spring return butterfly valve actuator, spring control method and butterfly valve assembly

摘要

spring return butterfly valve actuator (1) including: a multi-coil electric dc motor (c1, c2, c3) (2) having an output shaft (4), a butterfly valve return spring (10) , a gear transmission (5) connected to the output shaft, a control unit (cpu) adapted to control the power supply to the dc motor (2), wherein the spring return butterfly valve actuator (1) It has a range of motion between the closed butterfly valve and the fully open butterfly valve. The control unit (CPU) includes a monitoring circuit adapted to monitor dc motor movement. the monitoring circuit is arranged to receive signals from at least one voltage sensor adapted to detect the induced voltage in at least one of the dc motor coils (c1, c2, c3) during a butterfly valve spring return, and the Monitoring circuit is arranged to create a representation of dc motor movement based on said signals.