| 摘要 |
<p>A microprocessor controlled system for use in a refrigeration system which includes a plurality of pulse controlled solenoid flow control valves (38) suitable for use as expansion valves. A pulse with modulated control signal is generated for cyclically opening and closing the flow through the solenoid expansion valve (38). The duty cycle of the pulsed control signal determines the average flow rate through the valve (38). The microprocessor (200) responds to the flow rate through each of the solenoid valves (38) to determine, on a system-wide basis, if each fixture in the system, as indicated by the flow rate through the expansion valve (38) associated therewith, is operating properly.</p> |
