摘要 |
<p>In a fluid valving system, binary fluid control lines are connected in parallel between a common fluid inlet and a common fluid outlet. Each line has a binary valve and a metering orifice for passing a predetermined rate of fluid flow. The rates are in a geometric progression in factors of two. An analog fluid control line is connected in parallel with the binary lines, and has a continuously adjustable flow rate regulator for passing any selected rate of fluid flow up to a maximum at least equal to the largest increment of rate change in the binary lines. The regulator is formed of a miniature solid state device. A controller sets each binary valve open or closed, and sets the regulator for a selected flow rate, such that cooperative settings provide for a smoothly variable rate of total fluid flow.</p> |