Voltage-type earth leakage protector
Technical field
The utility model relates to a kind of safeguard protection electrical equipment of low voltage electrical equipment.
Background technology
The electrocution-proof protection of low voltage electrical equipment, be adopt ground protection mode to realize at present, this is traditional way.For conventional TT protection system to earth, it to the requirement between earth resistance, safe voltage, trip protection electric current three is:
R≤U/I(1)
In formula: R is the earth resistance of protected electric equipment metal shell, generally elects 4-10 Europe as;
I is the tripping current of protected electric equipment;
U is selected safe voltage, generally selects 50V.
The metal shell of such electric equipment there will not be the dangerous voltage of more than 50V, once occur that the protection switch of electric equipment will be made to trip reaches safety.But in practice in a lot of situation, 1. R=4-10 Europe is difficult to accomplish, qualification rate is very low; 2. drop into huge fund make earth resistance reach qualified after, but I often again meet (1) formula requirement.In this TT protection practice, effect is bad, and Frequent Accidents, this is in the urgent need to address.
In prior art; disclosing a kind of publication number as known technology is: 102780203A; name is called "-kind of over under-voltage protection circuit "; voltage usually can exist because 380V voltage is applied on 220V circuit or the electrical network overvoltage of power supply that causes of instability or under voltage by wiring error, burns the situation of circuit breaker lower end load equipment.Its operation principle drives controllable silicon to realize protection of threading off after monitored voltage commutation by voltage-stabiliser tube.The difficulty that this patent is used in this place is: sampled voltage (namely overvoltage value is 50V or 24V) is lower and singal source resistance is higher, the power that can export is very little, release can not be driven to realize threading off, the way realizing threading off is additional accessory power supply, but be difficult in many situations, and expense strengthen.
Utility model content
The purpose of this utility model is exactly outside existing ground protection; a kind of voltage-type earth leakage protector is provided; its general principle is still for meeting (1) formula requirement; but change the voltage that thinking changes the metal shell directly measuring electric equipment into; when reaching 50V; arrange special circuit brake in addition go tripping operation or send alarm sound, thus reach effect same.
For achieving the above object, the utility model adopts following technical scheme: a kind of voltage-type earth leakage protector, comprises input circuit, rectification circuit, accumulator, circuits for triggering, executive circuit;
Input circuit: it comprises two inputs, an exposed conductive part connecing protected electrical equipment, another is grounded probe;
Rectification circuit: described rectification circuit comprises bridge rectifier or full-wave rectifier is that the signal introduced by input circuit is transformed into direct current through bridge rectifier or full-wave rectifier;
Accumulator: the direct voltage obtained by rectification circuit is input to storage capacitor thus store electrical energy;
Circuits for triggering, circuits for triggering are connected with controllable silicon positive pole by the negative pole of TVS or voltage-stabiliser tube or are connected with storage capacitor positive pole, the positive pole of TVS or voltage-stabiliser tube is connected with control machines pole, controllable silicon negative pole is connected with storage capacitor negative pole, predetermined value is reached when voltage on storage capacitor rises gradually, controllable silicon is triggered, and storage capacitor discharges to executive circuit;
Executive circuit: executive circuit comprises tripping coil or alarm, described tripping coil is made up of electromagnet and automatic switch, and electromagnet receives the discharging current of storage capacitor, electromagnet action thus promote automatic switch tripping operation, or storage capacitor discharges to alarm, release alarm sound.
One of the present utility model is optimized, described input circuit comprises the first current-limiting resistance, described executive circuit is form tripping coil by electromagnet and automatic switch, described circuits for triggering comprise controllable silicon, voltage-stabiliser tube, described rectification circuit is bridge rectifier, bridge rectifier comprises a pin (a), second pin (b), 3rd pin (c), 4th pin (d), conductive shell and first pin (a) of protected power consumption equipment are serially connected with the first current-limiting resistance, grounded probe is connected with the 3rd pin (c), second pin (b) is held with the M1 of tripping coil and is connected, the M2 end of tripping coil is held with silicon controlled A3 and is connected, silicon controlled K1 end is connected with the 4th pin (d), be connected to storage capacitor between second pin (b) and the 4th pin (d), silicon controlled G2 holds the positive pole with voltage-stabiliser tube
End is connected, and the M2 of the negative pole end of voltage-stabiliser tube and the second pin (b) or tripping coil holds and is connected.
Optimize for one of the present utility model, the described storage capacitor for storage power selects rated capacity to be 470UF-1200UF, and rated voltage is 35V-50V.
Optimize for one of the present utility model, the resistance of the first current-limiting resistance is 470 Ω ~ 1000 Ω, and it burns out backend electronics circuit and a metering function after preventing being subject to 220V and above voltage turn-on.
Optimize for one of the present utility model, silicon controlled G2 end is connected with the positive terminal of voltage-stabiliser tube by the second current-limiting resistance, and the resistance of the second current-limiting resistance is 0 ~ 5.1K Ω.
Optimize for one of the present utility model, TVS or voltage-stabiliser tube, controllable silicon is packaged as a whole becomes the trigger tube of two-terminal or three terminals.
Optimize for one of the present utility model, TVS or voltage-stabiliser tube, controllable silicon, rectifier bridge are encapsulated in the trigger formed in same body.
Optimize for one of the present utility model, described voltage-type earth leakage protector is have the shell of split mounting type and the entirety of split mounting type circuit breaker composition, and the electromagnet of executive circuit promotes the gangbar action of stretching out outside shell, and circuit breaker tripping is tripped.
Optimize for one of the present utility model, described voltage-type earth leakage protector and miniature circuit breaker are structure as a whole.
The utility model is compared with background technology; there is the problem making up current street lamp post grounding system difference, less demanding for grounding system, and do not need external power source; as long as input signal has certain voltage to exist; once lamp stand electric leakage, after now storage capacitor voltage reaches voltage-stabiliser tube conducting voltage value range, voltage-stabiliser tube conducting; instantaneous trigger controllable silicon; make tripping coil action, thus earth leakage protector action makes power supply major loop switch disconnect, and ensures safety.
Accompanying drawing explanation
Fig. 1 is one of theory diagram of voltage-type earth leakage protector.
Fig. 2 is the theory diagram two of voltage-type earth leakage protector.
Fig. 3 is the theory diagram that the voltage-type earth leakage protector of alarm is arranged to by executive circuit.
Fig. 4 is controllable silicon, voltage stabilizing didoe, bridge rectifier bridge the schematic diagram be integrated.
Embodiment
Embodiment 1: with reference to Fig. 1 ~ 4.A kind of voltage-type earth leakage protector, comprises input circuit, rectification circuit, accumulator, circuits for triggering, executive circuit;
Input circuit: it comprises two inputs, an exposed conductive part connecing protected electrical equipment, another is grounded probe 8, can conduct electricity the vertical or horizontal distance having L between part and grounded probe, generally selects 50cm or larger.
Rectification circuit: described rectification circuit comprises bridge rectifier or full-wave rectifier is that the signal introduced by input circuit is transformed into direct current through bridge rectifier or full-wave rectifier; The signal voltage collected by input circuit is connected after a resistance R1 and is entered rectifier.Described rectifier is bridge rectifier or full-wave rectifier, and it exports a direct voltage.Series resistance R1 plays metering function, prevents unexpected voltage from attacking and causes subsequent conditioning circuit to damage.
Accumulator: the direct voltage obtained by rectification circuit is input to storage capacitor thus store electrical energy.
Circuits for triggering, circuits for triggering are connected with controllable silicon positive pole by the negative pole of TVS or voltage-stabiliser tube or are connected with storage capacitor positive pole, the positive pole of TVS or voltage-stabiliser tube is connected with control machines pole, controllable silicon negative pole is connected with storage capacitor negative pole, predetermined value is reached when voltage on storage capacitor rises gradually, controllable silicon is triggered, and storage capacitor discharges to executive circuit; Namely when there being voltage interim, the voltage on storage capacitor rises gradually, and when voltage reaches predetermined value, circuits for triggering are triggered, and storage capacitor is discharged to executive circuit.
Executive circuit: executive circuit comprises tripping coil or alarm, described tripping coil is made up of electromagnet and automatic switch, and electromagnet receives the discharging current of storage capacitor, electromagnet action thus promote automatic switch tripping operation, or storage capacitor discharges to alarm, release alarm sound.
Wherein, TVS or voltage-stabiliser tube, controllable silicon is packaged as a whole becomes the trigger tube of two-terminal or three terminals; Or be encapsulated in by TVS or voltage-stabiliser tube, controllable silicon, rectifier bridge the trigger formed in same body.
Described voltage-type earth leakage protector is have the shell of split mounting type and the entirety of split mounting type circuit breaker composition, and the electromagnet of executive circuit promotes the gangbar action of stretching out outside shell, and circuit breaker tripping is tripped.
Described voltage-type earth leakage protector and miniature circuit breaker are structure as a whole.
Embodiment 2: with reference to Fig. 1 ~ 4.Described input circuit comprises the first current-limiting resistance 1, described executive circuit is form tripping coil 5 by electromagnet and automatic switch, described circuits for triggering comprise controllable silicon 6, voltage-stabiliser tube 4, described rectification circuit is bridge rectifier 2, bridge rectifier 2 comprises the first pin a, second pin b, 3rd pin c, 4th pin d, conductive shell and the first pin a of power consumption equipment are serially connected with the first current-limiting resistance 1, grounded probe is connected with the 3rd pin c, second pin b holds with the M1 of tripping coil 5 and is connected, the M2 end of tripping coil 5 is held with the A3 of controllable silicon 6 and is connected, the K1 end of controllable silicon 6 is connected with the 4th pin d, be connected to storage capacitor 3 between second pin b and the 4th pin d, the G2 end of controllable silicon 6 is connected with the positive terminal of voltage-stabiliser tube 4, the M2 of the negative pole end of voltage-stabiliser tube 4 and the second pin b or tripping coil 5 holds and is connected.The G2 end of controllable silicon 6 is connected with the anode tap of voltage-stabiliser tube 4 by the second current-limiting resistance 9.The described storage capacitor 3 for storage power selects rated capacity to be 470UF-1200UF, and rated voltage is 35V-50V.The resistance of the first current-limiting resistance 1 is 470 Ω-1000 Ω, and it burns out backend electronics circuit and a metering function after preventing being subject to 220V and above voltage turn-on.
Wherein, the G2 end of controllable silicon 6 is connected with the positive terminal of voltage-stabiliser tube 4 by the second current-limiting resistance 9, and the resistance of the second current-limiting resistance 9 is 0 ~ 5.1K Ω.
Its operation principle is: the conductive shell of power consumption equipment is street lamp post, and grounded probe is connected with the 3rd pin c.When having voltage between conductive shell and the two ends of earth terminal, be direct voltage through rectifier bridge 2 rectification and charge to storage capacitor; After storage capacitor 3 voltage reaches voltage-stabiliser tube 4 conducting voltage value range, voltage-stabiliser tube 4 conducting, instantaneous trigger controllable silicon 6, makes tripping coil 5 action, thus deenergization; Also controllable silicon can be made to go to promote sounder and to send alarm sound.
Embodiment 3: with reference to Fig. 1 ~ 4.Below using light pole as a concrete instance: be the safety of protection light fixture in light pole; it must have the switch of overcurrent and short-circuit protection; cheap general split mounting type miniature circuit breaker selected by present this switch; this switch itself has a wicket to enter a gangbar from outside, stirs gently and just can realize tripping operation.Earth leakage protector is also contained in akin split mounting type shell, and both form perfect assembled combination.Sample circuit, rectification circuit, accumulator, circuits for triggering and executive circuit are installed in earth leakage protector inside; when there is more than 24v dangerous voltage in lamp stand; signal is sampled, rectification, energy storage; when reaching setting; storage capacitor is triggered to the electric discharge of execution electromagnet, and electromagnet drives gangbar to make assembled miniature circuit breaker tripping operation.
It is to be understood that: although the present embodiment to be contrasted detailed description to the utility model; but these explanations; just to simple declaration of the present utility model; instead of to restriction of the present utility model; any innovation and creation do not exceeded in the utility model connotation, all fall into protection range of the present utility model.