SU1226333A2 - Device for determining 90-degree phase shift - Google Patents

Abstract

The invention relates to the field of phase metering and relates to the formation and determination of quadrature stresses. The purpose of the invention is to improve the accuracy of the formation and determination of the 90-degree phase shift. The device contains a generator 1, a transformer with windings 2 and 3 and an additional winding 8, capacitors 15 and 16, variable resistors 5, 13, and 14, resistor 6, null indicator 7, auxiliary phase shifter 9, voltage regulator 10 and power amplifier 11. The introduction of additional circuits, ensuring the constancy of the load at the output of the amplifier and the windings of the transformer, makes it possible to reduce the error of the device by 1–2 times. In this case, the effect of the load on the transformer windings and on the amplifier is reduced by approximately 100 times. 1 hp f-ly, 1 ill. Yu O O) O9 OO 00

Description

The invention relates to phase metering, to the formation and determination of quadrature voltages, and is an improvement of the invention according to the author. St. No. 976397.

The purpose of the invention is to increase the accuracy of forming and determining the 90-degree phase shift by introducing additional circuits into the known device, which ensure the stability of the output of the amplifier and the transformer windings, which leads to an increase in the accuracy of formation and quadrature stresses.

The drawing shows a circuit diagram of the proposed device.

The device contains a generator 1, a transformer with a primary 2 and secondary. 3 windings, capacitor 4, variable resistor 5, resistor 6, null-indikator 7, additional winding 8 of the transformer, auxiliary phase shifter 9, voltage regulator 10, power amplifier 11, switch 12 with three switching contacts, additional variable resistors 13 and 14 and capacitors 15 and 16.

When this generator 1 is connected to the primary winding 2 of the transformer, the secondary winding 3 of the transformer is connected to the zero point with the common potential and the indicator 7 zero, the first leads of the capacitor 16, resistor 14, capacitor 15, resistor 13 and: common terminals of power amplifier 1 and regulator

10th marry. The first output of the secondary winding 3 through the first normally open contact of the switch

12 is connected to the second lead of the resistor 14 and through series-connected capacitor 4, resistors 5 and 6 to the second lead of the capacitor

16 and through the normally closed second contact of the switch 12 to the second output of the secondary winding of the transformer. The first normally closed contact of switch 2 and its second normally open contact are combined and connected to the output of power amplifier I1. The inputs of the additional phase shifter 9. are connected to the additional winding 8 of the transformer, and the output through the voltage regulator 10 to the input of the amplifier

1i power. First winding

five

0 5

five

0

five

five

0

3 is connected to the third normally closed contact of the switch 12, the second output of the same winding 3 of the transformer is connected to the third normal, but the open contact of the same. the switch 12, and its common contact is connected to the second taps of the resistor 13 and the capacitor 15.

The device works as follows.

The voltage from the generator 1 through the transformer with the primary winding 2 is supplied to the secondary winding 3 and the additional winding 8, which are connected to the zero-indicator 7 and to the phase shifter, 9. Through the voltage regulator 10 and the power amplifier 11, the voltage is applied to one of the bridge arms, the second arm of which is formed by half the secondary winding 3 of the transformer, the third and fourth arms comprise a capacitor 4 with a variable resistor 5 and a resistor 6. In one of the positions switch 12 is achieved by adjusting the phase shifter 9, voltage regulator 10, capacitor 4 and variable resistor 5 so that the indicator light 7 shows zero, switch switch 12 and, adjusting the variable values of elements 4, 5, 9 and 10, achieve The zero zero indication is given: ator 7. By means of sequential switching and adjustments, it is necessary in both positions of switch 12 to achieve zero indication of zero indicator 7. In this position, the voltage at the output of power amplifier 11 is in quadrature with the secondary winding voltage of 3 transformers and is equal in magnitude to half the voltage of the winding 3 transformer. The technique of transformer windings with single voltages in amplitude and phase is known.

As shown by experimental verification, the effect of the load on the transformer windings and on the amplifier decreases by a factor of about 100.

The accuracy of the proposed device in comparison with the known one is about 1-2 times less.

Claims (2)

1. A device for determining the 90-degree phase shift by ed. St. No. 976397, distinguished by the fact that, in order to increase accuracy, it is equipped with two variables and capacitors, two variable resistors and a third switching contact on the switch, with the third normally closed contact connected to the first normally open contact, the third normally open contact connected With the second normally closed contact, the first additional variable resistor and the first additional variable capacitor, second 263334 A secondary variable resistor is connected by a single output to the first switching contact, a second additional variable capacitor is connected to the second switching contact by one end, and the second higher voltage switches of the additional variable resistors and capacitors are connected to the midpoint of the secondary winding. 10 transformers. 2. A device according to claim I, characterized in that the axes of all variable capacitors are mechanically connected 15 to each other.