SU789922A1 - Constant-flux magnetic bridge - Google Patents

Description

one

The invention relates to a measurement technique, in particular, to magnetic DC bridges with an electromechanical indicator / and can be used to measure magnetic, mechanical and electrical quantities.

The magnetic bridge of a constant flow is known, in the gap of the measuring diaggsha of which there is a permanent magnet magnetized along the diameter ij.

However, due to the presence of an air gap. And a large mass of the moving part, this bridge does not have sufficiently high sensitivity.

. The closest in technical essence to the present invention is a direct current magnetic bridge for measuring magnetic and electrical quantities. In its measuring diagonal there is an air gap in which the movable part of the measuring mechanism of the magnetoelectric system is installed as an indicator. The frame of the mechanism is powered by direct current from an auxiliary source of electrical energy, induction in the gap is created when the bridge is unbalanced, and

2

the opposing moment is created by the use of moment springs 1.2,

The main disadvantage of the known permanent magnetic flux bridge with an electromechanical indicator is the presence of an air gap in the measuring diagonal, which drastically reduces its sensitivity.

The purpose of the invention is to increase

10 sensitivity of a constant-current magnetic bridge.

This goal is achieved by the fact that in the magnetic bridge the post

The t5 of the flow containing the movable frame, its diagonal is made in the form of a whole magnetic core with a cylindrical hole in the middle part, inside of which there is a sub cylindrical core and a movable frame whose axis of rotation coincides with the axis of the hole and the cylinder and perpendicular to the flatness which is located shoulders

25 bridges.

FIG. 1 is a schematic diagram of the proposed magnetic bridge in FIG. 2 and 3 - the location of the magnetic flux in the measuring diagonal.

The magnetic bridge contains a permanent magnet 1 (or a permanent electromagnet) with pole pieces 2, between which there is a magnetic core, the extreme rods 3 and 4 of which form, together with gaps

5 shoulder magnetic bridge. Jumper

The 6 magnet guide, forming the measuring diagonal of the bridge, is branched in the middle part in the form of a ring, inside which a cylindrical core 7 is installed concentrically with it. The frame 8 of the measuring mechanism covers the core 7 and can be rotated around it. The frame 9 is fixedly connected to the arrow 9 and the ends of the spring springs, through which a direct current is supplied to the frame and from an auxiliary current source (torque springs are not conventionally shown). In one of the gaps

5, or the test substance is introduced into two opposite gaps.

The magnetic bridge works as follows.

In the equilibrium state of the bridge (Fig. 2), when the flux f is zero by means of torque springs, the movable part of the measuring mechanism is set to the initial position (o (0). The magnetic flux created by the magnetizing current of the 3 frames closes through the distributed air. Gap between the core 7 and the ring. The resulting magnitude of this flux is denoted by φ. Since there is the same magnetic resistance in any position of the frame in the flow path φ, the magnetic field energy of the ring is constant. The equilibrium of the bridge (d 0) does not affect the moving part of the measuring mechanism and the arrow takes the initial position (ol О). If there is a flow imbalance Φ, the magnetic field in the ring changes (Fig. 3). fluxes F and} are directed in a different way: according or opposite. Depending on the angle of rotation of the frame oL, the energy is magnetically about the ring floor, as the volumes of the sections with

. or counter-acting flows F and F-. For example, when I am

indicated in FIG. 3, the energy of the magnetic field of the ring is greater than at ot O. The energy of the magnetic fields of the remaining sections of the magnetic bridge, as well as the core 7, does not depend on the rotation d, the moving part, therefore the torque acting on the moving part is due only to energy of the magnetic field of the ring. In this case, the movable part tends to occupy a position in which the energy of the magnetic field of the ring is maximum. Thus, if the imbalance flow F has the direction indicated in FIG. 3, then the frame is acted upon by a torque that turns it clockwise. When the frame is rotated, the opposing moment of the springs appears, which is proportional to the value of ot, and the frame takes a position depending on the value of the flow φ. When the direction f changes, the direction of the torque is reversed.

5, Comparison of the proposed and known magnetic bridges shows that, due to the absence of an air gap in the measuring diagonal, the sensitivity of the proposed bridge

0 significantly higher than the sensitivity of the famous bridge.

Claims (2)

Invention Formula A magnetic constant flow bridge containing a movable frame, which is tactile in that, in order to increase the sensitivity, the measuring diagonal of the bridge is made in A whole magnetic circuit with a cylindrical hole in the middle part, inside of which a fixed cylindrical core and a movable frame are installed, the axis of rotation of which 5 coincides with the axis of the hole and the cylinder. Sources of information taken into account in the examination O 1, OlA Patent No. 2827609, cl. 32434. 2. USSR author's certificate No. 67548, cl. Q01 R 33/00.   1 111 hull w.