Energy efficient circuitry is provided for rapid transfer of charge to and
from a reactive load while avoiding excessive peak currents and
significant resistive energy dissipation. For example, circuitry of the
invention provides for rapid actuation of a piezoelectric mass flow valve
actuator while significantly reducing electrical input power and power
dissipation requirements. The invention also features circuitry for
recovering a substantial portion of the energy delivered to the reactive
load while still permitting rapid cycling of the load drive circuit.
Controlling the activation interval of the drive circuitry provides for
incremental actuation or positioning of the reactive load.