Reduced-energy-consumption latching actuator

The present invention is directed to latching actuators and in particular to the systems that control them. A latching-valve system () includes a piezoelectric transducer () mounted on its housing (). To change the valve's state, a microcontroller () causes a valve driver () to drive current through the actuator's coil (). It continues driving current through the coil () until the transducer's output reaches a magnitude characteristic of the disturbance that typically results when the actuator's armature () reaches the end of its travel. At that point, the microcontroller () stops driving current through the coil. If the characteristic sound does not occur within a predetermined duration, the microcontroller () causes a voltage-multiplier circuit (QLD) to increase the voltage that the valve driver () applies to the coil.