DE3734679A1 - SCALE FOR A TRANSFORMER FOR MEASURING SHIFTING - Google Patents

Abstract

A scale (3) for a transducer (1) for the measurement of displacements, comprises at least two separate windings (4, 5) made in the form of periodic zig-zags or square waves with active conductors arranged substantially perpendicularly to a direction of relative motion between the scale (3) and a cooperable slider (2), the direction of motion being parallel to a surface formed by the active conductors, and wherein the windings (4, 5) are displaced with respect to one another by one quarter part of their common pitch T, thereby to reduce measurement error by means of differential compensation between the windings (4, 5). The slider winding is energised from supply (6), the measurement outputs being taken from windings (4, 5). <IMAGE>

Description

The invention relates to a scale for a transformer for displacement measurement and can be used for metalworking machines with digital program control, in institutions for automatic assembly in mechanical engineering, device construction, in electronics, on measuring stands, at coordinate measuring machines and find application for measuring robots. From BG-A-34 146/83 is a scale for a transformer for measuring ver known shifts, the at least two separate pressure Contains windings that are periodically zigzag are effective with the direction of relative movement of the Scale of conductors arranged perpendicular to the glider, the direction of movement parallel to that through the effective same conductor formed area lies.

A disadvantage of the known scale is due to each other following connection and the horizontal arrangement of the wick the high value of the cyclical internal crotch lers.

The object of the invention is to provide a scale for transformers for measuring displacements with a reduced interior to create step errors.

This object is achieved by the in the patent spell described scale solved.

The advantage of the invention is that the internal step error is reduced by differential compensation.

An exemplary embodiment of the invention is shown in the drawing appropriate scale explained. It shows

Fig. 1 shifts a scale for transformers for measuring Ver and its connection to the measuring circuit,

Fig. 2 shows the arrangement of the windings,

Fig. 3 shows the change in the error of a first in the diagram,

Fig. 4 shows the change in the error of a second winding and

Fig. 5 shows the error at the output of the computing unit.

A transformer 1 for measuring displacements consists, according to FIG. 1, of a slider 2 and a metal base of the scale 3 , to which windings 4 and 5 are glued by means of an insulation layer. The windings 4 and 5 are periodically zigzag-shaped with the same step. Their effective conductors are arranged perpendicular to the direction of the relative movement of the slider 2 with respect to the scale 3 , the direction of movement being parallel to the surface formed by the active conductors. The winding of the slider 2 is connected directly to the output of a supply unit 6 and inductively connected to the windings 4 and 5 , the leads of which are connected via preamplifiers 7 and 8 and measuring units 9 and 10 to the information inputs of a computing unit 11 .

A characteristic of the scale is that the windings 4 and 5 according to FIG. 2 are offset from one another by a part of their step 12 , so that the differential compensation according to FIGS. 3, 4 and 5 reduces the internal step error of the scale 3 .

The operation of the scale for a transformer for measurement The displacement is as follows:

Through the supply unit 6 , the glider 2 from the transformer 1 voltage is supplied, which induces these voltages in the windings 4 and 5 . The induced voltage is fed to the preamplifiers 7 and 8 , which amplify this voltage to the required value and feed the measuring units 9 and 10 , which measure the change in the phases and amplitudes of the voltage. The results in numerical values, which correspond to the geometric displacement of the windings 4 and 5 , reach the computing unit 11 , where their arithmetic mean is calculated.

Claims (1)

Scale for a transformer for measuring displacements, with at least two separate periodically zigzag-shaped pressure windings ( 4, 5 ) with the same step, with effective conductors arranged perpendicular to the direction of the relative movement of the scale opposite a slider ( 2 ), the direction of movement is parallel to the surface formed by the effective conductor, characterized in that the windings ( 4, 5 ) are offset from one another by part of their step ( 12 ).