FIELD: physics.
SUBSTANCE: differential amplifier with a Wien bridge is included in a positive and negative feedback. First and second operational amplifiers included in the negative feedback are connected by inverting inputs to the output and the inverting input of the differential amplifier. Said amplifiers are connected by resistors to the first and second series arms of the Wien bridge, respectively. The output and the inverting input of the differential amplifier are connected to stand-alone power supplies of the first and second operational amplifiers, respectively. Their non-inverting inputs are respectively connected to sliding contacts of the first and second parts of a double potentiometre, respectively connected in parallel resistors in the second and first circuits of the series arm of the Wien bridge.
EFFECT: preventing dependency of the value of phase shift on frequency in an amplifier - phase shifter.
