SCHALTUNGSANORDNUNG ZUM UNTERDRUECKEN VON SCHWINGUNGEN.

摘要

Acoustic input signals are converted by a microphone (1) into electrical signals which are amplified (3) and presented to a loudspeaker (2) with which an oscillation suppression circuit (4) is associated. The output (S2) of the amplifier (3) is applied to an oscillation recognition circuit (6) whose output (S3) controls a frequency search circuit (7). A sequence of signals (S4) commands a frequency filter circuit (8) sending a corrective signal (S5) to a subtractor (5) connected between the microphone (1) and its amplifier (3). The search circuit (7) incorporates a counter and logic for holding fast the recognised oscillatory frequency, so that the phase-locked loop removes such oscillations from the output