This is another solution, for sprinklers on a golf course, so relevant to a pump for a pond.
What happens is the screwnuts and that black cylinder get wet when it rains, causing a short and stopping the sprinkler from firing up. Later, when everything dries up, it is obvious that the greens need water, so the sprinkler turns on. Simple.
![[ElectriciansForums.net] Solar panel and pond pump](https://www.electriciansforums.net/attachments/sprinkler-jpg.49614/ "[ElectriciansForums.net] Solar panel and pond pump")
The gate valve is supported by a custom moulded concrete block, and the solenoid is cleverly balanced on a strategically placed, erm...bit of concrete...which is wedge shaped, to allow easy regulation of height.
What happens is the screwnuts and that black cylinder get wet when it rains, causing a short and stopping the sprinkler from firing up. Later, when everything dries up, it is obvious that the greens need water, so the sprinkler turns on. Simple.
The gate valve is supported by a custom moulded concrete block, and the solenoid is cleverly balanced on a strategically placed, erm...bit of concrete...which is wedge shaped, to allow easy regulation of height.
