A drive circuit is provided in a full H-bridge and half H-bridge
configuration for controlling one or more piezoelectric fuel injectors.
The drive circuit includes a voltage input for receiving a voltage signal,
an energy storage device coupled to the voltage input for storing an
electrical charge, a bidirectional current path coupled to one or more
piezoelectric injectors, an inductor coupled in series with the
piezoelectric injector(s) in the bidirectional current path, and switching
circuitry for controlling current flow through the piezoelectric
injector(s) and the inductor to open and close the piezoelectric
injector(s). The switching circuitry is controlled to provide a
recirculation current to recover energy stored in the piezoelectric
injector(s) for storage in the energy storage device.
