CN202167713U

CN202167713U - Leakage protective plug

Info

Publication number: CN202167713U
Application number: CN2011202859416U
Authority: CN
Inventors: 刘睿刚
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-09
Filing date: 2011-08-09
Publication date: 2012-03-14
Anticipated expiration: 2021-08-09

Abstract

The utility model discloses a leakage protective plug, which can not only avoid electric shock accidents caused by electrical faults, but also avoid electric shock accidents caused by the fact that a grounding wire is electrified accidentally. The leakage protective plug is further provided with a weak current detection sensor which is provided with an iron core, a primary winding and a secondary winding, and the primary winding and the secondary winding of the weak current detection sensor are both wound on the iron core and separated in insulating mode. A detection return circuit formed by connecting the primary winding of the weak current detection sensor and a current-limiting capacitance resistant element in series mode is connected between the grounding wire and a zero line, and the output end of the secondary winding of the weak current detection sensor and the output end of a secondary winding of a zero sequence current transformer are respectively in parallel connection with the input end of a driving circuit of an electromagnetic coil.

Description

A kind of leakage protecting plug

Technical field

The utility model relates to Electrical Safety resist technology field, especially relates to a kind of leakage protecting plug.

Background technology

Chinese patent document CN1142618C discloses the leakage protecting plug that a kind of ground wire can open and close; Not only be provided with zero sequence current mutual inductor that phase line and zero line all pass on this leakage protecting plug, also be provided with the ground wire electrified detection inductor that ground wire passes; Therefore it not only can detect between load end phase line and the zero line and have or not residual current; (for example: 10mA), it will be threaded off immediately, cuts off phase line, zero line and ground wire when occurring residual current between phase, the zero line and reaching the threshold values that presets; And when the ground protection system exception causes the ground wire accident charged; It can also detect the load end ground wire has the zero accident electric current; (for example: 10mA), it also can be threaded off immediately, cuts off phase line, zero line and ground wire when ground wire unexpected electric current occurs and reaches the threshold values that presets.

By on can know; Existing leakage protecting plug is exactly must have between load end phase, the zero line must have a mind to extrinsic current on residual current or the load end ground wire and flow through and could thread off in the unexpected precondition that can thread off when charged of the electric leakage of load end fault or ground wire; So just there is following defective in existing leakage protecting plug: during use; No matter be when ground protection system ground wire disappearance (for example: the virtual connection of socket ground wire causes no ground connection) and the electric leakage of leakage protecting plug load end consuming device insulation fault; Still when ground protection system exception (for example: phase line, earth short) causes the ground wire accident charged; Dangerous voltage on the exposed metal parts band of consuming device is caused in the capital; But they all do not constitute the loop thereby also do not produce the unexpected electric current of residual current or ground wire, so, although consuming device exposed metal parts have been with dangerous voltage; But existing leakage protecting plug can not threaded off in this case automatically; Have only when human body or livestock touch these with the exposed metal parts that power on, just form the loop, leakage protecting plug is threaded off and phase line, zero line, ground wire disconnection in 0.1S thereby produce residual current or the unexpected electric current of ground wire through human body or livestock; Though in time threading off, it has protected the life security of people or livestock; But existing leakage protecting plug be in this case must be earlier through human body or livestock get an electric shock produce residual current or the unexpected electric current of ground wire and flow through human body or livestock after, it could thread off phase line, zero line, ground wire disconnection, still can cause the electric shock accidents of human body or livestock so have leakage protecting plug now.

Summary of the invention

The purpose of the utility model is to provide a kind of leakage protecting plug that can overcome above-mentioned existing leakage protecting plug defective; Electric leakage or load end ground wire not only can take place in load end phase, zero line road and meet accident and all break off phase line contact, zero line contact and ground wire contact in time when charged in it; And it when ground protection system earth disappearance (for example: the virtual connection of socket ground wire causes no ground connection) and the electric leakage of leakage protecting plug load end consuming device cause on the electric appliance casing band dangerous voltage or the ground protection system can also touch consuming device people or livestock when taking place to cause the ground wire accident to be with dangerous voltage unusually and will thread off automatically before; In time break off phase line, zero line and ground wire; For people provide better Electrical Safety guarantee, and it has also improved the reliability of leakage protecting plug.

The technical solution that the utility model proposed is such:

A kind of leakage protecting plug; Comprise zero sequence current mutual inductor, test loop, electromagnetic trip and locker that shell and latch, phase line, zero line, ground wire, phase line and zero line all pass; This electromagnetic trip and locker comprise solenoid and drive circuit, contact, spring, push rod resets; The drive circuit of said solenoid mainly is made up of rectification circuit, controllable silicon; Also be provided with weak current and detect inductor; Said weak current detects inductor and is provided with iron core, elementary winding and secondary winding; Said weak current detection elementary winding of inductor and secondary winding all detect on the inductor iron core around said weak current, and said weak current detects between elementary winding of inductor and the secondary winding and insulate separately, between ground wire and zero line, are connected with the detection loop that is in series by said weak current detection elementary winding of inductor and current limliting Resistor-Capacitor Unit; Said weak current detects sensor secondary winding output and is connected in parallel with said zero sequence current mutual inductor secondary winding output respectively, and said zero sequence current mutual inductor secondary winding output is connected in parallel with the drive circuit input of said solenoid respectively.

When the drive circuit of said solenoid is made up of rectification circuit, controllable silicon and amplifying circuit; Said zero sequence current mutual inductor secondary winding output is connected in parallel with said input amplifier respectively; Said amplifying circuit triggers output and is connected with said controllable silicon trigger electrode; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

When the drive circuit of said solenoid by rectification circuit, when controllable silicon is formed; Said zero sequence current mutual inductor secondary winding output is connected in parallel with said controllable silicon trigger electrode and negative electrode respectively; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

When the drive circuit of said solenoid by rectification circuit, controllable silicon, clamp diode, the 1st resistance, the 2nd resistance, when voltage stabilizing didoe is formed; Be connected with the loop that is in series by the 1st resistance, the 2nd resistance, clamp diode between said rectification circuit output end positive pole and the negative pole; The 1st resistance one end is connected with rectification circuit output end is anodal; The 1st resistance other end is connected with the 2nd resistance one end, and the 2nd resistance other end is connected with clamp diode is anodal, and the clamp diode negative pole is connected with the rectification circuit output end negative pole; The 1st resistance other end, the 2nd resistance one end also are connected with the voltage stabilizing didoe negative pole respectively; Voltage stabilizing didoe is anodal to be connected with the rectification circuit output end negative pole, and said zero sequence current mutual inductor secondary winding one output is connected with said controllable silicon trigger electrode, and its another output is connected with said clamp diode is anodal; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

Said current limliting Resistor-Capacitor Unit is resistance or electric capacity or resistance and capacitance component.

Said weak current detects the inductor iron core and is processed by permalloy or amorphous alloy or ultramicro-crystal alloy material.

Said weak current detects between ground wire and the zero line that detection loop that the elementary winding of inductor and current limliting Resistor-Capacitor Unit be in series is connected power end or between the ground wire and zero line of load end.

The substantive features of the utility model be except the same with the leakage protecting plug of prior art can detect have or not residual current between load phase, the zero line and detect ground wire whether charged, when between phase, the zero line and ground wire break down respectively or simultaneously Shi Douhui move immediately all break off phase, zero, ground wire; Also be between the ground wire of leakage protecting plug and zero line, to be provided with testing circuit; When causing the ground wire accident, the ground protection system exception is with dangerous voltage or when the electric leakage of ground protection system earth disappearance and consuming device causes on exposed metal parts and the ground tape dangerous voltage; It can detect, respond to the output signal automatically and leakage protecting plug is threaded off automatically; Break off phase line, zero line, ground wire; Thereby realized human body or livestock touch these with on just break off phase line, zero line, ground wire entirely before the exposed metal parts of dangerous voltage, and the weak current that ground wire also need not pass on the leakage protecting plug detects inductor.

Compared with prior art, the utlity model has following beneficial effect:

(1), the leakage protecting plug of the utility model is owing to be connected with the detection loop that is composed in series by weak current detection elementary winding of inductor and current limliting Resistor-Capacitor Unit between ground wire and zero line; When in use; In case when electric leakage of the consuming device fault on leakage protecting plug load end phase, the zero line and ground protection system ground wire disappearance (for example: the virtual connection of socket ground wire causes no ground connection); Metal parts that consuming device exposes and leakage protecting plug ground wire all can be with dangerous voltage; Weak current detects inductor will detect, responds to and export signal; Leakage protecting plug, human body or livestock just can in time be broken off phase line, zero line and ground wire before touching consuming device entirely; It must human body than existing leakage protecting plug in this case the time or livestock touch and flow through could thread off after the residual current better technical solution is provided, so it is more safer than existing leakage protecting plug.

(2), the leakage protecting plug of the utility model is owing to be connected with the detection loop that is composed in series by weak current detection elementary winding of inductor and current limliting Resistor-Capacitor Unit between ground wire and zero line; When in use; When in case the ground protection system exception causes the ground wire accident to be with dangerous voltage; Weak current detects inductor will detect, responds to and export signal; Leakage protecting plug, human body or livestock just can in time be broken off phase line, zero line and ground wire before touching electrical equipment entirely; It must human body than existing leakage protecting plug in this case the time or livestock touch and flow through could thread off after the unexpected electric current of ground wire better technical solution is provided, so it is more safer than existing leakage protecting plug.

(3), the leakage protecting plug of the utility model is because the elementary winding of weak current detection inductor that is connected between ground wire and the zero line also can detect, responds to and export signal to the low current signal that flows through it; And this elementary winding do not have the restriction of minimum starting voltage, thus it to ground wire with the voltage height unrestricted, reach the threshold values (for example: 10 microamperes) that presets as long as flow through the electric current that weak current detects the elementary winding of inductor; Leakage protecting plug of the present invention will be threaded off; Therefore, it not only ground wire (or consuming device exposed metal parts) with dangerous voltage high can thread off during for 250V, and ground wire with voltage (or lower when being low to moderate predetermined 36V safe voltage; For example: 24V) also can reliably thread off; When ground wire with voltage when being lower than predetermined 36V safe voltage, it just need not threaded off to avoid misoperation, the voltage range that it can shield is wide; So leakage protecting plug of the present invention is not only good to be used but also safety and reliability.

(4), the leakage protecting plug of the utility model also can be threaded off when the phase line of power end and zero line reversal connection automatically; Can not reset; Have only just coming into operation after the correction of the wiring state of supply socket phase line and zero line; Forcibly standard the user side supply socket wiring requirement that must meet national regulation connect, in case other contingencies take place when using.

(5), the leakage protecting plug of the utility model need not be provided with ground wire electrified detection inductor or the instrument transformer that ground wire passes on ground wire; Phase line, zero line, ground wire also need not pass weak current of the present invention and detect inductor; Therefore, can be convenient to produce and save cost.

(6), the leakage protecting plug of the utility model weak current detect the elementary winding of inductor and secondary winding separate the independence setting make insulated from each other between them, separate; Make between leakage protecting plug power end and the load end and phase line and zero line improve insulation property between the ground wire and anti-electrical strength ability, thereby improved the reliability of leakage protecting plug.

The leakage protecting plug of the utility model is mainly used on the earth leakage protective of various household electrical appliance.

Description of drawings

Fig. 1 is the leakage protecting plug electrical principle sketch map of the utility model embodiment 1, and its zero sequence current mutual inductor secondary winding output is connected in parallel with input amplifier respectively.

Fig. 2 is the leakage protecting plug electrical principle sketch map of the utility model embodiment 2, and its zero sequence current mutual inductor secondary winding output is connected in parallel with controllable silicon trigger electrode and negative electrode respectively.

Fig. 3 is the leakage protecting plug electrical principle sketch map of the utility model embodiment 3, and its zero sequence current mutual inductor secondary winding one output is connected with the controllable silicon trigger electrode, and its another output is connected with clamp diode is anodal.

Embodiment

Through following embodiment the utility model is done further to set forth in detail.

Embodiment 1:

Referring to shown in Figure 1, a kind of leakage protecting plug mainly by plug body and phase, zero, three utmost point latches, the phase line 5 of power end, zero line 6, ground wire 7, rectification circuit 12, controllable silicon 13, zero sequence current mutual inductor 15, test loop 16, the weak current phase line 8, zero line 9, ground wire 10, amplifying circuit 18, electromagnetic trip and the locker that detect inductor 14, current limliting Resistor-Capacitor Unit 17, load end form.Electromagnetic trip and locker mainly are made up of solenoid 11 and drive circuit, phase line contact 1-1 and 2-1, zero line contact 1-2 and 2-2, ground wire contact 3 and 4, spring, the push rod that resets.The detection loop that is composed in series by weak current detection inductor 14 elementary windings and current limliting Resistor-Capacitor Unit 17 is connected between the ground wire 7 and zero line 6 of power end, and weak current detects inductor 14 secondary winding outputs and is connected in parallel with zero sequence current mutual inductor 15 secondary winding outputs respectively.

In the present embodiment; Current limliting Resistor-Capacitor Unit 17 is a current-limiting resistance; Also can adopt electric capacity or resistance and capacitance component; The drive circuit of said solenoid 11 mainly is made up of rectification circuit 12, controllable silicon 13 and amplifying circuit 18; Zero sequence current mutual inductor 15 secondary winding outputs and amplifying circuit 18 inputs are connected in parallel, and amplifying circuit 18 triggers output and is connected with controllable silicon 13 trigger electrodes, and controllable silicon 13 anodes are connected with negative pole with rectification circuit 12 output head anodes respectively with negative electrode; The signal of zero sequence current mutual inductor 15 secondary winding output triggers controllable silicon 13 conductings after amplifying circuit 18 amplifies, to solenoid 11 power supplies leakage protecting plug is threaded off through controllable silicon 13 and rectification circuit 12.

In the present embodiment; Weak current detects inductor 14 iron cores and adopts the permalloy material to process; Also can adopt amorphous alloy or ultramicro-crystal alloy material to process; Weak current detects the detection loop that inductor 14 elementary windings and current limliting Resistor-Capacitor Unit 17 be in series and is connected between the ground wire 7 and zero line 6 of power end, also can detect this between ground wire 10 and zero line 9 that loop is connected load end.

During use; Press the push rod that resets of leakage protecting plug; Phase line contact 1-1 and 2-1, zero line contact 1-2 and 2-2 and ground wire contact 3 and 4 are all normally connected; The phase line 8 of load end, zero line 9, ground wire 10 are connected with phase line 5, zero line 6, the ground wire 7 of power end respectively; Ground wire 7 and 10 is because the effect of ground connection is clamped at about zero volt voltage, and zero

line

6 and 9 also is about zero volt simultaneously, and the electric current that being connected the weak current detection inductor 18 elementary windings between leakage protecting plug power end ground wire 7 and the zero line 6 does not so just have electric current to flow through or flow through does not reach the threshold values (for example: 10 microamperes) that presets; This moment, leakage protecting plug remained on the "on" position that resets, thereby for the power supply of the consuming device of its lower end with ground connection is provided.

During use; If the consuming device fault on the phase line of load end 8, the zero line 9 electric leakage and in the normal situation of ground protection system following time; Can produce a residual current through ground wire 10 and 7; Zero sequence current mutual inductor 15 can detect the residual current between phase, the zero line and export a signal and give amplifying circuit 18; And when residual current reaches predefined threshold values (for example: 10 milliamperes); Controllable silicon 13 is exaggerated circuit 18 triggering and conducting, and the solenoid 11 on electromagnetic trip and the locker gets the electric leakage protecting plug that makes and threads off, and before people touch consuming device, just can in time all break off phase line contact 1-1 and 2-1, zero line contact 1-2 and 2-2, ground wire contact 3 and 4; If the consuming device fault on the phase line of load end 8, the zero line 9 electric leakage and when not having ground connection (for example: the ground wire virtual connection causes no ground connection on the socket) in the ground protection system; Metal parts that consuming device exposes and leakage protecting plug ground wire 10 and 7 all can be with dangerous voltage; The elementary winding that ground wire 7 and the weak current between the zero line 6 that is connected the leakage protecting plug power end detects inductor 14 just has a weak current and flows through; Weak current detects inductor 14 secondary winding can export a signal to amplifying circuit 18; And when weak current reaches predefined threshold values (for example: 10 microamperes); Controllable silicon 13 is exaggerated circuit 18 triggering and conducting; Solenoid 11 on electromagnetic trip and the locker the electric leakage protecting plug that make is threaded off, before people touch consuming device, just can in time all break off phase line contact 1-1 and 2-1, zero line contact 1-2 and 2-2, ground wire contact 3 and 4, thereby better Electrical Safety guarantee is provided for people.

During use; If the ground protection system takes place to cause ground wire 7 and 10 accidents to be with dangerous voltage unusually; Ground wire 7 and the weak current between the zero line 6 that is connected power end like this detects inductor 14 elementary windings and just has a weak current and flow through; Weak current detects inductor 14 secondary winding can export a signal to amplifying circuit 18; And when weak current reached predefined threshold values (for example: 10 microamperes), controllable silicon 13 was exaggerated circuit 18 triggering and conducting, and the solenoid 11 on electromagnetic trip and the locker gets the electric leakage protecting plug that makes and threads off; Touch people and just can in time all break off phase line contact 1-1 and 2-1, zero line contact 1-2 and 2-2, ground wire contact 3 and 4 before the consuming device, thereby protected people's safety better.

Embodiment 2:

Referring to shown in Figure 2; Compare with embodiment 1; Cancelled in the present embodiment and implemented 1 described amplifying circuit 18; And by being connected in parallel with embodiment 1 described amplifying circuit 18 inputs controllable silicon 13 trigger electrodes and the negative electrode that changes to respectively with present embodiment that be connected in parallel respectively, controllable silicon 13 anodes are connected with negative pole with rectification circuit 12 output head anodes respectively with negative electrode, make the signal of zero sequence current mutual inductor 15 secondary winding output directly trigger controllable silicon 13 zero sequence current mutual inductor 15 secondary winding outputs; Because the signal of said zero sequence current mutual inductor 15 secondary winding output is enough big, can not trigger controllable silicon 13 so just need not amplify.

In the present embodiment; Current limliting Resistor-Capacitor Unit 17 is a current-limiting resistance; Also can adopt electric capacity or resistance and capacitance component, the drive circuit of solenoid 11 is made up of said rectification circuit 12, controllable silicon 13, and zero sequence current mutual inductor 15 secondary winding outputs and controllable silicon 13 trigger electrodes are parallelly connected with negative electrode; Controllable silicon 13 anodes are connected with negative pole with rectification circuit 12 output head anodes respectively with negative electrode, to solenoid 11 power supplies leakage protecting plug are threaded off with rectification circuit 12 through triggering controllable silicon 13.

In the present embodiment; Weak current detects inductor 14 iron cores and adopts the ultramicro-crystal alloy material to process; Also can adopt permalloy or amorphous alloy material to process; The detection loop that weak current detection inductor 14 elementary windings and current limliting Resistor-Capacitor Unit 17 are in series is connected between the ground wire 7 and zero line 6 of power end; Also can detect this between ground wire 10 and zero line 9 that loop is connected load end, weak current detects inductor 14 secondary winding outputs and is connected in parallel with zero sequence current mutual inductor 15 secondary winding outputs respectively.

Because the remaining circuit structure of present embodiment leakage protecting plug is all identical with embodiment 1, only be the control mode difference that triggers controllable silicon 13, do not give unnecessary details at this.

Embodiment 3:

Referring to shown in Figure 3; Compare with embodiment 2; Present embodiment has increased the clamp diode 19 anodal clamp circuits that combined by the 1st resistance the 21, the 2nd resistance 20, clamp diode 19, voltage stabilizing didoe 22 in the drive circuit of solenoid; Clamp diode 19 be connected between rectification circuit 12 output head anodes and the negative pole after the 2nd resistance the 20, the 1st resistance 21 is connected, the 1st resistance 21 1 ends are connected with rectification circuit 12 output head anodes, the 1st resistance 21 other ends are connected with the 2nd resistance 20 1 ends; The 2nd resistance 20 other ends and 19 anodal connections of clamp diode; Clamp diode 19 negative poles are connected with rectification circuit 12 negative pole of output end, and the 1st resistance 21 other ends, the 2nd resistance 20 1 ends also are connected with voltage stabilizing didoe 22 negative poles respectively, and voltage stabilizing didoe 22 positive poles are connected with rectification circuit 12 negative pole of output end; Controllable silicon 13 anodes are connected with negative pole with rectification circuit 12 output head anodes respectively with negative electrode, thereby have reduced the requirement to zero sequence current mutual inductor 15 secondary winding output voltages.

In the present embodiment; Current limliting Resistor-Capacitor Unit 17 is a current-limiting resistance; Also can adopt electric capacity or resistance and capacitance component; The drive circuit of solenoid 11 is made up of rectification circuit 12, controllable silicon 13, clamp diode the 19, the 1st resistance the 21, the 2nd resistance 20, voltage stabilizing didoe 22; Zero sequence current mutual inductor 15 secondary winding one output is connected with controllable silicon 13 trigger electrodes; 19 anodal connections of its another output and clamp diode are superimposed upon on the basis of clamp diode 19 conduction voltage drops (about 0.3V) signal of zero sequence current mutual inductor 15 secondary winding output and trigger controllable silicon 13 conductings, and supplying power to solenoid 11 with rectification circuit 12 through controllable silicon 13 makes the leakage protecting plug dropout.

In the present embodiment; Weak current detects inductor 14 iron cores and adopts the ultramicro-crystal alloy material to process; Also can adopt amorphous alloy or permalloy material to process; Weak current detects the detection loop that inductor 14 elementary windings and current limliting Resistor-Capacitor Unit 17 be in series and is connected between the ground wire 10 and zero line 9 of load end, also can detect this between ground wire 7 and zero line 6 that loop is connected power end.

Weak current detects inductor 14 secondary winding outputs and is connected in parallel with zero sequence current mutual inductor 15 secondary winding outputs respectively.

Claims

1. leakage protecting plug; Comprise zero sequence current mutual inductor, test loop, electromagnetic trip and locker that shell and latch, phase line, zero line, ground wire, phase line and zero line all pass; This electromagnetic trip and locker comprise solenoid and drive circuit, contact, spring, push rod resets; The drive circuit of said solenoid mainly is made up of rectification circuit, controllable silicon; It is characterized in that: also be provided with weak current and detect inductor; Said weak current detects inductor and is provided with iron core, elementary winding and secondary winding, and said weak current detects the elementary winding of inductor and secondary winding all detects on the inductor iron core around said weak current, and said weak current detects and insulate between elementary winding of inductor and the secondary winding separately; Between ground wire and zero line, be connected with the detection loop that is in series by said weak current detection elementary winding of inductor and current limliting Resistor-Capacitor Unit; Said weak current detects sensor secondary winding output and is connected in parallel with said zero sequence current mutual inductor secondary winding output respectively; Said zero sequence current mutual inductor secondary winding output is connected in parallel with the drive circuit input of said solenoid respectively.

2. leakage protecting plug according to claim 1; It is characterized in that: the drive circuit of said solenoid is made up of rectification circuit, controllable silicon and amplifying circuit; Said zero sequence current mutual inductor secondary winding output is connected in parallel with said input amplifier respectively; Said amplifying circuit triggers output and is connected with said controllable silicon trigger electrode; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

3. leakage protecting plug according to claim 1; It is characterized in that: the drive circuit of said solenoid is made up of rectification circuit, controllable silicon; Said zero sequence current mutual inductor secondary winding output is connected in parallel with said controllable silicon trigger electrode and negative electrode respectively; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

4. leakage protecting plug according to claim 1 is characterized in that: the drive circuit of said solenoid is made up of rectification circuit, controllable silicon, clamp diode, the 1st resistance, the 2nd resistance, voltage stabilizing didoe; Be connected with the loop that is in series by the 1st resistance, the 2nd resistance, clamp diode between said rectification circuit output end positive pole and the negative pole; The 1st resistance one end is connected with rectification circuit output end is anodal; The 1st resistance other end is connected with the 2nd resistance one end; The 2nd resistance other end is connected with clamp diode is anodal; The clamp diode negative pole is connected with the rectification circuit output end negative pole, and the 1st resistance other end, the 2nd resistance one end also are connected with the voltage stabilizing didoe negative pole respectively, and voltage stabilizing didoe is anodal to be connected with the rectification circuit output end negative pole; Said zero sequence current mutual inductor secondary winding one output is connected with said controllable silicon trigger electrode; Its another output is connected with said clamp diode is anodal; Said controllable silicon anode is connected with negative pole with said rectification circuit output end is anodal respectively with negative electrode, supplies power to solenoid through triggering controllable silicon and rectification circuit.

5. leakage protecting plug according to claim 1 is characterized in that: said current limliting Resistor-Capacitor Unit is resistance or electric capacity or resistance and capacitance component.

6. leakage protecting plug according to claim 1 is characterized in that: said weak current detects the inductor iron core and is processed by permalloy or amorphous alloy or ultramicro-crystal alloy material.

7. leakage protecting plug according to claim 1 is characterized in that: said weak current detects between ground wire and the zero line that detection loop that the elementary winding of inductor and current limliting Resistor-Capacitor Unit be in series is connected power end or between the ground wire and zero line of load end.