solar drain pump

Hi there,

just thinking modding one of those solar pool pumps
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to pump wate from a drainage ditch/pond. Since it fills just some times I would put in two float switches and a relay to create a latching circuit like this
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relay would be this
https://www.electro-tech-online.com/custompdfs/2011/12/HFD31_en.pdf

do I need something else since the pump may drain too much from the panel? I.e. something to switch it on when the voltage is more than 6V or so? Read earlier on a relay would do?

Thanks,

Case

PS: am aware the schematic is 12V and the ebay pumps are 6V....

case-sensitive said:

something to switch it on when the voltage is more than 6V or so? Read earlier on a relay would do?

Click to expand...

Yes, the 6V version of that relay has a pull-in voltage of 4.5V, so it probably won't activate until the voltage is high enough to run the pump. I assume S2 is the "high water" switch and S1 is the "low water" cutout. If so, the circuit looks fine. I might suggest backspike diodes on the relay coil and motor to extend the life of the switches - but for the watt and a half it runs at it won't make much difference.

like so?

**broken link removed**
yes, S1 is lower and S2 upper level

Yes, looks great. Happy solar water pumping!

at last, its done! Panels, battery, PCB board, pond. Got side tracked, had to restore the house first....

Don't you just love it when a project which has stalled for several years is finally finished and is now doing something useful.

Well done!

JimB

got my other electronic projects finished as well at last, now have to look for new challenges