second connecting wire (22).

4. The circuit structure for controlling the zero-crossing breaking of the relay current according to claim 3, wherein the first conducting wire (11) and the second conducting wire (12) respectively extend to the junction of the first circuit board (1) and the second circuit board (2), a third connecting wire (23) connected with the first live wire interface L1 and a fourth connecting wire (24) connected with the second live wire interface L2 are distributed on the second circuit board (2), the third connecting wire (23) extends to the junction of the second circuit board (2) and the first circuit board (1) and is butted with the first conducting wire (11), and the fourth connecting wire (24) extends to the junction of the second circuit board (2) and the first circuit board (1) and is butted with the second conducting wire (12).

5. The circuit structure for controlling relay current zero-crossing breaking according to claim 4, wherein a joint of the conductive wire three (13) and the connecting wire one (21) is connected by welding, a joint of the conductive wire four (14) and the connecting wire two (22) is connected by welding, a joint of the conductive wire one (11) and the connecting wire three (23) is connected by welding, and a joint of the conductive wire two (12) and the connecting wire four (24) is connected by welding.

6. A circuit structure for controlling relay current zero-crossing breaking according to any one of claims 2-5, characterized in that a first conducting hole (27) for connecting with a resistor R1 and a diode D1 and a second conducting hole (28) for connecting with a ground wire are further arranged on the second circuit board (2).

7. A circuit structure for controlling the zero-crossing breaking of current of a relay according to any one of claims 1-5, characterized in that the relay structure further comprises an L-shaped mounting frame (5), the mounting frame (5) comprises a first fixing plate (51) and a second fixing plate (52), a first clamping groove (53) is formed in each side edge of the first fixing plate (51), the second circuit board (2) is inserted into the first clamping groove (53), a second clamping groove (54) is formed in each side edge of the second fixing plate (52), and the first circuit board (1) is inserted into the second clamping groove (54).