The invention makes use of human perception to derive potential faults of at least one component of the technical installation. Chopping modulation and demodulation circuitry use direct and cross-over switches to modulate low frequency noise, such as 1f noise, out of a signal baseband. A plurality of drive electrodes 24 are formed the upper surface of each piezoelectric sheet 121a, 121c, 121e, 123. The switch is alternately gated on and off by a signal from a controller until sufficient energy is transferred from the stack to the battery. The bearing mounting plate and bearing plate are coupled to retain the bearing and bearing inserts therebetween firming a seal wherein the actuator is angularly movable about the bearing.