| 摘要 |
<p>A fluid flow control valve system has a plurality of pairs of 3 port, 2 position (3/2) control valves ( 6, 6 ') each valve being movable between its two positions by a pair of electrically-operable actuators ( 1, 2 ). A logic controller selectively generates electrical control signals for independently controlling operation of the pairs of 3/2 control valves, and a circuit means ( 11 ) is associated with each 3/2 control valve pair ( 6, 6 ') to receive the control signals and provide electrical outputs to eit actuators ( 1, 2 ) of each 3/2 control valve of each pair. Variable switch means ( 14 ) forming part of the circuit means ( 11 ) pr the actuators ( 1, 2 ) to which the output is applied. Varying the switch means ( 14 ) programmes the fluid output mode of each 3/2 control valve pair to provide any one of a number of different effective valve types.</p> |
