Method of accurately setting the flow rate of a variable-flow metering pump, and a metering pump employing the method

摘要

A pump in accordance with the invention has moving equipment (32) driven by a reversible synchronous motor (42) whose windings (44, 45) are connected to a power source by means of optocoupled triacs (48, 49) which, under microprocessor control, are used to adjust the flow rate of the pump by acting on its admission period (by powering the windings in one direction) and on the pumping cycle time (by varying the period for which the pump is unpowered in each cycle).