SU624351A1 - Phase-shifting arrangement - Google Patents

Description

The invention relates to radio engineering and can be used in devices for measuring phase difference, in synchronous detectors and other radio engineering devices.

A phase shifter is known a device containing a phase inverter with a phase-shifting RC circuit connected to its outputs made in the form of a series-connected capacitor and a controlled resistive element, and a phase detector, one of whose inputs is connected to the phase-inverter input and the output connected to the control input of the controllable resistive element ij.

However, the known device does not provide adjustment of the phase shift, which has a fixed value of 9 O, which reduces its functional capabilities.

The aim of the invention is to expand the phase range of the device.

To do this, a differential amplifier is introduced into the proposed phase-shifting device, a non-inverting input terminal is connected to the junction of the capacitor and a controllable cutting element of the phase-shifting KS-yepn, and the output is connected to the second input of the phase detector, and the potentiometer connected parallel to the phase-shifting RC whose moving contact is connected to the inverting input of a differential amplifier.

FIG. 1 shows the structural electrical circuit of the proposed device; in fig. 2 is a vector voltage chart illustrating its operation.

Claims (1)

A phase shifter contains a phase inverter 1 with an RC circuit connected to its outputs, an RC circuit made as a series-connected capacitor 2 and a controlled resistive element 3, and a phase detector 4, one of the inputs of which is connected to the input of the phase inverter 1, and the output connected to the control input of the controlled resistive element 3, the differential amplifier 5, its non-inverting input is connected to the junction of the capacitor 2 of the controlled resistance element 3, and the output is connected to the second input of the 4, and a potentiometer 6 connected in parallel with the phase-shifting RC circuit, with a movable contact connected to the inverting input of the differential amplifier 5. The input of the phase inverter 1 is the device input, the junction point of the capacitor ii and the controlled resistive element 3 is the output devices. The device works as follows. From the point of connection of the capacitor 2 and the controlled resistive element 3, the voltage is amplitude equal to the input, but shifted in phase relative to the input, and the common-mode input voltage is removed from the moving contract of potentiometer 6, the amplitude and sign of which are determined by the position of the moving contact. These yarns are fed to the inputs of the differential amplifier 5, where they are subtracting them vectorially. The differential voltage is detected by a phase detector 4, which operates as a mismatch sensor, and outputs an error signal at the output. This signal changes the resistance of the controlled resistive element 3 until the equilibrium state of the device is reached. The operation of the device is explained by the voltage vector diagram (Fig. 2), where point A corresponds to the voltage at the phase inverter 1 output point B - at the antiphase output of phase inverter 1, point B at the connection point of the capacitor 2 with the resistive element 3, point Mr. on the movable contact potentiometer 6, and the point O-at the ground point. In the state of 1 –––––––––––––– –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––. When the input voltage frequency changes or due to the influence of other factors (temperature instabilities, element aging) at the initial moment, point B is shifted along the arc of a circle, and the HS vector deviates from the normal to the AB vector through some angle f. Then, at the output of the phase detector 4, an error signal appears, which is proportional to Sin Af, which changes the resistance of the resistive element 3 and returns the circuit to an equilibrium state, in it the vector GW is perpendicular to the vector AB. Thus, at a constant voltage on the movable contact of potentiometer 6 (the amplitude vector and phase of the output voltage (RH vector) are invariant with respect to frequency change. The phase of the output voltage depends on the voltage of the potentiometer 6 (GH vector) and can be adjusted from 0 to 180. The proposed phase of the motor device as compared with the known one has a wider phase range, which allows it to be used as an accurate and stable sensor of phase shifts in the device. Formula of the invention Phase-shifting device containing a phase inverter connected with its phase outputs by a moving RC circuit made in the form of a series-connected capacitor and a controlled resistive element, and a phase detector, one of the inputs of which is connected to the phase inverter input, and An output is connected to a control input of a controllable resistive element, characterized in that, in order to expand the phase range of the device, a differential amplifier is introduced that is non-inverting in d which is connected to a place of the compound of the capacitor and a controllable resistive element fazosdvigayushey RC-circuit, and an output coupled to a second input of the phase detector, and a potentiometer connected across the phase-shifting RC-circuit, the movable contact of which is connected to the inverting input of the differential amplifier. Sources of information taken into account in the examination: 1. Kostenko V, U. and others. Phaser for the range of 1-2 O kHz. Instruments and Experimental Technique, 1975, N9 1, p. 154-155. /