DC bias scheme for field induced piezoelectric power generators

A d.c. bias arrangement for increasing the efficiency of electrical power extraction from a piezoelectric transducer comprising a piezoelectric material, particularly of the electrostrictive type, contacted by first and second electrodes. The first electrode is connected directly to an electrical load connected directly to ground potential. The second electrode is connected by two in-parallel paths to the ground potential, one of the paths comprising a d.c. voltage source in series with a large bias resistor, and the other of the paths comprising a large a.c. power bypassing capacitor.