Modular electric energy metering machine
Technical field
What the present invention relates to is a kind of Application of Power Metering Instruments, particularly be a kind of basic electric power meter with modular characteristics.
Background technology
Along with expanding economy; The national economy every field improves constantly the dependence of electric power energy, in order to measure the quantity with electric consumption, the on-the-spot realization of electric power electricity consumption is effectively managed; So Application of Power Metering Instruments is arisen at the historic moment, and become a focus direction of constantly bringing forth new ideas in the power technology field.
Mainly be electric energy meter for the existing power metering outfit, its can for single epi-position electric energy meter also can be multi-epitope electric energy meter, but find still to exist following defective through for many years management of power use practice;
At first; Because manufacturer is various, the difference of production product specification is therefore in the on-the-spot unification that is difficult to the realization standard of power department electricity consumption; Often in order to realize multi-functional requirement; Therefore will around existing ammeter, increase auxiliary device, and cause the electric-power metering set of equipments bulky, production cost increases;
Secondly; In case power department changes to electricity consumption on-the-spot management expectancy or standard; Manufacturer just need exert from newly the structure of electric-power metering set of equipments being transformed, and original product just can only be eliminated, and the cost of power supply department is wasted greatly;
Once more; For power department; Existing power metering set of equipments needs a large amount of winding displacement wirings in application process, need expend very big cost of labor, and simultaneously numerous and jumbled construction package is given to install and correctly brought great difficulty; Be unfavorable for the on-the-spot realization of electricity consumption fine-grained management, use electrical loss thereby caused;
At last, in a single day existing power metering set of equipments breaks down or needs periodic replacement, and it is all superseded just can only to put in order table, thereby the electric-power metering set of equipments that more renews has caused overlapping investment, for user and power department have increased cost.
Creator of the present invention through research and practice for a long time, adopts the standardized thought of a kind of modularization finally, has obtained this creation.
Summary of the invention
The objective of the invention is to, a kind of modular electric energy metering machine is provided, in order to overcome above-mentioned defective.
For realizing above-mentioned technical purpose, the present invention provides a kind of modular electric energy metering machine, and it comprises:
One power supply unit is in order to provide power for operation;
One line of electric force input-output unit, it comprises: phase line incoming end and zero line incoming end and line output terminal mutually, described phase line incoming end is connected with phase line in the power circuit, and it is connected described phase line output terminal with the next stage power equipment;
One electric energy metrical unit calculates the meritorious/reactive energy value via described phase line incoming end and zero line incoming end;
One pulse signal output unit, the energy value that described electric energy metrical unit is calculated is converted into the pulse signal output that is directly proportional with described energy value.
Preferable; Also comprise a box body; Described power supply unit, line of electric force input-output unit, electric energy metrical unit and pulse signal output unit are arranged in the described box body, and it has a cap, and described phase line incoming end and line output terminal mutually are arranged at the two ends of described box body.
Preferable, described power supply unit comprises:
One power-switching circuit, it carries out transformation with power voltage line handles, in order to electric device power for operation being provided.
Preferable, also comprise:
One standby power supply;
One charging circuit, it is connected with the output terminal of described power-switching circuit, and to described standby power supply power supply;
One detecting commutation circuit, whether it has voltage output in order to detect described power-switching circuit, and when described power-switching circuit no-voltage was exported, starting described standby power supply provided power for operation;
Preferable, also comprise:
One acousto-optic warning device, it is connected with described detecting commutation circuit, when described power-switching circuit no-voltage is exported, in order to carry out sound and light alarm.
Preferable, described electric energy metrical unit, it comprises:
One current signal Acquisition Circuit is in order to the current signal on the real-time collection line of electric force;
One voltage signal acquisition circuit is in order to the voltage signal on the real-time collection line of electric force;
One computing and treatment circuit obtain the instantaneous power value in order to described current signal and described voltage signal are multiplied each other, and obtain the energy value in the determining time through integrator;
Preferable, described pulse signal output unit is a voltage/frequency conversion frequency dividing circuit;
Preferable, the output terminal of described zero line input end and described pulse signal output unit is the differing needles that is integrated in a serial plug;
Preferable, comprising that also one uses power detection circuit, it comprises:
Whether one current detection circuit has electric current to flow through in order to detect described phase line input end;
Whether one pulse-detecting circuit has pulse signal output in order to detect described pulse signal output unit;
One detects decision circuitry, and when described phase line input end has electric current to flow through, and the output of described pulse signal output unit pulse-free signal judges that then modular electric energy metering machine of the present invention breaks down;
Preferable, also comprising an acousto-optic warning device, it is connected with the power detection circuit output terminal with described;
Preferable, also comprising an acousto-optic warning device, it is connected with described detection decision circuitry output terminal, when confirming that modular electric energy metering machine of the present invention breaks down, in order to carry out sound and light alarm;
Preferable, described current detection circuit comprises:
One telefault, it is set on the described phase line;
One comparer, one input end are provided with a reference voltage, and its another input end is connected with the output terminal of described telefault;
Preferable, described pulse-detecting circuit comprises:
One comparer, one input end are provided with a reference voltage, and its another input end is connected with the output terminal of described pulse signal output unit;
Preferable; Described detection decision circuitry is a processor; The one of which input interface links to each other with the output terminal of described current detection circuit, and an input interface links to each other with described pulse-detecting circuit output terminal, judges that through described processor said modular electric energy metering machine breaks down;
Preferable, described processor in order to receiving the status signal of corresponding units, and sends control signal to each said unit, and described processor is single-chip microcomputer, embedded system or FPGA control;
Preferable, also comprising a display unit, it comprises:
One display screen, it is embedded on described box body;
One drive circuit, it drives said display screen and shows power consumption according to the data-signal of the output of control signal that receives said processor output or said metering units.
Preferable, also comprising a display unit, it comprises:
One mechanical register, it is embedded on described box body;
One stepper motor, it drives said mechanical register action and makes described mechanical register show power consumption according to the data-signal of the output of control signal that receives said processor output or said metering units;
Preferable, also comprise: a counting unit, it comprises:
One data processing circuit, the data-signal of output that it receives pulse signal or the said metering units of the output of described pulse signal output unit carries out the energy value stored counts;
One internal communication circuit, it links together described data processing circuit and described processor;
Preferable, also comprising a failure detector circuit, described testing circuit is connected with described data processing circuit, in the no signal output when energy value adds up of described data processing circuit, judges that then described counting unit has fault.
Preferable, also comprising the unit that prevents the box body unnormal unlocking, it comprises: an open detection circuit or an executive circuit, wherein,
Whether described open detection circuit is opened in order to detect box body, when opening, sends detection signal and gives described processor and generate a control signal;
Described executive circuit receives described control signal, and produces the action of reporting to the police or cutting off the line of electric force connection of place circuit;
Preferable, described open detection circuit is a pressure transducer or normal open switch, wherein,
Described pressure transducer, it is arranged at the cap place of said box body, when the pressure at cap place during less than a certain threshold value, produces described detection signal;
Described normal open switch, it is arranged at the cap place of said box body, when the cap place does not have the space, described normal open switch no signal output, on the contrary then normal open switch produces described detection signal;
Preferable, described executive circuit is an acoustic-optic alarm or a line of electric force open circuit, wherein, the line of electric force open circuit is that a relay or isolating switch are arranged on the described phase alignment circuit;
Preferable, also comprise: a memory circuit, it is connected with described data processing circuit and said open detection circuit respectively mutually, when having a power failure, with the energy value of described data processing circuit accumulation, stores in the described memory circuit; When restoring electricity, read the energy value of storing in the described memory circuit by described data processing circuit; And described memory circuit writes down an event information when unnormal unlocking takes place.
Preferable, also comprise a relay or isolating switch, when breaking down situation, cut off line of electric force.
Be with prior art beneficial effect more of the present invention,
One, modular electric energy metering machine of the present invention not only can be used as the basic module of single epi-position ammeter; The more important thing is that it can become the basic module of multi-epitope ammeter, and the basis of the various functional units that need as electricity consumption situ metrology administrative institute of integrated power department;
Two, because the modular characteristics of modular electric energy metering machine of the present invention makes production division realize the scale High-efficient Production, reduced production cost greatly;
Three, the electric energy measuring equipment of producing through modular electric energy metering machine of the present invention makes power department in application process, greatly reduce metering overall investment cost and installation work-hour; Provide the on-the-spot fine-grained management of electricity consumption necessary technical conditions simultaneously, used electrical loss thereby reduced;
Four, the electric energy measuring equipment produced of modular electric energy metering machine of the present invention in use breaks down or when regularly replacing, through changing corresponding modular unit, has avoided overlapping investment, for user and power department have been practiced thrift cost.
Description of drawings
Fig. 1 is the functional block diagram of modular electric energy metering machine preferred embodiment one of the present invention;
Fig. 2 A is the main three-dimensional structure diagram of modular electric energy metering machine box body structure one preferred embodiment of the present invention;
Fig. 2 B is the secondary three-dimensional structure diagram of modular electric energy metering machine box body structure one preferred embodiment of the present invention;
Fig. 3 is the functional block diagram of modular electric energy metering machine power supply unit of the present invention;
Fig. 4 is the functional block diagram of modular electric energy metering machine electric energy metrical of the present invention unit;
Fig. 5 is the functional block diagram of another preferred embodiment of modular electric energy metering machine of the present invention;
Fig. 6 has the functional block diagram of expanding element one preferred embodiment for modular electric energy metering machine of the present invention;
Fig. 7 is the functional block diagram of modular electric energy metering machine counting unit of the present invention;
Fig. 8 A is the functional block diagram of modular electric energy metering machine display unit one preferred embodiment of the present invention;
Fig. 8 B is the functional block diagram of another preferred embodiment of modular electric energy metering machine display unit of the present invention;
Fig. 9 is the functional block diagram of modular electric energy metering machine of the present invention from detecting unit;
Figure 10 is the functional block diagram of modular electric energy metering machine of the present invention with power detection circuit;
Figure 10 A is the circuit diagram of modular electric energy metering machine of the present invention with power detection circuit;
Figure 10 B has the functional block diagram of the counting unit of counting unit testing circuit for modular electric energy metering machine of the present invention;
Figure 11 A prevents the functional block diagram of the unit of box body unnormal unlocking for modular electric energy metering machine of the present invention;
Figure 11 B prevents the structural representation of open detection circuit embodiments one in the unit of box body unnormal unlocking for modular electric energy metering machine of the present invention;
Figure 11 C prevents the structural representation of open detection circuit embodiments two in the unit of box body unnormal unlocking for modular electric energy metering machine of the present invention.
Embodiment
Below in conjunction with accompanying drawing, do more detailed explanation with other technical characterictic and advantage to the present invention is above-mentioned.
See also shown in Figure 1; It is for the functional block diagram of modular electric energy metering machine preferred embodiment one of the present invention; It comprises: line of electric force input-output unit 2, one power supply units, 1, one an electric energy metrical unit 3 and a pulse signal output unit 4; Wherein, Described line of electric force input-output unit 2 comprises: phase line incoming end 22 and zero line incoming end 21 and line output terminal 23 mutually, and described phase line incoming end 22 is connected with phase line in the power circuit, and described phase line output terminal 23 is connected with the next stage power equipment; Described power supply unit 1 provides power for operation in order to obtain described phase line incoming end 22 and the voltage that zero line incoming end 21 inserts through other electricity consumption device that converts modular electric energy metering machine of the present invention accordingly into; Described electric energy metrical unit 3 is connected with described power supply unit 1, calculates the meritorious/reactive energy value via described phase line incoming end 22 and zero line incoming end 21; Described pulse signal output unit 4; It is connected with described electric energy metrical unit 3; The energy value that described electric energy metrical unit 3 is calculated is converted into the pulse signal output that is directly proportional with described energy value, and the pulse signal of generation can be used as the data input signal of other expanding element.
For preferred embodiment one disclosed modular electric energy metering machine of the present invention; It needs a box body 5 structures that its circuit part is encapsulated and protects; See also shown in Fig. 2 A; It is the main three-dimensional structure diagram of modular electric energy metering machine box body structure one preferred embodiment of the present invention, and it comprises: a base plate 50, in order to carry the device of the inner installing of box body; One cap 52; It is located on the described base plate 50; Described device is protected; Be provided with phase line incoming end 5 in the upper end of said cap 52, be that its relative end is provided with phase line output terminal 54, is provided with locking hole 55 at described cap 52 upper surfaces; In order to be screwed onto with described base plate 50 through screw, these all are that the functional structure expansion of modular electric energy metering machine of the present invention provides corresponding physical construction interface on described cap 52, also to have display screen form 58, pulse matching hole 56 and a pulse indicator lamp hole 57.
See also shown in Fig. 2 B; It is the secondary three-dimensional structure diagram of modular electric energy metering machine box body structure one preferred embodiment of the present invention, and it is to carry out projection from the proceeds posterolateral of said box body 5, can significantly see; On described base plate 50, be provided with some fastener holes 59; It it is emphasized that especially that in order to realize the location that carry out said box body 5 and installation site and to fixedly install a characteristic of the present invention just is for outstanding modular characteristics; It comprises: a phase line upstream end 51 and line output terminal 54 and part input end 61 mutually; And described zero line input end 61 is integrated on the serial plug 6 with the output terminal of described pulse signal output unit 4, and is corresponding with differing needles, is implemented in through plug on the basis of described modular electric energy metering machine to carry out the function expansion.
See also shown in Figure 3ly, it is for the functional block diagram of modular electric energy metering machine power supply unit of the present invention; It comprises: a power converting circuit 11, and it carries out transformation with power voltage line handles, and in order to power for operation to be provided, described power converting circuit 11 is connected with zero line input end 21 with described phase line input end 22; One charging circuit 12, it is arranged between the output terminal and described standby power supply 13 of described power-switching circuit 11, in order to supply power to described standby power supply 13; One detecting commutation circuit 14; Whether it has voltage output in order to detect described power-switching circuit 11; When described power-switching circuit 11 no-voltages are exported; Start described standby power supply 13 and power for operation is provided for the electricity consumption device of described modular electric energy metering machine; Because the accumulate finite capacity of described standby power supply is therefore once the situation of generation power converting circuit fault just must be informed the user; Perhaps cut off circuit 942 (isolating switch) and cut off power circuit to prevent management of power use department being caused waste of power resources and loss owing to said power supply unit 1 breaks down through a line of electric force; Can certainly adopt an acoustic-optic alarm 941 to be connected, when described power-switching circuit 11 no-voltages are exported, trigger the sound and light of alarm of described acoustic-optic alarm 941 with described detecting commutation circuit 14.
See also shown in Figure 4ly, it is for the functional block diagram of modular electric energy metering machine electric energy metrical of the present invention unit; Described electric energy metrical unit 3 is its core textures for modular electric energy metering machine of the present invention, and it comprises: a current signal Acquisition Circuit 31, in order to the current signal on the real-time collection line of electric force; One voltage signal acquisition circuit 32 is in order to the voltage signal on the real-time collection line of electric force; One computing and treatment circuit 33; It comprises: a multiplier 331 and an integrator 332; Through described multiplier 331 described current signal and described voltage signal are multiplied each other and to obtain the instantaneous power value; Obtain interior energy value of determining time through described integrator 332 then, and convert the energy value that obtains into pulse signal output through a pulse signal output unit 4, described pulse signal output unit 4 can be a voltage/frequency conversion frequency dividing circuit.
Certainly for the user; Modular electric energy metering machine of the present invention is applied to concrete production practices obviously more to be of practical significance; Therefore see also shown in Figure 5ly, it be the functional block diagram of another preferred embodiment of modular electric energy metering machine of the present invention, and the difference of itself and above-mentioned Fig. 1 structure composition is; In order to improve the function of the foregoing description; Make the user can clearly obtain it uses electric energy in a period of time of confirming information, be convenient to the inquiry that management of power use unit consumes each family power consumption simultaneously, the present invention has increased a counting unit 7 and a display unit 8; Described counting unit 7 is connected with the output terminal of described metering units 8; Thereby and the pulse signal of its generation added up produce a data-signal, described display unit 8 receives described data-signal, will be shown by the electric energy aggregate-value of electricity consumer consumption through modular electric energy metering machine of the present invention; That is to say that present embodiment has possessed the function of a basic electric energy meter, can insert in user's the power line circuit and use.
In order to adapt to modular electric energy metering machine function expansion needs of the present invention; The present invention provides a separate processor 9; In order to receive the status signal of corresponding units or circuit; And send control signal to units corresponding and circuit; Thereby the function of coordinating described modular electric energy metering machine realizes also can carrying out condition monitoring simultaneously, and described processor 9 is single-chip microcomputer, embedded system or FPGA control, selects which kind of device to require, require decision to modular electric energy metering machine functional requirement according to the invention and to the ultimate small product size of the present invention according to the data processing total amount.
For the extendability of this standard modular electric energy metering machine is clearly introduced; The spy provides Fig. 6; It is the functional block diagram of modular electric energy metering machine functional expansion unit one preferred embodiment of the present invention, and the difference of itself and above-mentioned Fig. 1 structure is, in order to satisfy the demand that modular electric energy metering machine of the present invention inserts some functional expansion units; The present invention has increased a counting unit 7, a processor 9 and a display unit 8; Utilize the characteristic of the multiport of said processor 9 can also introduce more expanding element 0 simultaneously, described expanding element 0 can be remote inquiry unit, pre-payment unit, communication unit etc., and described counting unit 7 is connected with the output terminal of said pulse signal output unit 4; Then the signal of its generation is added up and produce a status signal; And it is transferred to the signal input part of described processor 9, described processor 9 through said processor 9 internal preset program of operation, produces control signal according to the status signal (command signal) of described status signal and the expanding element 0 that is connected with other port; The processing of control data and the action of corresponding units; Described processor 9 is connected with described display unit 8, receives described control signal, will be shown by the energy value of electricity consumer consumption through modular electric energy metering machine of the present invention.
Occurred counting unit in the above embodiments, seen also shown in Figure 7ly, it is the functional block diagram of modular electric energy metering machine counting unit of the present invention; Described counting unit 7 comprises: a data processing circuit 72, and it receives the pulse signal of described pulse signal output unit 4 outputs, and carries out the energy value stored counts, also can directly obtain the energy value signal of said metering units 3; One internal communication circuit 73; It links together described data processing circuit 72 with described processor 9; It is transferred to said processor 9 one data-signals, thereby makes described processor 9 produce control signal corresponding, is sent to corresponding receiving element or circuit.
For display unit 8, see also shown in Fig. 8 A and Fig. 8 B, it is respectively the functional block diagram of two preferred embodiments of modular electric energy metering machine display unit of the present invention; Described display unit 8 receives the data-signal that described processor 9 sends, and carries out data presentation, and embodiment one adopts liquid crystal display or electronics to show that it comprises: a display screen 81, and it is embedded on described box body 5; One drive circuit 82, it drives said display screen 81 demonstration power consumptions according to receiving said control signal.What embodiment two adopted is that machinery shows that it comprises: a mechanical register 83 need be embedded equally on described box body 5; One stepper motor 84 according to the pulse signal that receives said processor 9 output units output, drives said mechanical register 83 actions and makes described mechanical register 83 show power consumption.
It is emphasized that characteristics especially for outstanding modular electric energy metering machine of the present invention; Another key character of the present invention is, is provided with from detecting unit and can the duty of units corresponding or circuit be detected automatically, judges through detecting whether corresponding unit or circuit working be normal; When breaking down; Produce corresponding action, see also shown in Figure 9ly, it is the functional block diagram of modular electric energy metering machine of the present invention from detecting unit; It comprises:
With power detection circuit 91, whether have electric current to flow through in order to detect line of electric force, and whether judge module electric energy metering device break down;
Whether one counting unit testing circuit 92 breaks down in order to the data processing circuit 72 to said counting unit 7 and to detect;
Whether one electric power detecting commutation circuit 93 breaks down in order to the power converting circuit to said power supply unit 1 and to detect;
Fault executive circuit 94; It comprises: acoustic-optic alarm 941; When finding that above-mentioned fault exists, carry out sound and light alarm, have fault, indicate the reason that produces fault like the pilot lamp or the different audio that adopt different colours in order to remind user's modular electric energy metering machine of the present invention; One line of electric force open circuit 942, it adopts isolating switch, is arranged on the described line of electric force, when non-power failure fault takes place, cuts off the electric power supply that flows to electricity consumer; Need to prove described electric power detecting commutation circuit 93 and corresponding fault topworks 94 thereof; In the structure of above-mentioned power supply unit, set forth; Here only be that the unit that its functional character carries out is sorted out; Therefore no longer its structure is given unnecessary details, three simultaneously above-mentioned detections can and be accepted or rejected according to the needs combination of reality, become product from detecting unit.
See also shown in Figure 10ly, it is the functional block diagram of modular electric energy metering machine of the present invention with power detection circuit; Of the present inventionly comprise with power detection circuit 91:
Whether one current detection circuit 911 has electric current to flow through in order to detect described phase line input end 22; One detects decision circuitry 913, when described phase line input end 22 has electric current to flow through, and during the output of described pulse signal output unit 4 pulse-free signals, judges that then modular electric energy metering machine of the present invention breaks down.
See also shown in Figure 10 A, it is the circuit diagram of modular electric energy metering machine of the present invention with power detection circuit; Described current detection circuit C2 comprises: a telefault L1, and it is set on the described phase line A; One comparer IC1; The one of which inverting input is provided with a reference voltage; Its in-phase end is connected with the output terminal of described telefault L1, on described phase line A, has electric current to flow through, and induces voltage signal and compares with the reference voltage of comparer IC1 inverting input; Thereby the output terminal that makes described comparer IC1 is exported a voltage signal, judges whether have electric current to flow through on the line of electric force through this voltage signal.
Described pulse-detecting circuit C1 comprises: a comparer IC2, and the one of which end of oppisite phase is provided with a reference voltage, and its in-phase end is connected with the output terminal of described pulse signal output unit 4; The output terminal of described comparer IC2 is connected with described detection decision circuitry; Described detection decision circuitry is a processor MCU; The one of which input interface links to each other with the output terminal of described current detection circuit C2, and an input interface links to each other with described pulse-detecting circuit C1 output terminal, when the in-phase end of the comparer IC2 of described pulse-detecting circuit receives pulse signal; Then it exports a noble potential; The comparer IC1 of described current detection circuit exports a noble potential to described processor MCU, in described one time period of processor MCU internal preset, when described current detection circuit input high potential signal gets into described processor MCU; If in described Preset Time, do not have the high potential signal input of pulse-detecting circuit, think that then modular electric energy metering machine of the present invention breaks down.
See also shown in Figure 10 B, it has the functional block diagram of the counting unit of counting unit testing circuit for modular electric energy metering machine of the present invention; When the signal that described counting unit testing circuit 92 obtains said metering units 3 at described data processing unit 71 carries out power consumption accumulative total; All obtain a pulse signal from described data processing unit 71 at every turn; When described data processing unit 71 has obtained the signal of said metering units 3 and described counting unit testing circuit 92 does not obtain pulse signal; Then described counting unit testing circuit 92 sends a status signal to described processor 9; Send control signal by described processor 9 to described fault executive circuit 94, thereby produce sound and light alarm or/and cut off the action of power circuit.
See also shown in Figure 11, Figure 11 A, Figure 11 B, its prevent for modular electric energy metering machine of the present invention the box body unnormal unlocking the unit functional block diagram with and two kinds of embodiments of open detection circuit; The described unit that prevents the box body unnormal unlocking is in order to when unnormal unlocking takes place in described box body 5; Produce the action of reporting to the police or cutting off power circuit; Its fundamental purpose is to prevent the illegal stealing of bad personnel, perhaps avoids the layman to open the adverse consequences that box body causes electric shock, and it comprises: an open detection circuit 41 and an executive circuit (fault executive circuit 94); Wherein
Whether described open detection circuit 41 is opened in order to detect box body, when opening, sends detection signal and gives described processor 9 and generate a control signal;
Described executive circuit (fault executive circuit 94) receives described control signal, and produces the action of reporting to the police or cutting off the line of electric force connection of place circuit.
See also shown in Figure 11 A; Described open detection circuit comprises: a pressure transducer 412, and wherein, described pressure transducer 412 is connected with an A/D converter 413; And link to each other with the status signal port of described processor 9; Pressure transducer 412 is arranged at cap 52 places of said box body, because the extruding of screw 411 produces described detection signal, and is sent to described status signal port; Through comparing with a threshold value preset in described processor 9; If less than this threshold value then export control signal and give described executive circuit, described executive circuit (fault executive circuit 94) can be the fault executive circuit 94 of self check measurement unit, through sound and light alarm with cut off power circuit and realize preventing the box body unnormal unlocking.
See also shown in Figure 11 B; Described open detection circuit comprises: a normal open switch 414 or a normally closed switch is that example describes with normal open switch 414 here, and described normal open switch 414 is arranged at encapsulation place of said box body cap 52; When encapsulation place does not have the space; Described normal open switch 414 no signals output, otherwise, when screw 411 has been revolved; Said normal open switch 414 is closed because spring 415 acts on; Thereby the output control signal is given described executive circuit (fault executive circuit 94), and described executive circuit (fault executive circuit 94) can be the fault executive circuit 94 of self check measurement unit, realizes preventing the box body unnormal unlocking through sound and light alarm and cut-out power circuit.
True the present invention has the function that writes down to the unusual condition that line of electric force took place; It is that corresponding historical information is stored in the memory circuit 13 of said counting unit; Described memory circuit 13 is connected with described data processing circuit 72 and said open detection circuit 41 respectively mutually; When having a power failure,, store in the described memory circuit 13 energy value of described data processing circuit 72 accumulations; When restoring electricity, read the energy value of storing in the described memory circuit 13 by described data processing circuit 72; And can when unnormal unlocking takes place box body 5, write down this event information.
The above is merely preferred embodiment of the present invention, only is illustrative for the purpose of the present invention, and nonrestrictive.Those skilled in the art is understood, and in spirit that claim of the present invention limited and scope, can carry out many changes to it, revise, in addition equivalent, but all will fall in protection scope of the present invention.