SU450117A1 - Device for testing the quality of teroidal magnetic cores - Google Patents

Description

one

Devices for testing the quality of toroidal magnetic cores are known, comprising a test voltage source, an input matching transformer, test and control coils, a current transformer, and measuring instruments.

In the proposed device, the test turn is made in the form of a detachable saw-head closed from the ends of conductive material, the base of which is connected by a conductive rod, and the test magnetic conductor, current transformer, control coil and matching transformer are located inside the cylinder.

Such an embodiment of the device makes it possible to improve the accuracy of measuring losses and no-load currents in the saturation region of the tested magnetic circuit.

To expand the range of monitored magnetic cores, the conductive rod is made removable.

FIG. 1 is a schematic diagram of the device described; in fig. 2 - its design scheme.

The device (see Fig. 1) contains an alternating voltage source 1, a matching transformer 2 with windings 3 and 4, a test core 5 with a control winding 6, a current transformer 7 with a winding 8, and measuring instruments 9-11.

From the source, the matching transformer is supplied with alternating voltage. The magnetic flux of the core of the matching transformer excites in the secondary winding,

which is the test coil, the emf, which causes the current flowing through the closed loop of the coil. The magnitude of this current depends on the size, cross section and quality of the core under test. Value control

voltage applied only to that part of the loop that covers the core under test is carried out with the help of the control loop on the test core and millivoltmeter 10. Loss values

and the no-load current is determined from the readings of an milli-wattmeter AND and a milliammeter 9, respectively.

The test coil (see Fig. 2) consists of two copper cups 12 and 13 with a threaded connection, forming a split cylinder closed at the ends. A conductive rod 14 is located along the axis of the cylinder. Reliable contact between the rod and the cylinder is provided by a nut 15. Inside the glass there is a matching transformer 2, a current transformer 1 and the test core 5, covered by a test coil 6, having a detachable connection 16, mounted on panel 17.

The overall dimensions of the device depend on the sizes of the tested pipelines.

Taking into account the need to observe a certain value of the ratio of the inductive and active resistances of the test turn when testing magnetic circuits of various sizes, the conductive rod 14 should be made removable and replaced with a rod of a different cross section.

Subject invention

1. Device for testing the quality of toroidal magnetic cores, containing a source of test voltage, an input matching transformer, a test

and control coils, current transformer and measuring devices, characterized in that, in order to improve the accuracy of measuring losses and no-load current in the saturation region of the magnetic cores, the test coil is made in the form of a detachable cylinder closed from the ends of a conductive material, the base of which is connected by a conductive core, and the matching transformer, control coil and current transformer are located inside the cylinder.

2. Device n. 1, characterized in that, in order to expand the range of monitored magnetic circuits, the conductive rod is made removable.

Pr / g7

6 5

P

ig. 2