I have a 12V solar surface pump which requires a circuit to do the following:
When the pump first runs (power from the existing pump controller is sent to the pump), I need a circuit which detects the power sent from the controller, opens a 12V sprinkler value for one -two minutes, then shuts down.
When the storage tank is full, a float signals to the pump controller to shut down. When the water level falls, the float tells the pump controller to activate the pump again. Every time power is detected at the pump, I want the sprinkler value to open for two minutes then shut down.
I noticed after experimenting with the pump, it will pump fine to the storage tank if it can run with very little water pressure for a couple minutes.
Right now, I am manually opening a spigot right by the pump when it starts and then closing the spigot down when the pump starts working. If I don't open the spigot, there is just too much water pressure up to the storage tank for the pump to work.
If I don't open the spigot, the pump will run for hours but won't actually pump any water to the storage tank which is about 20 feet above the water source. Just by opening the spigot, lets the pump build enough pressure to work just fine.
This is the water solenoid switch
This is the 12V surface pump
This is the 12V pump controller: