CN2932394Y

CN2932394Y - Metering device with a wide current measuring range

Info

Publication number: CN2932394Y
Application number: CN 200620026961
Authority: CN
Inventors: 王铁镰; 徐卫生; 陈军
Original assignee: Tianjin Baili Electronic Co Ltd
Current assignee: Tianjin Baili Electronic Co Ltd
Priority date: 2006-08-08
Filing date: 2006-08-08
Publication date: 2007-08-08
Anticipated expiration: 2016-08-08

Abstract

The utility model relates to an ammeter device with a wide measure range of current, comprising an ammeter, a current transformer, a voltage regulator, a transformer, a contactor, a current-limiting protection resistor, and a step coil. The sublevel of the voltage regulator exports to the low-level of the transformer, and the sublevel of the transformer has a large current coil and a small current coil whose output ends switch circuits respectively with the current slender step formed by the ammeter, the contactor, the current-limiting protection resistor, the connecting terminal, the step coil, and the main switch contactor. The step coil is wound around the current transformer whose two ends is parallel connected with the ammeter through the circuit formed by the normally open contact of the high-current contactor. Due to the adoption of the measure method of single ammeter and commutation circuit, the utility model not only achieves the wide measure range of current by only one ammeter, but also is simple in structure, low in cost, and convenient to use. Further, the utility model can achieve flexible and accurate switch among different current ranges, and improve the measure precision by the measure of single ammeter.

Description

Measure the wide reometer device of range of current

Affiliated technical field

The utility model belongs to a kind of current measuring device, particularly relates to a kind of wide reometer device of range of current of measuring.

Background technology

Present known reometer is at work in order to solve wide current measurement technique for displaying problem, and adopts the mode of the reometer areal survey of a plurality of different ranges.Electrical equipment detection for different current classes just needs very wide current measuring range like this, needs constantly to change the reometer and the mutual inductor of several different ranges in testing process.It is loaded down with trivial details especially to work together like this, and directly have influence on the precision of detection, its precision of reometer of different ranges also is not quite similar, measured parameter and standard and disunity, and reduced detection efficiency, repeatedly disconnect the line operating process, for example relay product is detected thing, can be able to damage the joint of relay product, cause human error easily again and have an accident.

Summary of the invention

The utility model provides a kind of wide reometer device of measurement range of current that replaces polylith reometer and mutual inductor for solving the technical matters that exists in the known technology.

The technical scheme that the utility model is taked for the technical matters that exists in the solution known technology is: it includes reometer, current transformer, and it also includes pressure regulator, transformer, contactor, current-limiting protection resistance and stepping coil; The secondary coil of pressure regulator outputs to the primary coil of transformer, the secondary coil of transformer has large and small current coil, little current coil output common port serial connection reometer, each branch circuit after as contactor serial connection current-limiting protection resistance of little electric current segmentation shelves circuit in parallel again, as the connection terminal that contactor and corresponding each the little electric current segmentation shelves branch circuit of serial connection of master switch inserts tested electrical equipment, connect the other end of each corresponding tap output of little current coil at last; The common port serial connection of big current coil output terminal is connected in series the parallel circuit of the big current branch circuit that constitutes, is connected in series the other end that each corresponding tap of connecing big current coil behind master switch contactor and two connection terminals is exported again by each tap of stepping coil and each contactor as big electric current segmentation shelves with current-limiting protection resistance; Described stepping coil is to be wrapped on the described current transformer, constitutes variable number of turn transformer, and current transformer is by leaving the parallel circuit of contact by the length of the contactor of each big electric current segmentation shelves branch circuit and at the reometer two ends.

Advantage and the good effect that the utlity model has are: because this single reometer of employing adds the metering system of commutation circuit, not only realized only just can measuring with a reometer purpose of wide-range current; And this apparatus structure is simple, cost is low, and is easy to use, and can be implemented in flexible, the accurately switching of different current ranges, by the measurement of single reometer, also can improve measuring accuracy.

Description of drawings

Fig. 1 is circuit theory diagrams of the present utility model.

Embodiment

For further understanding summary of the invention of the present utility model, characteristics and effect, now exemplify and following the present invention is used for embodiment on the three-phase electronic overload relay testing table, and conjunction with figs. is described in detail as follows (because that A, B, C three-phase circuit constitute is identical, below only describe mutually in conjunction with C):

As shown in Figure 1, elementary C, the N0 of pressure regulator T1 connect power supply, and secondary coil outputs to the primary coil of transformer T2, and the secondary coil output end voltage of transformer T2 is respectively: L3-1.2V; L4-0.8V; L1-4V; L26V.Wherein the common port of L3, L4 is N2, and the common port of L1, L2 is N1; Its corresponding external cabling terminal is respectively: A1, A2, A3, A4, A5, A6 can meet corresponding connection terminal A1, A2, A3, A4, A5 and A6 according to the size of current choosing of test product.

The end of reometer A is connected on the transformer T2 output terminal N1, the other end connects the length of contactor KM3, KM4 respectively and opens an end of contact, the long other end of opening the contact of contactor KM3, KM4 is connected with the long end of opening the contact of contactor KM9 by current-limiting protection resistance R 3, R4 respectively, and this long other end and connection terminal A6 that opens the contact of contactor KM9 joins; Transformer T2 output terminal N2 is connected on the initiating terminal of stepping coil N one circle coil, the length of contactor KM1, KM2 is left on the end of 1 circle that the contact is connected respectively to stepping coil N and 10 circles, the long other end of opening the contact of contactor KM1, KM2 is connected with another long end of opening the contact of contactor KM9 by current-limiting protection resistance R 1, R2 respectively, the long other end and the connection terminal A3 that opens the contact of contactor KM9 this another joins, and selects the concrete range of little electric current; Stepping coil N itself is on current transformer L, and mutual inductor L at this moment and stepping coil N can regard a variable number of turn transformer as; Mutual inductor L leaves the contact and at reometer A two ends, can select big electric current matrix range by KM1, KM2 through the length of KM1, KM2.

Described contactor KM1, KM2, KM3, KM4 all are available manually-operated or computer operation, and the computing machine during by computer control can be single-chip microcomputer, industrial computer or PLC.

Its course of work is: KM9 is at first closed when measuring beginning, when measuring range of current is: KM4 closure during 0～100mA, and KM1, KM2, KM3 disconnect, and selecting connecting terminal is A5, A6; The measurement range of current is: KM3 closure during 100mA～1A, and KM1, KM2, KM4 disconnect, and selecting connecting terminal is A4, A6; Be small current measurement this moment.When measuring range of current be: KM1 closure during 1A～10A, KM3, KM4, KM2 disconnect, and selecting connecting terminal is A1, A3; The measurement range of current is: KM2 closure during 10A～100A, and KM1, KM3, KM4 disconnect, and selecting connecting terminal is A2, A3; Be Super-Current Measurement this moment.

Claims

1. measure the wide reometer device of range of current for one kind, it includes reometer, current transformer, it is characterized in that: further comprising pressure regulator is arranged, transformer, contactor, current-limiting protection resistance and stepping coil; The secondary coil of pressure regulator outputs to the primary coil of transformer, the secondary coil of transformer has large and small current coil, little current coil output common port serial connection reometer, each branch circuit after as contactor serial connection current-limiting protection resistance of little electric current segmentation shelves circuit in parallel again, as the connection terminal that contactor and corresponding each the little electric current segmentation shelves branch circuit of serial connection of master switch inserts tested electrical equipment, connect the other end of each corresponding tap output of little current coil at last; The common port serial connection of big current coil output terminal is connected in series the parallel circuit of the big current branch circuit that constitutes, is connected in series the other end that each corresponding tap of connecing big current coil behind master switch contactor and two connection terminals is exported again by each tap of stepping coil and each contactor as big electric current segmentation shelves with current-limiting protection resistance; Described stepping coil is to be wrapped on the described current transformer, constitutes variable number of turn transformer, and current transformer is by leaving the parallel circuit of contact by the length of the contactor of each big electric current segmentation shelves branch circuit and at the reometer two ends.