since a turbomolecular pump is a highly specialised multi-stage turbine, this is a 3-phase motor controller with analogue speed feedback taken from the voltage across a couple of the motor phases.

The control circuit is completed through the liquid ... and when the level rises to this electrode the relay is energized and the pump motor started. A longer electrode is immersed in the liquid ...

These devices have key drawbacks. Water level indicators require manual pump operation and often waste power as multiple LEDs ...

The pump and controller user manuals offered only sketchy details about the sensored BLDC motor used in the pump. The low phase-to-phase resistance implied low drive voltage, and [Mark] decided to ...

It found that the motor successfully follows the ... they suggested suggested further testing the novel controller in a larger-scale PV-powered water pump system, along with its combination ...