A Simple Domestic Irrigation System
Town water: Normal household supply (can vary considerably) around 20 litres/minute at 210 kPa (30PSI).
Rain water: From underground or above ground tanks via a pump. Depending on the capacity of the pump supply around 20 litres/minute at 210 kPa (30PSI).
Bore water: From a bore or sand spear and pump.
Control the supply of water to the sprinklers in that zone turned on by a low voltage signal from a controller. Normally a 24V AC.
Normally powered by 240V AC. These units provide a low voltage signal to the solenoid valves to open or close the valve. Can be programmed to operate the valves on any day(s) at any time and for any period of time. These units are designed for the "set and forget" operation. There are also available simple mechanical timers, but these require much more daily input by the operator.
Zones or groups or sprinklers
There are many different types of sprinklers, from large geared sprinklers, to small micro sprays. Due to the different precipitation rates they are not mixed within a zone, i.e. large geared sprinklers for lawn (turf) areas and, small micro sprays for garden beds.
A huge variety of pumps are available to supply water to an irrigation system (or household supply) for a normal (average) suburban garden a small 240V AC pump with an output of at least 20 litres/minute at 210 kPa (30PSI) is required. The greater the demand on the pump the larger the pump must be.
Pump controllers (control heads) may be mechanical or electronic. They turn the pump on or off according to demand. Without a pump controller the pump would continue to run even though there is no demand.