SU613253A1 - Digital transformer-type bridge - Google Patents

Description

one

The invention relates to measurement technology and can be used to create digital devices having a linear conversion function of the primary converter.

A linear approximating transformer bridge containing a tetrad balance winding is known, in series with which are included exemplary elements changing the balancing step, and approximating circuits consisting of successively connected windings and exemplary elements fixing the approximation points.

The disadvantage of such a bridge is that as the measurement range or accuracy is increased, the number of model elements must be increased. The purpose of the invention is to improve the measurement accuracy.

This goal is achieved due to the fact that a digital transformer bridge containing a generator, to the output of which a voltage transformer is connected, the secondary winding of which forms the first shoulder of the bridge, the ten-day windings of the same transformer with keys form the other shoulder of the bridge, and the terminals for connecting the sensor and an exemplary capacitor - the other two shoulders; approximating transformers were introduced.

decadal windings are connected in series through switches and approximating transformers, with the secondary winding of the last approximating transformer connected to a reference capacitor.

FIG. 1 shows a diagram of the proposed lotost; in fig. 2 is a curve of the sensor conversion function.

The bridge contains a voltage transformer having a supply winding 1, a shoulder winding 2, decadal balancing windings 3-5 with numbers of turns n, n HZ, / 14, "5, respectively, and

 ten. . De «3 4

cadre windings 3 and 4 are connected nosledovatelpo through approximating transformers 6 and 7, and the older decade 5 through approximating transformer 8 is connected to an exemplary capacitor 9. In the other arm

the bridge is switched on a capacitive transducer (sensor) 10. The balancing of the bridge is made by closing the keys 11-21.

Suppose the transducer has the transform function shown in

FIG. 2, curve (X), which is approximated by straight lines O A, AB, BV, B G. Under the influence of the input quantity A is balanced: e starts from the youngest ten-day winding 3. The key 11 closes, and the voltage corresponding to the unit of the younger bit , through transformer 6, switch 14, transformer 7, switch 18 and transformer 8 are supplied to an exemplary capacitor 9. When the switch 12 is closed, a voltage corresponding to two low-order units is fed to the exemplary capacitor along the same circuit, but a change occurs the angle of inclination of the segment AB to mask defined by a change in the transformation ratio of the transformer 6 JRi.

When filling the lower bit in the higher bits, there will be similar changes in the transformation ratios 2 and transformers 7 and 8.

As a result, the approximating function at the approximation points will correspond to the transformation function

Пз (X) + «4 (-Y) +« 5 (X)

WITH

k, (X) k, (X) /, (X),

2

where Co is the capacitance of the reference capacitor.

The invention differs from the known solution in that for any measuring range and high accuracy one exemplary element is used.

Claims (1)

Invention Formula A digital transformer bridge containing a generator, to the output of which a voltage transformer is connected, one secondary winding of which forms a nerve bridge, the ten-day windings of the same transformer with keys form another bridge arm, and the terminals for connecting the sensor and the reference cable; 1tor - the other two shoulders, characterized in that, in order to improve the accuracy of measurement, approximating transformers are introduced into the model, with the ten-day windings connected in series through the keys and approximating transformers, with the secondary winding of the last approximating transformer connected to the reference condator. ipus g