The TOTAL Automatic Pump Control 10A, Starting Pressure: 1.5Bar is what you need in order to make the
Peripheral Water Pump 370W (0.5HP) (TWP137016) or
Peripheral Water Pump 370W (0.5 HP) For Farm Use Only (TWP13706) work automatically.
It has a gauge on its outside which will show you what pressure the pump is currently set to.