Feedback (Rk), feedback, is a circuitry measure in electronic circuits. In feedback, part of the output signal of an active quadripole is fed back to the input of the quadripole and linked to the input signal.
As long as the feedback signal has the same phase as the output signal, it is referred to as positive feedback. In positive feedback (Mk), also known as positive feedback, the feedback signal is added to the original input signal. In negative feedback (Gk), the two signals are subtracted because the feedback signal is rotated 180 degrees beforehand.
The ratio between the output amplitude and the amplitude of the feedback signal is the feedback factor.
The feedback principle is used wherever the feedback signal is used to perform a control function or where the feedback signal is intended to trigger an oscillatory state, as in the oscillator, in analog signal processing, in control engineering or in robotics.