Patent ID: 8240635

Claim:
A valve assembly with variable flow rate of fluid delivery and optimizes the flow rate accuracy by compensating for at least one fluidic parameter of the valve assembly, comprising: a power supply; charge pump circuitry powered by the power supply; a piezoelectric actuator charged by the charge pump circuitry, the charge applied across the piezoelectric actuator reaching a predetermined voltage threshold over a predetermined rise time; and a valve transitioning from a CLOSED state to an OPENED state when the charge applied across the piezoelectric actuator exceeds the predetermined voltage threshold; the valve assembly having a duty cycle, including a valve opening time and a valve closing time, adaptable to vary the flaw rate of the fluid delivered by the valve; wherein the at least one fluidic parameter of the valve assembly is calibrated at the time of manufacture of the valve assembly, for a particular flow rate the valve opening time and the valve closing time are calculated based on the particular flow rate and the at least one fluidic parameter; wherein the duty cycle represents a ratio of valve OPENED time to valve CLOSED time.