Patent ID: 6935471

Claim:
A dynamic beater comprising a vibrating mass unit having a mass M and a drive motor, said mass M being actuated by said drive motor to compensate for vibrations of a host structure, and a spring for coupling the mass unit to said host structure for damping, the beater presenting a first acceleration sensor secured to said mass and delivering a first signal s 1 , and a second acceleration sensor for mounting on the host structure and delivering a second signal s 2 , and also having a power amplifier supplying an output signal for controlling the drive motor in response to an input signal E which is a function of a difference between the signals from the first and second acceleration sensors after passing at least one of said signals through at least one lowpass filter and/or phase delay type filter, and including a first loop comprising a first said filter in series with said power amplifier, the first said filter having an inverting input for said first signal s 1 ; and a second loop comprising a second said filter having an input for said second signal s 2 and the second said filter having an output connected to a non-inverting input of the first said filter.