CN2267464Y - Current sensing device used for current measuring sampling - Google Patents

Abstract

The utility model discloses a technical proposal of a current sensor used for current measuring and sampling in a cable wire in non-contact way. In the scheme, the utility model comprises a casing, a box whose inner part is provided with a C-shaped magnetic core, and a circuit board. A Hall element in an electronic circuit is positioned at the opening position of the C-shaped magnetic core; the sampled cable can be threaded out from a hole at the middle of the casing; the magnetic core can make the stray magnetic field at the periphery of the cable concentrated; then, the current is transmitted to a magnetic sensitive element namely the Hall element; the current is amplified and outputted. The utility model has the advantages of simple structure, small size, and high sensitivity. The utility model can overcome the problem that the direct current instrument transformer has dead zone. When the utility model is in use, the utility model has simpler wiring. The utility model is a product replacing the older generation of the direct current instrument transformer.

Description

The current sensor of current measurement sampling usefulness

The utility model relates to the measurement mechanism of electric current, specifically a kind of current sensor of current measurement sampling usefulness.

The ancient mode of the measurement of electric current is to disconnect access type, and it is many more that the wiring end points increases, and the safety coefficient in loop is low more, under big electric current, high-power or high voltage situation, is easy to cause the sparking of wiring end points even burns; And when little electric signal, the end points contact resistance will be can not ignore, and directly the standard of sampling is measured in influence.Therefore, the noncontacting measurement sampling has very important significance.Aspect the noncontacting measurement sampling, domestic first generation product is a direct current instrument transformer.More much better with direct current instrument transformer sampling nature than breakaway-element, but volume is big, the dead band is arranged on the measurement range, former secondary isolation performance is poor, wiring complexity during application, and also price is more expensive.

The purpose of this utility model is that a kind of volume ratio of design is less, remolding sensitivity is higher, do not have the dead band, uses the current sensor of fairly simple current measurement sampling usefulness.

Principle of the present utility model is to utilize the magnetoelectricity conversion performance of semiconductor Hall element, is converted into electric signal after directly gathering the field signal around the cable, exports through amplifying after.Concrete technical scheme is divided three parts: i.e. shell, magnetic core and wiring board.Shell is made up of the front shroud and the back support plate of square hole " returning " font side plate and centre.There is the fixedly fixed-wing of usefulness the both sides, base of " returning " the font side plate.Between " returning " font side plate two " mouth " font side plate, " C " font magnetic core is arranged, the outside surface of magnetic core open side and outside wiring board is arranged between " mouth " font side plate inside surface.A Hall element H is arranged in the wiring board, and this Hall element is suspended at the opening part of " C " shape magnetic core.The pin 1 of Hall element connects triode Q collector, pin 3 meets power cathode V-, pin 2, pin 4 connecting resistance R respectively ₃, R ₄The anode of the base stage of triode Q and diode D links, emitter passes through resistance R ₂Link with positive supply.The anode of the negative terminal of diode D and voltage stabilizing diode Dw links and passes through resistance R simultaneously ₁Link with negative supply.The negative terminal of voltage stabilizing diode Dw connects positive supply.Resistance R ₃Another termination discharge circuit Ic negative input end, pass through resistance R simultaneously ₅With potentiometer W ₁Center head links.Resistance R ₄The other end and discharge circuit Ic positive input terminal link, pass through resistance R simultaneously ₆With potentiometer W ₂Center head link.Potentiometer W ₁One end and positive supply V+ link, and the other end and negative supply V-link.Potentiometer W ₂A termination discharge circuit Ic output terminal, another termination negative supply V-.Discharge circuit Ic positive supply input termination positive supply V+, negative supply input termination negative supply.The output terminal connecting resistance R of discharge circuit ₇, R ₇Another termination connection terminal, capacitor C one termination positive supply, other end ground connection.On " mouth " font side plate connection terminal is housed outside, connection terminal has 4 binding posts, for using the connections of signal output part, positive and negative power supply and ground connection.

A cable with supply line during use passes from the centre of interior " mouth " font side plate, when having electric current to pass through in the cable, promptly produce magnetic field around the cable, electric current changes, the magnetic field size also changes, and magnetic core disperses magnetic field concentration with around the cable, is that Hall element is transformed into electric signal with magnetic signal by magnetic-sensitive elements again, become the electric signal that to measure through amplification, so the utility model is specialized in current measurement sampling usefulness.

The utility model is because relatively simple for structure, and volume can be made smallerly, because Hall element can both experience very faint magnetic field, and its work is linear, so sensitivity of the present utility model is very high, also do not have dead-time problem.Tested cable is isolated fully with output, and promptly former secondary isolation performance is good.Wiring is fairly simple during use.

The designer has made an embodiment, below embodiment is described:

Fig. 1 is the front view of embodiment

Fig. 2 is the vertical view of embodiment

Fig. 3 is the view behind the front shroud of removing of embodiment

Fig. 4 is the electronic schematic of embodiment

By Fig. 1, Fig. 2, Fig. 3 as seen, the shell of the utility model embodiment comprises " returning " font side plate, " return " outer " mouth " font side plate (4) of font side plate and interior " mouth " font side plate (6) has square hole by the centre gluing being integral of back plate (5), there is front shroud (2) front of " returning " the font side plate, between interior " mouth " font side plate and outer " mouth " font side plate " C " font magnetic core (7) is arranged, it is Hall element (H) that suitable for reading of magnetic core has a magnet-sensitive element, between the inside surface of top and outer " mouth " font side plate of magnetic core wiring board (8) is arranged, connection terminal (1) is equipped with at place, the upper right corner of " mouth " font side plate outward, connection terminal has 4 binding posts, and there are two fixed-wings (3) at two inferior horn places of outer " mouth " font side plate.

As seen from Figure 4: the utility model electronic circuit partly comprises power circuit, magnetic field detection circuit, signal amplification circuit, output circuit, adjustment and feedback circuit composition.Wherein power circuit is made up of the external power supply of ± 12-24 volt and the capacitor C that is connected between positive supply V+ and the ground; Magnetic sensor circuit comprises Hall element H, triode Q, diode D, voltage stabilizing diode Dw and resistance R ₁, R ₂, signal amplification circuit is by discharge circuit Ic and resistance R ₃, R ₄Form, output circuit is by discharge circuit Ic and resistance R ₇Form.The levelling feedback circuit is by potentiometer W ₁, W ₂And resistance R ₅, R ₆Form.The connection method of each components and parts is described with the front.It is worthy of note that triode Q plays the constant current effect, diode D compensation triode Q temperature characterisitic, voltage stabilizing diode Dw cooperates triode to play the constant current effect, potentiometer W ₁Play the static zeroing effect that does not promptly have under the input state of magnetic field, potentiometer W ₂The output valve of levelling when field signal is imported requires to adjust to 5 volts, and connection terminal (1) has 4 binding posts, uses for positive supply V+, negative supply V-, output M and ground connection respectively.

Present embodiment length * height * thick=113 * 74 * 28mm, Hall element is selected the THS119 type, to the coefficient of Hall element, promptly will screen consistent with enlargement factor zero point.The magnetic stamen selects soft magnetic material to plate not alloy or high-quality silicon steel sheet is made, because this material initial magnetic permeability height, magnetization curve is more straight, and magnetic saturation intensity is higher.

Claims (1)

1, the current sensor of current measurement sampling usefulness, it is characterized in that comprising one by " returning " font side plate, rear bearing sheet (5), the shell that front shroud (2) is formed, there are two fixed-wings (3) at two inferior horn places of shell, on outer " mouth " font side plate of shell connection terminal (1) is housed, interior " mouth " the font side plate (6) of " returning " font side plate and outside " C " font magnetic core (7) is housed between " mouth " font side plate (4), between the inside surface of the outside surface of magnetic core open side and outer " mouth " font side plate wiring board is housed, comprise a Hall element H in the wiring board, this Hall element is suspended at the opening part of " C " shape magnetic core, and the pin 1 of Hall element connects the collector plate of triode Q, pin 3 meets power cathode V-, pin 2 and pin 4 be connecting resistance R respectively ₃, R ₄, the base stage of triode Q connects the anode of diode D, and the emitter of triode Q passes through resistance R ₂V+ joins with positive supply, and the anode of the negative terminal of diode D and voltage stabilizing diode Dn links, and passes through resistance R simultaneously ₁V-joins with negative supply, and the negative terminal of voltage stabilizing diode Dn connects positive supply V+, resistance R ₃Another termination discharge circuit Ic negative input end, pass through resistance R simultaneously ₅Meet potentiometer W ₁Center head, resistance R ₄The other end and discharge circuit I _cPositive input terminal links, and passes through resistance R simultaneously ₆With potentiometer W ₂Center head link potentiometer W ₁An end and positive supply V+ join, the other end and negative supply V-join, potentiometer W ₂An end and the output terminal of discharge circuit Ic join another termination negative supply V-, the positive supply of discharge circuit Ic input termination positive supply V+, negative supply input termination negative supply V-, the output terminal connecting resistance R of discharge circuit Ic ₇, resistance R ₇Another termination connection terminal, a termination positive supply V+ of capacitor C, other end ground connection, connection terminal (1) has 4 binding posts, is respectively positive supply V+, negative supply V-, signal output M and earth terminal.

Images